Pileus Git - ~andy/linux/blob - security/selinux/hooks.c

   1 /*
   2  *  NSA Security-Enhanced Linux (SELinux) security module
   3  *
   4  *  This file contains the SELinux hook function implementations.
   5  *
   6  *  Authors:  Stephen Smalley, <sds@epoch.ncsc.mil>
   7  *            Chris Vance, <cvance@nai.com>
   8  *            Wayne Salamon, <wsalamon@nai.com>
   9  *            James Morris <jmorris@redhat.com>
  10  *
  11  *  Copyright (C) 2001,2002 Networks Associates Technology, Inc.
  12  *  Copyright (C) 2003-2008 Red Hat, Inc., James Morris <jmorris@redhat.com>
  13  *                                         Eric Paris <eparis@redhat.com>
  14  *  Copyright (C) 2004-2005 Trusted Computer Solutions, Inc.
  15  *                          <dgoeddel@trustedcs.com>
  16  *  Copyright (C) 2006, 2007, 2009 Hewlett-Packard Development Company, L.P.
  17  *      Paul Moore <paul@paul-moore.com>
  18  *  Copyright (C) 2007 Hitachi Software Engineering Co., Ltd.
  19  *                     Yuichi Nakamura <ynakam@hitachisoft.jp>
  20  *
  21  *      This program is free software; you can redistribute it and/or modify
  22  *      it under the terms of the GNU General Public License version 2,
  23  *      as published by the Free Software Foundation.
  24  */
  25
  26 #include <linux/init.h>
  27 #include <linux/kd.h>
  28 #include <linux/kernel.h>
  29 #include <linux/tracehook.h>
  30 #include <linux/errno.h>
  31 #include <linux/sched.h>
  32 #include <linux/security.h>
  33 #include <linux/xattr.h>
  34 #include <linux/capability.h>
  35 #include <linux/unistd.h>
  36 #include <linux/mm.h>
  37 #include <linux/mman.h>
  38 #include <linux/slab.h>
  39 #include <linux/pagemap.h>
  40 #include <linux/proc_fs.h>
  41 #include <linux/swap.h>
  42 #include <linux/spinlock.h>
  43 #include <linux/syscalls.h>
  44 #include <linux/dcache.h>
  45 #include <linux/file.h>
  46 #include <linux/fdtable.h>
  47 #include <linux/namei.h>
  48 #include <linux/mount.h>
  49 #include <linux/netfilter_ipv4.h>
  50 #include <linux/netfilter_ipv6.h>
  51 #include <linux/tty.h>
  52 #include <net/icmp.h>
  53 #include <net/ip.h>             /* for local_port_range[] */
  54 #include <net/tcp.h>            /* struct or_callable used in sock_rcv_skb */
  55 #include <net/net_namespace.h>
  56 #include <net/netlabel.h>
  57 #include <linux/uaccess.h>
  58 #include <asm/ioctls.h>
  59 #include <linux/atomic.h>
  60 #include <linux/bitops.h>
  61 #include <linux/interrupt.h>
  62 #include <linux/netdevice.h>    /* for network interface checks */
  63 #include <linux/netlink.h>
  64 #include <linux/tcp.h>
  65 #include <linux/udp.h>
  66 #include <linux/dccp.h>
  67 #include <linux/quota.h>
  68 #include <linux/un.h>           /* for Unix socket types */
  69 #include <net/af_unix.h>        /* for Unix socket types */
  70 #include <linux/parser.h>
  71 #include <linux/nfs_mount.h>
  72 #include <net/ipv6.h>
  73 #include <linux/hugetlb.h>
  74 #include <linux/personality.h>
  75 #include <linux/audit.h>
  76 #include <linux/string.h>
  77 #include <linux/selinux.h>
  78 #include <linux/mutex.h>
  79 #include <linux/posix-timers.h>
  80 #include <linux/syslog.h>
  81 #include <linux/user_namespace.h>
  82 #include <linux/export.h>
  83 #include <linux/msg.h>
  84 #include <linux/shm.h>
  85
  86 #include "avc.h"
  87 #include "objsec.h"
  88 #include "netif.h"
  89 #include "netnode.h"
  90 #include "netport.h"
  91 #include "xfrm.h"
  92 #include "netlabel.h"
  93 #include "audit.h"
  94 #include "avc_ss.h"
  95
  96 #define NUM_SEL_MNT_OPTS 5
  97
  98 extern struct security_operations *security_ops;
  99
 100 /* SECMARK reference count */
 101 static atomic_t selinux_secmark_refcount = ATOMIC_INIT(0);
 102
 103 #ifdef CONFIG_SECURITY_SELINUX_DEVELOP
 104 int selinux_enforcing;
 105
 106 static int __init enforcing_setup(char *str)
 107 {
 108         unsigned long enforcing;
 109         if (!strict_strtoul(str, 0, &enforcing))
 110                 selinux_enforcing = enforcing ? 1 : 0;
 111         return 1;
 112 }
 113 __setup("enforcing=", enforcing_setup);
 114 #endif
 115
 116 #ifdef CONFIG_SECURITY_SELINUX_BOOTPARAM
 117 int selinux_enabled = CONFIG_SECURITY_SELINUX_BOOTPARAM_VALUE;
 118
 119 static int __init selinux_enabled_setup(char *str)
 120 {
 121         unsigned long enabled;
 122         if (!strict_strtoul(str, 0, &enabled))
 123                 selinux_enabled = enabled ? 1 : 0;
 124         return 1;
 125 }
 126 __setup("selinux=", selinux_enabled_setup);
 127 #else
 128 int selinux_enabled = 1;
 129 #endif
 130
 131 static struct kmem_cache *sel_inode_cache;
 132
 133 /**
 134  * selinux_secmark_enabled - Check to see if SECMARK is currently enabled
 135  *
 136  * Description:
 137  * This function checks the SECMARK reference counter to see if any SECMARK
 138  * targets are currently configured, if the reference counter is greater than
 139  * zero SECMARK is considered to be enabled.  Returns true (1) if SECMARK is
 140  * enabled, false (0) if SECMARK is disabled.
 141  *
 142  */
 143 static int selinux_secmark_enabled(void)
 144 {
 145         return (atomic_read(&selinux_secmark_refcount) > 0);
 146 }
 147
 148 /*
 149  * initialise the security for the init task
 150  */
 151 static void cred_init_security(void)
 152 {
 153         struct cred *cred = (struct cred *) current->real_cred;
 154         struct task_security_struct *tsec;
 155
 156         tsec = kzalloc(sizeof(struct task_security_struct), GFP_KERNEL);
 157         if (!tsec)
 158                 panic("SELinux:  Failed to initialize initial task.\n");
 159
 160         tsec->osid = tsec->sid = SECINITSID_KERNEL;
 161         cred->security = tsec;
 162 }
 163
 164 /*
 165  * get the security ID of a set of credentials
 166  */
 167 static inline u32 cred_sid(const struct cred *cred)
 168 {
 169         const struct task_security_struct *tsec;
 170
 171         tsec = cred->security;
 172         return tsec->sid;
 173 }
 174
 175 /*
 176  * get the objective security ID of a task
 177  */
 178 static inline u32 task_sid(const struct task_struct *task)
 179 {
 180         u32 sid;
 181
 182         rcu_read_lock();
 183         sid = cred_sid(__task_cred(task));
 184         rcu_read_unlock();
 185         return sid;
 186 }
 187
 188 /*
 189  * get the subjective security ID of the current task
 190  */
 191 static inline u32 current_sid(void)
 192 {
 193         const struct task_security_struct *tsec = current_security();
 194
 195         return tsec->sid;
 196 }
 197
 198 /* Allocate and free functions for each kind of security blob. */
 199
 200 static int inode_alloc_security(struct inode *inode)
 201 {
 202         struct inode_security_struct *isec;
 203         u32 sid = current_sid();
 204
 205         isec = kmem_cache_zalloc(sel_inode_cache, GFP_NOFS);
 206         if (!isec)
 207                 return -ENOMEM;
 208
 209         mutex_init(&isec->lock);
 210         INIT_LIST_HEAD(&isec->list);
 211         isec->inode = inode;
 212         isec->sid = SECINITSID_UNLABELED;
 213         isec->sclass = SECCLASS_FILE;
 214         isec->task_sid = sid;
 215         inode->i_security = isec;
 216
 217         return 0;
 218 }
 219
 220 static void inode_free_security(struct inode *inode)
 221 {
 222         struct inode_security_struct *isec = inode->i_security;
 223         struct superblock_security_struct *sbsec = inode->i_sb->s_security;
 224
 225         spin_lock(&sbsec->isec_lock);
 226         if (!list_empty(&isec->list))
 227                 list_del_init(&isec->list);
 228         spin_unlock(&sbsec->isec_lock);
 229
 230         inode->i_security = NULL;
 231         kmem_cache_free(sel_inode_cache, isec);
 232 }
 233
 234 static int file_alloc_security(struct file *file)
 235 {
 236         struct file_security_struct *fsec;
 237         u32 sid = current_sid();
 238
 239         fsec = kzalloc(sizeof(struct file_security_struct), GFP_KERNEL);
 240         if (!fsec)
 241                 return -ENOMEM;
 242
 243         fsec->sid = sid;
 244         fsec->fown_sid = sid;
 245         file->f_security = fsec;
 246
 247         return 0;
 248 }
 249
 250 static void file_free_security(struct file *file)
 251 {
 252         struct file_security_struct *fsec = file->f_security;
 253         file->f_security = NULL;
 254         kfree(fsec);
 255 }
 256
 257 static int superblock_alloc_security(struct super_block *sb)
 258 {
 259         struct superblock_security_struct *sbsec;
 260
 261         sbsec = kzalloc(sizeof(struct superblock_security_struct), GFP_KERNEL);
 262         if (!sbsec)
 263                 return -ENOMEM;
 264
 265         mutex_init(&sbsec->lock);
 266         INIT_LIST_HEAD(&sbsec->isec_head);
 267         spin_lock_init(&sbsec->isec_lock);
 268         sbsec->sb = sb;
 269         sbsec->sid = SECINITSID_UNLABELED;
 270         sbsec->def_sid = SECINITSID_FILE;
 271         sbsec->mntpoint_sid = SECINITSID_UNLABELED;
 272         sb->s_security = sbsec;
 273
 274         return 0;
 275 }
 276
 277 static void superblock_free_security(struct super_block *sb)
 278 {
 279         struct superblock_security_struct *sbsec = sb->s_security;
 280         sb->s_security = NULL;
 281         kfree(sbsec);
 282 }
 283
 284 /* The file system's label must be initialized prior to use. */
 285
 286 static const char *labeling_behaviors[6] = {
 287         "uses xattr",
 288         "uses transition SIDs",
 289         "uses task SIDs",
 290         "uses genfs_contexts",
 291         "not configured for labeling",
 292         "uses mountpoint labeling",
 293 };
 294
 295 static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry);
 296
 297 static inline int inode_doinit(struct inode *inode)
 298 {
 299         return inode_doinit_with_dentry(inode, NULL);
 300 }
 301
 302 enum {
 303         Opt_error = -1,
 304         Opt_context = 1,
 305         Opt_fscontext = 2,
 306         Opt_defcontext = 3,
 307         Opt_rootcontext = 4,
 308         Opt_labelsupport = 5,
 309 };
 310
 311 static const match_table_t tokens = {
 312         {Opt_context, CONTEXT_STR "%s"},
 313         {Opt_fscontext, FSCONTEXT_STR "%s"},
 314         {Opt_defcontext, DEFCONTEXT_STR "%s"},
 315         {Opt_rootcontext, ROOTCONTEXT_STR "%s"},
 316         {Opt_labelsupport, LABELSUPP_STR},
 317         {Opt_error, NULL},
 318 };
 319
 320 #define SEL_MOUNT_FAIL_MSG "SELinux:  duplicate or incompatible mount options\n"
 321
 322 static int may_context_mount_sb_relabel(u32 sid,
 323                         struct superblock_security_struct *sbsec,
 324                         const struct cred *cred)
 325 {
 326         const struct task_security_struct *tsec = cred->security;
 327         int rc;
 328
 329         rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
 330                           FILESYSTEM__RELABELFROM, NULL);
 331         if (rc)
 332                 return rc;
 333
 334         rc = avc_has_perm(tsec->sid, sid, SECCLASS_FILESYSTEM,
 335                           FILESYSTEM__RELABELTO, NULL);
 336         return rc;
 337 }
 338
 339 static int may_context_mount_inode_relabel(u32 sid,
 340                         struct superblock_security_struct *sbsec,
 341                         const struct cred *cred)
 342 {
 343         const struct task_security_struct *tsec = cred->security;
 344         int rc;
 345         rc = avc_has_perm(tsec->sid, sbsec->sid, SECCLASS_FILESYSTEM,
 346                           FILESYSTEM__RELABELFROM, NULL);
 347         if (rc)
 348                 return rc;
 349
 350         rc = avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM,
 351                           FILESYSTEM__ASSOCIATE, NULL);
 352         return rc;
 353 }
 354
 355 static int sb_finish_set_opts(struct super_block *sb)
 356 {
 357         struct superblock_security_struct *sbsec = sb->s_security;
 358         struct dentry *root = sb->s_root;
 359         struct inode *root_inode = root->d_inode;
 360         int rc = 0;
 361
 362         if (sbsec->behavior == SECURITY_FS_USE_XATTR) {
 363                 /* Make sure that the xattr handler exists and that no
 364                    error other than -ENODATA is returned by getxattr on
 365                    the root directory.  -ENODATA is ok, as this may be
 366                    the first boot of the SELinux kernel before we have
 367                    assigned xattr values to the filesystem. */
 368                 if (!root_inode->i_op->getxattr) {
 369                         printk(KERN_WARNING "SELinux: (dev %s, type %s) has no "
 370                                "xattr support\n", sb->s_id, sb->s_type->name);
 371                         rc = -EOPNOTSUPP;
 372                         goto out;
 373                 }
 374                 rc = root_inode->i_op->getxattr(root, XATTR_NAME_SELINUX, NULL, 0);
 375                 if (rc < 0 && rc != -ENODATA) {
 376                         if (rc == -EOPNOTSUPP)
 377                                 printk(KERN_WARNING "SELinux: (dev %s, type "
 378                                        "%s) has no security xattr handler\n",
 379                                        sb->s_id, sb->s_type->name);
 380                         else
 381                                 printk(KERN_WARNING "SELinux: (dev %s, type "
 382                                        "%s) getxattr errno %d\n", sb->s_id,
 383                                        sb->s_type->name, -rc);
 384                         goto out;
 385                 }
 386         }
 387
 388         sbsec->flags |= (SE_SBINITIALIZED | SE_SBLABELSUPP);
 389
 390         if (sbsec->behavior > ARRAY_SIZE(labeling_behaviors))
 391                 printk(KERN_ERR "SELinux: initialized (dev %s, type %s), unknown behavior\n",
 392                        sb->s_id, sb->s_type->name);
 393         else
 394                 printk(KERN_DEBUG "SELinux: initialized (dev %s, type %s), %s\n",
 395                        sb->s_id, sb->s_type->name,
 396                        labeling_behaviors[sbsec->behavior-1]);
 397
 398         if (sbsec->behavior == SECURITY_FS_USE_GENFS ||
 399             sbsec->behavior == SECURITY_FS_USE_MNTPOINT ||
 400             sbsec->behavior == SECURITY_FS_USE_NONE ||
 401             sbsec->behavior > ARRAY_SIZE(labeling_behaviors))
 402                 sbsec->flags &= ~SE_SBLABELSUPP;
 403
 404         /* Special handling for sysfs. Is genfs but also has setxattr handler*/
 405         if (strncmp(sb->s_type->name, "sysfs", sizeof("sysfs")) == 0)
 406                 sbsec->flags |= SE_SBLABELSUPP;
 407
 408         /* Initialize the root inode. */
 409         rc = inode_doinit_with_dentry(root_inode, root);
 410
 411         /* Initialize any other inodes associated with the superblock, e.g.
 412            inodes created prior to initial policy load or inodes created
 413            during get_sb by a pseudo filesystem that directly
 414            populates itself. */
 415         spin_lock(&sbsec->isec_lock);
 416 next_inode:
 417         if (!list_empty(&sbsec->isec_head)) {
 418                 struct inode_security_struct *isec =
 419                                 list_entry(sbsec->isec_head.next,
 420                                            struct inode_security_struct, list);
 421                 struct inode *inode = isec->inode;
 422                 spin_unlock(&sbsec->isec_lock);
 423                 inode = igrab(inode);
 424                 if (inode) {
 425                         if (!IS_PRIVATE(inode))
 426                                 inode_doinit(inode);
 427                         iput(inode);
 428                 }
 429                 spin_lock(&sbsec->isec_lock);
 430                 list_del_init(&isec->list);
 431                 goto next_inode;
 432         }
 433         spin_unlock(&sbsec->isec_lock);
 434 out:
 435         return rc;
 436 }
 437
 438 /*
 439  * This function should allow an FS to ask what it's mount security
 440  * options were so it can use those later for submounts, displaying
 441  * mount options, or whatever.
 442  */
 443 static int selinux_get_mnt_opts(const struct super_block *sb,
 444                                 struct security_mnt_opts *opts)
 445 {
 446         int rc = 0, i;
 447         struct superblock_security_struct *sbsec = sb->s_security;
 448         char *context = NULL;
 449         u32 len;
 450         char tmp;
 451
 452         security_init_mnt_opts(opts);
 453
 454         if (!(sbsec->flags & SE_SBINITIALIZED))
 455                 return -EINVAL;
 456
 457         if (!ss_initialized)
 458                 return -EINVAL;
 459
 460         tmp = sbsec->flags & SE_MNTMASK;
 461         /* count the number of mount options for this sb */
 462         for (i = 0; i < 8; i++) {
 463                 if (tmp & 0x01)
 464                         opts->num_mnt_opts++;
 465                 tmp >>= 1;
 466         }
 467         /* Check if the Label support flag is set */
 468         if (sbsec->flags & SE_SBLABELSUPP)
 469                 opts->num_mnt_opts++;
 470
 471         opts->mnt_opts = kcalloc(opts->num_mnt_opts, sizeof(char *), GFP_ATOMIC);
 472         if (!opts->mnt_opts) {
 473                 rc = -ENOMEM;
 474                 goto out_free;
 475         }
 476
 477         opts->mnt_opts_flags = kcalloc(opts->num_mnt_opts, sizeof(int), GFP_ATOMIC);
 478         if (!opts->mnt_opts_flags) {
 479                 rc = -ENOMEM;
 480                 goto out_free;
 481         }
 482
 483         i = 0;
 484         if (sbsec->flags & FSCONTEXT_MNT) {
 485                 rc = security_sid_to_context(sbsec->sid, &context, &len);
 486                 if (rc)
 487                         goto out_free;
 488                 opts->mnt_opts[i] = context;
 489                 opts->mnt_opts_flags[i++] = FSCONTEXT_MNT;
 490         }
 491         if (sbsec->flags & CONTEXT_MNT) {
 492                 rc = security_sid_to_context(sbsec->mntpoint_sid, &context, &len);
 493                 if (rc)
 494                         goto out_free;
 495                 opts->mnt_opts[i] = context;
 496                 opts->mnt_opts_flags[i++] = CONTEXT_MNT;
 497         }
 498         if (sbsec->flags & DEFCONTEXT_MNT) {
 499                 rc = security_sid_to_context(sbsec->def_sid, &context, &len);
 500                 if (rc)
 501                         goto out_free;
 502                 opts->mnt_opts[i] = context;
 503                 opts->mnt_opts_flags[i++] = DEFCONTEXT_MNT;
 504         }
 505         if (sbsec->flags & ROOTCONTEXT_MNT) {
 506                 struct inode *root = sbsec->sb->s_root->d_inode;
 507                 struct inode_security_struct *isec = root->i_security;
 508
 509                 rc = security_sid_to_context(isec->sid, &context, &len);
 510                 if (rc)
 511                         goto out_free;
 512                 opts->mnt_opts[i] = context;
 513                 opts->mnt_opts_flags[i++] = ROOTCONTEXT_MNT;
 514         }
 515         if (sbsec->flags & SE_SBLABELSUPP) {
 516                 opts->mnt_opts[i] = NULL;
 517                 opts->mnt_opts_flags[i++] = SE_SBLABELSUPP;
 518         }
 519
 520         BUG_ON(i != opts->num_mnt_opts);
 521
 522         return 0;
 523
 524 out_free:
 525         security_free_mnt_opts(opts);
 526         return rc;
 527 }
 528
 529 static int bad_option(struct superblock_security_struct *sbsec, char flag,
 530                       u32 old_sid, u32 new_sid)
 531 {
 532         char mnt_flags = sbsec->flags & SE_MNTMASK;
 533
 534         /* check if the old mount command had the same options */
 535         if (sbsec->flags & SE_SBINITIALIZED)
 536                 if (!(sbsec->flags & flag) ||
 537                     (old_sid != new_sid))
 538                         return 1;
 539
 540         /* check if we were passed the same options twice,
 541          * aka someone passed context=a,context=b
 542          */
 543         if (!(sbsec->flags & SE_SBINITIALIZED))
 544                 if (mnt_flags & flag)
 545                         return 1;
 546         return 0;
 547 }
 548
 549 /*
 550  * Allow filesystems with binary mount data to explicitly set mount point
 551  * labeling information.
 552  */
 553 static int selinux_set_mnt_opts(struct super_block *sb,
 554                                 struct security_mnt_opts *opts)
 555 {
 556         const struct cred *cred = current_cred();
 557         int rc = 0, i;
 558         struct superblock_security_struct *sbsec = sb->s_security;
 559         const char *name = sb->s_type->name;
 560         struct inode *inode = sbsec->sb->s_root->d_inode;
 561         struct inode_security_struct *root_isec = inode->i_security;
 562         u32 fscontext_sid = 0, context_sid = 0, rootcontext_sid = 0;
 563         u32 defcontext_sid = 0;
 564         char **mount_options = opts->mnt_opts;
 565         int *flags = opts->mnt_opts_flags;
 566         int num_opts = opts->num_mnt_opts;
 567
 568         mutex_lock(&sbsec->lock);
 569
 570         if (!ss_initialized) {
 571                 if (!num_opts) {
 572                         /* Defer initialization until selinux_complete_init,
 573                            after the initial policy is loaded and the security
 574                            server is ready to handle calls. */
 575                         goto out;
 576                 }
 577                 rc = -EINVAL;
 578                 printk(KERN_WARNING "SELinux: Unable to set superblock options "
 579                         "before the security server is initialized\n");
 580                 goto out;
 581         }
 582
 583         /*
 584          * Binary mount data FS will come through this function twice.  Once
 585          * from an explicit call and once from the generic calls from the vfs.
 586          * Since the generic VFS calls will not contain any security mount data
 587          * we need to skip the double mount verification.
 588          *
 589          * This does open a hole in which we will not notice if the first
 590          * mount using this sb set explict options and a second mount using
 591          * this sb does not set any security options.  (The first options
 592          * will be used for both mounts)
 593          */
 594         if ((sbsec->flags & SE_SBINITIALIZED) && (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA)
 595             && (num_opts == 0))
 596                 goto out;
 597
 598         /*
 599          * parse the mount options, check if they are valid sids.
 600          * also check if someone is trying to mount the same sb more
 601          * than once with different security options.
 602          */
 603         for (i = 0; i < num_opts; i++) {
 604                 u32 sid;
 605
 606                 if (flags[i] == SE_SBLABELSUPP)
 607                         continue;
 608                 rc = security_context_to_sid(mount_options[i],
 609                                              strlen(mount_options[i]), &sid);
 610                 if (rc) {
 611                         printk(KERN_WARNING "SELinux: security_context_to_sid"
 612                                "(%s) failed for (dev %s, type %s) errno=%d\n",
 613                                mount_options[i], sb->s_id, name, rc);
 614                         goto out;
 615                 }
 616                 switch (flags[i]) {
 617                 case FSCONTEXT_MNT:
 618                         fscontext_sid = sid;
 619
 620                         if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid,
 621                                         fscontext_sid))
 622                                 goto out_double_mount;
 623
 624                         sbsec->flags |= FSCONTEXT_MNT;
 625                         break;
 626                 case CONTEXT_MNT:
 627                         context_sid = sid;
 628
 629                         if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid,
 630                                         context_sid))
 631                                 goto out_double_mount;
 632
 633                         sbsec->flags |= CONTEXT_MNT;
 634                         break;
 635                 case ROOTCONTEXT_MNT:
 636                         rootcontext_sid = sid;
 637
 638                         if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid,
 639                                         rootcontext_sid))
 640                                 goto out_double_mount;
 641
 642                         sbsec->flags |= ROOTCONTEXT_MNT;
 643
 644                         break;
 645                 case DEFCONTEXT_MNT:
 646                         defcontext_sid = sid;
 647
 648                         if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid,
 649                                         defcontext_sid))
 650                                 goto out_double_mount;
 651
 652                         sbsec->flags |= DEFCONTEXT_MNT;
 653
 654                         break;
 655                 default:
 656                         rc = -EINVAL;
 657                         goto out;
 658                 }
 659         }
 660
 661         if (sbsec->flags & SE_SBINITIALIZED) {
 662                 /* previously mounted with options, but not on this attempt? */
 663                 if ((sbsec->flags & SE_MNTMASK) && !num_opts)
 664                         goto out_double_mount;
 665                 rc = 0;
 666                 goto out;
 667         }
 668
 669         if (strcmp(sb->s_type->name, "proc") == 0)
 670                 sbsec->flags |= SE_SBPROC;
 671
 672         /* Determine the labeling behavior to use for this filesystem type. */
 673         rc = security_fs_use((sbsec->flags & SE_SBPROC) ? "proc" : sb->s_type->name, &sbsec->behavior, &sbsec->sid);
 674         if (rc) {
 675                 printk(KERN_WARNING "%s: security_fs_use(%s) returned %d\n",
 676                        __func__, sb->s_type->name, rc);
 677                 goto out;
 678         }
 679
 680         /* sets the context of the superblock for the fs being mounted. */
 681         if (fscontext_sid) {
 682                 rc = may_context_mount_sb_relabel(fscontext_sid, sbsec, cred);
 683                 if (rc)
 684                         goto out;
 685
 686                 sbsec->sid = fscontext_sid;
 687         }
 688
 689         /*
 690          * Switch to using mount point labeling behavior.
 691          * sets the label used on all file below the mountpoint, and will set
 692          * the superblock context if not already set.
 693          */
 694         if (context_sid) {
 695                 if (!fscontext_sid) {
 696                         rc = may_context_mount_sb_relabel(context_sid, sbsec,
 697                                                           cred);
 698                         if (rc)
 699                                 goto out;
 700                         sbsec->sid = context_sid;
 701                 } else {
 702                         rc = may_context_mount_inode_relabel(context_sid, sbsec,
 703                                                              cred);
 704                         if (rc)
 705                                 goto out;
 706                 }
 707                 if (!rootcontext_sid)
 708                         rootcontext_sid = context_sid;
 709
 710                 sbsec->mntpoint_sid = context_sid;
 711                 sbsec->behavior = SECURITY_FS_USE_MNTPOINT;
 712         }
 713
 714         if (rootcontext_sid) {
 715                 rc = may_context_mount_inode_relabel(rootcontext_sid, sbsec,
 716                                                      cred);
 717                 if (rc)
 718                         goto out;
 719
 720                 root_isec->sid = rootcontext_sid;
 721                 root_isec->initialized = 1;
 722         }
 723
 724         if (defcontext_sid) {
 725                 if (sbsec->behavior != SECURITY_FS_USE_XATTR) {
 726                         rc = -EINVAL;
 727                         printk(KERN_WARNING "SELinux: defcontext option is "
 728                                "invalid for this filesystem type\n");
 729                         goto out;
 730                 }
 731
 732                 if (defcontext_sid != sbsec->def_sid) {
 733                         rc = may_context_mount_inode_relabel(defcontext_sid,
 734                                                              sbsec, cred);
 735                         if (rc)
 736                                 goto out;
 737                 }
 738
 739                 sbsec->def_sid = defcontext_sid;
 740         }
 741
 742         rc = sb_finish_set_opts(sb);
 743 out:
 744         mutex_unlock(&sbsec->lock);
 745         return rc;
 746 out_double_mount:
 747         rc = -EINVAL;
 748         printk(KERN_WARNING "SELinux: mount invalid.  Same superblock, different "
 749                "security settings for (dev %s, type %s)\n", sb->s_id, name);
 750         goto out;
 751 }
 752
 753 static void selinux_sb_clone_mnt_opts(const struct super_block *oldsb,
 754                                         struct super_block *newsb)
 755 {
 756         const struct superblock_security_struct *oldsbsec = oldsb->s_security;
 757         struct superblock_security_struct *newsbsec = newsb->s_security;
 758
 759         int set_fscontext =     (oldsbsec->flags & FSCONTEXT_MNT);
 760         int set_context =       (oldsbsec->flags & CONTEXT_MNT);
 761         int set_rootcontext =   (oldsbsec->flags & ROOTCONTEXT_MNT);
 762
 763         /*
 764          * if the parent was able to be mounted it clearly had no special lsm
 765          * mount options.  thus we can safely deal with this superblock later
 766          */
 767         if (!ss_initialized)
 768                 return;
 769
 770         /* how can we clone if the old one wasn't set up?? */
 771         BUG_ON(!(oldsbsec->flags & SE_SBINITIALIZED));
 772
 773         /* if fs is reusing a sb, just let its options stand... */
 774         if (newsbsec->flags & SE_SBINITIALIZED)
 775                 return;
 776
 777         mutex_lock(&newsbsec->lock);
 778
 779         newsbsec->flags = oldsbsec->flags;
 780
 781         newsbsec->sid = oldsbsec->sid;
 782         newsbsec->def_sid = oldsbsec->def_sid;
 783         newsbsec->behavior = oldsbsec->behavior;
 784
 785         if (set_context) {
 786                 u32 sid = oldsbsec->mntpoint_sid;
 787
 788                 if (!set_fscontext)
 789                         newsbsec->sid = sid;
 790                 if (!set_rootcontext) {
 791                         struct inode *newinode = newsb->s_root->d_inode;
 792                         struct inode_security_struct *newisec = newinode->i_security;
 793                         newisec->sid = sid;
 794                 }
 795                 newsbsec->mntpoint_sid = sid;
 796         }
 797         if (set_rootcontext) {
 798                 const struct inode *oldinode = oldsb->s_root->d_inode;
 799                 const struct inode_security_struct *oldisec = oldinode->i_security;
 800                 struct inode *newinode = newsb->s_root->d_inode;
 801                 struct inode_security_struct *newisec = newinode->i_security;
 802
 803                 newisec->sid = oldisec->sid;
 804         }
 805
 806         sb_finish_set_opts(newsb);
 807         mutex_unlock(&newsbsec->lock);
 808 }
 809
 810 static int selinux_parse_opts_str(char *options,
 811                                   struct security_mnt_opts *opts)
 812 {
 813         char *p;
 814         char *context = NULL, *defcontext = NULL;
 815         char *fscontext = NULL, *rootcontext = NULL;
 816         int rc, num_mnt_opts = 0;
 817
 818         opts->num_mnt_opts = 0;
 819
 820         /* Standard string-based options. */
 821         while ((p = strsep(&options, "|")) != NULL) {
 822                 int token;
 823                 substring_t args[MAX_OPT_ARGS];
 824
 825                 if (!*p)
 826                         continue;
 827
 828                 token = match_token(p, tokens, args);
 829
 830                 switch (token) {
 831                 case Opt_context:
 832                         if (context || defcontext) {
 833                                 rc = -EINVAL;
 834                                 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
 835                                 goto out_err;
 836                         }
 837                         context = match_strdup(&args[0]);
 838                         if (!context) {
 839                                 rc = -ENOMEM;
 840                                 goto out_err;
 841                         }
 842                         break;
 843
 844                 case Opt_fscontext:
 845                         if (fscontext) {
 846                                 rc = -EINVAL;
 847                                 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
 848                                 goto out_err;
 849                         }
 850                         fscontext = match_strdup(&args[0]);
 851                         if (!fscontext) {
 852                                 rc = -ENOMEM;
 853                                 goto out_err;
 854                         }
 855                         break;
 856
 857                 case Opt_rootcontext:
 858                         if (rootcontext) {
 859                                 rc = -EINVAL;
 860                                 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
 861                                 goto out_err;
 862                         }
 863                         rootcontext = match_strdup(&args[0]);
 864                         if (!rootcontext) {
 865                                 rc = -ENOMEM;
 866                                 goto out_err;
 867                         }
 868                         break;
 869
 870                 case Opt_defcontext:
 871                         if (context || defcontext) {
 872                                 rc = -EINVAL;
 873                                 printk(KERN_WARNING SEL_MOUNT_FAIL_MSG);
 874                                 goto out_err;
 875                         }
 876                         defcontext = match_strdup(&args[0]);
 877                         if (!defcontext) {
 878                                 rc = -ENOMEM;
 879                                 goto out_err;
 880                         }
 881                         break;
 882                 case Opt_labelsupport:
 883                         break;
 884                 default:
 885                         rc = -EINVAL;
 886                         printk(KERN_WARNING "SELinux:  unknown mount option\n");
 887                         goto out_err;
 888
 889                 }
 890         }
 891
 892         rc = -ENOMEM;
 893         opts->mnt_opts = kcalloc(NUM_SEL_MNT_OPTS, sizeof(char *), GFP_ATOMIC);
 894         if (!opts->mnt_opts)
 895                 goto out_err;
 896
 897         opts->mnt_opts_flags = kcalloc(NUM_SEL_MNT_OPTS, sizeof(int), GFP_ATOMIC);
 898         if (!opts->mnt_opts_flags) {
 899                 kfree(opts->mnt_opts);
 900                 goto out_err;
 901         }
 902
 903         if (fscontext) {
 904                 opts->mnt_opts[num_mnt_opts] = fscontext;
 905                 opts->mnt_opts_flags[num_mnt_opts++] = FSCONTEXT_MNT;
 906         }
 907         if (context) {
 908                 opts->mnt_opts[num_mnt_opts] = context;
 909                 opts->mnt_opts_flags[num_mnt_opts++] = CONTEXT_MNT;
 910         }
 911         if (rootcontext) {
 912                 opts->mnt_opts[num_mnt_opts] = rootcontext;
 913                 opts->mnt_opts_flags[num_mnt_opts++] = ROOTCONTEXT_MNT;
 914         }
 915         if (defcontext) {
 916                 opts->mnt_opts[num_mnt_opts] = defcontext;
 917                 opts->mnt_opts_flags[num_mnt_opts++] = DEFCONTEXT_MNT;
 918         }
 919
 920         opts->num_mnt_opts = num_mnt_opts;
 921         return 0;
 922
 923 out_err:
 924         kfree(context);
 925         kfree(defcontext);
 926         kfree(fscontext);
 927         kfree(rootcontext);
 928         return rc;
 929 }
 930 /*
 931  * string mount options parsing and call set the sbsec
 932  */
 933 static int superblock_doinit(struct super_block *sb, void *data)
 934 {
 935         int rc = 0;
 936         char *options = data;
 937         struct security_mnt_opts opts;
 938
 939         security_init_mnt_opts(&opts);
 940
 941         if (!data)
 942                 goto out;
 943
 944         BUG_ON(sb->s_type->fs_flags & FS_BINARY_MOUNTDATA);
 945
 946         rc = selinux_parse_opts_str(options, &opts);
 947         if (rc)
 948                 goto out_err;
 949
 950 out:
 951         rc = selinux_set_mnt_opts(sb, &opts);
 952
 953 out_err:
 954         security_free_mnt_opts(&opts);
 955         return rc;
 956 }
 957
 958 static void selinux_write_opts(struct seq_file *m,
 959                                struct security_mnt_opts *opts)
 960 {
 961         int i;
 962         char *prefix;
 963
 964         for (i = 0; i < opts->num_mnt_opts; i++) {
 965                 char *has_comma;
 966
 967                 if (opts->mnt_opts[i])
 968                         has_comma = strchr(opts->mnt_opts[i], ',');
 969                 else
 970                         has_comma = NULL;
 971
 972                 switch (opts->mnt_opts_flags[i]) {
 973                 case CONTEXT_MNT:
 974                         prefix = CONTEXT_STR;
 975                         break;
 976                 case FSCONTEXT_MNT:
 977                         prefix = FSCONTEXT_STR;
 978                         break;
 979                 case ROOTCONTEXT_MNT:
 980                         prefix = ROOTCONTEXT_STR;
 981                         break;
 982                 case DEFCONTEXT_MNT:
 983                         prefix = DEFCONTEXT_STR;
 984                         break;
 985                 case SE_SBLABELSUPP:
 986                         seq_putc(m, ',');
 987                         seq_puts(m, LABELSUPP_STR);
 988                         continue;
 989                 default:
 990                         BUG();
 991                         return;
 992                 };
 993                 /* we need a comma before each option */
 994                 seq_putc(m, ',');
 995                 seq_puts(m, prefix);
 996                 if (has_comma)
 997                         seq_putc(m, '\"');
 998                 seq_puts(m, opts->mnt_opts[i]);
 999                 if (has_comma)
1000                         seq_putc(m, '\"');
1001         }
1002 }
1003
1004 static int selinux_sb_show_options(struct seq_file *m, struct super_block *sb)
1005 {
1006         struct security_mnt_opts opts;
1007         int rc;
1008
1009         rc = selinux_get_mnt_opts(sb, &opts);
1010         if (rc) {
1011                 /* before policy load we may get EINVAL, don't show anything */
1012                 if (rc == -EINVAL)
1013                         rc = 0;
1014                 return rc;
1015         }
1016
1017         selinux_write_opts(m, &opts);
1018
1019         security_free_mnt_opts(&opts);
1020
1021         return rc;
1022 }
1023
1024 static inline u16 inode_mode_to_security_class(umode_t mode)
1025 {
1026         switch (mode & S_IFMT) {
1027         case S_IFSOCK:
1028                 return SECCLASS_SOCK_FILE;
1029         case S_IFLNK:
1030                 return SECCLASS_LNK_FILE;
1031         case S_IFREG:
1032                 return SECCLASS_FILE;
1033         case S_IFBLK:
1034                 return SECCLASS_BLK_FILE;
1035         case S_IFDIR:
1036                 return SECCLASS_DIR;
1037         case S_IFCHR:
1038                 return SECCLASS_CHR_FILE;
1039         case S_IFIFO:
1040                 return SECCLASS_FIFO_FILE;
1041
1042         }
1043
1044         return SECCLASS_FILE;
1045 }
1046
1047 static inline int default_protocol_stream(int protocol)
1048 {
1049         return (protocol == IPPROTO_IP || protocol == IPPROTO_TCP);
1050 }
1051
1052 static inline int default_protocol_dgram(int protocol)
1053 {
1054         return (protocol == IPPROTO_IP || protocol == IPPROTO_UDP);
1055 }
1056
1057 static inline u16 socket_type_to_security_class(int family, int type, int protocol)
1058 {
1059         switch (family) {
1060         case PF_UNIX:
1061                 switch (type) {
1062                 case SOCK_STREAM:
1063                 case SOCK_SEQPACKET:
1064                         return SECCLASS_UNIX_STREAM_SOCKET;
1065                 case SOCK_DGRAM:
1066                         return SECCLASS_UNIX_DGRAM_SOCKET;
1067                 }
1068                 break;
1069         case PF_INET:
1070         case PF_INET6:
1071                 switch (type) {
1072                 case SOCK_STREAM:
1073                         if (default_protocol_stream(protocol))
1074                                 return SECCLASS_TCP_SOCKET;
1075                         else
1076                                 return SECCLASS_RAWIP_SOCKET;
1077                 case SOCK_DGRAM:
1078                         if (default_protocol_dgram(protocol))
1079                                 return SECCLASS_UDP_SOCKET;
1080                         else
1081                                 return SECCLASS_RAWIP_SOCKET;
1082                 case SOCK_DCCP:
1083                         return SECCLASS_DCCP_SOCKET;
1084                 default:
1085                         return SECCLASS_RAWIP_SOCKET;
1086                 }
1087                 break;
1088         case PF_NETLINK:
1089                 switch (protocol) {
1090                 case NETLINK_ROUTE:
1091                         return SECCLASS_NETLINK_ROUTE_SOCKET;
1092                 case NETLINK_FIREWALL:
1093                         return SECCLASS_NETLINK_FIREWALL_SOCKET;
1094                 case NETLINK_SOCK_DIAG:
1095                         return SECCLASS_NETLINK_TCPDIAG_SOCKET;
1096                 case NETLINK_NFLOG:
1097                         return SECCLASS_NETLINK_NFLOG_SOCKET;
1098                 case NETLINK_XFRM:
1099                         return SECCLASS_NETLINK_XFRM_SOCKET;
1100                 case NETLINK_SELINUX:
1101                         return SECCLASS_NETLINK_SELINUX_SOCKET;
1102                 case NETLINK_AUDIT:
1103                         return SECCLASS_NETLINK_AUDIT_SOCKET;
1104                 case NETLINK_IP6_FW:
1105                         return SECCLASS_NETLINK_IP6FW_SOCKET;
1106                 case NETLINK_DNRTMSG:
1107                         return SECCLASS_NETLINK_DNRT_SOCKET;
1108                 case NETLINK_KOBJECT_UEVENT:
1109                         return SECCLASS_NETLINK_KOBJECT_UEVENT_SOCKET;
1110                 default:
1111                         return SECCLASS_NETLINK_SOCKET;
1112                 }
1113         case PF_PACKET:
1114                 return SECCLASS_PACKET_SOCKET;
1115         case PF_KEY:
1116                 return SECCLASS_KEY_SOCKET;
1117         case PF_APPLETALK:
1118                 return SECCLASS_APPLETALK_SOCKET;
1119         }
1120
1121         return SECCLASS_SOCKET;
1122 }
1123
1124 #ifdef CONFIG_PROC_FS
1125 static int selinux_proc_get_sid(struct dentry *dentry,
1126                                 u16 tclass,
1127                                 u32 *sid)
1128 {
1129         int rc;
1130         char *buffer, *path;
1131
1132         buffer = (char *)__get_free_page(GFP_KERNEL);
1133         if (!buffer)
1134                 return -ENOMEM;
1135
1136         path = dentry_path_raw(dentry, buffer, PAGE_SIZE);
1137         if (IS_ERR(path))
1138                 rc = PTR_ERR(path);
1139         else {
1140                 /* each process gets a /proc/PID/ entry. Strip off the
1141                  * PID part to get a valid selinux labeling.
1142                  * e.g. /proc/1/net/rpc/nfs -> /net/rpc/nfs */
1143                 while (path[1] >= '0' && path[1] <= '9') {
1144                         path[1] = '/';
1145                         path++;
1146                 }
1147                 rc = security_genfs_sid("proc", path, tclass, sid);
1148         }
1149         free_page((unsigned long)buffer);
1150         return rc;
1151 }
1152 #else
1153 static int selinux_proc_get_sid(struct dentry *dentry,
1154                                 u16 tclass,
1155                                 u32 *sid)
1156 {
1157         return -EINVAL;
1158 }
1159 #endif
1160
1161 /* The inode's security attributes must be initialized before first use. */
1162 static int inode_doinit_with_dentry(struct inode *inode, struct dentry *opt_dentry)
1163 {
1164         struct superblock_security_struct *sbsec = NULL;
1165         struct inode_security_struct *isec = inode->i_security;
1166         u32 sid;
1167         struct dentry *dentry;
1168 #define INITCONTEXTLEN 255
1169         char *context = NULL;
1170         unsigned len = 0;
1171         int rc = 0;
1172
1173         if (isec->initialized)
1174                 goto out;
1175
1176         mutex_lock(&isec->lock);
1177         if (isec->initialized)
1178                 goto out_unlock;
1179
1180         sbsec = inode->i_sb->s_security;
1181         if (!(sbsec->flags & SE_SBINITIALIZED)) {
1182                 /* Defer initialization until selinux_complete_init,
1183                    after the initial policy is loaded and the security
1184                    server is ready to handle calls. */
1185                 spin_lock(&sbsec->isec_lock);
1186                 if (list_empty(&isec->list))
1187                         list_add(&isec->list, &sbsec->isec_head);
1188                 spin_unlock(&sbsec->isec_lock);
1189                 goto out_unlock;
1190         }
1191
1192         switch (sbsec->behavior) {
1193         case SECURITY_FS_USE_XATTR:
1194                 if (!inode->i_op->getxattr) {
1195                         isec->sid = sbsec->def_sid;
1196                         break;
1197                 }
1198
1199                 /* Need a dentry, since the xattr API requires one.
1200                    Life would be simpler if we could just pass the inode. */
1201                 if (opt_dentry) {
1202                         /* Called from d_instantiate or d_splice_alias. */
1203                         dentry = dget(opt_dentry);
1204                 } else {
1205                         /* Called from selinux_complete_init, try to find a dentry. */
1206                         dentry = d_find_alias(inode);
1207                 }
1208                 if (!dentry) {
1209                         /*
1210                          * this is can be hit on boot when a file is accessed
1211                          * before the policy is loaded.  When we load policy we
1212                          * may find inodes that have no dentry on the
1213                          * sbsec->isec_head list.  No reason to complain as these
1214                          * will get fixed up the next time we go through
1215                          * inode_doinit with a dentry, before these inodes could
1216                          * be used again by userspace.
1217                          */
1218                         goto out_unlock;
1219                 }
1220
1221                 len = INITCONTEXTLEN;
1222                 context = kmalloc(len+1, GFP_NOFS);
1223                 if (!context) {
1224                         rc = -ENOMEM;
1225                         dput(dentry);
1226                         goto out_unlock;
1227                 }
1228                 context[len] = '\0';
1229                 rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX,
1230                                            context, len);
1231                 if (rc == -ERANGE) {
1232                         kfree(context);
1233
1234                         /* Need a larger buffer.  Query for the right size. */
1235                         rc = inode->i_op->getxattr(dentry, XATTR_NAME_SELINUX,
1236                                                    NULL, 0);
1237                         if (rc < 0) {
1238                                 dput(dentry);
1239                                 goto out_unlock;
1240                         }
1241                         len = rc;
1242                         context = kmalloc(len+1, GFP_NOFS);
1243                         if (!context) {
1244                                 rc = -ENOMEM;
1245                                 dput(dentry);
1246                                 goto out_unlock;
1247                         }
1248                         context[len] = '\0';
1249                         rc = inode->i_op->getxattr(dentry,
1250                                                    XATTR_NAME_SELINUX,
1251                                                    context, len);
1252                 }
1253                 dput(dentry);
1254                 if (rc < 0) {
1255                         if (rc != -ENODATA) {
1256                                 printk(KERN_WARNING "SELinux: %s:  getxattr returned "
1257                                        "%d for dev=%s ino=%ld\n", __func__,
1258                                        -rc, inode->i_sb->s_id, inode->i_ino);
1259                                 kfree(context);
1260                                 goto out_unlock;
1261                         }
1262                         /* Map ENODATA to the default file SID */
1263                         sid = sbsec->def_sid;
1264                         rc = 0;
1265                 } else {
1266                         rc = security_context_to_sid_default(context, rc, &sid,
1267                                                              sbsec->def_sid,
1268                                                              GFP_NOFS);
1269                         if (rc) {
1270                                 char *dev = inode->i_sb->s_id;
1271                                 unsigned long ino = inode->i_ino;
1272
1273                                 if (rc == -EINVAL) {
1274                                         if (printk_ratelimit())
1275                                                 printk(KERN_NOTICE "SELinux: inode=%lu on dev=%s was found to have an invalid "
1276                                                         "context=%s.  This indicates you may need to relabel the inode or the "
1277                                                         "filesystem in question.\n", ino, dev, context);
1278                                 } else {
1279                                         printk(KERN_WARNING "SELinux: %s:  context_to_sid(%s) "
1280                                                "returned %d for dev=%s ino=%ld\n",
1281                                                __func__, context, -rc, dev, ino);
1282                                 }
1283                                 kfree(context);
1284                                 /* Leave with the unlabeled SID */
1285                                 rc = 0;
1286                                 break;
1287                         }
1288                 }
1289                 kfree(context);
1290                 isec->sid = sid;
1291                 break;
1292         case SECURITY_FS_USE_TASK:
1293                 isec->sid = isec->task_sid;
1294                 break;
1295         case SECURITY_FS_USE_TRANS:
1296                 /* Default to the fs SID. */
1297                 isec->sid = sbsec->sid;
1298
1299                 /* Try to obtain a transition SID. */
1300                 isec->sclass = inode_mode_to_security_class(inode->i_mode);
1301                 rc = security_transition_sid(isec->task_sid, sbsec->sid,
1302                                              isec->sclass, NULL, &sid);
1303                 if (rc)
1304                         goto out_unlock;
1305                 isec->sid = sid;
1306                 break;
1307         case SECURITY_FS_USE_MNTPOINT:
1308                 isec->sid = sbsec->mntpoint_sid;
1309                 break;
1310         default:
1311                 /* Default to the fs superblock SID. */
1312                 isec->sid = sbsec->sid;
1313
1314                 if ((sbsec->flags & SE_SBPROC) && !S_ISLNK(inode->i_mode)) {
1315                         if (opt_dentry) {
1316                                 isec->sclass = inode_mode_to_security_class(inode->i_mode);
1317                                 rc = selinux_proc_get_sid(opt_dentry,
1318                                                           isec->sclass,
1319                                                           &sid);
1320                                 if (rc)
1321                                         goto out_unlock;
1322                                 isec->sid = sid;
1323                         }
1324                 }
1325                 break;
1326         }
1327
1328         isec->initialized = 1;
1329
1330 out_unlock:
1331         mutex_unlock(&isec->lock);
1332 out:
1333         if (isec->sclass == SECCLASS_FILE)
1334                 isec->sclass = inode_mode_to_security_class(inode->i_mode);
1335         return rc;
1336 }
1337
1338 /* Convert a Linux signal to an access vector. */
1339 static inline u32 signal_to_av(int sig)
1340 {
1341         u32 perm = 0;
1342
1343         switch (sig) {
1344         case SIGCHLD:
1345                 /* Commonly granted from child to parent. */
1346                 perm = PROCESS__SIGCHLD;
1347                 break;
1348         case SIGKILL:
1349                 /* Cannot be caught or ignored */
1350                 perm = PROCESS__SIGKILL;
1351                 break;
1352         case SIGSTOP:
1353                 /* Cannot be caught or ignored */
1354                 perm = PROCESS__SIGSTOP;
1355                 break;
1356         default:
1357                 /* All other signals. */
1358                 perm = PROCESS__SIGNAL;
1359                 break;
1360         }
1361
1362         return perm;
1363 }
1364
1365 /*
1366  * Check permission between a pair of credentials
1367  * fork check, ptrace check, etc.
1368  */
1369 static int cred_has_perm(const struct cred *actor,
1370                          const struct cred *target,
1371                          u32 perms)
1372 {
1373         u32 asid = cred_sid(actor), tsid = cred_sid(target);
1374
1375         return avc_has_perm(asid, tsid, SECCLASS_PROCESS, perms, NULL);
1376 }
1377
1378 /*
1379  * Check permission between a pair of tasks, e.g. signal checks,
1380  * fork check, ptrace check, etc.
1381  * tsk1 is the actor and tsk2 is the target
1382  * - this uses the default subjective creds of tsk1
1383  */
1384 static int task_has_perm(const struct task_struct *tsk1,
1385                          const struct task_struct *tsk2,
1386                          u32 perms)
1387 {
1388         const struct task_security_struct *__tsec1, *__tsec2;
1389         u32 sid1, sid2;
1390
1391         rcu_read_lock();
1392         __tsec1 = __task_cred(tsk1)->security;  sid1 = __tsec1->sid;
1393         __tsec2 = __task_cred(tsk2)->security;  sid2 = __tsec2->sid;
1394         rcu_read_unlock();
1395         return avc_has_perm(sid1, sid2, SECCLASS_PROCESS, perms, NULL);
1396 }
1397
1398 /*
1399  * Check permission between current and another task, e.g. signal checks,
1400  * fork check, ptrace check, etc.
1401  * current is the actor and tsk2 is the target
1402  * - this uses current's subjective creds
1403  */
1404 static int current_has_perm(const struct task_struct *tsk,
1405                             u32 perms)
1406 {
1407         u32 sid, tsid;
1408
1409         sid = current_sid();
1410         tsid = task_sid(tsk);
1411         return avc_has_perm(sid, tsid, SECCLASS_PROCESS, perms, NULL);
1412 }
1413
1414 #if CAP_LAST_CAP > 63
1415 #error Fix SELinux to handle capabilities > 63.
1416 #endif
1417
1418 /* Check whether a task is allowed to use a capability. */
1419 static int cred_has_capability(const struct cred *cred,
1420                                int cap, int audit)
1421 {
1422         struct common_audit_data ad;
1423         struct selinux_audit_data sad = {0,};
1424         struct av_decision avd;
1425         u16 sclass;
1426         u32 sid = cred_sid(cred);
1427         u32 av = CAP_TO_MASK(cap);
1428         int rc;
1429
1430         COMMON_AUDIT_DATA_INIT(&ad, CAP);
1431         ad.selinux_audit_data = &sad;
1432         ad.tsk = current;
1433         ad.u.cap = cap;
1434
1435         switch (CAP_TO_INDEX(cap)) {
1436         case 0:
1437                 sclass = SECCLASS_CAPABILITY;
1438                 break;
1439         case 1:
1440                 sclass = SECCLASS_CAPABILITY2;
1441                 break;
1442         default:
1443                 printk(KERN_ERR
1444                        "SELinux:  out of range capability %d\n", cap);
1445                 BUG();
1446                 return -EINVAL;
1447         }
1448
1449         rc = avc_has_perm_noaudit(sid, sid, sclass, av, 0, &avd);
1450         if (audit == SECURITY_CAP_AUDIT) {
1451                 int rc2 = avc_audit(sid, sid, sclass, av, &avd, rc, &ad, 0);
1452                 if (rc2)
1453                         return rc2;
1454         }
1455         return rc;
1456 }
1457
1458 /* Check whether a task is allowed to use a system operation. */
1459 static int task_has_system(struct task_struct *tsk,
1460                            u32 perms)
1461 {
1462         u32 sid = task_sid(tsk);
1463
1464         return avc_has_perm(sid, SECINITSID_KERNEL,
1465                             SECCLASS_SYSTEM, perms, NULL);
1466 }
1467
1468 /* Check whether a task has a particular permission to an inode.
1469    The 'adp' parameter is optional and allows other audit
1470    data to be passed (e.g. the dentry). */
1471 static int inode_has_perm(const struct cred *cred,
1472                           struct inode *inode,
1473                           u32 perms,
1474                           struct common_audit_data *adp,
1475                           unsigned flags)
1476 {
1477         struct inode_security_struct *isec;
1478         u32 sid;
1479
1480         validate_creds(cred);
1481
1482         if (unlikely(IS_PRIVATE(inode)))
1483                 return 0;
1484
1485         sid = cred_sid(cred);
1486         isec = inode->i_security;
1487
1488         return avc_has_perm_flags(sid, isec->sid, isec->sclass, perms, adp, flags);
1489 }
1490
1491 static int inode_has_perm_noadp(const struct cred *cred,
1492                                 struct inode *inode,
1493                                 u32 perms,
1494                                 unsigned flags)
1495 {
1496         struct common_audit_data ad;
1497         struct selinux_audit_data sad = {0,};
1498
1499         COMMON_AUDIT_DATA_INIT(&ad, INODE);
1500         ad.u.inode = inode;
1501         ad.selinux_audit_data = &sad;
1502         return inode_has_perm(cred, inode, perms, &ad, flags);
1503 }
1504
1505 /* Same as inode_has_perm, but pass explicit audit data containing
1506    the dentry to help the auditing code to more easily generate the
1507    pathname if needed. */
1508 static inline int dentry_has_perm(const struct cred *cred,
1509                                   struct dentry *dentry,
1510                                   u32 av)
1511 {
1512         struct inode *inode = dentry->d_inode;
1513         struct common_audit_data ad;
1514         struct selinux_audit_data sad = {0,};
1515
1516         COMMON_AUDIT_DATA_INIT(&ad, DENTRY);
1517         ad.u.dentry = dentry;
1518         ad.selinux_audit_data = &sad;
1519         return inode_has_perm(cred, inode, av, &ad, 0);
1520 }
1521
1522 /* Same as inode_has_perm, but pass explicit audit data containing
1523    the path to help the auditing code to more easily generate the
1524    pathname if needed. */
1525 static inline int path_has_perm(const struct cred *cred,
1526                                 struct path *path,
1527                                 u32 av)
1528 {
1529         struct inode *inode = path->dentry->d_inode;
1530         struct common_audit_data ad;
1531         struct selinux_audit_data sad = {0,};
1532
1533         COMMON_AUDIT_DATA_INIT(&ad, PATH);
1534         ad.u.path = *path;
1535         ad.selinux_audit_data = &sad;
1536         return inode_has_perm(cred, inode, av, &ad, 0);
1537 }
1538
1539 /* Check whether a task can use an open file descriptor to
1540    access an inode in a given way.  Check access to the
1541    descriptor itself, and then use dentry_has_perm to
1542    check a particular permission to the file.
1543    Access to the descriptor is implicitly granted if it
1544    has the same SID as the process.  If av is zero, then
1545    access to the file is not checked, e.g. for cases
1546    where only the descriptor is affected like seek. */
1547 static int file_has_perm(const struct cred *cred,
1548                          struct file *file,
1549                          u32 av)
1550 {
1551         struct file_security_struct *fsec = file->f_security;
1552         struct inode *inode = file->f_path.dentry->d_inode;
1553         struct common_audit_data ad;
1554         struct selinux_audit_data sad = {0,};
1555         u32 sid = cred_sid(cred);
1556         int rc;
1557
1558         COMMON_AUDIT_DATA_INIT(&ad, PATH);
1559         ad.u.path = file->f_path;
1560         ad.selinux_audit_data = &sad;
1561
1562         if (sid != fsec->sid) {
1563                 rc = avc_has_perm(sid, fsec->sid,
1564                                   SECCLASS_FD,
1565                                   FD__USE,
1566                                   &ad);
1567                 if (rc)
1568                         goto out;
1569         }
1570
1571         /* av is zero if only checking access to the descriptor. */
1572         rc = 0;
1573         if (av)
1574                 rc = inode_has_perm(cred, inode, av, &ad, 0);
1575
1576 out:
1577         return rc;
1578 }
1579
1580 /* Check whether a task can create a file. */
1581 static int may_create(struct inode *dir,
1582                       struct dentry *dentry,
1583                       u16 tclass)
1584 {
1585         const struct task_security_struct *tsec = current_security();
1586         struct inode_security_struct *dsec;
1587         struct superblock_security_struct *sbsec;
1588         u32 sid, newsid;
1589         struct common_audit_data ad;
1590         struct selinux_audit_data sad = {0,};
1591         int rc;
1592
1593         dsec = dir->i_security;
1594         sbsec = dir->i_sb->s_security;
1595
1596         sid = tsec->sid;
1597         newsid = tsec->create_sid;
1598
1599         COMMON_AUDIT_DATA_INIT(&ad, DENTRY);
1600         ad.u.dentry = dentry;
1601         ad.selinux_audit_data = &sad;
1602
1603         rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR,
1604                           DIR__ADD_NAME | DIR__SEARCH,
1605                           &ad);
1606         if (rc)
1607                 return rc;
1608
1609         if (!newsid || !(sbsec->flags & SE_SBLABELSUPP)) {
1610                 rc = security_transition_sid(sid, dsec->sid, tclass,
1611                                              &dentry->d_name, &newsid);
1612                 if (rc)
1613                         return rc;
1614         }
1615
1616         rc = avc_has_perm(sid, newsid, tclass, FILE__CREATE, &ad);
1617         if (rc)
1618                 return rc;
1619
1620         return avc_has_perm(newsid, sbsec->sid,
1621                             SECCLASS_FILESYSTEM,
1622                             FILESYSTEM__ASSOCIATE, &ad);
1623 }
1624
1625 /* Check whether a task can create a key. */
1626 static int may_create_key(u32 ksid,
1627                           struct task_struct *ctx)
1628 {
1629         u32 sid = task_sid(ctx);
1630
1631         return avc_has_perm(sid, ksid, SECCLASS_KEY, KEY__CREATE, NULL);
1632 }
1633
1634 #define MAY_LINK        0
1635 #define MAY_UNLINK      1
1636 #define MAY_RMDIR       2
1637
1638 /* Check whether a task can link, unlink, or rmdir a file/directory. */
1639 static int may_link(struct inode *dir,
1640                     struct dentry *dentry,
1641                     int kind)
1642
1643 {
1644         struct inode_security_struct *dsec, *isec;
1645         struct common_audit_data ad;
1646         struct selinux_audit_data sad = {0,};
1647         u32 sid = current_sid();
1648         u32 av;
1649         int rc;
1650
1651         dsec = dir->i_security;
1652         isec = dentry->d_inode->i_security;
1653
1654         COMMON_AUDIT_DATA_INIT(&ad, DENTRY);
1655         ad.u.dentry = dentry;
1656         ad.selinux_audit_data = &sad;
1657
1658         av = DIR__SEARCH;
1659         av |= (kind ? DIR__REMOVE_NAME : DIR__ADD_NAME);
1660         rc = avc_has_perm(sid, dsec->sid, SECCLASS_DIR, av, &ad);
1661         if (rc)
1662                 return rc;
1663
1664         switch (kind) {
1665         case MAY_LINK:
1666                 av = FILE__LINK;
1667                 break;
1668         case MAY_UNLINK:
1669                 av = FILE__UNLINK;
1670                 break;
1671         case MAY_RMDIR:
1672                 av = DIR__RMDIR;
1673                 break;
1674         default:
1675                 printk(KERN_WARNING "SELinux: %s:  unrecognized kind %d\n",
1676                         __func__, kind);
1677                 return 0;
1678         }
1679
1680         rc = avc_has_perm(sid, isec->sid, isec->sclass, av, &ad);
1681         return rc;
1682 }
1683
1684 static inline int may_rename(struct inode *old_dir,
1685                              struct dentry *old_dentry,
1686                              struct inode *new_dir,
1687                              struct dentry *new_dentry)
1688 {
1689         struct inode_security_struct *old_dsec, *new_dsec, *old_isec, *new_isec;
1690         struct common_audit_data ad;
1691         struct selinux_audit_data sad = {0,};
1692         u32 sid = current_sid();
1693         u32 av;
1694         int old_is_dir, new_is_dir;
1695         int rc;
1696
1697         old_dsec = old_dir->i_security;
1698         old_isec = old_dentry->d_inode->i_security;
1699         old_is_dir = S_ISDIR(old_dentry->d_inode->i_mode);
1700         new_dsec = new_dir->i_security;
1701
1702         COMMON_AUDIT_DATA_INIT(&ad, DENTRY);
1703         ad.selinux_audit_data = &sad;
1704
1705         ad.u.dentry = old_dentry;
1706         rc = avc_has_perm(sid, old_dsec->sid, SECCLASS_DIR,
1707                           DIR__REMOVE_NAME | DIR__SEARCH, &ad);
1708         if (rc)
1709                 return rc;
1710         rc = avc_has_perm(sid, old_isec->sid,
1711                           old_isec->sclass, FILE__RENAME, &ad);
1712         if (rc)
1713                 return rc;
1714         if (old_is_dir && new_dir != old_dir) {
1715                 rc = avc_has_perm(sid, old_isec->sid,
1716                                   old_isec->sclass, DIR__REPARENT, &ad);
1717                 if (rc)
1718                         return rc;
1719         }
1720
1721         ad.u.dentry = new_dentry;
1722         av = DIR__ADD_NAME | DIR__SEARCH;
1723         if (new_dentry->d_inode)
1724                 av |= DIR__REMOVE_NAME;
1725         rc = avc_has_perm(sid, new_dsec->sid, SECCLASS_DIR, av, &ad);
1726         if (rc)
1727                 return rc;
1728         if (new_dentry->d_inode) {
1729                 new_isec = new_dentry->d_inode->i_security;
1730                 new_is_dir = S_ISDIR(new_dentry->d_inode->i_mode);
1731                 rc = avc_has_perm(sid, new_isec->sid,
1732                                   new_isec->sclass,
1733                                   (new_is_dir ? DIR__RMDIR : FILE__UNLINK), &ad);
1734                 if (rc)
1735                         return rc;
1736         }
1737
1738         return 0;
1739 }
1740
1741 /* Check whether a task can perform a filesystem operation. */
1742 static int superblock_has_perm(const struct cred *cred,
1743                                struct super_block *sb,
1744                                u32 perms,
1745                                struct common_audit_data *ad)
1746 {
1747         struct superblock_security_struct *sbsec;
1748         u32 sid = cred_sid(cred);
1749
1750         sbsec = sb->s_security;
1751         return avc_has_perm(sid, sbsec->sid, SECCLASS_FILESYSTEM, perms, ad);
1752 }
1753
1754 /* Convert a Linux mode and permission mask to an access vector. */
1755 static inline u32 file_mask_to_av(int mode, int mask)
1756 {
1757         u32 av = 0;
1758
1759         if (!S_ISDIR(mode)) {
1760                 if (mask & MAY_EXEC)
1761                         av |= FILE__EXECUTE;
1762                 if (mask & MAY_READ)
1763                         av |= FILE__READ;
1764
1765                 if (mask & MAY_APPEND)
1766                         av |= FILE__APPEND;
1767                 else if (mask & MAY_WRITE)
1768                         av |= FILE__WRITE;
1769
1770         } else {
1771                 if (mask & MAY_EXEC)
1772                         av |= DIR__SEARCH;
1773                 if (mask & MAY_WRITE)
1774                         av |= DIR__WRITE;
1775                 if (mask & MAY_READ)
1776                         av |= DIR__READ;
1777         }
1778
1779         return av;
1780 }
1781
1782 /* Convert a Linux file to an access vector. */
1783 static inline u32 file_to_av(struct file *file)
1784 {
1785         u32 av = 0;
1786
1787         if (file->f_mode & FMODE_READ)
1788                 av |= FILE__READ;
1789         if (file->f_mode & FMODE_WRITE) {
1790                 if (file->f_flags & O_APPEND)
1791                         av |= FILE__APPEND;
1792                 else
1793                         av |= FILE__WRITE;
1794         }
1795         if (!av) {
1796                 /*
1797                  * Special file opened with flags 3 for ioctl-only use.
1798                  */
1799                 av = FILE__IOCTL;
1800         }
1801
1802         return av;
1803 }
1804
1805 /*
1806  * Convert a file to an access vector and include the correct open
1807  * open permission.
1808  */
1809 static inline u32 open_file_to_av(struct file *file)
1810 {
1811         u32 av = file_to_av(file);
1812
1813         if (selinux_policycap_openperm)
1814                 av |= FILE__OPEN;
1815
1816         return av;
1817 }
1818
1819 /* Hook functions begin here. */
1820
1821 static int selinux_ptrace_access_check(struct task_struct *child,
1822                                      unsigned int mode)
1823 {
1824         int rc;
1825
1826         rc = cap_ptrace_access_check(child, mode);
1827         if (rc)
1828                 return rc;
1829
1830         if (mode & PTRACE_MODE_READ) {
1831                 u32 sid = current_sid();
1832                 u32 csid = task_sid(child);
1833                 return avc_has_perm(sid, csid, SECCLASS_FILE, FILE__READ, NULL);
1834         }
1835
1836         return current_has_perm(child, PROCESS__PTRACE);
1837 }
1838
1839 static int selinux_ptrace_traceme(struct task_struct *parent)
1840 {
1841         int rc;
1842
1843         rc = cap_ptrace_traceme(parent);
1844         if (rc)
1845                 return rc;
1846
1847         return task_has_perm(parent, current, PROCESS__PTRACE);
1848 }
1849
1850 static int selinux_capget(struct task_struct *target, kernel_cap_t *effective,
1851                           kernel_cap_t *inheritable, kernel_cap_t *permitted)
1852 {
1853         int error;
1854
1855         error = current_has_perm(target, PROCESS__GETCAP);
1856         if (error)
1857                 return error;
1858
1859         return cap_capget(target, effective, inheritable, permitted);
1860 }
1861
1862 static int selinux_capset(struct cred *new, const struct cred *old,
1863                           const kernel_cap_t *effective,
1864                           const kernel_cap_t *inheritable,
1865                           const kernel_cap_t *permitted)
1866 {
1867         int error;
1868
1869         error = cap_capset(new, old,
1870                                       effective, inheritable, permitted);
1871         if (error)
1872                 return error;
1873
1874         return cred_has_perm(old, new, PROCESS__SETCAP);
1875 }
1876
1877 /*
1878  * (This comment used to live with the selinux_task_setuid hook,
1879  * which was removed).
1880  *
1881  * Since setuid only affects the current process, and since the SELinux
1882  * controls are not based on the Linux identity attributes, SELinux does not
1883  * need to control this operation.  However, SELinux does control the use of
1884  * the CAP_SETUID and CAP_SETGID capabilities using the capable hook.
1885  */
1886
1887 static int selinux_capable(const struct cred *cred, struct user_namespace *ns,
1888                            int cap, int audit)
1889 {
1890         int rc;
1891
1892         rc = cap_capable(cred, ns, cap, audit);
1893         if (rc)
1894                 return rc;
1895
1896         return cred_has_capability(cred, cap, audit);
1897 }
1898
1899 static int selinux_quotactl(int cmds, int type, int id, struct super_block *sb)
1900 {
1901         const struct cred *cred = current_cred();
1902         int rc = 0;
1903
1904         if (!sb)
1905                 return 0;
1906
1907         switch (cmds) {
1908         case Q_SYNC:
1909         case Q_QUOTAON:
1910         case Q_QUOTAOFF:
1911         case Q_SETINFO:
1912         case Q_SETQUOTA:
1913                 rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAMOD, NULL);
1914                 break;
1915         case Q_GETFMT:
1916         case Q_GETINFO:
1917         case Q_GETQUOTA:
1918                 rc = superblock_has_perm(cred, sb, FILESYSTEM__QUOTAGET, NULL);
1919                 break;
1920         default:
1921                 rc = 0;  /* let the kernel handle invalid cmds */
1922                 break;
1923         }
1924         return rc;
1925 }
1926
1927 static int selinux_quota_on(struct dentry *dentry)
1928 {
1929         const struct cred *cred = current_cred();
1930
1931         return dentry_has_perm(cred, dentry, FILE__QUOTAON);
1932 }
1933
1934 static int selinux_syslog(int type)
1935 {
1936         int rc;
1937
1938         switch (type) {
1939         case SYSLOG_ACTION_READ_ALL:    /* Read last kernel messages */
1940         case SYSLOG_ACTION_SIZE_BUFFER: /* Return size of the log buffer */
1941                 rc = task_has_system(current, SYSTEM__SYSLOG_READ);
1942                 break;
1943         case SYSLOG_ACTION_CONSOLE_OFF: /* Disable logging to console */
1944         case SYSLOG_ACTION_CONSOLE_ON:  /* Enable logging to console */
1945         /* Set level of messages printed to console */
1946         case SYSLOG_ACTION_CONSOLE_LEVEL:
1947                 rc = task_has_system(current, SYSTEM__SYSLOG_CONSOLE);
1948                 break;
1949         case SYSLOG_ACTION_CLOSE:       /* Close log */
1950         case SYSLOG_ACTION_OPEN:        /* Open log */
1951         case SYSLOG_ACTION_READ:        /* Read from log */
1952         case SYSLOG_ACTION_READ_CLEAR:  /* Read/clear last kernel messages */
1953         case SYSLOG_ACTION_CLEAR:       /* Clear ring buffer */
1954         default:
1955                 rc = task_has_system(current, SYSTEM__SYSLOG_MOD);
1956                 break;
1957         }
1958         return rc;
1959 }
1960
1961 /*
1962  * Check that a process has enough memory to allocate a new virtual
1963  * mapping. 0 means there is enough memory for the allocation to
1964  * succeed and -ENOMEM implies there is not.
1965  *
1966  * Do not audit the selinux permission check, as this is applied to all
1967  * processes that allocate mappings.
1968  */
1969 static int selinux_vm_enough_memory(struct mm_struct *mm, long pages)
1970 {
1971         int rc, cap_sys_admin = 0;
1972
1973         rc = selinux_capable(current_cred(), &init_user_ns, CAP_SYS_ADMIN,
1974                              SECURITY_CAP_NOAUDIT);
1975         if (rc == 0)
1976                 cap_sys_admin = 1;
1977
1978         return __vm_enough_memory(mm, pages, cap_sys_admin);
1979 }
1980
1981 /* binprm security operations */
1982
1983 static int selinux_bprm_set_creds(struct linux_binprm *bprm)
1984 {
1985         const struct task_security_struct *old_tsec;
1986         struct task_security_struct *new_tsec;
1987         struct inode_security_struct *isec;
1988         struct common_audit_data ad;
1989         struct selinux_audit_data sad = {0,};
1990         struct inode *inode = bprm->file->f_path.dentry->d_inode;
1991         int rc;
1992
1993         rc = cap_bprm_set_creds(bprm);
1994         if (rc)
1995                 return rc;
1996
1997         /* SELinux context only depends on initial program or script and not
1998          * the script interpreter */
1999         if (bprm->cred_prepared)
2000                 return 0;
2001
2002         old_tsec = current_security();
2003         new_tsec = bprm->cred->security;
2004         isec = inode->i_security;
2005
2006         /* Default to the current task SID. */
2007         new_tsec->sid = old_tsec->sid;
2008         new_tsec->osid = old_tsec->sid;
2009
2010         /* Reset fs, key, and sock SIDs on execve. */
2011         new_tsec->create_sid = 0;
2012         new_tsec->keycreate_sid = 0;
2013         new_tsec->sockcreate_sid = 0;
2014
2015         if (old_tsec->exec_sid) {
2016                 new_tsec->sid = old_tsec->exec_sid;
2017                 /* Reset exec SID on execve. */
2018                 new_tsec->exec_sid = 0;
2019         } else {
2020                 /* Check for a default transition on this program. */
2021                 rc = security_transition_sid(old_tsec->sid, isec->sid,
2022                                              SECCLASS_PROCESS, NULL,
2023                                              &new_tsec->sid);
2024                 if (rc)
2025                         return rc;
2026         }
2027
2028         COMMON_AUDIT_DATA_INIT(&ad, PATH);
2029         ad.selinux_audit_data = &sad;
2030         ad.u.path = bprm->file->f_path;
2031
2032         if (bprm->file->f_path.mnt->mnt_flags & MNT_NOSUID)
2033                 new_tsec->sid = old_tsec->sid;
2034
2035         if (new_tsec->sid == old_tsec->sid) {
2036                 rc = avc_has_perm(old_tsec->sid, isec->sid,
2037                                   SECCLASS_FILE, FILE__EXECUTE_NO_TRANS, &ad);
2038                 if (rc)
2039                         return rc;
2040         } else {
2041                 /* Check permissions for the transition. */
2042                 rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
2043                                   SECCLASS_PROCESS, PROCESS__TRANSITION, &ad);
2044                 if (rc)
2045                         return rc;
2046
2047                 rc = avc_has_perm(new_tsec->sid, isec->sid,
2048                                   SECCLASS_FILE, FILE__ENTRYPOINT, &ad);
2049                 if (rc)
2050                         return rc;
2051
2052                 /* Check for shared state */
2053                 if (bprm->unsafe & LSM_UNSAFE_SHARE) {
2054                         rc = avc_has_perm(old_tsec->sid, new_tsec->sid,
2055                                           SECCLASS_PROCESS, PROCESS__SHARE,
2056                                           NULL);
2057                         if (rc)
2058                                 return -EPERM;
2059                 }
2060
2061                 /* Make sure that anyone attempting to ptrace over a task that
2062                  * changes its SID has the appropriate permit */
2063                 if (bprm->unsafe &
2064                     (LSM_UNSAFE_PTRACE | LSM_UNSAFE_PTRACE_CAP)) {
2065                         struct task_struct *tracer;
2066                         struct task_security_struct *sec;
2067                         u32 ptsid = 0;
2068
2069                         rcu_read_lock();
2070                         tracer = ptrace_parent(current);
2071                         if (likely(tracer != NULL)) {
2072                                 sec = __task_cred(tracer)->security;
2073                                 ptsid = sec->sid;
2074                         }
2075                         rcu_read_unlock();
2076
2077                         if (ptsid != 0) {
2078                                 rc = avc_has_perm(ptsid, new_tsec->sid,
2079                                                   SECCLASS_PROCESS,
2080                                                   PROCESS__PTRACE, NULL);
2081                                 if (rc)
2082                                         return -EPERM;
2083                         }
2084                 }
2085
2086                 /* Clear any possibly unsafe personality bits on exec: */
2087                 bprm->per_clear |= PER_CLEAR_ON_SETID;
2088         }
2089
2090         return 0;
2091 }
2092
2093 static int selinux_bprm_secureexec(struct linux_binprm *bprm)
2094 {
2095         const struct task_security_struct *tsec = current_security();
2096         u32 sid, osid;
2097         int atsecure = 0;
2098
2099         sid = tsec->sid;
2100         osid = tsec->osid;
2101
2102         if (osid != sid) {
2103                 /* Enable secure mode for SIDs transitions unless
2104                    the noatsecure permission is granted between
2105                    the two SIDs, i.e. ahp returns 0. */
2106                 atsecure = avc_has_perm(osid, sid,
2107                                         SECCLASS_PROCESS,
2108                                         PROCESS__NOATSECURE, NULL);
2109         }
2110
2111         return (atsecure || cap_bprm_secureexec(bprm));
2112 }
2113
2114 /* Derived from fs/exec.c:flush_old_files. */
2115 static inline void flush_unauthorized_files(const struct cred *cred,
2116                                             struct files_struct *files)
2117 {
2118         struct common_audit_data ad;
2119         struct selinux_audit_data sad = {0,};
2120         struct file *file, *devnull = NULL;
2121         struct tty_struct *tty;
2122         struct fdtable *fdt;
2123         long j = -1;
2124         int drop_tty = 0;
2125
2126         tty = get_current_tty();
2127         if (tty) {
2128                 spin_lock(&tty_files_lock);
2129                 if (!list_empty(&tty->tty_files)) {
2130                         struct tty_file_private *file_priv;
2131                         struct inode *inode;
2132
2133                         /* Revalidate access to controlling tty.
2134                            Use inode_has_perm on the tty inode directly rather
2135                            than using file_has_perm, as this particular open
2136                            file may belong to another process and we are only
2137                            interested in the inode-based check here. */
2138                         file_priv = list_first_entry(&tty->tty_files,
2139                                                 struct tty_file_private, list);
2140                         file = file_priv->file;
2141                         inode = file->f_path.dentry->d_inode;
2142                         if (inode_has_perm_noadp(cred, inode,
2143                                            FILE__READ | FILE__WRITE, 0)) {
2144                                 drop_tty = 1;
2145                         }
2146                 }
2147                 spin_unlock(&tty_files_lock);
2148                 tty_kref_put(tty);
2149         }
2150         /* Reset controlling tty. */
2151         if (drop_tty)
2152                 no_tty();
2153
2154         /* Revalidate access to inherited open files. */
2155
2156         COMMON_AUDIT_DATA_INIT(&ad, INODE);
2157         ad.selinux_audit_data = &sad;
2158
2159         spin_lock(&files->file_lock);
2160         for (;;) {
2161                 unsigned long set, i;
2162                 int fd;
2163
2164                 j++;
2165                 i = j * __NFDBITS;
2166                 fdt = files_fdtable(files);
2167                 if (i >= fdt->max_fds)
2168                         break;
2169                 set = fdt->open_fds[j];
2170                 if (!set)
2171                         continue;
2172                 spin_unlock(&files->file_lock);
2173                 for ( ; set ; i++, set >>= 1) {
2174                         if (set & 1) {
2175                                 file = fget(i);
2176                                 if (!file)
2177                                         continue;
2178                                 if (file_has_perm(cred,
2179                                                   file,
2180                                                   file_to_av(file))) {
2181                                         sys_close(i);
2182                                         fd = get_unused_fd();
2183                                         if (fd != i) {
2184                                                 if (fd >= 0)
2185                                                         put_unused_fd(fd);
2186                                                 fput(file);
2187                                                 continue;
2188                                         }
2189                                         if (devnull) {
2190                                                 get_file(devnull);
2191                                         } else {
2192                                                 devnull = dentry_open(
2193                                                         dget(selinux_null),
2194                                                         mntget(selinuxfs_mount),
2195                                                         O_RDWR, cred);
2196                                                 if (IS_ERR(devnull)) {
2197                                                         devnull = NULL;
2198                                                         put_unused_fd(fd);
2199                                                         fput(file);
2200                                                         continue;
2201                                                 }
2202                                         }
2203                                         fd_install(fd, devnull);
2204                                 }
2205                                 fput(file);
2206                         }
2207                 }
2208                 spin_lock(&files->file_lock);
2209
2210         }
2211         spin_unlock(&files->file_lock);
2212 }
2213
2214 /*
2215  * Prepare a process for imminent new credential changes due to exec
2216  */
2217 static void selinux_bprm_committing_creds(struct linux_binprm *bprm)
2218 {
2219         struct task_security_struct *new_tsec;
2220         struct rlimit *rlim, *initrlim;
2221         int rc, i;
2222
2223         new_tsec = bprm->cred->security;
2224         if (new_tsec->sid == new_tsec->osid)
2225                 return;
2226
2227         /* Close files for which the new task SID is not authorized. */
2228         flush_unauthorized_files(bprm->cred, current->files);
2229
2230         /* Always clear parent death signal on SID transitions. */
2231         current->pdeath_signal = 0;
2232
2233         /* Check whether the new SID can inherit resource limits from the old
2234          * SID.  If not, reset all soft limits to the lower of the current
2235          * task's hard limit and the init task's soft limit.
2236          *
2237          * Note that the setting of hard limits (even to lower them) can be
2238          * controlled by the setrlimit check.  The inclusion of the init task's
2239          * soft limit into the computation is to avoid resetting soft limits
2240          * higher than the default soft limit for cases where the default is
2241          * lower than the hard limit, e.g. RLIMIT_CORE or RLIMIT_STACK.
2242          */
2243         rc = avc_has_perm(new_tsec->osid, new_tsec->sid, SECCLASS_PROCESS,
2244                           PROCESS__RLIMITINH, NULL);
2245         if (rc) {
2246                 /* protect against do_prlimit() */
2247                 task_lock(current);
2248                 for (i = 0; i < RLIM_NLIMITS; i++) {
2249                         rlim = current->signal->rlim + i;
2250                         initrlim = init_task.signal->rlim + i;
2251                         rlim->rlim_cur = min(rlim->rlim_max, initrlim->rlim_cur);
2252                 }
2253                 task_unlock(current);
2254                 update_rlimit_cpu(current, rlimit(RLIMIT_CPU));
2255         }
2256 }
2257
2258 /*
2259  * Clean up the process immediately after the installation of new credentials
2260  * due to exec
2261  */
2262 static void selinux_bprm_committed_creds(struct linux_binprm *bprm)
2263 {
2264         const struct task_security_struct *tsec = current_security();
2265         struct itimerval itimer;
2266         u32 osid, sid;
2267         int rc, i;
2268
2269         osid = tsec->osid;
2270         sid = tsec->sid;
2271
2272         if (sid == osid)
2273                 return;
2274
2275         /* Check whether the new SID can inherit signal state from the old SID.
2276          * If not, clear itimers to avoid subsequent signal generation and
2277          * flush and unblock signals.
2278          *
2279          * This must occur _after_ the task SID has been updated so that any
2280          * kill done after the flush will be checked against the new SID.
2281          */
2282         rc = avc_has_perm(osid, sid, SECCLASS_PROCESS, PROCESS__SIGINH, NULL);
2283         if (rc) {
2284                 memset(&itimer, 0, sizeof itimer);
2285                 for (i = 0; i < 3; i++)
2286                         do_setitimer(i, &itimer, NULL);
2287                 spin_lock_irq(&current->sighand->siglock);
2288                 if (!(current->signal->flags & SIGNAL_GROUP_EXIT)) {
2289                         __flush_signals(current);
2290                         flush_signal_handlers(current, 1);
2291                         sigemptyset(&current->blocked);
2292                 }
2293                 spin_unlock_irq(&current->sighand->siglock);
2294         }
2295
2296         /* Wake up the parent if it is waiting so that it can recheck
2297          * wait permission to the new task SID. */
2298         read_lock(&tasklist_lock);
2299         __wake_up_parent(current, current->real_parent);
2300         read_unlock(&tasklist_lock);
2301 }
2302
2303 /* superblock security operations */
2304
2305 static int selinux_sb_alloc_security(struct super_block *sb)
2306 {
2307         return superblock_alloc_security(sb);
2308 }
2309
2310 static void selinux_sb_free_security(struct super_block *sb)
2311 {
2312         superblock_free_security(sb);
2313 }
2314
2315 static inline int match_prefix(char *prefix, int plen, char *option, int olen)
2316 {
2317         if (plen > olen)
2318                 return 0;
2319
2320         return !memcmp(prefix, option, plen);
2321 }
2322
2323 static inline int selinux_option(char *option, int len)
2324 {
2325         return (match_prefix(CONTEXT_STR, sizeof(CONTEXT_STR)-1, option, len) ||
2326                 match_prefix(FSCONTEXT_STR, sizeof(FSCONTEXT_STR)-1, option, len) ||
2327                 match_prefix(DEFCONTEXT_STR, sizeof(DEFCONTEXT_STR)-1, option, len) ||
2328                 match_prefix(ROOTCONTEXT_STR, sizeof(ROOTCONTEXT_STR)-1, option, len) ||
2329                 match_prefix(LABELSUPP_STR, sizeof(LABELSUPP_STR)-1, option, len));
2330 }
2331
2332 static inline void take_option(char **to, char *from, int *first, int len)
2333 {
2334         if (!*first) {
2335                 **to = ',';
2336                 *to += 1;
2337         } else
2338                 *first = 0;
2339         memcpy(*to, from, len);
2340         *to += len;
2341 }
2342
2343 static inline void take_selinux_option(char **to, char *from, int *first,
2344                                        int len)
2345 {
2346         int current_size = 0;
2347
2348         if (!*first) {
2349                 **to = '|';
2350                 *to += 1;
2351         } else
2352                 *first = 0;
2353
2354         while (current_size < len) {
2355                 if (*from != '"') {
2356                         **to = *from;
2357                         *to += 1;
2358                 }
2359                 from += 1;
2360                 current_size += 1;
2361         }
2362 }
2363
2364 static int selinux_sb_copy_data(char *orig, char *copy)
2365 {
2366         int fnosec, fsec, rc = 0;
2367         char *in_save, *in_curr, *in_end;
2368         char *sec_curr, *nosec_save, *nosec;
2369         int open_quote = 0;
2370
2371         in_curr = orig;
2372         sec_curr = copy;
2373
2374         nosec = (char *)get_zeroed_page(GFP_KERNEL);
2375         if (!nosec) {
2376                 rc = -ENOMEM;
2377                 goto out;
2378         }
2379
2380         nosec_save = nosec;
2381         fnosec = fsec = 1;
2382         in_save = in_end = orig;
2383
2384         do {
2385                 if (*in_end == '"')
2386                         open_quote = !open_quote;
2387                 if ((*in_end == ',' && open_quote == 0) ||
2388                                 *in_end == '\0') {
2389                         int len = in_end - in_curr;
2390
2391                         if (selinux_option(in_curr, len))
2392                                 take_selinux_option(&sec_curr, in_curr, &fsec, len);
2393                         else
2394                                 take_option(&nosec, in_curr, &fnosec, len);
2395
2396                         in_curr = in_end + 1;
2397                 }
2398         } while (*in_end++);
2399
2400         strcpy(in_save, nosec_save);
2401         free_page((unsigned long)nosec_save);
2402 out:
2403         return rc;
2404 }
2405
2406 static int selinux_sb_remount(struct super_block *sb, void *data)
2407 {
2408         int rc, i, *flags;
2409         struct security_mnt_opts opts;
2410         char *secdata, **mount_options;
2411         struct superblock_security_struct *sbsec = sb->s_security;
2412
2413         if (!(sbsec->flags & SE_SBINITIALIZED))
2414                 return 0;
2415
2416         if (!data)
2417                 return 0;
2418
2419         if (sb->s_type->fs_flags & FS_BINARY_MOUNTDATA)
2420                 return 0;
2421
2422         security_init_mnt_opts(&opts);
2423         secdata = alloc_secdata();
2424         if (!secdata)
2425                 return -ENOMEM;
2426         rc = selinux_sb_copy_data(data, secdata);
2427         if (rc)
2428                 goto out_free_secdata;
2429
2430         rc = selinux_parse_opts_str(secdata, &opts);
2431         if (rc)
2432                 goto out_free_secdata;
2433
2434         mount_options = opts.mnt_opts;
2435         flags = opts.mnt_opts_flags;
2436
2437         for (i = 0; i < opts.num_mnt_opts; i++) {
2438                 u32 sid;
2439                 size_t len;
2440
2441                 if (flags[i] == SE_SBLABELSUPP)
2442                         continue;
2443                 len = strlen(mount_options[i]);
2444                 rc = security_context_to_sid(mount_options[i], len, &sid);
2445                 if (rc) {
2446                         printk(KERN_WARNING "SELinux: security_context_to_sid"
2447                                "(%s) failed for (dev %s, type %s) errno=%d\n",
2448                                mount_options[i], sb->s_id, sb->s_type->name, rc);
2449                         goto out_free_opts;
2450                 }
2451                 rc = -EINVAL;
2452                 switch (flags[i]) {
2453                 case FSCONTEXT_MNT:
2454                         if (bad_option(sbsec, FSCONTEXT_MNT, sbsec->sid, sid))
2455                                 goto out_bad_option;
2456                         break;
2457                 case CONTEXT_MNT:
2458                         if (bad_option(sbsec, CONTEXT_MNT, sbsec->mntpoint_sid, sid))
2459                                 goto out_bad_option;
2460                         break;
2461                 case ROOTCONTEXT_MNT: {
2462                         struct inode_security_struct *root_isec;
2463                         root_isec = sb->s_root->d_inode->i_security;
2464
2465                         if (bad_option(sbsec, ROOTCONTEXT_MNT, root_isec->sid, sid))
2466                                 goto out_bad_option;
2467                         break;
2468                 }
2469                 case DEFCONTEXT_MNT:
2470                         if (bad_option(sbsec, DEFCONTEXT_MNT, sbsec->def_sid, sid))
2471                                 goto out_bad_option;
2472                         break;
2473                 default:
2474                         goto out_free_opts;
2475                 }
2476         }
2477
2478         rc = 0;
2479 out_free_opts:
2480         security_free_mnt_opts(&opts);
2481 out_free_secdata:
2482         free_secdata(secdata);
2483         return rc;
2484 out_bad_option:
2485         printk(KERN_WARNING "SELinux: unable to change security options "
2486                "during remount (dev %s, type=%s)\n", sb->s_id,
2487                sb->s_type->name);
2488         goto out_free_opts;
2489 }
2490
2491 static int selinux_sb_kern_mount(struct super_block *sb, int flags, void *data)
2492 {
2493         const struct cred *cred = current_cred();
2494         struct common_audit_data ad;
2495         struct selinux_audit_data sad = {0,};
2496         int rc;
2497
2498         rc = superblock_doinit(sb, data);
2499         if (rc)
2500                 return rc;
2501
2502         /* Allow all mounts performed by the kernel */
2503         if (flags & MS_KERNMOUNT)
2504                 return 0;
2505
2506         COMMON_AUDIT_DATA_INIT(&ad, DENTRY);
2507         ad.selinux_audit_data = &sad;
2508         ad.u.dentry = sb->s_root;
2509         return superblock_has_perm(cred, sb, FILESYSTEM__MOUNT, &ad);
2510 }
2511
2512 static int selinux_sb_statfs(struct dentry *dentry)
2513 {
2514         const struct cred *cred = current_cred();
2515         struct common_audit_data ad;
2516         struct selinux_audit_data sad = {0,};
2517
2518         COMMON_AUDIT_DATA_INIT(&ad, DENTRY);
2519         ad.selinux_audit_data = &sad;
2520         ad.u.dentry = dentry->d_sb->s_root;
2521         return superblock_has_perm(cred, dentry->d_sb, FILESYSTEM__GETATTR, &ad);
2522 }
2523
2524 static int selinux_mount(char *dev_name,
2525                          struct path *path,
2526                          char *type,
2527                          unsigned long flags,
2528                          void *data)
2529 {
2530         const struct cred *cred = current_cred();
2531
2532         if (flags & MS_REMOUNT)
2533                 return superblock_has_perm(cred, path->dentry->d_sb,
2534                                            FILESYSTEM__REMOUNT, NULL);
2535         else
2536                 return path_has_perm(cred, path, FILE__MOUNTON);
2537 }
2538
2539 static int selinux_umount(struct vfsmount *mnt, int flags)
2540 {
2541         const struct cred *cred = current_cred();
2542
2543         return superblock_has_perm(cred, mnt->mnt_sb,
2544                                    FILESYSTEM__UNMOUNT, NULL);
2545 }
2546
2547 /* inode security operations */
2548
2549 static int selinux_inode_alloc_security(struct inode *inode)
2550 {
2551         return inode_alloc_security(inode);
2552 }
2553
2554 static void selinux_inode_free_security(struct inode *inode)
2555 {
2556         inode_free_security(inode);
2557 }
2558
2559 static int selinux_inode_init_security(struct inode *inode, struct inode *dir,
2560                                        const struct qstr *qstr, char **name,
2561                                        void **value, size_t *len)
2562 {
2563         const struct task_security_struct *tsec = current_security();
2564         struct inode_security_struct *dsec;
2565         struct superblock_security_struct *sbsec;
2566         u32 sid, newsid, clen;
2567         int rc;
2568         char *namep = NULL, *context;
2569
2570         dsec = dir->i_security;
2571         sbsec = dir->i_sb->s_security;
2572
2573         sid = tsec->sid;
2574         newsid = tsec->create_sid;
2575
2576         if ((sbsec->flags & SE_SBINITIALIZED) &&
2577             (sbsec->behavior == SECURITY_FS_USE_MNTPOINT))
2578                 newsid = sbsec->mntpoint_sid;
2579         else if (!newsid || !(sbsec->flags & SE_SBLABELSUPP)) {
2580                 rc = security_transition_sid(sid, dsec->sid,
2581                                              inode_mode_to_security_class(inode->i_mode),
2582                                              qstr, &newsid);
2583                 if (rc) {
2584                         printk(KERN_WARNING "%s:  "
2585                                "security_transition_sid failed, rc=%d (dev=%s "
2586                                "ino=%ld)\n",
2587                                __func__,
2588                                -rc, inode->i_sb->s_id, inode->i_ino);
2589                         return rc;
2590                 }
2591         }
2592
2593         /* Possibly defer initialization to selinux_complete_init. */
2594         if (sbsec->flags & SE_SBINITIALIZED) {
2595                 struct inode_security_struct *isec = inode->i_security;
2596                 isec->sclass = inode_mode_to_security_class(inode->i_mode);
2597                 isec->sid = newsid;
2598                 isec->initialized = 1;
2599         }
2600
2601         if (!ss_initialized || !(sbsec->flags & SE_SBLABELSUPP))
2602                 return -EOPNOTSUPP;
2603
2604         if (name) {
2605                 namep = kstrdup(XATTR_SELINUX_SUFFIX, GFP_NOFS);
2606                 if (!namep)
2607                         return -ENOMEM;
2608                 *name = namep;
2609         }
2610
2611         if (value && len) {
2612                 rc = security_sid_to_context_force(newsid, &context, &clen);
2613                 if (rc) {
2614                         kfree(namep);
2615                         return rc;
2616                 }
2617                 *value = context;
2618                 *len = clen;
2619         }
2620
2621         return 0;
2622 }
2623
2624 static int selinux_inode_create(struct inode *dir, struct dentry *dentry, umode_t mode)
2625 {
2626         return may_create(dir, dentry, SECCLASS_FILE);
2627 }
2628
2629 static int selinux_inode_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_dentry)
2630 {
2631         return may_link(dir, old_dentry, MAY_LINK);
2632 }
2633
2634 static int selinux_inode_unlink(struct inode *dir, struct dentry *dentry)
2635 {
2636         return may_link(dir, dentry, MAY_UNLINK);
2637 }
2638
2639 static int selinux_inode_symlink(struct inode *dir, struct dentry *dentry, const char *name)
2640 {
2641         return may_create(dir, dentry, SECCLASS_LNK_FILE);
2642 }
2643
2644 static int selinux_inode_mkdir(struct inode *dir, struct dentry *dentry, umode_t mask)
2645 {
2646         return may_create(dir, dentry, SECCLASS_DIR);
2647 }
2648
2649 static int selinux_inode_rmdir(struct inode *dir, struct dentry *dentry)
2650 {
2651         return may_link(dir, dentry, MAY_RMDIR);
2652 }
2653
2654 static int selinux_inode_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev)
2655 {
2656         return may_create(dir, dentry, inode_mode_to_security_class(mode));
2657 }
2658
2659 static int selinux_inode_rename(struct inode *old_inode, struct dentry *old_dentry,
2660                                 struct inode *new_inode, struct dentry *new_dentry)
2661 {
2662         return may_rename(old_inode, old_dentry, new_inode, new_dentry);
2663 }
2664
2665 static int selinux_inode_readlink(struct dentry *dentry)
2666 {
2667         const struct cred *cred = current_cred();
2668
2669         return dentry_has_perm(cred, dentry, FILE__READ);
2670 }
2671
2672 static int selinux_inode_follow_link(struct dentry *dentry, struct nameidata *nameidata)
2673 {
2674         const struct cred *cred = current_cred();
2675
2676         return dentry_has_perm(cred, dentry, FILE__READ);
2677 }
2678
2679 static int selinux_inode_permission(struct inode *inode, int mask)
2680 {
2681         const struct cred *cred = current_cred();
2682         struct common_audit_data ad;
2683         struct selinux_audit_data sad = {0,};
2684         u32 perms;
2685         bool from_access;
2686         unsigned flags = mask & MAY_NOT_BLOCK;
2687         struct inode_security_struct *isec;
2688         u32 sid;
2689         struct av_decision avd;
2690         int rc, rc2;
2691         u32 audited, denied;
2692
2693         from_access = mask & MAY_ACCESS;
2694         mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND);
2695
2696         /* No permission to check.  Existence test. */
2697         if (!mask)
2698                 return 0;
2699
2700         validate_creds(cred);
2701
2702         if (unlikely(IS_PRIVATE(inode)))
2703                 return 0;
2704
2705         perms = file_mask_to_av(inode->i_mode, mask);
2706
2707         sid = cred_sid(cred);
2708         isec = inode->i_security;
2709
2710         rc = avc_has_perm_noaudit(sid, isec->sid, isec->sclass, perms, 0, &avd);
2711         audited = avc_audit_required(perms, &avd, rc,
2712                                      from_access ? FILE__AUDIT_ACCESS : 0,
2713                                      &denied);
2714         if (likely(!audited))
2715                 return rc;
2716
2717         COMMON_AUDIT_DATA_INIT(&ad, INODE);
2718         ad.selinux_audit_data = &sad;
2719         ad.u.inode = inode;
2720
2721         if (from_access)
2722                 ad.selinux_audit_data->auditdeny |= FILE__AUDIT_ACCESS;
2723
2724         rc2 = slow_avc_audit(sid, isec->sid, isec->sclass, perms,
2725                              audited, denied, &ad, flags);
2726         if (rc2)
2727                 return rc2;
2728         return rc;
2729 }
2730
2731 static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr)
2732 {
2733         const struct cred *cred = current_cred();
2734         unsigned int ia_valid = iattr->ia_valid;
2735         __u32 av = FILE__WRITE;
2736
2737         /* ATTR_FORCE is just used for ATTR_KILL_S[UG]ID. */
2738         if (ia_valid & ATTR_FORCE) {
2739                 ia_valid &= ~(ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_MODE |
2740                               ATTR_FORCE);
2741                 if (!ia_valid)
2742                         return 0;
2743         }
2744
2745         if (ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID |
2746                         ATTR_ATIME_SET | ATTR_MTIME_SET | ATTR_TIMES_SET))
2747                 return dentry_has_perm(cred, dentry, FILE__SETATTR);
2748
2749         if (ia_valid & ATTR_SIZE)
2750                 av |= FILE__OPEN;
2751
2752         return dentry_has_perm(cred, dentry, av);
2753 }
2754
2755 static int selinux_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
2756 {
2757         const struct cred *cred = current_cred();
2758         struct path path;
2759
2760         path.dentry = dentry;
2761         path.mnt = mnt;
2762
2763         return path_has_perm(cred, &path, FILE__GETATTR);
2764 }
2765
2766 static int selinux_inode_setotherxattr(struct dentry *dentry, const char *name)
2767 {
2768         const struct cred *cred = current_cred();
2769
2770         if (!strncmp(name, XATTR_SECURITY_PREFIX,
2771                      sizeof XATTR_SECURITY_PREFIX - 1)) {
2772                 if (!strcmp(name, XATTR_NAME_CAPS)) {
2773                         if (!capable(CAP_SETFCAP))
2774                                 return -EPERM;
2775                 } else if (!capable(CAP_SYS_ADMIN)) {
2776                         /* A different attribute in the security namespace.
2777                            Restrict to administrator. */
2778                         return -EPERM;
2779                 }
2780         }
2781
2782         /* Not an attribute we recognize, so just check the
2783            ordinary setattr permission. */
2784         return dentry_has_perm(cred, dentry, FILE__SETATTR);
2785 }
2786
2787 static int selinux_inode_setxattr(struct dentry *dentry, const char *name,
2788                                   const void *value, size_t size, int flags)
2789 {
2790         struct inode *inode = dentry->d_inode;
2791         struct inode_security_struct *isec = inode->i_security;
2792         struct superblock_security_struct *sbsec;
2793         struct common_audit_data ad;
2794         struct selinux_audit_data sad = {0,};
2795         u32 newsid, sid = current_sid();
2796         int rc = 0;
2797
2798         if (strcmp(name, XATTR_NAME_SELINUX))
2799                 return selinux_inode_setotherxattr(dentry, name);
2800
2801         sbsec = inode->i_sb->s_security;
2802         if (!(sbsec->flags & SE_SBLABELSUPP))
2803                 return -EOPNOTSUPP;
2804
2805         if (!inode_owner_or_capable(inode))
2806                 return -EPERM;
2807
2808         COMMON_AUDIT_DATA_INIT(&ad, DENTRY);
2809         ad.selinux_audit_data = &sad;
2810         ad.u.dentry = dentry;
2811
2812         rc = avc_has_perm(sid, isec->sid, isec->sclass,
2813                           FILE__RELABELFROM, &ad);
2814         if (rc)
2815                 return rc;
2816
2817         rc = security_context_to_sid(value, size, &newsid);
2818         if (rc == -EINVAL) {
2819                 if (!capable(CAP_MAC_ADMIN)) {
2820                         struct audit_buffer *ab;
2821                         size_t audit_size;
2822                         const char *str;
2823
2824                         /* We strip a nul only if it is at the end, otherwise the
2825                          * context contains a nul and we should audit that */
2826                         str = value;
2827                         if (str[size - 1] == '\0')
2828                                 audit_size = size - 1;
2829                         else
2830                                 audit_size = size;
2831                         ab = audit_log_start(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR);
2832                         audit_log_format(ab, "op=setxattr invalid_context=");
2833                         audit_log_n_untrustedstring(ab, value, audit_size);
2834                         audit_log_end(ab);
2835
2836                         return rc;
2837                 }
2838                 rc = security_context_to_sid_force(value, size, &newsid);
2839         }
2840         if (rc)
2841                 return rc;
2842
2843         rc = avc_has_perm(sid, newsid, isec->sclass,
2844                           FILE__RELABELTO, &ad);
2845         if (rc)
2846                 return rc;
2847
2848         rc = security_validate_transition(isec->sid, newsid, sid,
2849                                           isec->sclass);
2850         if (rc)
2851                 return rc;
2852
2853         return avc_has_perm(newsid,
2854                             sbsec->sid,
2855                             SECCLASS_FILESYSTEM,
2856                             FILESYSTEM__ASSOCIATE,
2857                             &ad);
2858 }
2859
2860 static void selinux_inode_post_setxattr(struct dentry *dentry, const char *name,
2861                                         const void *value, size_t size,
2862                                         int flags)
2863 {
2864         struct inode *inode = dentry->d_inode;
2865         struct inode_security_struct *isec = inode->i_security;
2866         u32 newsid;
2867         int rc;
2868
2869         if (strcmp(name, XATTR_NAME_SELINUX)) {
2870                 /* Not an attribute we recognize, so nothing to do. */
2871                 return;
2872         }
2873
2874         rc = security_context_to_sid_force(value, size, &newsid);
2875         if (rc) {
2876                 printk(KERN_ERR "SELinux:  unable to map context to SID"
2877                        "for (%s, %lu), rc=%d\n",
2878                        inode->i_sb->s_id, inode->i_ino, -rc);
2879                 return;
2880         }
2881
2882         isec->sid = newsid;
2883         return;
2884 }
2885
2886 static int selinux_inode_getxattr(struct dentry *dentry, const char *name)
2887 {
2888         const struct cred *cred = current_cred();
2889
2890         return dentry_has_perm(cred, dentry, FILE__GETATTR);
2891 }
2892
2893 static int selinux_inode_listxattr(struct dentry *dentry)
2894 {
2895         const struct cred *cred = current_cred();
2896
2897         return dentry_has_perm(cred, dentry, FILE__GETATTR);
2898 }
2899
2900 static int selinux_inode_removexattr(struct dentry *dentry, const char *name)
2901 {
2902         if (strcmp(name, XATTR_NAME_SELINUX))
2903                 return selinux_inode_setotherxattr(dentry, name);
2904
2905         /* No one is allowed to remove a SELinux security label.
2906            You can change the label, but all data must be labeled. */
2907         return -EACCES;
2908 }
2909
2910 /*
2911  * Copy the inode security context value to the user.
2912  *
2913  * Permission check is handled by selinux_inode_getxattr hook.
2914  */
2915 static int selinux_inode_getsecurity(const struct inode *inode, const char *name, void **buffer, bool alloc)
2916 {
2917         u32 size;
2918         int error;
2919         char *context = NULL;
2920         struct inode_security_struct *isec = inode->i_security;
2921
2922         if (strcmp(name, XATTR_SELINUX_SUFFIX))
2923                 return -EOPNOTSUPP;
2924
2925         /*
2926          * If the caller has CAP_MAC_ADMIN, then get the raw context
2927          * value even if it is not defined by current policy; otherwise,
2928          * use the in-core value under current policy.
2929          * Use the non-auditing forms of the permission checks since
2930          * getxattr may be called by unprivileged processes commonly
2931          * and lack of permission just means that we fall back to the
2932          * in-core context value, not a denial.
2933          */
2934         error = selinux_capable(current_cred(), &init_user_ns, CAP_MAC_ADMIN,
2935                                 SECURITY_CAP_NOAUDIT);
2936         if (!error)
2937                 error = security_sid_to_context_force(isec->sid, &context,
2938                                                       &size);
2939         else
2940                 error = security_sid_to_context(isec->sid, &context, &size);
2941         if (error)
2942                 return error;
2943         error = size;
2944         if (alloc) {
2945                 *buffer = context;
2946                 goto out_nofree;
2947         }
2948         kfree(context);
2949 out_nofree:
2950         return error;
2951 }
2952
2953 static int selinux_inode_setsecurity(struct inode *inode, const char *name,
2954                                      const void *value, size_t size, int flags)
2955 {
2956         struct inode_security_struct *isec = inode->i_security;
2957         u32 newsid;
2958         int rc;
2959
2960         if (strcmp(name, XATTR_SELINUX_SUFFIX))
2961                 return -EOPNOTSUPP;
2962
2963         if (!value || !size)
2964                 return -EACCES;
2965
2966         rc = security_context_to_sid((void *)value, size, &newsid);
2967         if (rc)
2968                 return rc;
2969
2970         isec->sid = newsid;
2971         isec->initialized = 1;
2972         return 0;
2973 }
2974
2975 static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size)
2976 {
2977         const int len = sizeof(XATTR_NAME_SELINUX);
2978         if (buffer && len <= buffer_size)
2979                 memcpy(buffer, XATTR_NAME_SELINUX, len);
2980         return len;
2981 }
2982
2983 static void selinux_inode_getsecid(const struct inode *inode, u32 *secid)
2984 {
2985         struct inode_security_struct *isec = inode->i_security;
2986         *secid = isec->sid;
2987 }
2988
2989 /* file security operations */
2990
2991 static int selinux_revalidate_file_permission(struct file *file, int mask)
2992 {
2993         const struct cred *cred = current_cred();
2994         struct inode *inode = file->f_path.dentry->d_inode;
2995
2996         /* file_mask_to_av won't add FILE__WRITE if MAY_APPEND is set */
2997         if ((file->f_flags & O_APPEND) && (mask & MAY_WRITE))
2998                 mask |= MAY_APPEND;
2999
3000         return file_has_perm(cred, file,
3001                              file_mask_to_av(inode->i_mode, mask));
3002 }
3003
3004 static int selinux_file_permission(struct file *file, int mask)
3005 {
3006         struct inode *inode = file->f_path.dentry->d_inode;
3007         struct file_security_struct *fsec = file->f_security;
3008         struct inode_security_struct *isec = inode->i_security;
3009         u32 sid = current_sid();
3010
3011         if (!mask)
3012                 /* No permission to check.  Existence test. */
3013                 return 0;
3014
3015         if (sid == fsec->sid && fsec->isid == isec->sid &&
3016             fsec->pseqno == avc_policy_seqno())
3017                 /* No change since file_open check. */
3018                 return 0;
3019
3020         return selinux_revalidate_file_permission(file, mask);
3021 }
3022
3023 static int selinux_file_alloc_security(struct file *file)
3024 {
3025         return file_alloc_security(file);
3026 }
3027
3028 static void selinux_file_free_security(struct file *file)
3029 {
3030         file_free_security(file);
3031 }
3032
3033 static int selinux_file_ioctl(struct file *file, unsigned int cmd,
3034                               unsigned long arg)
3035 {
3036         const struct cred *cred = current_cred();
3037         int error = 0;
3038
3039         switch (cmd) {
3040         case FIONREAD:
3041         /* fall through */
3042         case FIBMAP:
3043         /* fall through */
3044         case FIGETBSZ:
3045         /* fall through */
3046         case FS_IOC_GETFLAGS:
3047         /* fall through */
3048         case FS_IOC_GETVERSION:
3049                 error = file_has_perm(cred, file, FILE__GETATTR);
3050                 break;
3051
3052         case FS_IOC_SETFLAGS:
3053         /* fall through */
3054         case FS_IOC_SETVERSION:
3055                 error = file_has_perm(cred, file, FILE__SETATTR);
3056                 break;
3057
3058         /* sys_ioctl() checks */
3059         case FIONBIO:
3060         /* fall through */
3061         case FIOASYNC:
3062                 error = file_has_perm(cred, file, 0);
3063                 break;
3064
3065         case KDSKBENT:
3066         case KDSKBSENT:
3067                 error = cred_has_capability(cred, CAP_SYS_TTY_CONFIG,
3068                                             SECURITY_CAP_AUDIT);
3069                 break;
3070
3071         /* default case assumes that the command will go
3072          * to the file's ioctl() function.
3073          */
3074         default:
3075                 error = file_has_perm(cred, file, FILE__IOCTL);
3076         }
3077         return error;
3078 }
3079
3080 static int default_noexec;
3081
3082 static int file_map_prot_check(struct file *file, unsigned long prot, int shared)
3083 {
3084         const struct cred *cred = current_cred();
3085         int rc = 0;
3086
3087         if (default_noexec &&
3088             (prot & PROT_EXEC) && (!file || (!shared && (prot & PROT_WRITE)))) {
3089                 /*
3090                  * We are making executable an anonymous mapping or a
3091                  * private file mapping that will also be writable.
3092                  * This has an additional check.
3093                  */
3094                 rc = cred_has_perm(cred, cred, PROCESS__EXECMEM);
3095                 if (rc)
3096                         goto error;
3097         }
3098
3099         if (file) {
3100                 /* read access is always possible with a mapping */
3101                 u32 av = FILE__READ;
3102
3103                 /* write access only matters if the mapping is shared */
3104                 if (shared && (prot & PROT_WRITE))
3105                         av |= FILE__WRITE;
3106
3107                 if (prot & PROT_EXEC)
3108                         av |= FILE__EXECUTE;
3109
3110                 return file_has_perm(cred, file, av);
3111         }
3112
3113 error:
3114         return rc;
3115 }
3116
3117 static int selinux_file_mmap(struct file *file, unsigned long reqprot,
3118                              unsigned long prot, unsigned long flags,
3119                              unsigned long addr, unsigned long addr_only)
3120 {
3121         int rc = 0;
3122         u32 sid = current_sid();
3123
3124         /*
3125          * notice that we are intentionally putting the SELinux check before
3126          * the secondary cap_file_mmap check.  This is such a likely attempt
3127          * at bad behaviour/exploit that we always want to get the AVC, even
3128          * if DAC would have also denied the operation.
3129          */
3130         if (addr < CONFIG_LSM_MMAP_MIN_ADDR) {
3131                 rc = avc_has_perm(sid, sid, SECCLASS_MEMPROTECT,
3132                                   MEMPROTECT__MMAP_ZERO, NULL);
3133                 if (rc)
3134                         return rc;
3135         }
3136
3137         /* do DAC check on address space usage */
3138         rc = cap_file_mmap(file, reqprot, prot, flags, addr, addr_only);
3139         if (rc || addr_only)
3140                 return rc;
3141
3142         if (selinux_checkreqprot)
3143                 prot = reqprot;
3144
3145         return file_map_prot_check(file, prot,
3146                                    (flags & MAP_TYPE) == MAP_SHARED);
3147 }
3148
3149 static int selinux_file_mprotect(struct vm_area_struct *vma,
3150                                  unsigned long reqprot,
3151                                  unsigned long prot)
3152 {
3153         const struct cred *cred = current_cred();
3154
3155         if (selinux_checkreqprot)
3156                 prot = reqprot;
3157
3158         if (default_noexec &&
3159             (prot & PROT_EXEC) && !(vma->vm_flags & VM_EXEC)) {
3160                 int rc = 0;
3161                 if (vma->vm_start >= vma->vm_mm->start_brk &&
3162                     vma->vm_end <= vma->vm_mm->brk) {
3163                         rc = cred_has_perm(cred, cred, PROCESS__EXECHEAP);
3164                 } else if (!vma->vm_file &&
3165                            vma->vm_start <= vma->vm_mm->start_stack &&
3166                            vma->vm_end >= vma->vm_mm->start_stack) {
3167                         rc = current_has_perm(current, PROCESS__EXECSTACK);
3168                 } else if (vma->vm_file && vma->anon_vma) {
3169                         /*
3170                          * We are making executable a file mapping that has
3171                          * had some COW done. Since pages might have been
3172                          * written, check ability to execute the possibly
3173                          * modified content.  This typically should only
3174                          * occur for text relocations.
3175                          */
3176                         rc = file_has_perm(cred, vma->vm_file, FILE__EXECMOD);
3177                 }
3178                 if (rc)
3179                         return rc;
3180         }
3181
3182         return file_map_prot_check(vma->vm_file, prot, vma->vm_flags&VM_SHARED);
3183 }
3184
3185 static int selinux_file_lock(struct file *file, unsigned int cmd)
3186 {
3187         const struct cred *cred = current_cred();
3188
3189         return file_has_perm(cred, file, FILE__LOCK);
3190 }
3191
3192 static int selinux_file_fcntl(struct file *file, unsigned int cmd,
3193                               unsigned long arg)
3194 {
3195         const struct cred *cred = current_cred();
3196         int err = 0;
3197
3198         switch (cmd) {
3199         case F_SETFL:
3200                 if (!file->f_path.dentry || !file->f_path.dentry->d_inode) {
3201                         err = -EINVAL;
3202                         break;
3203                 }
3204
3205                 if ((file->f_flags & O_APPEND) && !(arg & O_APPEND)) {
3206                         err = file_has_perm(cred, file, FILE__WRITE);
3207                         break;
3208                 }
3209                 /* fall through */
3210         case F_SETOWN:
3211         case F_SETSIG:
3212         case F_GETFL:
3213         case F_GETOWN:
3214         case F_GETSIG:
3215                 /* Just check FD__USE permission */
3216                 err = file_has_perm(cred, file, 0);
3217                 break;
3218         case F_GETLK:
3219         case F_SETLK:
3220         case F_SETLKW:
3221 #if BITS_PER_LONG == 32
3222         case F_GETLK64:
3223         case F_SETLK64:
3224         case F_SETLKW64:
3225 #endif
3226                 if (!file->f_path.dentry || !file->f_path.dentry->d_inode) {
3227                         err = -EINVAL;
3228                         break;
3229                 }
3230                 err = file_has_perm(cred, file, FILE__LOCK);
3231                 break;
3232         }
3233
3234         return err;
3235 }
3236
3237 static int selinux_file_set_fowner(struct file *file)
3238 {
3239         struct file_security_struct *fsec;
3240
3241         fsec = file->f_security;
3242         fsec->fown_sid = current_sid();
3243
3244         return 0;
3245 }
3246
3247 static int selinux_file_send_sigiotask(struct task_struct *tsk,
3248                                        struct fown_struct *fown, int signum)
3249 {
3250         struct file *file;
3251         u32 sid = task_sid(tsk);
3252         u32 perm;
3253         struct file_security_struct *fsec;
3254
3255         /* struct fown_struct is never outside the context of a struct file */
3256         file = container_of(fown, struct file, f_owner);
3257
3258         fsec = file->f_security;
3259
3260         if (!signum)
3261                 perm = signal_to_av(SIGIO); /* as per send_sigio_to_task */
3262         else
3263                 perm = signal_to_av(signum);
3264
3265         return avc_has_perm(fsec->fown_sid, sid,
3266                             SECCLASS_PROCESS, perm, NULL);
3267 }
3268
3269 static int selinux_file_receive(struct file *file)
3270 {
3271         const struct cred *cred = current_cred();
3272
3273         return file_has_perm(cred, file, file_to_av(file));
3274 }
3275
3276 static int selinux_file_open(struct file *file, const struct cred *cred)
3277 {
3278         struct file_security_struct *fsec;
3279         struct inode *inode;
3280         struct inode_security_struct *isec;
3281
3282         inode = file->f_path.dentry->d_inode;
3283         fsec = file->f_security;
3284         isec = inode->i_security;
3285         /*
3286          * Save inode label and policy sequence number
3287          * at open-time so that selinux_file_permission
3288          * can determine whether revalidation is necessary.
3289          * Task label is already saved in the file security
3290          * struct as its SID.
3291          */
3292         fsec->isid = isec->sid;
3293         fsec->pseqno = avc_policy_seqno();
3294         /*
3295          * Since the inode label or policy seqno may have changed
3296          * between the selinux_inode_permission check and the saving
3297          * of state above, recheck that access is still permitted.
3298          * Otherwise, access might never be revalidated against the
3299          * new inode label or new policy.
3300          * This check is not redundant - do not remove.
3301          */
3302         return inode_has_perm_noadp(cred, inode, open_file_to_av(file), 0);
3303 }
3304
3305 /* task security operations */
3306
3307 static int selinux_task_create(unsigned long clone_flags)
3308 {
3309         return current_has_perm(current, PROCESS__FORK);
3310 }
3311
3312 /*
3313  * allocate the SELinux part of blank credentials
3314  */
3315 static int selinux_cred_alloc_blank(struct cred *cred, gfp_t gfp)
3316 {
3317         struct task_security_struct *tsec;
3318
3319         tsec = kzalloc(sizeof(struct task_security_struct), gfp);
3320         if (!tsec)
3321                 return -ENOMEM;
3322
3323         cred->security = tsec;
3324         return 0;
3325 }
3326
3327 /*
3328  * detach and free the LSM part of a set of credentials
3329  */
3330 static void selinux_cred_free(struct cred *cred)
3331 {
3332         struct task_security_struct *tsec = cred->security;
3333
3334         /*
3335          * cred->security == NULL if security_cred_alloc_blank() or
3336          * security_prepare_creds() returned an error.
3337          */
3338         BUG_ON(cred->security && (unsigned long) cred->security < PAGE_SIZE);
3339         cred->security = (void *) 0x7UL;
3340         kfree(tsec);
3341 }
3342
3343 /*
3344  * prepare a new set of credentials for modification
3345  */
3346 static int selinux_cred_prepare(struct cred *new, const struct cred *old,
3347                                 gfp_t gfp)
3348 {
3349         const struct task_security_struct *old_tsec;
3350         struct task_security_struct *tsec;
3351
3352         old_tsec = old->security;
3353
3354         tsec = kmemdup(old_tsec, sizeof(struct task_security_struct), gfp);
3355         if (!tsec)
3356                 return -ENOMEM;
3357
3358         new->security = tsec;
3359         return 0;
3360 }
3361
3362 /*
3363  * transfer the SELinux data to a blank set of creds
3364  */
3365 static void selinux_cred_transfer(struct cred *new, const struct cred *old)
3366 {
3367         const struct task_security_struct *old_tsec = old->security;
3368         struct task_security_struct *tsec = new->security;
3369
3370         *tsec = *old_tsec;
3371 }
3372
3373 /*
3374  * set the security data for a kernel service
3375  * - all the creation contexts are set to unlabelled
3376  */
3377 static int selinux_kernel_act_as(struct cred *new, u32 secid)
3378 {
3379         struct task_security_struct *tsec = new->security;
3380         u32 sid = current_sid();
3381         int ret;
3382
3383         ret = avc_has_perm(sid, secid,
3384                            SECCLASS_KERNEL_SERVICE,
3385                            KERNEL_SERVICE__USE_AS_OVERRIDE,
3386                            NULL);
3387         if (ret == 0) {
3388                 tsec->sid = secid;
3389                 tsec->create_sid = 0;
3390                 tsec->keycreate_sid = 0;
3391                 tsec->sockcreate_sid = 0;
3392         }
3393         return ret;
3394 }
3395
3396 /*
3397  * set the file creation context in a security record to the same as the
3398  * objective context of the specified inode
3399  */
3400 static int selinux_kernel_create_files_as(struct cred *new, struct inode *inode)
3401 {
3402         struct inode_security_struct *isec = inode->i_security;
3403         struct task_security_struct *tsec = new->security;
3404         u32 sid = current_sid();
3405         int ret;
3406
3407         ret = avc_has_perm(sid, isec->sid,
3408                            SECCLASS_KERNEL_SERVICE,
3409                            KERNEL_SERVICE__CREATE_FILES_AS,
3410                            NULL);
3411
3412         if (ret == 0)
3413                 tsec->create_sid = isec->sid;
3414         return ret;
3415 }
3416
3417 static int selinux_kernel_module_request(char *kmod_name)
3418 {
3419         u32 sid;
3420         struct common_audit_data ad;
3421         struct selinux_audit_data sad = {0,};
3422
3423         sid = task_sid(current);
3424
3425         COMMON_AUDIT_DATA_INIT(&ad, KMOD);
3426         ad.selinux_audit_data = &sad;
3427         ad.u.kmod_name = kmod_name;
3428
3429         return avc_has_perm(sid, SECINITSID_KERNEL, SECCLASS_SYSTEM,
3430                             SYSTEM__MODULE_REQUEST, &ad);
3431 }
3432
3433 static int selinux_task_setpgid(struct task_struct *p, pid_t pgid)
3434 {
3435         return current_has_perm(p, PROCESS__SETPGID);
3436 }
3437
3438 static int selinux_task_getpgid(struct task_struct *p)
3439 {
3440         return current_has_perm(p, PROCESS__GETPGID);
3441 }
3442
3443 static int selinux_task_getsid(struct task_struct *p)
3444 {
3445         return current_has_perm(p, PROCESS__GETSESSION);
3446 }
3447
3448 static void selinux_task_getsecid(struct task_struct *p, u32 *secid)
3449 {
3450         *secid = task_sid(p);
3451 }
3452
3453 static int selinux_task_setnice(struct task_struct *p, int nice)
3454 {
3455         int rc;
3456
3457         rc = cap_task_setnice(p, nice);
3458         if (rc)
3459                 return rc;
3460
3461         return current_has_perm(p, PROCESS__SETSCHED);
3462 }
3463
3464 static int selinux_task_setioprio(struct task_struct *p, int ioprio)
3465 {
3466         int rc;
3467
3468         rc = cap_task_setioprio(p, ioprio);
3469         if (rc)
3470                 return rc;
3471
3472         return current_has_perm(p, PROCESS__SETSCHED);
3473 }
3474
3475 static int selinux_task_getioprio(struct task_struct *p)
3476 {
3477         return current_has_perm(p, PROCESS__GETSCHED);
3478 }
3479
3480 static int selinux_task_setrlimit(struct task_struct *p, unsigned int resource,
3481                 struct rlimit *new_rlim)
3482 {
3483         struct rlimit *old_rlim = p->signal->rlim + resource;
3484
3485         /* Control the ability to change the hard limit (whether
3486            lowering or raising it), so that the hard limit can
3487            later be used as a safe reset point for the soft limit
3488            upon context transitions.  See selinux_bprm_committing_creds. */
3489         if (old_rlim->rlim_max != new_rlim->rlim_max)
3490                 return current_has_perm(p, PROCESS__SETRLIMIT);
3491
3492         return 0;
3493 }
3494
3495 static int selinux_task_setscheduler(struct task_struct *p)
3496 {
3497         int rc;
3498
3499         rc = cap_task_setscheduler(p);
3500         if (rc)
3501                 return rc;
3502
3503         return current_has_perm(p, PROCESS__SETSCHED);
3504 }
3505
3506 static int selinux_task_getscheduler(struct task_struct *p)
3507 {
3508         return current_has_perm(p, PROCESS__GETSCHED);
3509 }
3510
3511 static int selinux_task_movememory(struct task_struct *p)
3512 {
3513         return current_has_perm(p, PROCESS__SETSCHED);
3514 }
3515
3516 static int selinux_task_kill(struct task_struct *p, struct siginfo *info,
3517                                 int sig, u32 secid)
3518 {
3519         u32 perm;
3520         int rc;
3521
3522         if (!sig)
3523                 perm = PROCESS__SIGNULL; /* null signal; existence test */
3524         else
3525                 perm = signal_to_av(sig);
3526         if (secid)
3527                 rc = avc_has_perm(secid, task_sid(p),
3528                                   SECCLASS_PROCESS, perm, NULL);
3529         else
3530                 rc = current_has_perm(p, perm);
3531         return rc;
3532 }
3533
3534 static int selinux_task_wait(struct task_struct *p)
3535 {
3536         return task_has_perm(p, current, PROCESS__SIGCHLD);
3537 }
3538
3539 static void selinux_task_to_inode(struct task_struct *p,
3540                                   struct inode *inode)
3541 {
3542         struct inode_security_struct *isec = inode->i_security;
3543         u32 sid = task_sid(p);
3544
3545         isec->sid = sid;
3546         isec->initialized = 1;
3547 }
3548
3549 /* Returns error only if unable to parse addresses */
3550 static int selinux_parse_skb_ipv4(struct sk_buff *skb,
3551                         struct common_audit_data *ad, u8 *proto)
3552 {
3553         int offset, ihlen, ret = -EINVAL;
3554         struct iphdr _iph, *ih;
3555
3556         offset = skb_network_offset(skb);
3557         ih = skb_header_pointer(skb, offset, sizeof(_iph), &_iph);
3558         if (ih == NULL)
3559                 goto out;
3560
3561         ihlen = ih->ihl * 4;
3562         if (ihlen < sizeof(_iph))
3563                 goto out;
3564
3565         ad->u.net->v4info.saddr = ih->saddr;
3566         ad->u.net->v4info.daddr = ih->daddr;
3567         ret = 0;
3568
3569         if (proto)
3570                 *proto = ih->protocol;
3571
3572         switch (ih->protocol) {
3573         case IPPROTO_TCP: {
3574                 struct tcphdr _tcph, *th;
3575
3576                 if (ntohs(ih->frag_off) & IP_OFFSET)
3577                         break;
3578
3579                 offset += ihlen;
3580                 th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
3581                 if (th == NULL)
3582                         break;
3583
3584                 ad->u.net->sport = th->source;
3585                 ad->u.net->dport = th->dest;
3586                 break;
3587         }
3588
3589         case IPPROTO_UDP: {
3590                 struct udphdr _udph, *uh;
3591
3592                 if (ntohs(ih->frag_off) & IP_OFFSET)
3593                         break;
3594
3595                 offset += ihlen;
3596                 uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
3597                 if (uh == NULL)
3598                         break;
3599
3600                 ad->u.net->sport = uh->source;
3601                 ad->u.net->dport = uh->dest;
3602                 break;
3603         }
3604
3605         case IPPROTO_DCCP: {
3606                 struct dccp_hdr _dccph, *dh;
3607
3608                 if (ntohs(ih->frag_off) & IP_OFFSET)
3609                         break;
3610
3611                 offset += ihlen;
3612                 dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph);
3613                 if (dh == NULL)
3614                         break;
3615
3616                 ad->u.net->sport = dh->dccph_sport;
3617                 ad->u.net->dport = dh->dccph_dport;
3618                 break;
3619         }
3620
3621         default:
3622                 break;
3623         }
3624 out:
3625         return ret;
3626 }
3627
3628 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
3629
3630 /* Returns error only if unable to parse addresses */
3631 static int selinux_parse_skb_ipv6(struct sk_buff *skb,
3632                         struct common_audit_data *ad, u8 *proto)
3633 {
3634         u8 nexthdr;
3635         int ret = -EINVAL, offset;
3636         struct ipv6hdr _ipv6h, *ip6;
3637         __be16 frag_off;
3638
3639         offset = skb_network_offset(skb);
3640         ip6 = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h);
3641         if (ip6 == NULL)
3642                 goto out;
3643
3644         ad->u.net->v6info.saddr = ip6->saddr;
3645         ad->u.net->v6info.daddr = ip6->daddr;
3646         ret = 0;
3647
3648         nexthdr = ip6->nexthdr;
3649         offset += sizeof(_ipv6h);
3650         offset = ipv6_skip_exthdr(skb, offset, &nexthdr, &frag_off);
3651         if (offset < 0)
3652                 goto out;
3653
3654         if (proto)
3655                 *proto = nexthdr;
3656
3657         switch (nexthdr) {
3658         case IPPROTO_TCP: {
3659                 struct tcphdr _tcph, *th;
3660
3661                 th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
3662                 if (th == NULL)
3663                         break;
3664
3665                 ad->u.net->sport = th->source;
3666                 ad->u.net->dport = th->dest;
3667                 break;
3668         }
3669
3670         case IPPROTO_UDP: {
3671                 struct udphdr _udph, *uh;
3672
3673                 uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
3674                 if (uh == NULL)
3675                         break;
3676
3677                 ad->u.net->sport = uh->source;
3678                 ad->u.net->dport = uh->dest;
3679                 break;
3680         }
3681
3682         case IPPROTO_DCCP: {
3683                 struct dccp_hdr _dccph, *dh;
3684
3685                 dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph);
3686                 if (dh == NULL)
3687                         break;
3688
3689                 ad->u.net->sport = dh->dccph_sport;
3690                 ad->u.net->dport = dh->dccph_dport;
3691                 break;
3692         }
3693
3694         /* includes fragments */
3695         default:
3696                 break;
3697         }
3698 out:
3699         return ret;
3700 }
3701
3702 #endif /* IPV6 */
3703
3704 static int selinux_parse_skb(struct sk_buff *skb, struct common_audit_data *ad,
3705                              char **_addrp, int src, u8 *proto)
3706 {
3707         char *addrp;
3708         int ret;
3709
3710         switch (ad->u.net->family) {
3711         case PF_INET:
3712                 ret = selinux_parse_skb_ipv4(skb, ad, proto);
3713                 if (ret)
3714                         goto parse_error;
3715                 addrp = (char *)(src ? &ad->u.net->v4info.saddr :
3716                                        &ad->u.net->v4info.daddr);
3717                 goto okay;
3718
3719 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
3720         case PF_INET6:
3721                 ret = selinux_parse_skb_ipv6(skb, ad, proto);
3722                 if (ret)
3723                         goto parse_error;
3724                 addrp = (char *)(src ? &ad->u.net->v6info.saddr :
3725                                        &ad->u.net->v6info.daddr);
3726                 goto okay;
3727 #endif  /* IPV6 */
3728         default:
3729                 addrp = NULL;
3730                 goto okay;
3731         }
3732
3733 parse_error:
3734         printk(KERN_WARNING
3735                "SELinux: failure in selinux_parse_skb(),"
3736                " unable to parse packet\n");
3737         return ret;
3738
3739 okay:
3740         if (_addrp)
3741                 *_addrp = addrp;
3742         return 0;
3743 }
3744
3745 /**
3746  * selinux_skb_peerlbl_sid - Determine the peer label of a packet
3747  * @skb: the packet
3748  * @family: protocol family
3749  * @sid: the packet's peer label SID
3750  *
3751  * Description:
3752  * Check the various different forms of network peer labeling and determine
3753  * the peer label/SID for the packet; most of the magic actually occurs in
3754  * the security server function security_net_peersid_cmp().  The function
3755  * returns zero if the value in @sid is valid (although it may be SECSID_NULL)
3756  * or -EACCES if @sid is invalid due to inconsistencies with the different
3757  * peer labels.
3758  *
3759  */
3760 static int selinux_skb_peerlbl_sid(struct sk_buff *skb, u16 family, u32 *sid)
3761 {
3762         int err;
3763         u32 xfrm_sid;
3764         u32 nlbl_sid;
3765         u32 nlbl_type;
3766
3767         selinux_skb_xfrm_sid(skb, &xfrm_sid);
3768         selinux_netlbl_skbuff_getsid(skb, family, &nlbl_type, &nlbl_sid);
3769
3770         err = security_net_peersid_resolve(nlbl_sid, nlbl_type, xfrm_sid, sid);
3771         if (unlikely(err)) {
3772                 printk(KERN_WARNING
3773                        "SELinux: failure in selinux_skb_peerlbl_sid(),"
3774                        " unable to determine packet's peer label\n");
3775                 return -EACCES;
3776         }
3777
3778         return 0;
3779 }
3780
3781 /* socket security operations */
3782
3783 static int socket_sockcreate_sid(const struct task_security_struct *tsec,
3784                                  u16 secclass, u32 *socksid)
3785 {
3786         if (tsec->sockcreate_sid > SECSID_NULL) {
3787                 *socksid = tsec->sockcreate_sid;
3788                 return 0;
3789         }
3790
3791         return security_transition_sid(tsec->sid, tsec->sid, secclass, NULL,
3792                                        socksid);
3793 }
3794
3795 static int sock_has_perm(struct task_struct *task, struct sock *sk, u32 perms)
3796 {
3797         struct sk_security_struct *sksec = sk->sk_security;
3798         struct common_audit_data ad;
3799         struct selinux_audit_data sad = {0,};
3800         struct lsm_network_audit net = {0,};
3801         u32 tsid = task_sid(task);
3802
3803         if (sksec->sid == SECINITSID_KERNEL)
3804                 return 0;
3805
3806         COMMON_AUDIT_DATA_INIT(&ad, NET);
3807         ad.selinux_audit_data = &sad;
3808         ad.u.net = &net;
3809         ad.u.net->sk = sk;
3810
3811         return avc_has_perm(tsid, sksec->sid, sksec->sclass, perms, &ad);
3812 }
3813
3814 static int selinux_socket_create(int family, int type,
3815                                  int protocol, int kern)
3816 {
3817         const struct task_security_struct *tsec = current_security();
3818         u32 newsid;
3819         u16 secclass;
3820         int rc;
3821
3822         if (kern)
3823                 return 0;
3824
3825         secclass = socket_type_to_security_class(family, type, protocol);
3826         rc = socket_sockcreate_sid(tsec, secclass, &newsid);
3827         if (rc)
3828                 return rc;
3829
3830         return avc_has_perm(tsec->sid, newsid, secclass, SOCKET__CREATE, NULL);
3831 }
3832
3833 static int selinux_socket_post_create(struct socket *sock, int family,
3834                                       int type, int protocol, int kern)
3835 {
3836         const struct task_security_struct *tsec = current_security();
3837         struct inode_security_struct *isec = SOCK_INODE(sock)->i_security;
3838         struct sk_security_struct *sksec;
3839         int err = 0;
3840
3841         isec->sclass = socket_type_to_security_class(family, type, protocol);
3842
3843         if (kern)
3844                 isec->sid = SECINITSID_KERNEL;
3845         else {
3846                 err = socket_sockcreate_sid(tsec, isec->sclass, &(isec->sid));
3847                 if (err)
3848                         return err;
3849         }
3850
3851         isec->initialized = 1;
3852
3853         if (sock->sk) {
3854                 sksec = sock->sk->sk_security;
3855                 sksec->sid = isec->sid;
3856                 sksec->sclass = isec->sclass;
3857                 err = selinux_netlbl_socket_post_create(sock->sk, family);
3858         }
3859
3860         return err;
3861 }
3862
3863 /* Range of port numbers used to automatically bind.
3864    Need to determine whether we should perform a name_bind
3865    permission check between the socket and the port number. */
3866
3867 static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, int addrlen)
3868 {
3869         struct sock *sk = sock->sk;
3870         u16 family;
3871         int err;
3872
3873         err = sock_has_perm(current, sk, SOCKET__BIND);
3874         if (err)
3875                 goto out;
3876
3877         /*
3878          * If PF_INET or PF_INET6, check name_bind permission for the port.
3879          * Multiple address binding for SCTP is not supported yet: we just
3880          * check the first address now.
3881          */
3882         family = sk->sk_family;
3883         if (family == PF_INET || family == PF_INET6) {
3884                 char *addrp;
3885                 struct sk_security_struct *sksec = sk->sk_security;
3886                 struct common_audit_data ad;
3887                 struct selinux_audit_data sad = {0,};
3888                 struct lsm_network_audit net = {0,};
3889                 struct sockaddr_in *addr4 = NULL;
3890                 struct sockaddr_in6 *addr6 = NULL;
3891                 unsigned short snum;
3892                 u32 sid, node_perm;
3893
3894                 if (family == PF_INET) {
3895                         addr4 = (struct sockaddr_in *)address;
3896                         snum = ntohs(addr4->sin_port);
3897                         addrp = (char *)&addr4->sin_addr.s_addr;
3898                 } else {
3899                         addr6 = (struct sockaddr_in6 *)address;
3900                         snum = ntohs(addr6->sin6_port);
3901                         addrp = (char *)&addr6->sin6_addr.s6_addr;
3902                 }
3903
3904                 if (snum) {
3905                         int low, high;
3906
3907                         inet_get_local_port_range(&low, &high);
3908
3909                         if (snum < max(PROT_SOCK, low) || snum > high) {
3910                                 err = sel_netport_sid(sk->sk_protocol,
3911                                                       snum, &sid);
3912                                 if (err)
3913                                         goto out;
3914                                 COMMON_AUDIT_DATA_INIT(&ad, NET);
3915                                 ad.selinux_audit_data = &sad;
3916                                 ad.u.net = &net;
3917                                 ad.u.net->sport = htons(snum);
3918                                 ad.u.net->family = family;
3919                                 err = avc_has_perm(sksec->sid, sid,
3920                                                    sksec->sclass,
3921                                                    SOCKET__NAME_BIND, &ad);
3922                                 if (err)
3923                                         goto out;
3924                         }
3925                 }
3926
3927                 switch (sksec->sclass) {
3928                 case SECCLASS_TCP_SOCKET:
3929                         node_perm = TCP_SOCKET__NODE_BIND;
3930                         break;
3931
3932                 case SECCLASS_UDP_SOCKET:
3933                         node_perm = UDP_SOCKET__NODE_BIND;
3934                         break;
3935
3936                 case SECCLASS_DCCP_SOCKET:
3937                         node_perm = DCCP_SOCKET__NODE_BIND;
3938                         break;
3939
3940                 default:
3941                         node_perm = RAWIP_SOCKET__NODE_BIND;
3942                         break;
3943                 }
3944
3945                 err = sel_netnode_sid(addrp, family, &sid);
3946                 if (err)
3947                         goto out;
3948
3949                 COMMON_AUDIT_DATA_INIT(&ad, NET);
3950                 ad.selinux_audit_data = &sad;
3951                 ad.u.net = &net;
3952                 ad.u.net->sport = htons(snum);
3953                 ad.u.net->family = family;
3954
3955                 if (family == PF_INET)
3956                         ad.u.net->v4info.saddr = addr4->sin_addr.s_addr;
3957                 else
3958                         ad.u.net->v6info.saddr = addr6->sin6_addr;
3959
3960                 err = avc_has_perm(sksec->sid, sid,
3961                                    sksec->sclass, node_perm, &ad);
3962                 if (err)
3963                         goto out;
3964         }
3965 out:
3966         return err;
3967 }
3968
3969 static int selinux_socket_connect(struct socket *sock, struct sockaddr *address, int addrlen)
3970 {
3971         struct sock *sk = sock->sk;
3972         struct sk_security_struct *sksec = sk->sk_security;
3973         int err;
3974
3975         err = sock_has_perm(current, sk, SOCKET__CONNECT);
3976         if (err)
3977                 return err;
3978
3979         /*
3980          * If a TCP or DCCP socket, check name_connect permission for the port.
3981          */
3982         if (sksec->sclass == SECCLASS_TCP_SOCKET ||
3983             sksec->sclass == SECCLASS_DCCP_SOCKET) {
3984                 struct common_audit_data ad;
3985                 struct selinux_audit_data sad = {0,};
3986                 struct lsm_network_audit net = {0,};
3987                 struct sockaddr_in *addr4 = NULL;
3988                 struct sockaddr_in6 *addr6 = NULL;
3989                 unsigned short snum;
3990                 u32 sid, perm;
3991
3992                 if (sk->sk_family == PF_INET) {
3993                         addr4 = (struct sockaddr_in *)address;
3994                         if (addrlen < sizeof(struct sockaddr_in))
3995                                 return -EINVAL;
3996                         snum = ntohs(addr4->sin_port);
3997                 } else {
3998                         addr6 = (struct sockaddr_in6 *)address;
3999                         if (addrlen < SIN6_LEN_RFC2133)
4000                                 return -EINVAL;
4001                         snum = ntohs(addr6->sin6_port);
4002                 }
4003
4004                 err = sel_netport_sid(sk->sk_protocol, snum, &sid);
4005                 if (err)
4006                         goto out;
4007
4008                 perm = (sksec->sclass == SECCLASS_TCP_SOCKET) ?
4009                        TCP_SOCKET__NAME_CONNECT : DCCP_SOCKET__NAME_CONNECT;
4010
4011                 COMMON_AUDIT_DATA_INIT(&ad, NET);
4012                 ad.selinux_audit_data = &sad;
4013                 ad.u.net = &net;
4014                 ad.u.net->dport = htons(snum);
4015                 ad.u.net->family = sk->sk_family;
4016                 err = avc_has_perm(sksec->sid, sid, sksec->sclass, perm, &ad);
4017                 if (err)
4018                         goto out;
4019         }
4020
4021         err = selinux_netlbl_socket_connect(sk, address);
4022
4023 out:
4024         return err;
4025 }
4026
4027 static int selinux_socket_listen(struct socket *sock, int backlog)
4028 {
4029         return sock_has_perm(current, sock->sk, SOCKET__LISTEN);
4030 }
4031
4032 static int selinux_socket_accept(struct socket *sock, struct socket *newsock)
4033 {
4034         int err;
4035         struct inode_security_struct *isec;
4036         struct inode_security_struct *newisec;
4037
4038         err = sock_has_perm(current, sock->sk, SOCKET__ACCEPT);
4039         if (err)
4040                 return err;
4041
4042         newisec = SOCK_INODE(newsock)->i_security;
4043
4044         isec = SOCK_INODE(sock)->i_security;
4045         newisec->sclass = isec->sclass;
4046         newisec->sid = isec->sid;
4047         newisec->initialized = 1;
4048
4049         return 0;
4050 }
4051
4052 static int selinux_socket_sendmsg(struct socket *sock, struct msghdr *msg,
4053                                   int size)
4054 {
4055         return sock_has_perm(current, sock->sk, SOCKET__WRITE);
4056 }
4057
4058 static int selinux_socket_recvmsg(struct socket *sock, struct msghdr *msg,
4059                                   int size, int flags)
4060 {
4061         return sock_has_perm(current, sock->sk, SOCKET__READ);
4062 }
4063
4064 static int selinux_socket_getsockname(struct socket *sock)
4065 {
4066         return sock_has_perm(current, sock->sk, SOCKET__GETATTR);
4067 }
4068
4069 static int selinux_socket_getpeername(struct socket *sock)
4070 {
4071         return sock_has_perm(current, sock->sk, SOCKET__GETATTR);
4072 }
4073
4074 static int selinux_socket_setsockopt(struct socket *sock, int level, int optname)
4075 {
4076         int err;
4077
4078         err = sock_has_perm(current, sock->sk, SOCKET__SETOPT);
4079         if (err)
4080                 return err;
4081
4082         return selinux_netlbl_socket_setsockopt(sock, level, optname);
4083 }
4084
4085 static int selinux_socket_getsockopt(struct socket *sock, int level,
4086                                      int optname)
4087 {
4088         return sock_has_perm(current, sock->sk, SOCKET__GETOPT);
4089 }
4090
4091 static int selinux_socket_shutdown(struct socket *sock, int how)
4092 {
4093         return sock_has_perm(current, sock->sk, SOCKET__SHUTDOWN);
4094 }
4095
4096 static int selinux_socket_unix_stream_connect(struct sock *sock,
4097                                               struct sock *other,
4098                                               struct sock *newsk)
4099 {
4100         struct sk_security_struct *sksec_sock = sock->sk_security;
4101         struct sk_security_struct *sksec_other = other->sk_security;
4102         struct sk_security_struct *sksec_new = newsk->sk_security;
4103         struct common_audit_data ad;
4104         struct selinux_audit_data sad = {0,};
4105         struct lsm_network_audit net = {0,};
4106         int err;
4107
4108         COMMON_AUDIT_DATA_INIT(&ad, NET);
4109         ad.selinux_audit_data = &sad;
4110         ad.u.net = &net;
4111         ad.u.net->sk = other;
4112
4113         err = avc_has_perm(sksec_sock->sid, sksec_other->sid,
4114                            sksec_other->sclass,
4115                            UNIX_STREAM_SOCKET__CONNECTTO, &ad);
4116         if (err)
4117                 return err;
4118
4119         /* server child socket */
4120         sksec_new->peer_sid = sksec_sock->sid;
4121         err = security_sid_mls_copy(sksec_other->sid, sksec_sock->sid,
4122                                     &sksec_new->sid);
4123         if (err)
4124                 return err;
4125
4126         /* connecting socket */
4127         sksec_sock->peer_sid = sksec_new->sid;
4128
4129         return 0;
4130 }
4131
4132 static int selinux_socket_unix_may_send(struct socket *sock,
4133                                         struct socket *other)
4134 {
4135         struct sk_security_struct *ssec = sock->sk->sk_security;
4136         struct sk_security_struct *osec = other->sk->sk_security;
4137         struct common_audit_data ad;
4138         struct selinux_audit_data sad = {0,};
4139         struct lsm_network_audit net = {0,};
4140
4141         COMMON_AUDIT_DATA_INIT(&ad, NET);
4142         ad.selinux_audit_data = &sad;
4143         ad.u.net = &net;
4144         ad.u.net->sk = other->sk;
4145
4146         return avc_has_perm(ssec->sid, osec->sid, osec->sclass, SOCKET__SENDTO,
4147                             &ad);
4148 }
4149
4150 static int selinux_inet_sys_rcv_skb(int ifindex, char *addrp, u16 family,
4151                                     u32 peer_sid,
4152                                     struct common_audit_data *ad)
4153 {
4154         int err;
4155         u32 if_sid;
4156         u32 node_sid;
4157
4158         err = sel_netif_sid(ifindex, &if_sid);
4159         if (err)
4160                 return err;
4161         err = avc_has_perm(peer_sid, if_sid,
4162                            SECCLASS_NETIF, NETIF__INGRESS, ad);
4163         if (err)
4164                 return err;
4165
4166         err = sel_netnode_sid(addrp, family, &node_sid);
4167         if (err)
4168                 return err;
4169         return avc_has_perm(peer_sid, node_sid,
4170                             SECCLASS_NODE, NODE__RECVFROM, ad);
4171 }
4172
4173 static int selinux_sock_rcv_skb_compat(struct sock *sk, struct sk_buff *skb,
4174                                        u16 family)
4175 {
4176         int err = 0;
4177         struct sk_security_struct *sksec = sk->sk_security;
4178         u32 sk_sid = sksec->sid;
4179         struct common_audit_data ad;
4180         struct selinux_audit_data sad = {0,};
4181         struct lsm_network_audit net = {0,};
4182         char *addrp;
4183
4184         COMMON_AUDIT_DATA_INIT(&ad, NET);
4185         ad.selinux_audit_data = &sad;
4186         ad.u.net = &net;
4187         ad.u.net->netif = skb->skb_iif;
4188         ad.u.net->family = family;
4189         err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL);
4190         if (err)
4191                 return err;
4192
4193         if (selinux_secmark_enabled()) {
4194                 err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET,
4195                                    PACKET__RECV, &ad);
4196                 if (err)
4197                         return err;
4198         }
4199
4200         err = selinux_netlbl_sock_rcv_skb(sksec, skb, family, &ad);
4201         if (err)
4202                 return err;
4203         err = selinux_xfrm_sock_rcv_skb(sksec->sid, skb, &ad);
4204
4205         return err;
4206 }
4207
4208 static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
4209 {
4210         int err;
4211         struct sk_security_struct *sksec = sk->sk_security;
4212         u16 family = sk->sk_family;
4213         u32 sk_sid = sksec->sid;
4214         struct common_audit_data ad;
4215         struct selinux_audit_data sad = {0,};
4216         struct lsm_network_audit net = {0,};
4217         char *addrp;
4218         u8 secmark_active;
4219         u8 peerlbl_active;
4220
4221         if (family != PF_INET && family != PF_INET6)
4222                 return 0;
4223
4224         /* Handle mapped IPv4 packets arriving via IPv6 sockets */
4225         if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
4226                 family = PF_INET;
4227
4228         /* If any sort of compatibility mode is enabled then handoff processing
4229          * to the selinux_sock_rcv_skb_compat() function to deal with the
4230          * special handling.  We do this in an attempt to keep this function
4231          * as fast and as clean as possible. */
4232         if (!selinux_policycap_netpeer)
4233                 return selinux_sock_rcv_skb_compat(sk, skb, family);
4234
4235         secmark_active = selinux_secmark_enabled();
4236         peerlbl_active = netlbl_enabled() || selinux_xfrm_enabled();
4237         if (!secmark_active && !peerlbl_active)
4238                 return 0;
4239
4240         COMMON_AUDIT_DATA_INIT(&ad, NET);
4241         ad.selinux_audit_data = &sad;
4242         ad.u.net = &net;
4243         ad.u.net->netif = skb->skb_iif;
4244         ad.u.net->family = family;
4245         err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL);
4246         if (err)
4247                 return err;
4248
4249         if (peerlbl_active) {
4250                 u32 peer_sid;
4251
4252                 err = selinux_skb_peerlbl_sid(skb, family, &peer_sid);
4253                 if (err)
4254                         return err;
4255                 err = selinux_inet_sys_rcv_skb(skb->skb_iif, addrp, family,
4256                                                peer_sid, &ad);
4257                 if (err) {
4258                         selinux_netlbl_err(skb, err, 0);
4259                         return err;
4260                 }
4261                 err = avc_has_perm(sk_sid, peer_sid, SECCLASS_PEER,
4262                                    PEER__RECV, &ad);
4263                 if (err)
4264                         selinux_netlbl_err(skb, err, 0);
4265         }
4266
4267         if (secmark_active) {
4268                 err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET,
4269                                    PACKET__RECV, &ad);
4270                 if (err)
4271                         return err;
4272         }
4273
4274         return err;
4275 }
4276
4277 static int selinux_socket_getpeersec_stream(struct socket *sock, char __user *optval,
4278                                             int __user *optlen, unsigned len)
4279 {
4280         int err = 0;
4281         char *scontext;
4282         u32 scontext_len;
4283         struct sk_security_struct *sksec = sock->sk->sk_security;
4284         u32 peer_sid = SECSID_NULL;
4285
4286         if (sksec->sclass == SECCLASS_UNIX_STREAM_SOCKET ||
4287             sksec->sclass == SECCLASS_TCP_SOCKET)
4288                 peer_sid = sksec->peer_sid;
4289         if (peer_sid == SECSID_NULL)
4290                 return -ENOPROTOOPT;
4291
4292         err = security_sid_to_context(peer_sid, &scontext, &scontext_len);
4293         if (err)
4294                 return err;
4295
4296         if (scontext_len > len) {
4297                 err = -ERANGE;
4298                 goto out_len;
4299         }
4300
4301         if (copy_to_user(optval, scontext, scontext_len))
4302                 err = -EFAULT;
4303
4304 out_len:
4305         if (put_user(scontext_len, optlen))
4306                 err = -EFAULT;
4307         kfree(scontext);
4308         return err;
4309 }
4310
4311 static int selinux_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, u32 *secid)
4312 {
4313         u32 peer_secid = SECSID_NULL;
4314         u16 family;
4315
4316         if (skb && skb->protocol == htons(ETH_P_IP))
4317                 family = PF_INET;
4318         else if (skb && skb->protocol == htons(ETH_P_IPV6))
4319                 family = PF_INET6;
4320         else if (sock)
4321                 family = sock->sk->sk_family;
4322         else
4323                 goto out;
4324
4325         if (sock && family == PF_UNIX)
4326                 selinux_inode_getsecid(SOCK_INODE(sock), &peer_secid);
4327         else if (skb)
4328                 selinux_skb_peerlbl_sid(skb, family, &peer_secid);
4329
4330 out:
4331         *secid = peer_secid;
4332         if (peer_secid == SECSID_NULL)
4333                 return -EINVAL;
4334         return 0;
4335 }
4336
4337 static int selinux_sk_alloc_security(struct sock *sk, int family, gfp_t priority)
4338 {
4339         struct sk_security_struct *sksec;
4340
4341         sksec = kzalloc(sizeof(*sksec), priority);
4342         if (!sksec)
4343                 return -ENOMEM;
4344
4345         sksec->peer_sid = SECINITSID_UNLABELED;
4346         sksec->sid = SECINITSID_UNLABELED;
4347         selinux_netlbl_sk_security_reset(sksec);
4348         sk->sk_security = sksec;
4349
4350         return 0;
4351 }
4352
4353 static void selinux_sk_free_security(struct sock *sk)
4354 {
4355         struct sk_security_struct *sksec = sk->sk_security;
4356
4357         sk->sk_security = NULL;
4358         selinux_netlbl_sk_security_free(sksec);
4359         kfree(sksec);
4360 }
4361
4362 static void selinux_sk_clone_security(const struct sock *sk, struct sock *newsk)
4363 {
4364         struct sk_security_struct *sksec = sk->sk_security;
4365         struct sk_security_struct *newsksec = newsk->sk_security;
4366
4367         newsksec->sid = sksec->sid;
4368         newsksec->peer_sid = sksec->peer_sid;
4369         newsksec->sclass = sksec->sclass;
4370
4371         selinux_netlbl_sk_security_reset(newsksec);
4372 }
4373
4374 static void selinux_sk_getsecid(struct sock *sk, u32 *secid)
4375 {
4376         if (!sk)
4377                 *secid = SECINITSID_ANY_SOCKET;
4378         else {
4379                 struct sk_security_struct *sksec = sk->sk_security;
4380
4381                 *secid = sksec->sid;
4382         }
4383 }
4384
4385 static void selinux_sock_graft(struct sock *sk, struct socket *parent)
4386 {
4387         struct inode_security_struct *isec = SOCK_INODE(parent)->i_security;
4388         struct sk_security_struct *sksec = sk->sk_security;
4389
4390         if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6 ||
4391             sk->sk_family == PF_UNIX)
4392                 isec->sid = sksec->sid;
4393         sksec->sclass = isec->sclass;
4394 }
4395
4396 static int selinux_inet_conn_request(struct sock *sk, struct sk_buff *skb,
4397                                      struct request_sock *req)
4398 {
4399         struct sk_security_struct *sksec = sk->sk_security;
4400         int err;
4401         u16 family = sk->sk_family;
4402         u32 newsid;
4403         u32 peersid;
4404
4405         /* handle mapped IPv4 packets arriving via IPv6 sockets */
4406         if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
4407                 family = PF_INET;
4408
4409         err = selinux_skb_peerlbl_sid(skb, family, &peersid);
4410         if (err)
4411                 return err;
4412         if (peersid == SECSID_NULL) {
4413                 req->secid = sksec->sid;
4414                 req->peer_secid = SECSID_NULL;
4415         } else {
4416                 err = security_sid_mls_copy(sksec->sid, peersid, &newsid);
4417                 if (err)
4418                         return err;
4419                 req->secid = newsid;
4420                 req->peer_secid = peersid;
4421         }
4422
4423         return selinux_netlbl_inet_conn_request(req, family);
4424 }
4425
4426 static void selinux_inet_csk_clone(struct sock *newsk,
4427                                    const struct request_sock *req)
4428 {
4429         struct sk_security_struct *newsksec = newsk->sk_security;
4430
4431         newsksec->sid = req->secid;
4432         newsksec->peer_sid = req->peer_secid;
4433         /* NOTE: Ideally, we should also get the isec->sid for the
4434            new socket in sync, but we don't have the isec available yet.
4435            So we will wait until sock_graft to do it, by which
4436            time it will have been created and available. */
4437
4438         /* We don't need to take any sort of lock here as we are the only
4439          * thread with access to newsksec */
4440         selinux_netlbl_inet_csk_clone(newsk, req->rsk_ops->family);
4441 }
4442
4443 static void selinux_inet_conn_established(struct sock *sk, struct sk_buff *skb)
4444 {
4445         u16 family = sk->sk_family;
4446         struct sk_security_struct *sksec = sk->sk_security;
4447
4448         /* handle mapped IPv4 packets arriving via IPv6 sockets */
4449         if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
4450                 family = PF_INET;
4451
4452         selinux_skb_peerlbl_sid(skb, family, &sksec->peer_sid);
4453 }
4454
4455 static int selinux_secmark_relabel_packet(u32 sid)
4456 {
4457         const struct task_security_struct *__tsec;
4458         u32 tsid;
4459
4460         __tsec = current_security();
4461         tsid = __tsec->sid;
4462
4463         return avc_has_perm(tsid, sid, SECCLASS_PACKET, PACKET__RELABELTO, NULL);
4464 }
4465
4466 static void selinux_secmark_refcount_inc(void)
4467 {
4468         atomic_inc(&selinux_secmark_refcount);
4469 }
4470
4471 static void selinux_secmark_refcount_dec(void)
4472 {
4473         atomic_dec(&selinux_secmark_refcount);
4474 }
4475
4476 static void selinux_req_classify_flow(const struct request_sock *req,
4477                                       struct flowi *fl)
4478 {
4479         fl->flowi_secid = req->secid;
4480 }
4481
4482 static int selinux_tun_dev_create(void)
4483 {
4484         u32 sid = current_sid();
4485
4486         /* we aren't taking into account the "sockcreate" SID since the socket
4487          * that is being created here is not a socket in the traditional sense,
4488          * instead it is a private sock, accessible only to the kernel, and
4489          * representing a wide range of network traffic spanning multiple
4490          * connections unlike traditional sockets - check the TUN driver to
4491          * get a better understanding of why this socket is special */
4492
4493         return avc_has_perm(sid, sid, SECCLASS_TUN_SOCKET, TUN_SOCKET__CREATE,
4494                             NULL);
4495 }
4496
4497 static void selinux_tun_dev_post_create(struct sock *sk)
4498 {
4499         struct sk_security_struct *sksec = sk->sk_security;
4500
4501         /* we don't currently perform any NetLabel based labeling here and it
4502          * isn't clear that we would want to do so anyway; while we could apply
4503          * labeling without the support of the TUN user the resulting labeled
4504          * traffic from the other end of the connection would almost certainly
4505          * cause confusion to the TUN user that had no idea network labeling
4506          * protocols were being used */
4507
4508         /* see the comments in selinux_tun_dev_create() about why we don't use
4509          * the sockcreate SID here */
4510
4511         sksec->sid = current_sid();
4512         sksec->sclass = SECCLASS_TUN_SOCKET;
4513 }
4514
4515 static int selinux_tun_dev_attach(struct sock *sk)
4516 {
4517         struct sk_security_struct *sksec = sk->sk_security;
4518         u32 sid = current_sid();
4519         int err;
4520
4521         err = avc_has_perm(sid, sksec->sid, SECCLASS_TUN_SOCKET,
4522                            TUN_SOCKET__RELABELFROM, NULL);
4523         if (err)
4524                 return err;
4525         err = avc_has_perm(sid, sid, SECCLASS_TUN_SOCKET,
4526                            TUN_SOCKET__RELABELTO, NULL);
4527         if (err)
4528                 return err;
4529
4530         sksec->sid = sid;
4531
4532         return 0;
4533 }
4534
4535 static int selinux_nlmsg_perm(struct sock *sk, struct sk_buff *skb)
4536 {
4537         int err = 0;
4538         u32 perm;
4539         struct nlmsghdr *nlh;
4540         struct sk_security_struct *sksec = sk->sk_security;
4541
4542         if (skb->len < NLMSG_SPACE(0)) {
4543                 err = -EINVAL;
4544                 goto out;
4545         }
4546         nlh = nlmsg_hdr(skb);
4547
4548         err = selinux_nlmsg_lookup(sksec->sclass, nlh->nlmsg_type, &perm);
4549         if (err) {
4550                 if (err == -EINVAL) {
4551                         audit_log(current->audit_context, GFP_KERNEL, AUDIT_SELINUX_ERR,
4552                                   "SELinux:  unrecognized netlink message"
4553                                   " type=%hu for sclass=%hu\n",
4554                                   nlh->nlmsg_type, sksec->sclass);
4555                         if (!selinux_enforcing || security_get_allow_unknown())
4556                                 err = 0;
4557                 }
4558
4559                 /* Ignore */
4560                 if (err == -ENOENT)
4561                         err = 0;
4562                 goto out;
4563         }
4564
4565         err = sock_has_perm(current, sk, perm);
4566 out:
4567         return err;
4568 }
4569
4570 #ifdef CONFIG_NETFILTER
4571
4572 static unsigned int selinux_ip_forward(struct sk_buff *skb, int ifindex,
4573                                        u16 family)
4574 {
4575         int err;
4576         char *addrp;
4577         u32 peer_sid;
4578         struct common_audit_data ad;
4579         struct selinux_audit_data sad = {0,};
4580         struct lsm_network_audit net = {0,};
4581         u8 secmark_active;
4582         u8 netlbl_active;
4583         u8 peerlbl_active;
4584
4585         if (!selinux_policycap_netpeer)
4586                 return NF_ACCEPT;
4587
4588         secmark_active = selinux_secmark_enabled();
4589         netlbl_active = netlbl_enabled();
4590         peerlbl_active = netlbl_active || selinux_xfrm_enabled();
4591         if (!secmark_active && !peerlbl_active)
4592                 return NF_ACCEPT;
4593
4594         if (selinux_skb_peerlbl_sid(skb, family, &peer_sid) != 0)
4595                 return NF_DROP;
4596
4597         COMMON_AUDIT_DATA_INIT(&ad, NET);
4598         ad.selinux_audit_data = &sad;
4599         ad.u.net = &net;
4600         ad.u.net->netif = ifindex;
4601         ad.u.net->family = family;
4602         if (selinux_parse_skb(skb, &ad, &addrp, 1, NULL) != 0)
4603                 return NF_DROP;
4604
4605         if (peerlbl_active) {
4606                 err = selinux_inet_sys_rcv_skb(ifindex, addrp, family,
4607                                                peer_sid, &ad);
4608                 if (err) {
4609                         selinux_netlbl_err(skb, err, 1);
4610                         return NF_DROP;
4611                 }
4612         }
4613
4614         if (secmark_active)
4615                 if (avc_has_perm(peer_sid, skb->secmark,
4616                                  SECCLASS_PACKET, PACKET__FORWARD_IN, &ad))
4617                         return NF_DROP;
4618
4619         if (netlbl_active)
4620                 /* we do this in the FORWARD path and not the POST_ROUTING
4621                  * path because we want to make sure we apply the necessary
4622                  * labeling before IPsec is applied so we can leverage AH
4623                  * protection */
4624                 if (selinux_netlbl_skbuff_setsid(skb, family, peer_sid) != 0)
4625                         return NF_DROP;
4626
4627         return NF_ACCEPT;
4628 }
4629
4630 static unsigned int selinux_ipv4_forward(unsigned int hooknum,
4631                                          struct sk_buff *skb,
4632                                          const struct net_device *in,
4633                                          const struct net_device *out,
4634                                          int (*okfn)(struct sk_buff *))
4635 {
4636         return selinux_ip_forward(skb, in->ifindex, PF_INET);
4637 }
4638
4639 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
4640 static unsigned int selinux_ipv6_forward(unsigned int hooknum,
4641                                          struct sk_buff *skb,
4642                                          const struct net_device *in,
4643                                          const struct net_device *out,
4644                                          int (*okfn)(struct sk_buff *))
4645 {
4646         return selinux_ip_forward(skb, in->ifindex, PF_INET6);
4647 }
4648 #endif  /* IPV6 */
4649
4650 static unsigned int selinux_ip_output(struct sk_buff *skb,
4651                                       u16 family)
4652 {
4653         u32 sid;
4654
4655         if (!netlbl_enabled())
4656                 return NF_ACCEPT;
4657
4658         /* we do this in the LOCAL_OUT path and not the POST_ROUTING path
4659          * because we want to make sure we apply the necessary labeling
4660          * before IPsec is applied so we can leverage AH protection */
4661         if (skb->sk) {
4662                 struct sk_security_struct *sksec = skb->sk->sk_security;
4663                 sid = sksec->sid;
4664         } else
4665                 sid = SECINITSID_KERNEL;
4666         if (selinux_netlbl_skbuff_setsid(skb, family, sid) != 0)
4667                 return NF_DROP;
4668
4669         return NF_ACCEPT;
4670 }
4671
4672 static unsigned int selinux_ipv4_output(unsigned int hooknum,
4673                                         struct sk_buff *skb,
4674                                         const struct net_device *in,
4675                                         const struct net_device *out,
4676                                         int (*okfn)(struct sk_buff *))
4677 {
4678         return selinux_ip_output(skb, PF_INET);
4679 }
4680
4681 static unsigned int selinux_ip_postroute_compat(struct sk_buff *skb,
4682                                                 int ifindex,
4683                                                 u16 family)
4684 {
4685         struct sock *sk = skb->sk;
4686         struct sk_security_struct *sksec;
4687         struct common_audit_data ad;
4688         struct selinux_audit_data sad = {0,};
4689         struct lsm_network_audit net = {0,};
4690         char *addrp;
4691         u8 proto;
4692
4693         if (sk == NULL)
4694                 return NF_ACCEPT;
4695         sksec = sk->sk_security;
4696
4697         COMMON_AUDIT_DATA_INIT(&ad, NET);
4698         ad.selinux_audit_data = &sad;
4699         ad.u.net = &net;
4700         ad.u.net->netif = ifindex;
4701         ad.u.net->family = family;
4702         if (selinux_parse_skb(skb, &ad, &addrp, 0, &proto))
4703                 return NF_DROP;
4704
4705         if (selinux_secmark_enabled())
4706                 if (avc_has_perm(sksec->sid, skb->secmark,
4707                                  SECCLASS_PACKET, PACKET__SEND, &ad))
4708                         return NF_DROP_ERR(-ECONNREFUSED);
4709
4710         if (selinux_xfrm_postroute_last(sksec->sid, skb, &ad, proto))
4711                 return NF_DROP_ERR(-ECONNREFUSED);
4712
4713         return NF_ACCEPT;
4714 }
4715
4716 static unsigned int selinux_ip_postroute(struct sk_buff *skb, int ifindex,
4717                                          u16 family)
4718 {
4719         u32 secmark_perm;
4720         u32 peer_sid;
4721         struct sock *sk;
4722         struct common_audit_data ad;
4723         struct selinux_audit_data sad = {0,};
4724         struct lsm_network_audit net = {0,};
4725         char *addrp;
4726         u8 secmark_active;
4727         u8 peerlbl_active;
4728
4729         /* If any sort of compatibility mode is enabled then handoff processing
4730          * to the selinux_ip_postroute_compat() function to deal with the
4731          * special handling.  We do this in an attempt to keep this function
4732          * as fast and as clean as possible. */
4733         if (!selinux_policycap_netpeer)
4734                 return selinux_ip_postroute_compat(skb, ifindex, family);
4735 #ifdef CONFIG_XFRM
4736         /* If skb->dst->xfrm is non-NULL then the packet is undergoing an IPsec
4737          * packet transformation so allow the packet to pass without any checks
4738          * since we'll have another chance to perform access control checks
4739          * when the packet is on it's final way out.
4740          * NOTE: there appear to be some IPv6 multicast cases where skb->dst
4741          *       is NULL, in this case go ahead and apply access control. */
4742         if (skb_dst(skb) != NULL && skb_dst(skb)->xfrm != NULL)
4743                 return NF_ACCEPT;
4744 #endif
4745         secmark_active = selinux_secmark_enabled();
4746         peerlbl_active = netlbl_enabled() || selinux_xfrm_enabled();
4747         if (!secmark_active && !peerlbl_active)
4748                 return NF_ACCEPT;
4749
4750         /* if the packet is being forwarded then get the peer label from the
4751          * packet itself; otherwise check to see if it is from a local
4752          * application or the kernel, if from an application get the peer label
4753          * from the sending socket, otherwise use the kernel's sid */
4754         sk = skb->sk;
4755         if (sk == NULL) {
4756                 if (skb->skb_iif) {
4757                         secmark_perm = PACKET__FORWARD_OUT;
4758                         if (selinux_skb_peerlbl_sid(skb, family, &peer_sid))
4759                                 return NF_DROP;
4760                 } else {
4761                         secmark_perm = PACKET__SEND;
4762                         peer_sid = SECINITSID_KERNEL;
4763                 }
4764         } else {
4765                 struct sk_security_struct *sksec = sk->sk_security;
4766                 peer_sid = sksec->sid;
4767                 secmark_perm = PACKET__SEND;
4768         }
4769
4770         COMMON_AUDIT_DATA_INIT(&ad, NET);
4771         ad.selinux_audit_data = &sad;
4772         ad.u.net = &net;
4773         ad.u.net->netif = ifindex;
4774         ad.u.net->family = family;
4775         if (selinux_parse_skb(skb, &ad, &addrp, 0, NULL))
4776                 return NF_DROP;
4777
4778         if (secmark_active)
4779                 if (avc_has_perm(peer_sid, skb->secmark,
4780                                  SECCLASS_PACKET, secmark_perm, &ad))
4781                         return NF_DROP_ERR(-ECONNREFUSED);
4782
4783         if (peerlbl_active) {
4784                 u32 if_sid;
4785                 u32 node_sid;
4786
4787                 if (sel_netif_sid(ifindex, &if_sid))
4788                         return NF_DROP;
4789                 if (avc_has_perm(peer_sid, if_sid,
4790                                  SECCLASS_NETIF, NETIF__EGRESS, &ad))
4791                         return NF_DROP_ERR(-ECONNREFUSED);
4792
4793                 if (sel_netnode_sid(addrp, family, &node_sid))
4794                         return NF_DROP;
4795                 if (avc_has_perm(peer_sid, node_sid,
4796                                  SECCLASS_NODE, NODE__SENDTO, &ad))
4797                         return NF_DROP_ERR(-ECONNREFUSED);
4798         }
4799
4800         return NF_ACCEPT;
4801 }
4802
4803 static unsigned int selinux_ipv4_postroute(unsigned int hooknum,
4804                                            struct sk_buff *skb,
4805                                            const struct net_device *in,
4806                                            const struct net_device *out,
4807                                            int (*okfn)(struct sk_buff *))
4808 {
4809         return selinux_ip_postroute(skb, out->ifindex, PF_INET);
4810 }
4811
4812 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
4813 static unsigned int selinux_ipv6_postroute(unsigned int hooknum,
4814                                            struct sk_buff *skb,
4815                                            const struct net_device *in,
4816                                            const struct net_device *out,
4817                                            int (*okfn)(struct sk_buff *))
4818 {
4819         return selinux_ip_postroute(skb, out->ifindex, PF_INET6);
4820 }
4821 #endif  /* IPV6 */
4822
4823 #endif  /* CONFIG_NETFILTER */
4824
4825 static int selinux_netlink_send(struct sock *sk, struct sk_buff *skb)
4826 {
4827         int err;
4828
4829         err = cap_netlink_send(sk, skb);
4830         if (err)
4831                 return err;
4832
4833         return selinux_nlmsg_perm(sk, skb);
4834 }
4835
4836 static int ipc_alloc_security(struct task_struct *task,
4837                               struct kern_ipc_perm *perm,
4838                               u16 sclass)
4839 {
4840         struct ipc_security_struct *isec;
4841         u32 sid;
4842
4843         isec = kzalloc(sizeof(struct ipc_security_struct), GFP_KERNEL);
4844         if (!isec)
4845                 return -ENOMEM;
4846
4847         sid = task_sid(task);
4848         isec->sclass = sclass;
4849         isec->sid = sid;
4850         perm->security = isec;
4851
4852         return 0;
4853 }
4854
4855 static void ipc_free_security(struct kern_ipc_perm *perm)
4856 {
4857         struct ipc_security_struct *isec = perm->security;
4858         perm->security = NULL;
4859         kfree(isec);
4860 }
4861
4862 static int msg_msg_alloc_security(struct msg_msg *msg)
4863 {
4864         struct msg_security_struct *msec;
4865
4866         msec = kzalloc(sizeof(struct msg_security_struct), GFP_KERNEL);
4867         if (!msec)
4868                 return -ENOMEM;
4869
4870         msec->sid = SECINITSID_UNLABELED;
4871         msg->security = msec;
4872
4873         return 0;
4874 }
4875
4876 static void msg_msg_free_security(struct msg_msg *msg)
4877 {
4878         struct msg_security_struct *msec = msg->security;
4879
4880         msg->security = NULL;
4881         kfree(msec);
4882 }
4883
4884 static int ipc_has_perm(struct kern_ipc_perm *ipc_perms,
4885                         u32 perms)
4886 {
4887         struct ipc_security_struct *isec;
4888         struct common_audit_data ad;
4889         struct selinux_audit_data sad = {0,};
4890         u32 sid = current_sid();
4891
4892         isec = ipc_perms->security;
4893
4894         COMMON_AUDIT_DATA_INIT(&ad, IPC);
4895         ad.selinux_audit_data = &sad;
4896         ad.u.ipc_id = ipc_perms->key;
4897
4898         return avc_has_perm(sid, isec->sid, isec->sclass, perms, &ad);
4899 }
4900
4901 static int selinux_msg_msg_alloc_security(struct msg_msg *msg)
4902 {
4903         return msg_msg_alloc_security(msg);
4904 }
4905
4906 static void selinux_msg_msg_free_security(struct msg_msg *msg)
4907 {
4908         msg_msg_free_security(msg);
4909 }
4910
4911 /* message queue security operations */
4912 static int selinux_msg_queue_alloc_security(struct msg_queue *msq)
4913 {
4914         struct ipc_security_struct *isec;
4915         struct common_audit_data ad;
4916         struct selinux_audit_data sad = {0,};
4917         u32 sid = current_sid();
4918         int rc;
4919
4920         rc = ipc_alloc_security(current, &msq->q_perm, SECCLASS_MSGQ);
4921         if (rc)
4922                 return rc;
4923
4924         isec = msq->q_perm.security;
4925
4926         COMMON_AUDIT_DATA_INIT(&ad, IPC);
4927         ad.selinux_audit_data = &sad;
4928         ad.u.ipc_id = msq->q_perm.key;
4929
4930         rc = avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
4931                           MSGQ__CREATE, &ad);
4932         if (rc) {
4933                 ipc_free_security(&msq->q_perm);
4934                 return rc;
4935         }
4936         return 0;
4937 }
4938
4939 static void selinux_msg_queue_free_security(struct msg_queue *msq)
4940 {
4941         ipc_free_security(&msq->q_perm);
4942 }
4943
4944 static int selinux_msg_queue_associate(struct msg_queue *msq, int msqflg)
4945 {
4946         struct ipc_security_struct *isec;
4947         struct common_audit_data ad;
4948         struct selinux_audit_data sad = {0,};
4949         u32 sid = current_sid();
4950
4951         isec = msq->q_perm.security;
4952
4953         COMMON_AUDIT_DATA_INIT(&ad, IPC);
4954         ad.selinux_audit_data = &sad;
4955         ad.u.ipc_id = msq->q_perm.key;
4956
4957         return avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
4958                             MSGQ__ASSOCIATE, &ad);
4959 }
4960
4961 static int selinux_msg_queue_msgctl(struct msg_queue *msq, int cmd)
4962 {
4963         int err;
4964         int perms;
4965
4966         switch (cmd) {
4967         case IPC_INFO:
4968         case MSG_INFO:
4969                 /* No specific object, just general system-wide information. */
4970                 return task_has_system(current, SYSTEM__IPC_INFO);
4971         case IPC_STAT:
4972         case MSG_STAT:
4973                 perms = MSGQ__GETATTR | MSGQ__ASSOCIATE;
4974                 break;
4975         case IPC_SET:
4976                 perms = MSGQ__SETATTR;
4977                 break;
4978         case IPC_RMID:
4979                 perms = MSGQ__DESTROY;
4980                 break;
4981         default:
4982                 return 0;
4983         }
4984
4985         err = ipc_has_perm(&msq->q_perm, perms);
4986         return err;
4987 }
4988
4989 static int selinux_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg, int msqflg)
4990 {
4991         struct ipc_security_struct *isec;
4992         struct msg_security_struct *msec;
4993         struct common_audit_data ad;
4994         struct selinux_audit_data sad = {0,};
4995         u32 sid = current_sid();
4996         int rc;
4997
4998         isec = msq->q_perm.security;
4999         msec = msg->security;
5000
5001         /*
5002          * First time through, need to assign label to the message
5003          */
5004         if (msec->sid == SECINITSID_UNLABELED) {
5005                 /*
5006                  * Compute new sid based on current process and
5007                  * message queue this message will be stored in
5008                  */
5009                 rc = security_transition_sid(sid, isec->sid, SECCLASS_MSG,
5010                                              NULL, &msec->sid);
5011                 if (rc)
5012                         return rc;
5013         }
5014
5015         COMMON_AUDIT_DATA_INIT(&ad, IPC);
5016         ad.selinux_audit_data = &sad;
5017         ad.u.ipc_id = msq->q_perm.key;
5018
5019         /* Can this process write to the queue? */
5020         rc = avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
5021                           MSGQ__WRITE, &ad);
5022         if (!rc)
5023                 /* Can this process send the message */
5024                 rc = avc_has_perm(sid, msec->sid, SECCLASS_MSG,
5025                                   MSG__SEND, &ad);
5026         if (!rc)
5027                 /* Can the message be put in the queue? */
5028                 rc = avc_has_perm(msec->sid, isec->sid, SECCLASS_MSGQ,
5029                                   MSGQ__ENQUEUE, &ad);
5030
5031         return rc;
5032 }
5033
5034 static int selinux_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg,
5035                                     struct task_struct *target,
5036                                     long type, int mode)
5037 {
5038         struct ipc_security_struct *isec;
5039         struct msg_security_struct *msec;
5040         struct common_audit_data ad;
5041         struct selinux_audit_data sad = {0,};
5042         u32 sid = task_sid(target);
5043         int rc;
5044
5045         isec = msq->q_perm.security;
5046         msec = msg->security;
5047
5048         COMMON_AUDIT_DATA_INIT(&ad, IPC);
5049         ad.selinux_audit_data = &sad;
5050         ad.u.ipc_id = msq->q_perm.key;
5051
5052         rc = avc_has_perm(sid, isec->sid,
5053                           SECCLASS_MSGQ, MSGQ__READ, &ad);
5054         if (!rc)
5055                 rc = avc_has_perm(sid, msec->sid,
5056                                   SECCLASS_MSG, MSG__RECEIVE, &ad);
5057         return rc;
5058 }
5059
5060 /* Shared Memory security operations */
5061 static int selinux_shm_alloc_security(struct shmid_kernel *shp)
5062 {
5063         struct ipc_security_struct *isec;
5064         struct common_audit_data ad;
5065         struct selinux_audit_data sad = {0,};
5066         u32 sid = current_sid();
5067         int rc;
5068
5069         rc = ipc_alloc_security(current, &shp->shm_perm, SECCLASS_SHM);
5070         if (rc)
5071                 return rc;
5072
5073         isec = shp->shm_perm.security;
5074
5075         COMMON_AUDIT_DATA_INIT(&ad, IPC);
5076         ad.selinux_audit_data = &sad;
5077         ad.u.ipc_id = shp->shm_perm.key;
5078
5079         rc = avc_has_perm(sid, isec->sid, SECCLASS_SHM,
5080                           SHM__CREATE, &ad);
5081         if (rc) {
5082                 ipc_free_security(&shp->shm_perm);
5083                 return rc;
5084         }
5085         return 0;
5086 }
5087
5088 static void selinux_shm_free_security(struct shmid_kernel *shp)
5089 {
5090         ipc_free_security(&shp->shm_perm);
5091 }
5092
5093 static int selinux_shm_associate(struct shmid_kernel *shp, int shmflg)
5094 {
5095         struct ipc_security_struct *isec;
5096         struct common_audit_data ad;
5097         struct selinux_audit_data sad = {0,};
5098         u32 sid = current_sid();
5099
5100         isec = shp->shm_perm.security;
5101
5102         COMMON_AUDIT_DATA_INIT(&ad, IPC);
5103         ad.selinux_audit_data = &sad;
5104         ad.u.ipc_id = shp->shm_perm.key;
5105
5106         return avc_has_perm(sid, isec->sid, SECCLASS_SHM,
5107                             SHM__ASSOCIATE, &ad);
5108 }
5109
5110 /* Note, at this point, shp is locked down */
5111 static int selinux_shm_shmctl(struct shmid_kernel *shp, int cmd)
5112 {
5113         int perms;
5114         int err;
5115
5116         switch (cmd) {
5117         case IPC_INFO:
5118         case SHM_INFO:
5119                 /* No specific object, just general system-wide information. */
5120                 return task_has_system(current, SYSTEM__IPC_INFO);
5121         case IPC_STAT:
5122         case SHM_STAT:
5123                 perms = SHM__GETATTR | SHM__ASSOCIATE;
5124                 break;
5125         case IPC_SET:
5126                 perms = SHM__SETATTR;
5127                 break;
5128         case SHM_LOCK:
5129         case SHM_UNLOCK:
5130                 perms = SHM__LOCK;
5131                 break;
5132         case IPC_RMID:
5133                 perms = SHM__DESTROY;
5134                 break;
5135         default:
5136                 return 0;
5137         }
5138
5139         err = ipc_has_perm(&shp->shm_perm, perms);
5140         return err;
5141 }
5142
5143 static int selinux_shm_shmat(struct shmid_kernel *shp,
5144                              char __user *shmaddr, int shmflg)
5145 {
5146         u32 perms;
5147
5148         if (shmflg & SHM_RDONLY)
5149                 perms = SHM__READ;
5150         else
5151                 perms = SHM__READ | SHM__WRITE;
5152
5153         return ipc_has_perm(&shp->shm_perm, perms);
5154 }
5155
5156 /* Semaphore security operations */
5157 static int selinux_sem_alloc_security(struct sem_array *sma)
5158 {
5159         struct ipc_security_struct *isec;
5160         struct common_audit_data ad;
5161         struct selinux_audit_data sad = {0,};
5162         u32 sid = current_sid();
5163         int rc;
5164
5165         rc = ipc_alloc_security(current, &sma->sem_perm, SECCLASS_SEM);
5166         if (rc)
5167                 return rc;
5168
5169         isec = sma->sem_perm.security;
5170
5171         COMMON_AUDIT_DATA_INIT(&ad, IPC);
5172         ad.selinux_audit_data = &sad;
5173         ad.u.ipc_id = sma->sem_perm.key;
5174
5175         rc = avc_has_perm(sid, isec->sid, SECCLASS_SEM,
5176                           SEM__CREATE, &ad);
5177         if (rc) {
5178                 ipc_free_security(&sma->sem_perm);
5179                 return rc;
5180         }
5181         return 0;
5182 }
5183
5184 static void selinux_sem_free_security(struct sem_array *sma)
5185 {
5186         ipc_free_security(&sma->sem_perm);
5187 }
5188
5189 static int selinux_sem_associate(struct sem_array *sma, int semflg)
5190 {
5191         struct ipc_security_struct *isec;
5192         struct common_audit_data ad;
5193         struct selinux_audit_data sad = {0,};
5194         u32 sid = current_sid();
5195
5196         isec = sma->sem_perm.security;
5197
5198         COMMON_AUDIT_DATA_INIT(&ad, IPC);
5199         ad.selinux_audit_data = &sad;
5200         ad.u.ipc_id = sma->sem_perm.key;
5201
5202         return avc_has_perm(sid, isec->sid, SECCLASS_SEM,
5203                             SEM__ASSOCIATE, &ad);
5204 }
5205
5206 /* Note, at this point, sma is locked down */
5207 static int selinux_sem_semctl(struct sem_array *sma, int cmd)
5208 {
5209         int err;
5210         u32 perms;
5211
5212         switch (cmd) {
5213         case IPC_INFO:
5214         case SEM_INFO:
5215                 /* No specific object, just general system-wide information. */
5216                 return task_has_system(current, SYSTEM__IPC_INFO);
5217         case GETPID:
5218         case GETNCNT:
5219         case GETZCNT:
5220                 perms = SEM__GETATTR;
5221                 break;
5222         case GETVAL:
5223         case GETALL:
5224                 perms = SEM__READ;
5225                 break;
5226         case SETVAL:
5227         case SETALL:
5228                 perms = SEM__WRITE;
5229                 break;
5230         case IPC_RMID:
5231                 perms = SEM__DESTROY;
5232                 break;
5233         case IPC_SET:
5234                 perms = SEM__SETATTR;
5235                 break;
5236         case IPC_STAT:
5237         case SEM_STAT:
5238                 perms = SEM__GETATTR | SEM__ASSOCIATE;
5239                 break;
5240         default:
5241                 return 0;
5242         }
5243
5244         err = ipc_has_perm(&sma->sem_perm, perms);
5245         return err;
5246 }
5247
5248 static int selinux_sem_semop(struct sem_array *sma,
5249                              struct sembuf *sops, unsigned nsops, int alter)
5250 {
5251         u32 perms;
5252
5253         if (alter)
5254                 perms = SEM__READ | SEM__WRITE;
5255         else
5256                 perms = SEM__READ;
5257
5258         return ipc_has_perm(&sma->sem_perm, perms);
5259 }
5260
5261 static int selinux_ipc_permission(struct kern_ipc_perm *ipcp, short flag)
5262 {
5263         u32 av = 0;
5264
5265         av = 0;
5266         if (flag & S_IRUGO)
5267                 av |= IPC__UNIX_READ;
5268         if (flag & S_IWUGO)
5269                 av |= IPC__UNIX_WRITE;
5270
5271         if (av == 0)
5272                 return 0;
5273
5274         return ipc_has_perm(ipcp, av);
5275 }
5276
5277 static void selinux_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
5278 {
5279         struct ipc_security_struct *isec = ipcp->security;
5280         *secid = isec->sid;
5281 }
5282
5283 static void selinux_d_instantiate(struct dentry *dentry, struct inode *inode)
5284 {
5285         if (inode)
5286                 inode_doinit_with_dentry(inode, dentry);
5287 }
5288
5289 static int selinux_getprocattr(struct task_struct *p,
5290                                char *name, char **value)
5291 {
5292         const struct task_security_struct *__tsec;
5293         u32 sid;
5294         int error;
5295         unsigned len;
5296
5297         if (current != p) {
5298                 error = current_has_perm(p, PROCESS__GETATTR);
5299                 if (error)
5300                         return error;
5301         }
5302
5303         rcu_read_lock();
5304         __tsec = __task_cred(p)->security;
5305
5306         if (!strcmp(name, "current"))
5307                 sid = __tsec->sid;
5308         else if (!strcmp(name, "prev"))
5309                 sid = __tsec->osid;
5310         else if (!strcmp(name, "exec"))
5311                 sid = __tsec->exec_sid;
5312         else if (!strcmp(name, "fscreate"))
5313                 sid = __tsec->create_sid;
5314         else if (!strcmp(name, "keycreate"))
5315                 sid = __tsec->keycreate_sid;
5316         else if (!strcmp(name, "sockcreate"))
5317                 sid = __tsec->sockcreate_sid;
5318         else
5319                 goto invalid;
5320         rcu_read_unlock();
5321
5322         if (!sid)
5323                 return 0;
5324
5325         error = security_sid_to_context(sid, value, &len);
5326         if (error)
5327                 return error;
5328         return len;
5329
5330 invalid:
5331         rcu_read_unlock();
5332         return -EINVAL;
5333 }
5334
5335 static int selinux_setprocattr(struct task_struct *p,
5336                                char *name, void *value, size_t size)
5337 {
5338         struct task_security_struct *tsec;
5339         struct task_struct *tracer;
5340         struct cred *new;
5341         u32 sid = 0, ptsid;
5342         int error;
5343         char *str = value;
5344
5345         if (current != p) {
5346                 /* SELinux only allows a process to change its own
5347                    security attributes. */
5348                 return -EACCES;
5349         }
5350
5351         /*
5352          * Basic control over ability to set these attributes at all.
5353          * current == p, but we'll pass them separately in case the
5354          * above restriction is ever removed.
5355          */
5356         if (!strcmp(name, "exec"))
5357                 error = current_has_perm(p, PROCESS__SETEXEC);
5358         else if (!strcmp(name, "fscreate"))
5359                 error = current_has_perm(p, PROCESS__SETFSCREATE);
5360         else if (!strcmp(name, "keycreate"))
5361                 error = current_has_perm(p, PROCESS__SETKEYCREATE);
5362         else if (!strcmp(name, "sockcreate"))
5363                 error = current_has_perm(p, PROCESS__SETSOCKCREATE);
5364         else if (!strcmp(name, "current"))
5365                 error = current_has_perm(p, PROCESS__SETCURRENT);
5366         else
5367                 error = -EINVAL;
5368         if (error)
5369                 return error;
5370
5371         /* Obtain a SID for the context, if one was specified. */
5372         if (size && str[1] && str[1] != '\n') {
5373                 if (str[size-1] == '\n') {
5374                         str[size-1] = 0;
5375                         size--;
5376                 }
5377                 error = security_context_to_sid(value, size, &sid);
5378                 if (error == -EINVAL && !strcmp(name, "fscreate")) {
5379                         if (!capable(CAP_MAC_ADMIN)) {
5380                                 struct audit_buffer *ab;
5381                                 size_t audit_size;
5382
5383                                 /* We strip a nul only if it is at the end, otherwise the
5384                                  * context contains a nul and we should audit that */
5385                                 if (str[size - 1] == '\0')
5386                                         audit_size = size - 1;
5387                                 else
5388                                         audit_size = size;
5389                                 ab = audit_log_start(current->audit_context, GFP_ATOMIC, AUDIT_SELINUX_ERR);
5390                                 audit_log_format(ab, "op=fscreate invalid_context=");
5391                                 audit_log_n_untrustedstring(ab, value, audit_size);
5392                                 audit_log_end(ab);
5393
5394                                 return error;
5395                         }
5396                         error = security_context_to_sid_force(value, size,
5397                                                               &sid);
5398                 }
5399                 if (error)
5400                         return error;
5401         }
5402
5403         new = prepare_creds();
5404         if (!new)
5405                 return -ENOMEM;
5406
5407         /* Permission checking based on the specified context is
5408            performed during the actual operation (execve,
5409            open/mkdir/...), when we know the full context of the
5410            operation.  See selinux_bprm_set_creds for the execve
5411            checks and may_create for the file creation checks. The
5412            operation will then fail if the context is not permitted. */
5413         tsec = new->security;
5414         if (!strcmp(name, "exec")) {
5415                 tsec->exec_sid = sid;
5416         } else if (!strcmp(name, "fscreate")) {
5417                 tsec->create_sid = sid;
5418         } else if (!strcmp(name, "keycreate")) {
5419                 error = may_create_key(sid, p);
5420                 if (error)
5421                         goto abort_change;
5422                 tsec->keycreate_sid = sid;
5423         } else if (!strcmp(name, "sockcreate")) {
5424                 tsec->sockcreate_sid = sid;
5425         } else if (!strcmp(name, "current")) {
5426                 error = -EINVAL;
5427                 if (sid == 0)
5428                         goto abort_change;
5429
5430                 /* Only allow single threaded processes to change context */
5431                 error = -EPERM;
5432                 if (!current_is_single_threaded()) {
5433                         error = security_bounded_transition(tsec->sid, sid);
5434                         if (error)
5435                                 goto abort_change;
5436                 }
5437
5438                 /* Check permissions for the transition. */
5439                 error = avc_has_perm(tsec->sid, sid, SECCLASS_PROCESS,
5440                                      PROCESS__DYNTRANSITION, NULL);
5441                 if (error)
5442                         goto abort_change;
5443
5444                 /* Check for ptracing, and update the task SID if ok.
5445                    Otherwise, leave SID unchanged and fail. */
5446                 ptsid = 0;
5447                 task_lock(p);
5448                 tracer = ptrace_parent(p);
5449                 if (tracer)
5450                         ptsid = task_sid(tracer);
5451                 task_unlock(p);
5452
5453                 if (tracer) {
5454                         error = avc_has_perm(ptsid, sid, SECCLASS_PROCESS,
5455                                              PROCESS__PTRACE, NULL);
5456                         if (error)
5457                                 goto abort_change;
5458                 }
5459
5460                 tsec->sid = sid;
5461         } else {
5462                 error = -EINVAL;
5463                 goto abort_change;
5464         }
5465
5466         commit_creds(new);
5467         return size;
5468
5469 abort_change:
5470         abort_creds(new);
5471         return error;
5472 }
5473
5474 static int selinux_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
5475 {
5476         return security_sid_to_context(secid, secdata, seclen);
5477 }
5478
5479 static int selinux_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
5480 {
5481         return security_context_to_sid(secdata, seclen, secid);
5482 }
5483
5484 static void selinux_release_secctx(char *secdata, u32 seclen)
5485 {
5486         kfree(secdata);
5487 }
5488
5489 /*
5490  *      called with inode->i_mutex locked
5491  */
5492 static int selinux_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen)
5493 {
5494         return selinux_inode_setsecurity(inode, XATTR_SELINUX_SUFFIX, ctx, ctxlen, 0);
5495 }
5496
5497 /*
5498  *      called with inode->i_mutex locked
5499  */
5500 static int selinux_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen)
5501 {
5502         return __vfs_setxattr_noperm(dentry, XATTR_NAME_SELINUX, ctx, ctxlen, 0);
5503 }
5504
5505 static int selinux_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen)
5506 {
5507         int len = 0;
5508         len = selinux_inode_getsecurity(inode, XATTR_SELINUX_SUFFIX,
5509                                                 ctx, true);
5510         if (len < 0)
5511                 return len;
5512         *ctxlen = len;
5513         return 0;
5514 }
5515 #ifdef CONFIG_KEYS
5516
5517 static int selinux_key_alloc(struct key *k, const struct cred *cred,
5518                              unsigned long flags)
5519 {
5520         const struct task_security_struct *tsec;
5521         struct key_security_struct *ksec;
5522
5523         ksec = kzalloc(sizeof(struct key_security_struct), GFP_KERNEL);
5524         if (!ksec)
5525                 return -ENOMEM;
5526
5527         tsec = cred->security;
5528         if (tsec->keycreate_sid)
5529                 ksec->sid = tsec->keycreate_sid;
5530         else
5531                 ksec->sid = tsec->sid;
5532
5533         k->security = ksec;
5534         return 0;
5535 }
5536
5537 static void selinux_key_free(struct key *k)
5538 {
5539         struct key_security_struct *ksec = k->security;
5540
5541         k->security = NULL;
5542         kfree(ksec);
5543 }
5544
5545 static int selinux_key_permission(key_ref_t key_ref,
5546                                   const struct cred *cred,
5547                                   key_perm_t perm)
5548 {
5549         struct key *key;
5550         struct key_security_struct *ksec;
5551         u32 sid;
5552
5553         /* if no specific permissions are requested, we skip the
5554            permission check. No serious, additional covert channels
5555            appear to be created. */
5556         if (perm == 0)
5557                 return 0;
5558
5559         sid = cred_sid(cred);
5560
5561         key = key_ref_to_ptr(key_ref);
5562         ksec = key->security;
5563
5564         return avc_has_perm(sid, ksec->sid, SECCLASS_KEY, perm, NULL);
5565 }
5566
5567 static int selinux_key_getsecurity(struct key *key, char **_buffer)
5568 {
5569         struct key_security_struct *ksec = key->security;
5570         char *context = NULL;
5571         unsigned len;
5572         int rc;
5573
5574         rc = security_sid_to_context(ksec->sid, &context, &len);
5575         if (!rc)
5576                 rc = len;
5577         *_buffer = context;
5578         return rc;
5579 }
5580
5581 #endif
5582
5583 static struct security_operations selinux_ops = {
5584         .name =                         "selinux",
5585
5586         .ptrace_access_check =          selinux_ptrace_access_check,
5587         .ptrace_traceme =               selinux_ptrace_traceme,
5588         .capget =                       selinux_capget,
5589         .capset =                       selinux_capset,
5590         .capable =                      selinux_capable,
5591         .quotactl =                     selinux_quotactl,
5592         .quota_on =                     selinux_quota_on,
5593         .syslog =                       selinux_syslog,
5594         .vm_enough_memory =             selinux_vm_enough_memory,
5595
5596         .netlink_send =                 selinux_netlink_send,
5597
5598         .bprm_set_creds =               selinux_bprm_set_creds,
5599         .bprm_committing_creds =        selinux_bprm_committing_creds,
5600         .bprm_committed_creds =         selinux_bprm_committed_creds,
5601         .bprm_secureexec =              selinux_bprm_secureexec,
5602
5603         .sb_alloc_security =            selinux_sb_alloc_security,
5604         .sb_free_security =             selinux_sb_free_security,
5605         .sb_copy_data =                 selinux_sb_copy_data,
5606         .sb_remount =                   selinux_sb_remount,
5607         .sb_kern_mount =                selinux_sb_kern_mount,
5608         .sb_show_options =              selinux_sb_show_options,
5609         .sb_statfs =                    selinux_sb_statfs,
5610         .sb_mount =                     selinux_mount,
5611         .sb_umount =                    selinux_umount,
5612         .sb_set_mnt_opts =              selinux_set_mnt_opts,
5613         .sb_clone_mnt_opts =            selinux_sb_clone_mnt_opts,
5614         .sb_parse_opts_str =            selinux_parse_opts_str,
5615
5616
5617         .inode_alloc_security =         selinux_inode_alloc_security,
5618         .inode_free_security =          selinux_inode_free_security,
5619         .inode_init_security =          selinux_inode_init_security,
5620         .inode_create =                 selinux_inode_create,
5621         .inode_link =                   selinux_inode_link,
5622         .inode_unlink =                 selinux_inode_unlink,
5623         .inode_symlink =                selinux_inode_symlink,
5624         .inode_mkdir =                  selinux_inode_mkdir,
5625         .inode_rmdir =                  selinux_inode_rmdir,
5626         .inode_mknod =                  selinux_inode_mknod,
5627         .inode_rename =                 selinux_inode_rename,
5628         .inode_readlink =               selinux_inode_readlink,
5629         .inode_follow_link =            selinux_inode_follow_link,
5630         .inode_permission =             selinux_inode_permission,
5631         .inode_setattr =                selinux_inode_setattr,
5632         .inode_getattr =                selinux_inode_getattr,
5633         .inode_setxattr =               selinux_inode_setxattr,
5634         .inode_post_setxattr =          selinux_inode_post_setxattr,
5635         .inode_getxattr =               selinux_inode_getxattr,
5636         .inode_listxattr =              selinux_inode_listxattr,
5637         .inode_removexattr =            selinux_inode_removexattr,
5638         .inode_getsecurity =            selinux_inode_getsecurity,
5639         .inode_setsecurity =            selinux_inode_setsecurity,
5640         .inode_listsecurity =           selinux_inode_listsecurity,
5641         .inode_getsecid =               selinux_inode_getsecid,
5642
5643         .file_permission =              selinux_file_permission,
5644         .file_alloc_security =          selinux_file_alloc_security,
5645         .file_free_security =           selinux_file_free_security,
5646         .file_ioctl =                   selinux_file_ioctl,
5647         .file_mmap =                    selinux_file_mmap,
5648         .file_mprotect =                selinux_file_mprotect,
5649         .file_lock =                    selinux_file_lock,
5650         .file_fcntl =                   selinux_file_fcntl,
5651         .file_set_fowner =              selinux_file_set_fowner,
5652         .file_send_sigiotask =          selinux_file_send_sigiotask,
5653         .file_receive =                 selinux_file_receive,
5654
5655         .file_open =                    selinux_file_open,
5656
5657         .task_create =                  selinux_task_create,
5658         .cred_alloc_blank =             selinux_cred_alloc_blank,
5659         .cred_free =                    selinux_cred_free,
5660         .cred_prepare =                 selinux_cred_prepare,
5661         .cred_transfer =                selinux_cred_transfer,
5662         .kernel_act_as =                selinux_kernel_act_as,
5663         .kernel_create_files_as =       selinux_kernel_create_files_as,
5664         .kernel_module_request =        selinux_kernel_module_request,
5665         .task_setpgid =                 selinux_task_setpgid,
5666         .task_getpgid =                 selinux_task_getpgid,
5667         .task_getsid =                  selinux_task_getsid,
5668         .task_getsecid =                selinux_task_getsecid,
5669         .task_setnice =                 selinux_task_setnice,
5670         .task_setioprio =               selinux_task_setioprio,
5671         .task_getioprio =               selinux_task_getioprio,
5672         .task_setrlimit =               selinux_task_setrlimit,
5673         .task_setscheduler =            selinux_task_setscheduler,
5674         .task_getscheduler =            selinux_task_getscheduler,
5675         .task_movememory =              selinux_task_movememory,
5676         .task_kill =                    selinux_task_kill,
5677         .task_wait =                    selinux_task_wait,
5678         .task_to_inode =                selinux_task_to_inode,
5679
5680         .ipc_permission =               selinux_ipc_permission,
5681         .ipc_getsecid =                 selinux_ipc_getsecid,
5682
5683         .msg_msg_alloc_security =       selinux_msg_msg_alloc_security,
5684         .msg_msg_free_security =        selinux_msg_msg_free_security,
5685
5686         .msg_queue_alloc_security =     selinux_msg_queue_alloc_security,
5687         .msg_queue_free_security =      selinux_msg_queue_free_security,
5688         .msg_queue_associate =          selinux_msg_queue_associate,
5689         .msg_queue_msgctl =             selinux_msg_queue_msgctl,
5690         .msg_queue_msgsnd =             selinux_msg_queue_msgsnd,
5691         .msg_queue_msgrcv =             selinux_msg_queue_msgrcv,
5692
5693         .shm_alloc_security =           selinux_shm_alloc_security,
5694         .shm_free_security =            selinux_shm_free_security,
5695         .shm_associate =                selinux_shm_associate,
5696         .shm_shmctl =                   selinux_shm_shmctl,
5697         .shm_shmat =                    selinux_shm_shmat,
5698
5699         .sem_alloc_security =           selinux_sem_alloc_security,
5700         .sem_free_security =            selinux_sem_free_security,
5701         .sem_associate =                selinux_sem_associate,
5702         .sem_semctl =                   selinux_sem_semctl,
5703         .sem_semop =                    selinux_sem_semop,
5704
5705         .d_instantiate =                selinux_d_instantiate,
5706
5707         .getprocattr =                  selinux_getprocattr,
5708         .setprocattr =                  selinux_setprocattr,
5709
5710         .secid_to_secctx =              selinux_secid_to_secctx,
5711         .secctx_to_secid =              selinux_secctx_to_secid,
5712         .release_secctx =               selinux_release_secctx,
5713         .inode_notifysecctx =           selinux_inode_notifysecctx,
5714         .inode_setsecctx =              selinux_inode_setsecctx,
5715         .inode_getsecctx =              selinux_inode_getsecctx,
5716
5717         .unix_stream_connect =          selinux_socket_unix_stream_connect,
5718         .unix_may_send =                selinux_socket_unix_may_send,
5719
5720         .socket_create =                selinux_socket_create,
5721         .socket_post_create =           selinux_socket_post_create,
5722         .socket_bind =                  selinux_socket_bind,
5723         .socket_connect =               selinux_socket_connect,
5724         .socket_listen =                selinux_socket_listen,
5725         .socket_accept =                selinux_socket_accept,
5726         .socket_sendmsg =               selinux_socket_sendmsg,
5727         .socket_recvmsg =               selinux_socket_recvmsg,
5728         .socket_getsockname =           selinux_socket_getsockname,
5729         .socket_getpeername =           selinux_socket_getpeername,
5730         .socket_getsockopt =            selinux_socket_getsockopt,
5731         .socket_setsockopt =            selinux_socket_setsockopt,
5732         .socket_shutdown =              selinux_socket_shutdown,
5733         .socket_sock_rcv_skb =          selinux_socket_sock_rcv_skb,
5734         .socket_getpeersec_stream =     selinux_socket_getpeersec_stream,
5735         .socket_getpeersec_dgram =      selinux_socket_getpeersec_dgram,
5736         .sk_alloc_security =            selinux_sk_alloc_security,
5737         .sk_free_security =             selinux_sk_free_security,
5738         .sk_clone_security =            selinux_sk_clone_security,
5739         .sk_getsecid =                  selinux_sk_getsecid,
5740         .sock_graft =                   selinux_sock_graft,
5741         .inet_conn_request =            selinux_inet_conn_request,
5742         .inet_csk_clone =               selinux_inet_csk_clone,
5743         .inet_conn_established =        selinux_inet_conn_established,
5744         .secmark_relabel_packet =       selinux_secmark_relabel_packet,
5745         .secmark_refcount_inc =         selinux_secmark_refcount_inc,
5746         .secmark_refcount_dec =         selinux_secmark_refcount_dec,
5747         .req_classify_flow =            selinux_req_classify_flow,
5748         .tun_dev_create =               selinux_tun_dev_create,
5749         .tun_dev_post_create =          selinux_tun_dev_post_create,
5750         .tun_dev_attach =               selinux_tun_dev_attach,
5751
5752 #ifdef CONFIG_SECURITY_NETWORK_XFRM
5753         .xfrm_policy_alloc_security =   selinux_xfrm_policy_alloc,
5754         .xfrm_policy_clone_security =   selinux_xfrm_policy_clone,
5755         .xfrm_policy_free_security =    selinux_xfrm_policy_free,
5756         .xfrm_policy_delete_security =  selinux_xfrm_policy_delete,
5757         .xfrm_state_alloc_security =    selinux_xfrm_state_alloc,
5758         .xfrm_state_free_security =     selinux_xfrm_state_free,
5759         .xfrm_state_delete_security =   selinux_xfrm_state_delete,
5760         .xfrm_policy_lookup =           selinux_xfrm_policy_lookup,
5761         .xfrm_state_pol_flow_match =    selinux_xfrm_state_pol_flow_match,
5762         .xfrm_decode_session =          selinux_xfrm_decode_session,
5763 #endif
5764
5765 #ifdef CONFIG_KEYS
5766         .key_alloc =                    selinux_key_alloc,
5767         .key_free =                     selinux_key_free,
5768         .key_permission =               selinux_key_permission,
5769         .key_getsecurity =              selinux_key_getsecurity,
5770 #endif
5771
5772 #ifdef CONFIG_AUDIT
5773         .audit_rule_init =              selinux_audit_rule_init,
5774         .audit_rule_known =             selinux_audit_rule_known,
5775         .audit_rule_match =             selinux_audit_rule_match,
5776         .audit_rule_free =              selinux_audit_rule_free,
5777 #endif
5778 };
5779
5780 static __init int selinux_init(void)
5781 {
5782         if (!security_module_enable(&selinux_ops)) {
5783                 selinux_enabled = 0;
5784                 return 0;
5785         }
5786
5787         if (!selinux_enabled) {
5788                 printk(KERN_INFO "SELinux:  Disabled at boot.\n");
5789                 return 0;
5790         }
5791
5792         printk(KERN_INFO "SELinux:  Initializing.\n");
5793
5794         /* Set the security state for the initial task. */
5795         cred_init_security();
5796
5797         default_noexec = !(VM_DATA_DEFAULT_FLAGS & VM_EXEC);
5798
5799         sel_inode_cache = kmem_cache_create("selinux_inode_security",
5800                                             sizeof(struct inode_security_struct),
5801                                             0, SLAB_PANIC, NULL);
5802         avc_init();
5803
5804         if (register_security(&selinux_ops))
5805                 panic("SELinux: Unable to register with kernel.\n");
5806
5807         if (selinux_enforcing)
5808                 printk(KERN_DEBUG "SELinux:  Starting in enforcing mode\n");
5809         else
5810                 printk(KERN_DEBUG "SELinux:  Starting in permissive mode\n");
5811
5812         return 0;
5813 }
5814
5815 static void delayed_superblock_init(struct super_block *sb, void *unused)
5816 {
5817         superblock_doinit(sb, NULL);
5818 }
5819
5820 void selinux_complete_init(void)
5821 {
5822         printk(KERN_DEBUG "SELinux:  Completing initialization.\n");
5823
5824         /* Set up any superblocks initialized prior to the policy load. */
5825         printk(KERN_DEBUG "SELinux:  Setting up existing superblocks.\n");
5826         iterate_supers(delayed_superblock_init, NULL);
5827 }
5828
5829 /* SELinux requires early initialization in order to label
5830    all processes and objects when they are created. */
5831 security_initcall(selinux_init);
5832
5833 #if defined(CONFIG_NETFILTER)
5834
5835 static struct nf_hook_ops selinux_ipv4_ops[] = {
5836         {
5837                 .hook =         selinux_ipv4_postroute,
5838                 .owner =        THIS_MODULE,
5839                 .pf =           PF_INET,
5840                 .hooknum =      NF_INET_POST_ROUTING,
5841                 .priority =     NF_IP_PRI_SELINUX_LAST,
5842         },
5843         {
5844                 .hook =         selinux_ipv4_forward,
5845                 .owner =        THIS_MODULE,
5846                 .pf =           PF_INET,
5847                 .hooknum =      NF_INET_FORWARD,
5848                 .priority =     NF_IP_PRI_SELINUX_FIRST,
5849         },
5850         {
5851                 .hook =         selinux_ipv4_output,
5852                 .owner =        THIS_MODULE,
5853                 .pf =           PF_INET,
5854                 .hooknum =      NF_INET_LOCAL_OUT,
5855                 .priority =     NF_IP_PRI_SELINUX_FIRST,
5856         }
5857 };
5858
5859 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
5860
5861 static struct nf_hook_ops selinux_ipv6_ops[] = {
5862         {
5863                 .hook =         selinux_ipv6_postroute,
5864                 .owner =        THIS_MODULE,
5865                 .pf =           PF_INET6,
5866                 .hooknum =      NF_INET_POST_ROUTING,
5867                 .priority =     NF_IP6_PRI_SELINUX_LAST,
5868         },
5869         {
5870                 .hook =         selinux_ipv6_forward,
5871                 .owner =        THIS_MODULE,
5872                 .pf =           PF_INET6,
5873                 .hooknum =      NF_INET_FORWARD,
5874                 .priority =     NF_IP6_PRI_SELINUX_FIRST,
5875         }
5876 };
5877
5878 #endif  /* IPV6 */
5879
5880 static int __init selinux_nf_ip_init(void)
5881 {
5882         int err = 0;
5883
5884         if (!selinux_enabled)
5885                 goto out;
5886
5887         printk(KERN_DEBUG "SELinux:  Registering netfilter hooks\n");
5888
5889         err = nf_register_hooks(selinux_ipv4_ops, ARRAY_SIZE(selinux_ipv4_ops));
5890         if (err)
5891                 panic("SELinux: nf_register_hooks for IPv4: error %d\n", err);
5892
5893 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
5894         err = nf_register_hooks(selinux_ipv6_ops, ARRAY_SIZE(selinux_ipv6_ops));
5895         if (err)
5896                 panic("SELinux: nf_register_hooks for IPv6: error %d\n", err);
5897 #endif  /* IPV6 */
5898
5899 out:
5900         return err;
5901 }
5902
5903 __initcall(selinux_nf_ip_init);
5904
5905 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
5906 static void selinux_nf_ip_exit(void)
5907 {
5908         printk(KERN_DEBUG "SELinux:  Unregistering netfilter hooks\n");
5909
5910         nf_unregister_hooks(selinux_ipv4_ops, ARRAY_SIZE(selinux_ipv4_ops));
5911 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
5912         nf_unregister_hooks(selinux_ipv6_ops, ARRAY_SIZE(selinux_ipv6_ops));
5913 #endif  /* IPV6 */
5914 }
5915 #endif
5916
5917 #else /* CONFIG_NETFILTER */
5918
5919 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
5920 #define selinux_nf_ip_exit()
5921 #endif
5922
5923 #endif /* CONFIG_NETFILTER */
5924
5925 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
5926 static int selinux_disabled;
5927
5928 int selinux_disable(void)
5929 {
5930         if (ss_initialized) {
5931                 /* Not permitted after initial policy load. */
5932                 return -EINVAL;
5933         }
5934
5935         if (selinux_disabled) {
5936                 /* Only do this once. */
5937                 return -EINVAL;
5938         }
5939
5940         printk(KERN_INFO "SELinux:  Disabled at runtime.\n");
5941
5942         selinux_disabled = 1;
5943         selinux_enabled = 0;
5944
5945         reset_security_ops();
5946
5947         /* Try to destroy the avc node cache */
5948         avc_disable();
5949
5950         /* Unregister netfilter hooks. */
5951         selinux_nf_ip_exit();
5952
5953         /* Unregister selinuxfs. */
5954         exit_sel_fs();
5955
5956         return 0;
5957 }
5958 #endif