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
2688         from_access = mask & MAY_ACCESS;
2689         mask &= (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND);
2690
2691         /* No permission to check.  Existence test. */
2692         if (!mask)
2693                 return 0;
2694
2695         COMMON_AUDIT_DATA_INIT(&ad, INODE);
2696         ad.selinux_audit_data = &sad;
2697         ad.u.inode = inode;
2698
2699         if (from_access)
2700                 ad.selinux_audit_data->auditdeny |= FILE__AUDIT_ACCESS;
2701
2702         perms = file_mask_to_av(inode->i_mode, mask);
2703
2704         return inode_has_perm(cred, inode, perms, &ad, flags);
2705 }
2706
2707 static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr)
2708 {
2709         const struct cred *cred = current_cred();
2710         unsigned int ia_valid = iattr->ia_valid;
2711
2712         /* ATTR_FORCE is just used for ATTR_KILL_S[UG]ID. */
2713         if (ia_valid & ATTR_FORCE) {
2714                 ia_valid &= ~(ATTR_KILL_SUID | ATTR_KILL_SGID | ATTR_MODE |
2715                               ATTR_FORCE);
2716                 if (!ia_valid)
2717                         return 0;
2718         }
2719
2720         if (ia_valid & (ATTR_MODE | ATTR_UID | ATTR_GID |
2721                         ATTR_ATIME_SET | ATTR_MTIME_SET | ATTR_TIMES_SET))
2722                 return dentry_has_perm(cred, dentry, FILE__SETATTR);
2723
2724         return dentry_has_perm(cred, dentry, FILE__WRITE);
2725 }
2726
2727 static int selinux_inode_getattr(struct vfsmount *mnt, struct dentry *dentry)
2728 {
2729         const struct cred *cred = current_cred();
2730         struct path path;
2731
2732         path.dentry = dentry;
2733         path.mnt = mnt;
2734
2735         return path_has_perm(cred, &path, FILE__GETATTR);
2736 }
2737
2738 static int selinux_inode_setotherxattr(struct dentry *dentry, const char *name)
2739 {
2740         const struct cred *cred = current_cred();
2741
2742         if (!strncmp(name, XATTR_SECURITY_PREFIX,
2743                      sizeof XATTR_SECURITY_PREFIX - 1)) {
2744                 if (!strcmp(name, XATTR_NAME_CAPS)) {
2745                         if (!capable(CAP_SETFCAP))
2746                                 return -EPERM;
2747                 } else if (!capable(CAP_SYS_ADMIN)) {
2748                         /* A different attribute in the security namespace.
2749                            Restrict to administrator. */
2750                         return -EPERM;
2751                 }
2752         }
2753
2754         /* Not an attribute we recognize, so just check the
2755            ordinary setattr permission. */
2756         return dentry_has_perm(cred, dentry, FILE__SETATTR);
2757 }
2758
2759 static int selinux_inode_setxattr(struct dentry *dentry, const char *name,
2760                                   const void *value, size_t size, int flags)
2761 {
2762         struct inode *inode = dentry->d_inode;
2763         struct inode_security_struct *isec = inode->i_security;
2764         struct superblock_security_struct *sbsec;
2765         struct common_audit_data ad;
2766         struct selinux_audit_data sad = {0,};
2767         u32 newsid, sid = current_sid();
2768         int rc = 0;
2769
2770         if (strcmp(name, XATTR_NAME_SELINUX))
2771                 return selinux_inode_setotherxattr(dentry, name);
2772
2773         sbsec = inode->i_sb->s_security;
2774         if (!(sbsec->flags & SE_SBLABELSUPP))
2775                 return -EOPNOTSUPP;
2776
2777         if (!inode_owner_or_capable(inode))
2778                 return -EPERM;
2779
2780         COMMON_AUDIT_DATA_INIT(&ad, DENTRY);
2781         ad.selinux_audit_data = &sad;
2782         ad.u.dentry = dentry;
2783
2784         rc = avc_has_perm(sid, isec->sid, isec->sclass,
2785                           FILE__RELABELFROM, &ad);
2786         if (rc)
2787                 return rc;
2788
2789         rc = security_context_to_sid(value, size, &newsid);
2790         if (rc == -EINVAL) {
2791                 if (!capable(CAP_MAC_ADMIN))
2792                         return rc;
2793                 rc = security_context_to_sid_force(value, size, &newsid);
2794         }
2795         if (rc)
2796                 return rc;
2797
2798         rc = avc_has_perm(sid, newsid, isec->sclass,
2799                           FILE__RELABELTO, &ad);
2800         if (rc)
2801                 return rc;
2802
2803         rc = security_validate_transition(isec->sid, newsid, sid,
2804                                           isec->sclass);
2805         if (rc)
2806                 return rc;
2807
2808         return avc_has_perm(newsid,
2809                             sbsec->sid,
2810                             SECCLASS_FILESYSTEM,
2811                             FILESYSTEM__ASSOCIATE,
2812                             &ad);
2813 }
2814
2815 static void selinux_inode_post_setxattr(struct dentry *dentry, const char *name,
2816                                         const void *value, size_t size,
2817                                         int flags)
2818 {
2819         struct inode *inode = dentry->d_inode;
2820         struct inode_security_struct *isec = inode->i_security;
2821         u32 newsid;
2822         int rc;
2823
2824         if (strcmp(name, XATTR_NAME_SELINUX)) {
2825                 /* Not an attribute we recognize, so nothing to do. */
2826                 return;
2827         }
2828
2829         rc = security_context_to_sid_force(value, size, &newsid);
2830         if (rc) {
2831                 printk(KERN_ERR "SELinux:  unable to map context to SID"
2832                        "for (%s, %lu), rc=%d\n",
2833                        inode->i_sb->s_id, inode->i_ino, -rc);
2834                 return;
2835         }
2836
2837         isec->sid = newsid;
2838         return;
2839 }
2840
2841 static int selinux_inode_getxattr(struct dentry *dentry, const char *name)
2842 {
2843         const struct cred *cred = current_cred();
2844
2845         return dentry_has_perm(cred, dentry, FILE__GETATTR);
2846 }
2847
2848 static int selinux_inode_listxattr(struct dentry *dentry)
2849 {
2850         const struct cred *cred = current_cred();
2851
2852         return dentry_has_perm(cred, dentry, FILE__GETATTR);
2853 }
2854
2855 static int selinux_inode_removexattr(struct dentry *dentry, const char *name)
2856 {
2857         if (strcmp(name, XATTR_NAME_SELINUX))
2858                 return selinux_inode_setotherxattr(dentry, name);
2859
2860         /* No one is allowed to remove a SELinux security label.
2861            You can change the label, but all data must be labeled. */
2862         return -EACCES;
2863 }
2864
2865 /*
2866  * Copy the inode security context value to the user.
2867  *
2868  * Permission check is handled by selinux_inode_getxattr hook.
2869  */
2870 static int selinux_inode_getsecurity(const struct inode *inode, const char *name, void **buffer, bool alloc)
2871 {
2872         u32 size;
2873         int error;
2874         char *context = NULL;
2875         struct inode_security_struct *isec = inode->i_security;
2876
2877         if (strcmp(name, XATTR_SELINUX_SUFFIX))
2878                 return -EOPNOTSUPP;
2879
2880         /*
2881          * If the caller has CAP_MAC_ADMIN, then get the raw context
2882          * value even if it is not defined by current policy; otherwise,
2883          * use the in-core value under current policy.
2884          * Use the non-auditing forms of the permission checks since
2885          * getxattr may be called by unprivileged processes commonly
2886          * and lack of permission just means that we fall back to the
2887          * in-core context value, not a denial.
2888          */
2889         error = selinux_capable(current_cred(), &init_user_ns, CAP_MAC_ADMIN,
2890                                 SECURITY_CAP_NOAUDIT);
2891         if (!error)
2892                 error = security_sid_to_context_force(isec->sid, &context,
2893                                                       &size);
2894         else
2895                 error = security_sid_to_context(isec->sid, &context, &size);
2896         if (error)
2897                 return error;
2898         error = size;
2899         if (alloc) {
2900                 *buffer = context;
2901                 goto out_nofree;
2902         }
2903         kfree(context);
2904 out_nofree:
2905         return error;
2906 }
2907
2908 static int selinux_inode_setsecurity(struct inode *inode, const char *name,
2909                                      const void *value, size_t size, int flags)
2910 {
2911         struct inode_security_struct *isec = inode->i_security;
2912         u32 newsid;
2913         int rc;
2914
2915         if (strcmp(name, XATTR_SELINUX_SUFFIX))
2916                 return -EOPNOTSUPP;
2917
2918         if (!value || !size)
2919                 return -EACCES;
2920
2921         rc = security_context_to_sid((void *)value, size, &newsid);
2922         if (rc)
2923                 return rc;
2924
2925         isec->sid = newsid;
2926         isec->initialized = 1;
2927         return 0;
2928 }
2929
2930 static int selinux_inode_listsecurity(struct inode *inode, char *buffer, size_t buffer_size)
2931 {
2932         const int len = sizeof(XATTR_NAME_SELINUX);
2933         if (buffer && len <= buffer_size)
2934                 memcpy(buffer, XATTR_NAME_SELINUX, len);
2935         return len;
2936 }
2937
2938 static void selinux_inode_getsecid(const struct inode *inode, u32 *secid)
2939 {
2940         struct inode_security_struct *isec = inode->i_security;
2941         *secid = isec->sid;
2942 }
2943
2944 /* file security operations */
2945
2946 static int selinux_revalidate_file_permission(struct file *file, int mask)
2947 {
2948         const struct cred *cred = current_cred();
2949         struct inode *inode = file->f_path.dentry->d_inode;
2950
2951         /* file_mask_to_av won't add FILE__WRITE if MAY_APPEND is set */
2952         if ((file->f_flags & O_APPEND) && (mask & MAY_WRITE))
2953                 mask |= MAY_APPEND;
2954
2955         return file_has_perm(cred, file,
2956                              file_mask_to_av(inode->i_mode, mask));
2957 }
2958
2959 static int selinux_file_permission(struct file *file, int mask)
2960 {
2961         struct inode *inode = file->f_path.dentry->d_inode;
2962         struct file_security_struct *fsec = file->f_security;
2963         struct inode_security_struct *isec = inode->i_security;
2964         u32 sid = current_sid();
2965
2966         if (!mask)
2967                 /* No permission to check.  Existence test. */
2968                 return 0;
2969
2970         if (sid == fsec->sid && fsec->isid == isec->sid &&
2971             fsec->pseqno == avc_policy_seqno())
2972                 /* No change since dentry_open check. */
2973                 return 0;
2974
2975         return selinux_revalidate_file_permission(file, mask);
2976 }
2977
2978 static int selinux_file_alloc_security(struct file *file)
2979 {
2980         return file_alloc_security(file);
2981 }
2982
2983 static void selinux_file_free_security(struct file *file)
2984 {
2985         file_free_security(file);
2986 }
2987
2988 static int selinux_file_ioctl(struct file *file, unsigned int cmd,
2989                               unsigned long arg)
2990 {
2991         const struct cred *cred = current_cred();
2992         int error = 0;
2993
2994         switch (cmd) {
2995         case FIONREAD:
2996         /* fall through */
2997         case FIBMAP:
2998         /* fall through */
2999         case FIGETBSZ:
3000         /* fall through */
3001         case FS_IOC_GETFLAGS:
3002         /* fall through */
3003         case FS_IOC_GETVERSION:
3004                 error = file_has_perm(cred, file, FILE__GETATTR);
3005                 break;
3006
3007         case FS_IOC_SETFLAGS:
3008         /* fall through */
3009         case FS_IOC_SETVERSION:
3010                 error = file_has_perm(cred, file, FILE__SETATTR);
3011                 break;
3012
3013         /* sys_ioctl() checks */
3014         case FIONBIO:
3015         /* fall through */
3016         case FIOASYNC:
3017                 error = file_has_perm(cred, file, 0);
3018                 break;
3019
3020         case KDSKBENT:
3021         case KDSKBSENT:
3022                 error = cred_has_capability(cred, CAP_SYS_TTY_CONFIG,
3023                                             SECURITY_CAP_AUDIT);
3024                 break;
3025
3026         /* default case assumes that the command will go
3027          * to the file's ioctl() function.
3028          */
3029         default:
3030                 error = file_has_perm(cred, file, FILE__IOCTL);
3031         }
3032         return error;
3033 }
3034
3035 static int default_noexec;
3036
3037 static int file_map_prot_check(struct file *file, unsigned long prot, int shared)
3038 {
3039         const struct cred *cred = current_cred();
3040         int rc = 0;
3041
3042         if (default_noexec &&
3043             (prot & PROT_EXEC) && (!file || (!shared && (prot & PROT_WRITE)))) {
3044                 /*
3045                  * We are making executable an anonymous mapping or a
3046                  * private file mapping that will also be writable.
3047                  * This has an additional check.
3048                  */
3049                 rc = cred_has_perm(cred, cred, PROCESS__EXECMEM);
3050                 if (rc)
3051                         goto error;
3052         }
3053
3054         if (file) {
3055                 /* read access is always possible with a mapping */
3056                 u32 av = FILE__READ;
3057
3058                 /* write access only matters if the mapping is shared */
3059                 if (shared && (prot & PROT_WRITE))
3060                         av |= FILE__WRITE;
3061
3062                 if (prot & PROT_EXEC)
3063                         av |= FILE__EXECUTE;
3064
3065                 return file_has_perm(cred, file, av);
3066         }
3067
3068 error:
3069         return rc;
3070 }
3071
3072 static int selinux_file_mmap(struct file *file, unsigned long reqprot,
3073                              unsigned long prot, unsigned long flags,
3074                              unsigned long addr, unsigned long addr_only)
3075 {
3076         int rc = 0;
3077         u32 sid = current_sid();
3078
3079         /*
3080          * notice that we are intentionally putting the SELinux check before
3081          * the secondary cap_file_mmap check.  This is such a likely attempt
3082          * at bad behaviour/exploit that we always want to get the AVC, even
3083          * if DAC would have also denied the operation.
3084          */
3085         if (addr < CONFIG_LSM_MMAP_MIN_ADDR) {
3086                 rc = avc_has_perm(sid, sid, SECCLASS_MEMPROTECT,
3087                                   MEMPROTECT__MMAP_ZERO, NULL);
3088                 if (rc)
3089                         return rc;
3090         }
3091
3092         /* do DAC check on address space usage */
3093         rc = cap_file_mmap(file, reqprot, prot, flags, addr, addr_only);
3094         if (rc || addr_only)
3095                 return rc;
3096
3097         if (selinux_checkreqprot)
3098                 prot = reqprot;
3099
3100         return file_map_prot_check(file, prot,
3101                                    (flags & MAP_TYPE) == MAP_SHARED);
3102 }
3103
3104 static int selinux_file_mprotect(struct vm_area_struct *vma,
3105                                  unsigned long reqprot,
3106                                  unsigned long prot)
3107 {
3108         const struct cred *cred = current_cred();
3109
3110         if (selinux_checkreqprot)
3111                 prot = reqprot;
3112
3113         if (default_noexec &&
3114             (prot & PROT_EXEC) && !(vma->vm_flags & VM_EXEC)) {
3115                 int rc = 0;
3116                 if (vma->vm_start >= vma->vm_mm->start_brk &&
3117                     vma->vm_end <= vma->vm_mm->brk) {
3118                         rc = cred_has_perm(cred, cred, PROCESS__EXECHEAP);
3119                 } else if (!vma->vm_file &&
3120                            vma->vm_start <= vma->vm_mm->start_stack &&
3121                            vma->vm_end >= vma->vm_mm->start_stack) {
3122                         rc = current_has_perm(current, PROCESS__EXECSTACK);
3123                 } else if (vma->vm_file && vma->anon_vma) {
3124                         /*
3125                          * We are making executable a file mapping that has
3126                          * had some COW done. Since pages might have been
3127                          * written, check ability to execute the possibly
3128                          * modified content.  This typically should only
3129                          * occur for text relocations.
3130                          */
3131                         rc = file_has_perm(cred, vma->vm_file, FILE__EXECMOD);
3132                 }
3133                 if (rc)
3134                         return rc;
3135         }
3136
3137         return file_map_prot_check(vma->vm_file, prot, vma->vm_flags&VM_SHARED);
3138 }
3139
3140 static int selinux_file_lock(struct file *file, unsigned int cmd)
3141 {
3142         const struct cred *cred = current_cred();
3143
3144         return file_has_perm(cred, file, FILE__LOCK);
3145 }
3146
3147 static int selinux_file_fcntl(struct file *file, unsigned int cmd,
3148                               unsigned long arg)
3149 {
3150         const struct cred *cred = current_cred();
3151         int err = 0;
3152
3153         switch (cmd) {
3154         case F_SETFL:
3155                 if (!file->f_path.dentry || !file->f_path.dentry->d_inode) {
3156                         err = -EINVAL;
3157                         break;
3158                 }
3159
3160                 if ((file->f_flags & O_APPEND) && !(arg & O_APPEND)) {
3161                         err = file_has_perm(cred, file, FILE__WRITE);
3162                         break;
3163                 }
3164                 /* fall through */
3165         case F_SETOWN:
3166         case F_SETSIG:
3167         case F_GETFL:
3168         case F_GETOWN:
3169         case F_GETSIG:
3170                 /* Just check FD__USE permission */
3171                 err = file_has_perm(cred, file, 0);
3172                 break;
3173         case F_GETLK:
3174         case F_SETLK:
3175         case F_SETLKW:
3176 #if BITS_PER_LONG == 32
3177         case F_GETLK64:
3178         case F_SETLK64:
3179         case F_SETLKW64:
3180 #endif
3181                 if (!file->f_path.dentry || !file->f_path.dentry->d_inode) {
3182                         err = -EINVAL;
3183                         break;
3184                 }
3185                 err = file_has_perm(cred, file, FILE__LOCK);
3186                 break;
3187         }
3188
3189         return err;
3190 }
3191
3192 static int selinux_file_set_fowner(struct file *file)
3193 {
3194         struct file_security_struct *fsec;
3195
3196         fsec = file->f_security;
3197         fsec->fown_sid = current_sid();
3198
3199         return 0;
3200 }
3201
3202 static int selinux_file_send_sigiotask(struct task_struct *tsk,
3203                                        struct fown_struct *fown, int signum)
3204 {
3205         struct file *file;
3206         u32 sid = task_sid(tsk);
3207         u32 perm;
3208         struct file_security_struct *fsec;
3209
3210         /* struct fown_struct is never outside the context of a struct file */
3211         file = container_of(fown, struct file, f_owner);
3212
3213         fsec = file->f_security;
3214
3215         if (!signum)
3216                 perm = signal_to_av(SIGIO); /* as per send_sigio_to_task */
3217         else
3218                 perm = signal_to_av(signum);
3219
3220         return avc_has_perm(fsec->fown_sid, sid,
3221                             SECCLASS_PROCESS, perm, NULL);
3222 }
3223
3224 static int selinux_file_receive(struct file *file)
3225 {
3226         const struct cred *cred = current_cred();
3227
3228         return file_has_perm(cred, file, file_to_av(file));
3229 }
3230
3231 static int selinux_dentry_open(struct file *file, const struct cred *cred)
3232 {
3233         struct file_security_struct *fsec;
3234         struct inode *inode;
3235         struct inode_security_struct *isec;
3236
3237         inode = file->f_path.dentry->d_inode;
3238         fsec = file->f_security;
3239         isec = inode->i_security;
3240         /*
3241          * Save inode label and policy sequence number
3242          * at open-time so that selinux_file_permission
3243          * can determine whether revalidation is necessary.
3244          * Task label is already saved in the file security
3245          * struct as its SID.
3246          */
3247         fsec->isid = isec->sid;
3248         fsec->pseqno = avc_policy_seqno();
3249         /*
3250          * Since the inode label or policy seqno may have changed
3251          * between the selinux_inode_permission check and the saving
3252          * of state above, recheck that access is still permitted.
3253          * Otherwise, access might never be revalidated against the
3254          * new inode label or new policy.
3255          * This check is not redundant - do not remove.
3256          */
3257         return inode_has_perm_noadp(cred, inode, open_file_to_av(file), 0);
3258 }
3259
3260 /* task security operations */
3261
3262 static int selinux_task_create(unsigned long clone_flags)
3263 {
3264         return current_has_perm(current, PROCESS__FORK);
3265 }
3266
3267 /*
3268  * allocate the SELinux part of blank credentials
3269  */
3270 static int selinux_cred_alloc_blank(struct cred *cred, gfp_t gfp)
3271 {
3272         struct task_security_struct *tsec;
3273
3274         tsec = kzalloc(sizeof(struct task_security_struct), gfp);
3275         if (!tsec)
3276                 return -ENOMEM;
3277
3278         cred->security = tsec;
3279         return 0;
3280 }
3281
3282 /*
3283  * detach and free the LSM part of a set of credentials
3284  */
3285 static void selinux_cred_free(struct cred *cred)
3286 {
3287         struct task_security_struct *tsec = cred->security;
3288
3289         /*
3290          * cred->security == NULL if security_cred_alloc_blank() or
3291          * security_prepare_creds() returned an error.
3292          */
3293         BUG_ON(cred->security && (unsigned long) cred->security < PAGE_SIZE);
3294         cred->security = (void *) 0x7UL;
3295         kfree(tsec);
3296 }
3297
3298 /*
3299  * prepare a new set of credentials for modification
3300  */
3301 static int selinux_cred_prepare(struct cred *new, const struct cred *old,
3302                                 gfp_t gfp)
3303 {
3304         const struct task_security_struct *old_tsec;
3305         struct task_security_struct *tsec;
3306
3307         old_tsec = old->security;
3308
3309         tsec = kmemdup(old_tsec, sizeof(struct task_security_struct), gfp);
3310         if (!tsec)
3311                 return -ENOMEM;
3312
3313         new->security = tsec;
3314         return 0;
3315 }
3316
3317 /*
3318  * transfer the SELinux data to a blank set of creds
3319  */
3320 static void selinux_cred_transfer(struct cred *new, const struct cred *old)
3321 {
3322         const struct task_security_struct *old_tsec = old->security;
3323         struct task_security_struct *tsec = new->security;
3324
3325         *tsec = *old_tsec;
3326 }
3327
3328 /*
3329  * set the security data for a kernel service
3330  * - all the creation contexts are set to unlabelled
3331  */
3332 static int selinux_kernel_act_as(struct cred *new, u32 secid)
3333 {
3334         struct task_security_struct *tsec = new->security;
3335         u32 sid = current_sid();
3336         int ret;
3337
3338         ret = avc_has_perm(sid, secid,
3339                            SECCLASS_KERNEL_SERVICE,
3340                            KERNEL_SERVICE__USE_AS_OVERRIDE,
3341                            NULL);
3342         if (ret == 0) {
3343                 tsec->sid = secid;
3344                 tsec->create_sid = 0;
3345                 tsec->keycreate_sid = 0;
3346                 tsec->sockcreate_sid = 0;
3347         }
3348         return ret;
3349 }
3350
3351 /*
3352  * set the file creation context in a security record to the same as the
3353  * objective context of the specified inode
3354  */
3355 static int selinux_kernel_create_files_as(struct cred *new, struct inode *inode)
3356 {
3357         struct inode_security_struct *isec = inode->i_security;
3358         struct task_security_struct *tsec = new->security;
3359         u32 sid = current_sid();
3360         int ret;
3361
3362         ret = avc_has_perm(sid, isec->sid,
3363                            SECCLASS_KERNEL_SERVICE,
3364                            KERNEL_SERVICE__CREATE_FILES_AS,
3365                            NULL);
3366
3367         if (ret == 0)
3368                 tsec->create_sid = isec->sid;
3369         return ret;
3370 }
3371
3372 static int selinux_kernel_module_request(char *kmod_name)
3373 {
3374         u32 sid;
3375         struct common_audit_data ad;
3376         struct selinux_audit_data sad = {0,};
3377
3378         sid = task_sid(current);
3379
3380         COMMON_AUDIT_DATA_INIT(&ad, KMOD);
3381         ad.selinux_audit_data = &sad;
3382         ad.u.kmod_name = kmod_name;
3383
3384         return avc_has_perm(sid, SECINITSID_KERNEL, SECCLASS_SYSTEM,
3385                             SYSTEM__MODULE_REQUEST, &ad);
3386 }
3387
3388 static int selinux_task_setpgid(struct task_struct *p, pid_t pgid)
3389 {
3390         return current_has_perm(p, PROCESS__SETPGID);
3391 }
3392
3393 static int selinux_task_getpgid(struct task_struct *p)
3394 {
3395         return current_has_perm(p, PROCESS__GETPGID);
3396 }
3397
3398 static int selinux_task_getsid(struct task_struct *p)
3399 {
3400         return current_has_perm(p, PROCESS__GETSESSION);
3401 }
3402
3403 static void selinux_task_getsecid(struct task_struct *p, u32 *secid)
3404 {
3405         *secid = task_sid(p);
3406 }
3407
3408 static int selinux_task_setnice(struct task_struct *p, int nice)
3409 {
3410         int rc;
3411
3412         rc = cap_task_setnice(p, nice);
3413         if (rc)
3414                 return rc;
3415
3416         return current_has_perm(p, PROCESS__SETSCHED);
3417 }
3418
3419 static int selinux_task_setioprio(struct task_struct *p, int ioprio)
3420 {
3421         int rc;
3422
3423         rc = cap_task_setioprio(p, ioprio);
3424         if (rc)
3425                 return rc;
3426
3427         return current_has_perm(p, PROCESS__SETSCHED);
3428 }
3429
3430 static int selinux_task_getioprio(struct task_struct *p)
3431 {
3432         return current_has_perm(p, PROCESS__GETSCHED);
3433 }
3434
3435 static int selinux_task_setrlimit(struct task_struct *p, unsigned int resource,
3436                 struct rlimit *new_rlim)
3437 {
3438         struct rlimit *old_rlim = p->signal->rlim + resource;
3439
3440         /* Control the ability to change the hard limit (whether
3441            lowering or raising it), so that the hard limit can
3442            later be used as a safe reset point for the soft limit
3443            upon context transitions.  See selinux_bprm_committing_creds. */
3444         if (old_rlim->rlim_max != new_rlim->rlim_max)
3445                 return current_has_perm(p, PROCESS__SETRLIMIT);
3446
3447         return 0;
3448 }
3449
3450 static int selinux_task_setscheduler(struct task_struct *p)
3451 {
3452         int rc;
3453
3454         rc = cap_task_setscheduler(p);
3455         if (rc)
3456                 return rc;
3457
3458         return current_has_perm(p, PROCESS__SETSCHED);
3459 }
3460
3461 static int selinux_task_getscheduler(struct task_struct *p)
3462 {
3463         return current_has_perm(p, PROCESS__GETSCHED);
3464 }
3465
3466 static int selinux_task_movememory(struct task_struct *p)
3467 {
3468         return current_has_perm(p, PROCESS__SETSCHED);
3469 }
3470
3471 static int selinux_task_kill(struct task_struct *p, struct siginfo *info,
3472                                 int sig, u32 secid)
3473 {
3474         u32 perm;
3475         int rc;
3476
3477         if (!sig)
3478                 perm = PROCESS__SIGNULL; /* null signal; existence test */
3479         else
3480                 perm = signal_to_av(sig);
3481         if (secid)
3482                 rc = avc_has_perm(secid, task_sid(p),
3483                                   SECCLASS_PROCESS, perm, NULL);
3484         else
3485                 rc = current_has_perm(p, perm);
3486         return rc;
3487 }
3488
3489 static int selinux_task_wait(struct task_struct *p)
3490 {
3491         return task_has_perm(p, current, PROCESS__SIGCHLD);
3492 }
3493
3494 static void selinux_task_to_inode(struct task_struct *p,
3495                                   struct inode *inode)
3496 {
3497         struct inode_security_struct *isec = inode->i_security;
3498         u32 sid = task_sid(p);
3499
3500         isec->sid = sid;
3501         isec->initialized = 1;
3502 }
3503
3504 /* Returns error only if unable to parse addresses */
3505 static int selinux_parse_skb_ipv4(struct sk_buff *skb,
3506                         struct common_audit_data *ad, u8 *proto)
3507 {
3508         int offset, ihlen, ret = -EINVAL;
3509         struct iphdr _iph, *ih;
3510
3511         offset = skb_network_offset(skb);
3512         ih = skb_header_pointer(skb, offset, sizeof(_iph), &_iph);
3513         if (ih == NULL)
3514                 goto out;
3515
3516         ihlen = ih->ihl * 4;
3517         if (ihlen < sizeof(_iph))
3518                 goto out;
3519
3520         ad->u.net.v4info.saddr = ih->saddr;
3521         ad->u.net.v4info.daddr = ih->daddr;
3522         ret = 0;
3523
3524         if (proto)
3525                 *proto = ih->protocol;
3526
3527         switch (ih->protocol) {
3528         case IPPROTO_TCP: {
3529                 struct tcphdr _tcph, *th;
3530
3531                 if (ntohs(ih->frag_off) & IP_OFFSET)
3532                         break;
3533
3534                 offset += ihlen;
3535                 th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
3536                 if (th == NULL)
3537                         break;
3538
3539                 ad->u.net.sport = th->source;
3540                 ad->u.net.dport = th->dest;
3541                 break;
3542         }
3543
3544         case IPPROTO_UDP: {
3545                 struct udphdr _udph, *uh;
3546
3547                 if (ntohs(ih->frag_off) & IP_OFFSET)
3548                         break;
3549
3550                 offset += ihlen;
3551                 uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
3552                 if (uh == NULL)
3553                         break;
3554
3555                 ad->u.net.sport = uh->source;
3556                 ad->u.net.dport = uh->dest;
3557                 break;
3558         }
3559
3560         case IPPROTO_DCCP: {
3561                 struct dccp_hdr _dccph, *dh;
3562
3563                 if (ntohs(ih->frag_off) & IP_OFFSET)
3564                         break;
3565
3566                 offset += ihlen;
3567                 dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph);
3568                 if (dh == NULL)
3569                         break;
3570
3571                 ad->u.net.sport = dh->dccph_sport;
3572                 ad->u.net.dport = dh->dccph_dport;
3573                 break;
3574         }
3575
3576         default:
3577                 break;
3578         }
3579 out:
3580         return ret;
3581 }
3582
3583 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
3584
3585 /* Returns error only if unable to parse addresses */
3586 static int selinux_parse_skb_ipv6(struct sk_buff *skb,
3587                         struct common_audit_data *ad, u8 *proto)
3588 {
3589         u8 nexthdr;
3590         int ret = -EINVAL, offset;
3591         struct ipv6hdr _ipv6h, *ip6;
3592         __be16 frag_off;
3593
3594         offset = skb_network_offset(skb);
3595         ip6 = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h);
3596         if (ip6 == NULL)
3597                 goto out;
3598
3599         ad->u.net.v6info.saddr = ip6->saddr;
3600         ad->u.net.v6info.daddr = ip6->daddr;
3601         ret = 0;
3602
3603         nexthdr = ip6->nexthdr;
3604         offset += sizeof(_ipv6h);
3605         offset = ipv6_skip_exthdr(skb, offset, &nexthdr, &frag_off);
3606         if (offset < 0)
3607                 goto out;
3608
3609         if (proto)
3610                 *proto = nexthdr;
3611
3612         switch (nexthdr) {
3613         case IPPROTO_TCP: {
3614                 struct tcphdr _tcph, *th;
3615
3616                 th = skb_header_pointer(skb, offset, sizeof(_tcph), &_tcph);
3617                 if (th == NULL)
3618                         break;
3619
3620                 ad->u.net.sport = th->source;
3621                 ad->u.net.dport = th->dest;
3622                 break;
3623         }
3624
3625         case IPPROTO_UDP: {
3626                 struct udphdr _udph, *uh;
3627
3628                 uh = skb_header_pointer(skb, offset, sizeof(_udph), &_udph);
3629                 if (uh == NULL)
3630                         break;
3631
3632                 ad->u.net.sport = uh->source;
3633                 ad->u.net.dport = uh->dest;
3634                 break;
3635         }
3636
3637         case IPPROTO_DCCP: {
3638                 struct dccp_hdr _dccph, *dh;
3639
3640                 dh = skb_header_pointer(skb, offset, sizeof(_dccph), &_dccph);
3641                 if (dh == NULL)
3642                         break;
3643
3644                 ad->u.net.sport = dh->dccph_sport;
3645                 ad->u.net.dport = dh->dccph_dport;
3646                 break;
3647         }
3648
3649         /* includes fragments */
3650         default:
3651                 break;
3652         }
3653 out:
3654         return ret;
3655 }
3656
3657 #endif /* IPV6 */
3658
3659 static int selinux_parse_skb(struct sk_buff *skb, struct common_audit_data *ad,
3660                              char **_addrp, int src, u8 *proto)
3661 {
3662         char *addrp;
3663         int ret;
3664
3665         switch (ad->u.net.family) {
3666         case PF_INET:
3667                 ret = selinux_parse_skb_ipv4(skb, ad, proto);
3668                 if (ret)
3669                         goto parse_error;
3670                 addrp = (char *)(src ? &ad->u.net.v4info.saddr :
3671                                        &ad->u.net.v4info.daddr);
3672                 goto okay;
3673
3674 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
3675         case PF_INET6:
3676                 ret = selinux_parse_skb_ipv6(skb, ad, proto);
3677                 if (ret)
3678                         goto parse_error;
3679                 addrp = (char *)(src ? &ad->u.net.v6info.saddr :
3680                                        &ad->u.net.v6info.daddr);
3681                 goto okay;
3682 #endif  /* IPV6 */
3683         default:
3684                 addrp = NULL;
3685                 goto okay;
3686         }
3687
3688 parse_error:
3689         printk(KERN_WARNING
3690                "SELinux: failure in selinux_parse_skb(),"
3691                " unable to parse packet\n");
3692         return ret;
3693
3694 okay:
3695         if (_addrp)
3696                 *_addrp = addrp;
3697         return 0;
3698 }
3699
3700 /**
3701  * selinux_skb_peerlbl_sid - Determine the peer label of a packet
3702  * @skb: the packet
3703  * @family: protocol family
3704  * @sid: the packet's peer label SID
3705  *
3706  * Description:
3707  * Check the various different forms of network peer labeling and determine
3708  * the peer label/SID for the packet; most of the magic actually occurs in
3709  * the security server function security_net_peersid_cmp().  The function
3710  * returns zero if the value in @sid is valid (although it may be SECSID_NULL)
3711  * or -EACCES if @sid is invalid due to inconsistencies with the different
3712  * peer labels.
3713  *
3714  */
3715 static int selinux_skb_peerlbl_sid(struct sk_buff *skb, u16 family, u32 *sid)
3716 {
3717         int err;
3718         u32 xfrm_sid;
3719         u32 nlbl_sid;
3720         u32 nlbl_type;
3721
3722         selinux_skb_xfrm_sid(skb, &xfrm_sid);
3723         selinux_netlbl_skbuff_getsid(skb, family, &nlbl_type, &nlbl_sid);
3724
3725         err = security_net_peersid_resolve(nlbl_sid, nlbl_type, xfrm_sid, sid);
3726         if (unlikely(err)) {
3727                 printk(KERN_WARNING
3728                        "SELinux: failure in selinux_skb_peerlbl_sid(),"
3729                        " unable to determine packet's peer label\n");
3730                 return -EACCES;
3731         }
3732
3733         return 0;
3734 }
3735
3736 /* socket security operations */
3737
3738 static int socket_sockcreate_sid(const struct task_security_struct *tsec,
3739                                  u16 secclass, u32 *socksid)
3740 {
3741         if (tsec->sockcreate_sid > SECSID_NULL) {
3742                 *socksid = tsec->sockcreate_sid;
3743                 return 0;
3744         }
3745
3746         return security_transition_sid(tsec->sid, tsec->sid, secclass, NULL,
3747                                        socksid);
3748 }
3749
3750 static int sock_has_perm(struct task_struct *task, struct sock *sk, u32 perms)
3751 {
3752         struct sk_security_struct *sksec = sk->sk_security;
3753         struct common_audit_data ad;
3754         struct selinux_audit_data sad = {0,};
3755         u32 tsid = task_sid(task);
3756
3757         if (sksec->sid == SECINITSID_KERNEL)
3758                 return 0;
3759
3760         COMMON_AUDIT_DATA_INIT(&ad, NET);
3761         ad.selinux_audit_data = &sad;
3762         ad.u.net.sk = sk;
3763
3764         return avc_has_perm(tsid, sksec->sid, sksec->sclass, perms, &ad);
3765 }
3766
3767 static int selinux_socket_create(int family, int type,
3768                                  int protocol, int kern)
3769 {
3770         const struct task_security_struct *tsec = current_security();
3771         u32 newsid;
3772         u16 secclass;
3773         int rc;
3774
3775         if (kern)
3776                 return 0;
3777
3778         secclass = socket_type_to_security_class(family, type, protocol);
3779         rc = socket_sockcreate_sid(tsec, secclass, &newsid);
3780         if (rc)
3781                 return rc;
3782
3783         return avc_has_perm(tsec->sid, newsid, secclass, SOCKET__CREATE, NULL);
3784 }
3785
3786 static int selinux_socket_post_create(struct socket *sock, int family,
3787                                       int type, int protocol, int kern)
3788 {
3789         const struct task_security_struct *tsec = current_security();
3790         struct inode_security_struct *isec = SOCK_INODE(sock)->i_security;
3791         struct sk_security_struct *sksec;
3792         int err = 0;
3793
3794         isec->sclass = socket_type_to_security_class(family, type, protocol);
3795
3796         if (kern)
3797                 isec->sid = SECINITSID_KERNEL;
3798         else {
3799                 err = socket_sockcreate_sid(tsec, isec->sclass, &(isec->sid));
3800                 if (err)
3801                         return err;
3802         }
3803
3804         isec->initialized = 1;
3805
3806         if (sock->sk) {
3807                 sksec = sock->sk->sk_security;
3808                 sksec->sid = isec->sid;
3809                 sksec->sclass = isec->sclass;
3810                 err = selinux_netlbl_socket_post_create(sock->sk, family);
3811         }
3812
3813         return err;
3814 }
3815
3816 /* Range of port numbers used to automatically bind.
3817    Need to determine whether we should perform a name_bind
3818    permission check between the socket and the port number. */
3819
3820 static int selinux_socket_bind(struct socket *sock, struct sockaddr *address, int addrlen)
3821 {
3822         struct sock *sk = sock->sk;
3823         u16 family;
3824         int err;
3825
3826         err = sock_has_perm(current, sk, SOCKET__BIND);
3827         if (err)
3828                 goto out;
3829
3830         /*
3831          * If PF_INET or PF_INET6, check name_bind permission for the port.
3832          * Multiple address binding for SCTP is not supported yet: we just
3833          * check the first address now.
3834          */
3835         family = sk->sk_family;
3836         if (family == PF_INET || family == PF_INET6) {
3837                 char *addrp;
3838                 struct sk_security_struct *sksec = sk->sk_security;
3839                 struct common_audit_data ad;
3840                 struct selinux_audit_data sad = {0,};
3841                 struct sockaddr_in *addr4 = NULL;
3842                 struct sockaddr_in6 *addr6 = NULL;
3843                 unsigned short snum;
3844                 u32 sid, node_perm;
3845
3846                 if (family == PF_INET) {
3847                         addr4 = (struct sockaddr_in *)address;
3848                         snum = ntohs(addr4->sin_port);
3849                         addrp = (char *)&addr4->sin_addr.s_addr;
3850                 } else {
3851                         addr6 = (struct sockaddr_in6 *)address;
3852                         snum = ntohs(addr6->sin6_port);
3853                         addrp = (char *)&addr6->sin6_addr.s6_addr;
3854                 }
3855
3856                 if (snum) {
3857                         int low, high;
3858
3859                         inet_get_local_port_range(&low, &high);
3860
3861                         if (snum < max(PROT_SOCK, low) || snum > high) {
3862                                 err = sel_netport_sid(sk->sk_protocol,
3863                                                       snum, &sid);
3864                                 if (err)
3865                                         goto out;
3866                                 COMMON_AUDIT_DATA_INIT(&ad, NET);
3867                                 ad.selinux_audit_data = &sad;
3868                                 ad.u.net.sport = htons(snum);
3869                                 ad.u.net.family = family;
3870                                 err = avc_has_perm(sksec->sid, sid,
3871                                                    sksec->sclass,
3872                                                    SOCKET__NAME_BIND, &ad);
3873                                 if (err)
3874                                         goto out;
3875                         }
3876                 }
3877
3878                 switch (sksec->sclass) {
3879                 case SECCLASS_TCP_SOCKET:
3880                         node_perm = TCP_SOCKET__NODE_BIND;
3881                         break;
3882
3883                 case SECCLASS_UDP_SOCKET:
3884                         node_perm = UDP_SOCKET__NODE_BIND;
3885                         break;
3886
3887                 case SECCLASS_DCCP_SOCKET:
3888                         node_perm = DCCP_SOCKET__NODE_BIND;
3889                         break;
3890
3891                 default:
3892                         node_perm = RAWIP_SOCKET__NODE_BIND;
3893                         break;
3894                 }
3895
3896                 err = sel_netnode_sid(addrp, family, &sid);
3897                 if (err)
3898                         goto out;
3899
3900                 COMMON_AUDIT_DATA_INIT(&ad, NET);
3901                 ad.selinux_audit_data = &sad;
3902                 ad.u.net.sport = htons(snum);
3903                 ad.u.net.family = family;
3904
3905                 if (family == PF_INET)
3906                         ad.u.net.v4info.saddr = addr4->sin_addr.s_addr;
3907                 else
3908                         ad.u.net.v6info.saddr = addr6->sin6_addr;
3909
3910                 err = avc_has_perm(sksec->sid, sid,
3911                                    sksec->sclass, node_perm, &ad);
3912                 if (err)
3913                         goto out;
3914         }
3915 out:
3916         return err;
3917 }
3918
3919 static int selinux_socket_connect(struct socket *sock, struct sockaddr *address, int addrlen)
3920 {
3921         struct sock *sk = sock->sk;
3922         struct sk_security_struct *sksec = sk->sk_security;
3923         int err;
3924
3925         err = sock_has_perm(current, sk, SOCKET__CONNECT);
3926         if (err)
3927                 return err;
3928
3929         /*
3930          * If a TCP or DCCP socket, check name_connect permission for the port.
3931          */
3932         if (sksec->sclass == SECCLASS_TCP_SOCKET ||
3933             sksec->sclass == SECCLASS_DCCP_SOCKET) {
3934                 struct common_audit_data ad;
3935                 struct selinux_audit_data sad = {0,};
3936                 struct sockaddr_in *addr4 = NULL;
3937                 struct sockaddr_in6 *addr6 = NULL;
3938                 unsigned short snum;
3939                 u32 sid, perm;
3940
3941                 if (sk->sk_family == PF_INET) {
3942                         addr4 = (struct sockaddr_in *)address;
3943                         if (addrlen < sizeof(struct sockaddr_in))
3944                                 return -EINVAL;
3945                         snum = ntohs(addr4->sin_port);
3946                 } else {
3947                         addr6 = (struct sockaddr_in6 *)address;
3948                         if (addrlen < SIN6_LEN_RFC2133)
3949                                 return -EINVAL;
3950                         snum = ntohs(addr6->sin6_port);
3951                 }
3952
3953                 err = sel_netport_sid(sk->sk_protocol, snum, &sid);
3954                 if (err)
3955                         goto out;
3956
3957                 perm = (sksec->sclass == SECCLASS_TCP_SOCKET) ?
3958                        TCP_SOCKET__NAME_CONNECT : DCCP_SOCKET__NAME_CONNECT;
3959
3960                 COMMON_AUDIT_DATA_INIT(&ad, NET);
3961                 ad.selinux_audit_data = &sad;
3962                 ad.u.net.dport = htons(snum);
3963                 ad.u.net.family = sk->sk_family;
3964                 err = avc_has_perm(sksec->sid, sid, sksec->sclass, perm, &ad);
3965                 if (err)
3966                         goto out;
3967         }
3968
3969         err = selinux_netlbl_socket_connect(sk, address);
3970
3971 out:
3972         return err;
3973 }
3974
3975 static int selinux_socket_listen(struct socket *sock, int backlog)
3976 {
3977         return sock_has_perm(current, sock->sk, SOCKET__LISTEN);
3978 }
3979
3980 static int selinux_socket_accept(struct socket *sock, struct socket *newsock)
3981 {
3982         int err;
3983         struct inode_security_struct *isec;
3984         struct inode_security_struct *newisec;
3985
3986         err = sock_has_perm(current, sock->sk, SOCKET__ACCEPT);
3987         if (err)
3988                 return err;
3989
3990         newisec = SOCK_INODE(newsock)->i_security;
3991
3992         isec = SOCK_INODE(sock)->i_security;
3993         newisec->sclass = isec->sclass;
3994         newisec->sid = isec->sid;
3995         newisec->initialized = 1;
3996
3997         return 0;
3998 }
3999
4000 static int selinux_socket_sendmsg(struct socket *sock, struct msghdr *msg,
4001                                   int size)
4002 {
4003         return sock_has_perm(current, sock->sk, SOCKET__WRITE);
4004 }
4005
4006 static int selinux_socket_recvmsg(struct socket *sock, struct msghdr *msg,
4007                                   int size, int flags)
4008 {
4009         return sock_has_perm(current, sock->sk, SOCKET__READ);
4010 }
4011
4012 static int selinux_socket_getsockname(struct socket *sock)
4013 {
4014         return sock_has_perm(current, sock->sk, SOCKET__GETATTR);
4015 }
4016
4017 static int selinux_socket_getpeername(struct socket *sock)
4018 {
4019         return sock_has_perm(current, sock->sk, SOCKET__GETATTR);
4020 }
4021
4022 static int selinux_socket_setsockopt(struct socket *sock, int level, int optname)
4023 {
4024         int err;
4025
4026         err = sock_has_perm(current, sock->sk, SOCKET__SETOPT);
4027         if (err)
4028                 return err;
4029
4030         return selinux_netlbl_socket_setsockopt(sock, level, optname);
4031 }
4032
4033 static int selinux_socket_getsockopt(struct socket *sock, int level,
4034                                      int optname)
4035 {
4036         return sock_has_perm(current, sock->sk, SOCKET__GETOPT);
4037 }
4038
4039 static int selinux_socket_shutdown(struct socket *sock, int how)
4040 {
4041         return sock_has_perm(current, sock->sk, SOCKET__SHUTDOWN);
4042 }
4043
4044 static int selinux_socket_unix_stream_connect(struct sock *sock,
4045                                               struct sock *other,
4046                                               struct sock *newsk)
4047 {
4048         struct sk_security_struct *sksec_sock = sock->sk_security;
4049         struct sk_security_struct *sksec_other = other->sk_security;
4050         struct sk_security_struct *sksec_new = newsk->sk_security;
4051         struct common_audit_data ad;
4052         struct selinux_audit_data sad = {0,};
4053         int err;
4054
4055         COMMON_AUDIT_DATA_INIT(&ad, NET);
4056         ad.selinux_audit_data = &sad;
4057         ad.u.net.sk = other;
4058
4059         err = avc_has_perm(sksec_sock->sid, sksec_other->sid,
4060                            sksec_other->sclass,
4061                            UNIX_STREAM_SOCKET__CONNECTTO, &ad);
4062         if (err)
4063                 return err;
4064
4065         /* server child socket */
4066         sksec_new->peer_sid = sksec_sock->sid;
4067         err = security_sid_mls_copy(sksec_other->sid, sksec_sock->sid,
4068                                     &sksec_new->sid);
4069         if (err)
4070                 return err;
4071
4072         /* connecting socket */
4073         sksec_sock->peer_sid = sksec_new->sid;
4074
4075         return 0;
4076 }
4077
4078 static int selinux_socket_unix_may_send(struct socket *sock,
4079                                         struct socket *other)
4080 {
4081         struct sk_security_struct *ssec = sock->sk->sk_security;
4082         struct sk_security_struct *osec = other->sk->sk_security;
4083         struct common_audit_data ad;
4084         struct selinux_audit_data sad = {0,};
4085
4086         COMMON_AUDIT_DATA_INIT(&ad, NET);
4087         ad.selinux_audit_data = &sad;
4088         ad.u.net.sk = other->sk;
4089
4090         return avc_has_perm(ssec->sid, osec->sid, osec->sclass, SOCKET__SENDTO,
4091                             &ad);
4092 }
4093
4094 static int selinux_inet_sys_rcv_skb(int ifindex, char *addrp, u16 family,
4095                                     u32 peer_sid,
4096                                     struct common_audit_data *ad)
4097 {
4098         int err;
4099         u32 if_sid;
4100         u32 node_sid;
4101
4102         err = sel_netif_sid(ifindex, &if_sid);
4103         if (err)
4104                 return err;
4105         err = avc_has_perm(peer_sid, if_sid,
4106                            SECCLASS_NETIF, NETIF__INGRESS, ad);
4107         if (err)
4108                 return err;
4109
4110         err = sel_netnode_sid(addrp, family, &node_sid);
4111         if (err)
4112                 return err;
4113         return avc_has_perm(peer_sid, node_sid,
4114                             SECCLASS_NODE, NODE__RECVFROM, ad);
4115 }
4116
4117 static int selinux_sock_rcv_skb_compat(struct sock *sk, struct sk_buff *skb,
4118                                        u16 family)
4119 {
4120         int err = 0;
4121         struct sk_security_struct *sksec = sk->sk_security;
4122         u32 sk_sid = sksec->sid;
4123         struct common_audit_data ad;
4124         struct selinux_audit_data sad = {0,};
4125         char *addrp;
4126
4127         COMMON_AUDIT_DATA_INIT(&ad, NET);
4128         ad.selinux_audit_data = &sad;
4129         ad.u.net.netif = skb->skb_iif;
4130         ad.u.net.family = family;
4131         err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL);
4132         if (err)
4133                 return err;
4134
4135         if (selinux_secmark_enabled()) {
4136                 err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET,
4137                                    PACKET__RECV, &ad);
4138                 if (err)
4139                         return err;
4140         }
4141
4142         err = selinux_netlbl_sock_rcv_skb(sksec, skb, family, &ad);
4143         if (err)
4144                 return err;
4145         err = selinux_xfrm_sock_rcv_skb(sksec->sid, skb, &ad);
4146
4147         return err;
4148 }
4149
4150 static int selinux_socket_sock_rcv_skb(struct sock *sk, struct sk_buff *skb)
4151 {
4152         int err;
4153         struct sk_security_struct *sksec = sk->sk_security;
4154         u16 family = sk->sk_family;
4155         u32 sk_sid = sksec->sid;
4156         struct common_audit_data ad;
4157         struct selinux_audit_data sad = {0,};
4158         char *addrp;
4159         u8 secmark_active;
4160         u8 peerlbl_active;
4161
4162         if (family != PF_INET && family != PF_INET6)
4163                 return 0;
4164
4165         /* Handle mapped IPv4 packets arriving via IPv6 sockets */
4166         if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
4167                 family = PF_INET;
4168
4169         /* If any sort of compatibility mode is enabled then handoff processing
4170          * to the selinux_sock_rcv_skb_compat() function to deal with the
4171          * special handling.  We do this in an attempt to keep this function
4172          * as fast and as clean as possible. */
4173         if (!selinux_policycap_netpeer)
4174                 return selinux_sock_rcv_skb_compat(sk, skb, family);
4175
4176         secmark_active = selinux_secmark_enabled();
4177         peerlbl_active = netlbl_enabled() || selinux_xfrm_enabled();
4178         if (!secmark_active && !peerlbl_active)
4179                 return 0;
4180
4181         COMMON_AUDIT_DATA_INIT(&ad, NET);
4182         ad.selinux_audit_data = &sad;
4183         ad.u.net.netif = skb->skb_iif;
4184         ad.u.net.family = family;
4185         err = selinux_parse_skb(skb, &ad, &addrp, 1, NULL);
4186         if (err)
4187                 return err;
4188
4189         if (peerlbl_active) {
4190                 u32 peer_sid;
4191
4192                 err = selinux_skb_peerlbl_sid(skb, family, &peer_sid);
4193                 if (err)
4194                         return err;
4195                 err = selinux_inet_sys_rcv_skb(skb->skb_iif, addrp, family,
4196                                                peer_sid, &ad);
4197                 if (err) {
4198                         selinux_netlbl_err(skb, err, 0);
4199                         return err;
4200                 }
4201                 err = avc_has_perm(sk_sid, peer_sid, SECCLASS_PEER,
4202                                    PEER__RECV, &ad);
4203                 if (err)
4204                         selinux_netlbl_err(skb, err, 0);
4205         }
4206
4207         if (secmark_active) {
4208                 err = avc_has_perm(sk_sid, skb->secmark, SECCLASS_PACKET,
4209                                    PACKET__RECV, &ad);
4210                 if (err)
4211                         return err;
4212         }
4213
4214         return err;
4215 }
4216
4217 static int selinux_socket_getpeersec_stream(struct socket *sock, char __user *optval,
4218                                             int __user *optlen, unsigned len)
4219 {
4220         int err = 0;
4221         char *scontext;
4222         u32 scontext_len;
4223         struct sk_security_struct *sksec = sock->sk->sk_security;
4224         u32 peer_sid = SECSID_NULL;
4225
4226         if (sksec->sclass == SECCLASS_UNIX_STREAM_SOCKET ||
4227             sksec->sclass == SECCLASS_TCP_SOCKET)
4228                 peer_sid = sksec->peer_sid;
4229         if (peer_sid == SECSID_NULL)
4230                 return -ENOPROTOOPT;
4231
4232         err = security_sid_to_context(peer_sid, &scontext, &scontext_len);
4233         if (err)
4234                 return err;
4235
4236         if (scontext_len > len) {
4237                 err = -ERANGE;
4238                 goto out_len;
4239         }
4240
4241         if (copy_to_user(optval, scontext, scontext_len))
4242                 err = -EFAULT;
4243
4244 out_len:
4245         if (put_user(scontext_len, optlen))
4246                 err = -EFAULT;
4247         kfree(scontext);
4248         return err;
4249 }
4250
4251 static int selinux_socket_getpeersec_dgram(struct socket *sock, struct sk_buff *skb, u32 *secid)
4252 {
4253         u32 peer_secid = SECSID_NULL;
4254         u16 family;
4255
4256         if (skb && skb->protocol == htons(ETH_P_IP))
4257                 family = PF_INET;
4258         else if (skb && skb->protocol == htons(ETH_P_IPV6))
4259                 family = PF_INET6;
4260         else if (sock)
4261                 family = sock->sk->sk_family;
4262         else
4263                 goto out;
4264
4265         if (sock && family == PF_UNIX)
4266                 selinux_inode_getsecid(SOCK_INODE(sock), &peer_secid);
4267         else if (skb)
4268                 selinux_skb_peerlbl_sid(skb, family, &peer_secid);
4269
4270 out:
4271         *secid = peer_secid;
4272         if (peer_secid == SECSID_NULL)
4273                 return -EINVAL;
4274         return 0;
4275 }
4276
4277 static int selinux_sk_alloc_security(struct sock *sk, int family, gfp_t priority)
4278 {
4279         struct sk_security_struct *sksec;
4280
4281         sksec = kzalloc(sizeof(*sksec), priority);
4282         if (!sksec)
4283                 return -ENOMEM;
4284
4285         sksec->peer_sid = SECINITSID_UNLABELED;
4286         sksec->sid = SECINITSID_UNLABELED;
4287         selinux_netlbl_sk_security_reset(sksec);
4288         sk->sk_security = sksec;
4289
4290         return 0;
4291 }
4292
4293 static void selinux_sk_free_security(struct sock *sk)
4294 {
4295         struct sk_security_struct *sksec = sk->sk_security;
4296
4297         sk->sk_security = NULL;
4298         selinux_netlbl_sk_security_free(sksec);
4299         kfree(sksec);
4300 }
4301
4302 static void selinux_sk_clone_security(const struct sock *sk, struct sock *newsk)
4303 {
4304         struct sk_security_struct *sksec = sk->sk_security;
4305         struct sk_security_struct *newsksec = newsk->sk_security;
4306
4307         newsksec->sid = sksec->sid;
4308         newsksec->peer_sid = sksec->peer_sid;
4309         newsksec->sclass = sksec->sclass;
4310
4311         selinux_netlbl_sk_security_reset(newsksec);
4312 }
4313
4314 static void selinux_sk_getsecid(struct sock *sk, u32 *secid)
4315 {
4316         if (!sk)
4317                 *secid = SECINITSID_ANY_SOCKET;
4318         else {
4319                 struct sk_security_struct *sksec = sk->sk_security;
4320
4321                 *secid = sksec->sid;
4322         }
4323 }
4324
4325 static void selinux_sock_graft(struct sock *sk, struct socket *parent)
4326 {
4327         struct inode_security_struct *isec = SOCK_INODE(parent)->i_security;
4328         struct sk_security_struct *sksec = sk->sk_security;
4329
4330         if (sk->sk_family == PF_INET || sk->sk_family == PF_INET6 ||
4331             sk->sk_family == PF_UNIX)
4332                 isec->sid = sksec->sid;
4333         sksec->sclass = isec->sclass;
4334 }
4335
4336 static int selinux_inet_conn_request(struct sock *sk, struct sk_buff *skb,
4337                                      struct request_sock *req)
4338 {
4339         struct sk_security_struct *sksec = sk->sk_security;
4340         int err;
4341         u16 family = sk->sk_family;
4342         u32 newsid;
4343         u32 peersid;
4344
4345         /* handle mapped IPv4 packets arriving via IPv6 sockets */
4346         if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
4347                 family = PF_INET;
4348
4349         err = selinux_skb_peerlbl_sid(skb, family, &peersid);
4350         if (err)
4351                 return err;
4352         if (peersid == SECSID_NULL) {
4353                 req->secid = sksec->sid;
4354                 req->peer_secid = SECSID_NULL;
4355         } else {
4356                 err = security_sid_mls_copy(sksec->sid, peersid, &newsid);
4357                 if (err)
4358                         return err;
4359                 req->secid = newsid;
4360                 req->peer_secid = peersid;
4361         }
4362
4363         return selinux_netlbl_inet_conn_request(req, family);
4364 }
4365
4366 static void selinux_inet_csk_clone(struct sock *newsk,
4367                                    const struct request_sock *req)
4368 {
4369         struct sk_security_struct *newsksec = newsk->sk_security;
4370
4371         newsksec->sid = req->secid;
4372         newsksec->peer_sid = req->peer_secid;
4373         /* NOTE: Ideally, we should also get the isec->sid for the
4374            new socket in sync, but we don't have the isec available yet.
4375            So we will wait until sock_graft to do it, by which
4376            time it will have been created and available. */
4377
4378         /* We don't need to take any sort of lock here as we are the only
4379          * thread with access to newsksec */
4380         selinux_netlbl_inet_csk_clone(newsk, req->rsk_ops->family);
4381 }
4382
4383 static void selinux_inet_conn_established(struct sock *sk, struct sk_buff *skb)
4384 {
4385         u16 family = sk->sk_family;
4386         struct sk_security_struct *sksec = sk->sk_security;
4387
4388         /* handle mapped IPv4 packets arriving via IPv6 sockets */
4389         if (family == PF_INET6 && skb->protocol == htons(ETH_P_IP))
4390                 family = PF_INET;
4391
4392         selinux_skb_peerlbl_sid(skb, family, &sksec->peer_sid);
4393 }
4394
4395 static int selinux_secmark_relabel_packet(u32 sid)
4396 {
4397         const struct task_security_struct *__tsec;
4398         u32 tsid;
4399
4400         __tsec = current_security();
4401         tsid = __tsec->sid;
4402
4403         return avc_has_perm(tsid, sid, SECCLASS_PACKET, PACKET__RELABELTO, NULL);
4404 }
4405
4406 static void selinux_secmark_refcount_inc(void)
4407 {
4408         atomic_inc(&selinux_secmark_refcount);
4409 }
4410
4411 static void selinux_secmark_refcount_dec(void)
4412 {
4413         atomic_dec(&selinux_secmark_refcount);
4414 }
4415
4416 static void selinux_req_classify_flow(const struct request_sock *req,
4417                                       struct flowi *fl)
4418 {
4419         fl->flowi_secid = req->secid;
4420 }
4421
4422 static int selinux_tun_dev_create(void)
4423 {
4424         u32 sid = current_sid();
4425
4426         /* we aren't taking into account the "sockcreate" SID since the socket
4427          * that is being created here is not a socket in the traditional sense,
4428          * instead it is a private sock, accessible only to the kernel, and
4429          * representing a wide range of network traffic spanning multiple
4430          * connections unlike traditional sockets - check the TUN driver to
4431          * get a better understanding of why this socket is special */
4432
4433         return avc_has_perm(sid, sid, SECCLASS_TUN_SOCKET, TUN_SOCKET__CREATE,
4434                             NULL);
4435 }
4436
4437 static void selinux_tun_dev_post_create(struct sock *sk)
4438 {
4439         struct sk_security_struct *sksec = sk->sk_security;
4440
4441         /* we don't currently perform any NetLabel based labeling here and it
4442          * isn't clear that we would want to do so anyway; while we could apply
4443          * labeling without the support of the TUN user the resulting labeled
4444          * traffic from the other end of the connection would almost certainly
4445          * cause confusion to the TUN user that had no idea network labeling
4446          * protocols were being used */
4447
4448         /* see the comments in selinux_tun_dev_create() about why we don't use
4449          * the sockcreate SID here */
4450
4451         sksec->sid = current_sid();
4452         sksec->sclass = SECCLASS_TUN_SOCKET;
4453 }
4454
4455 static int selinux_tun_dev_attach(struct sock *sk)
4456 {
4457         struct sk_security_struct *sksec = sk->sk_security;
4458         u32 sid = current_sid();
4459         int err;
4460
4461         err = avc_has_perm(sid, sksec->sid, SECCLASS_TUN_SOCKET,
4462                            TUN_SOCKET__RELABELFROM, NULL);
4463         if (err)
4464                 return err;
4465         err = avc_has_perm(sid, sid, SECCLASS_TUN_SOCKET,
4466                            TUN_SOCKET__RELABELTO, NULL);
4467         if (err)
4468                 return err;
4469
4470         sksec->sid = sid;
4471
4472         return 0;
4473 }
4474
4475 static int selinux_nlmsg_perm(struct sock *sk, struct sk_buff *skb)
4476 {
4477         int err = 0;
4478         u32 perm;
4479         struct nlmsghdr *nlh;
4480         struct sk_security_struct *sksec = sk->sk_security;
4481
4482         if (skb->len < NLMSG_SPACE(0)) {
4483                 err = -EINVAL;
4484                 goto out;
4485         }
4486         nlh = nlmsg_hdr(skb);
4487
4488         err = selinux_nlmsg_lookup(sksec->sclass, nlh->nlmsg_type, &perm);
4489         if (err) {
4490                 if (err == -EINVAL) {
4491                         audit_log(current->audit_context, GFP_KERNEL, AUDIT_SELINUX_ERR,
4492                                   "SELinux:  unrecognized netlink message"
4493                                   " type=%hu for sclass=%hu\n",
4494                                   nlh->nlmsg_type, sksec->sclass);
4495                         if (!selinux_enforcing || security_get_allow_unknown())
4496                                 err = 0;
4497                 }
4498
4499                 /* Ignore */
4500                 if (err == -ENOENT)
4501                         err = 0;
4502                 goto out;
4503         }
4504
4505         err = sock_has_perm(current, sk, perm);
4506 out:
4507         return err;
4508 }
4509
4510 #ifdef CONFIG_NETFILTER
4511
4512 static unsigned int selinux_ip_forward(struct sk_buff *skb, int ifindex,
4513                                        u16 family)
4514 {
4515         int err;
4516         char *addrp;
4517         u32 peer_sid;
4518         struct common_audit_data ad;
4519         struct selinux_audit_data sad = {0,};
4520         u8 secmark_active;
4521         u8 netlbl_active;
4522         u8 peerlbl_active;
4523
4524         if (!selinux_policycap_netpeer)
4525                 return NF_ACCEPT;
4526
4527         secmark_active = selinux_secmark_enabled();
4528         netlbl_active = netlbl_enabled();
4529         peerlbl_active = netlbl_active || selinux_xfrm_enabled();
4530         if (!secmark_active && !peerlbl_active)
4531                 return NF_ACCEPT;
4532
4533         if (selinux_skb_peerlbl_sid(skb, family, &peer_sid) != 0)
4534                 return NF_DROP;
4535
4536         COMMON_AUDIT_DATA_INIT(&ad, NET);
4537         ad.selinux_audit_data = &sad;
4538         ad.u.net.netif = ifindex;
4539         ad.u.net.family = family;
4540         if (selinux_parse_skb(skb, &ad, &addrp, 1, NULL) != 0)
4541                 return NF_DROP;
4542
4543         if (peerlbl_active) {
4544                 err = selinux_inet_sys_rcv_skb(ifindex, addrp, family,
4545                                                peer_sid, &ad);
4546                 if (err) {
4547                         selinux_netlbl_err(skb, err, 1);
4548                         return NF_DROP;
4549                 }
4550         }
4551
4552         if (secmark_active)
4553                 if (avc_has_perm(peer_sid, skb->secmark,
4554                                  SECCLASS_PACKET, PACKET__FORWARD_IN, &ad))
4555                         return NF_DROP;
4556
4557         if (netlbl_active)
4558                 /* we do this in the FORWARD path and not the POST_ROUTING
4559                  * path because we want to make sure we apply the necessary
4560                  * labeling before IPsec is applied so we can leverage AH
4561                  * protection */
4562                 if (selinux_netlbl_skbuff_setsid(skb, family, peer_sid) != 0)
4563                         return NF_DROP;
4564
4565         return NF_ACCEPT;
4566 }
4567
4568 static unsigned int selinux_ipv4_forward(unsigned int hooknum,
4569                                          struct sk_buff *skb,
4570                                          const struct net_device *in,
4571                                          const struct net_device *out,
4572                                          int (*okfn)(struct sk_buff *))
4573 {
4574         return selinux_ip_forward(skb, in->ifindex, PF_INET);
4575 }
4576
4577 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
4578 static unsigned int selinux_ipv6_forward(unsigned int hooknum,
4579                                          struct sk_buff *skb,
4580                                          const struct net_device *in,
4581                                          const struct net_device *out,
4582                                          int (*okfn)(struct sk_buff *))
4583 {
4584         return selinux_ip_forward(skb, in->ifindex, PF_INET6);
4585 }
4586 #endif  /* IPV6 */
4587
4588 static unsigned int selinux_ip_output(struct sk_buff *skb,
4589                                       u16 family)
4590 {
4591         u32 sid;
4592
4593         if (!netlbl_enabled())
4594                 return NF_ACCEPT;
4595
4596         /* we do this in the LOCAL_OUT path and not the POST_ROUTING path
4597          * because we want to make sure we apply the necessary labeling
4598          * before IPsec is applied so we can leverage AH protection */
4599         if (skb->sk) {
4600                 struct sk_security_struct *sksec = skb->sk->sk_security;
4601                 sid = sksec->sid;
4602         } else
4603                 sid = SECINITSID_KERNEL;
4604         if (selinux_netlbl_skbuff_setsid(skb, family, sid) != 0)
4605                 return NF_DROP;
4606
4607         return NF_ACCEPT;
4608 }
4609
4610 static unsigned int selinux_ipv4_output(unsigned int hooknum,
4611                                         struct sk_buff *skb,
4612                                         const struct net_device *in,
4613                                         const struct net_device *out,
4614                                         int (*okfn)(struct sk_buff *))
4615 {
4616         return selinux_ip_output(skb, PF_INET);
4617 }
4618
4619 static unsigned int selinux_ip_postroute_compat(struct sk_buff *skb,
4620                                                 int ifindex,
4621                                                 u16 family)
4622 {
4623         struct sock *sk = skb->sk;
4624         struct sk_security_struct *sksec;
4625         struct common_audit_data ad;
4626         struct selinux_audit_data sad = {0,};
4627         char *addrp;
4628         u8 proto;
4629
4630         if (sk == NULL)
4631                 return NF_ACCEPT;
4632         sksec = sk->sk_security;
4633
4634         COMMON_AUDIT_DATA_INIT(&ad, NET);
4635         ad.selinux_audit_data = &sad;
4636         ad.u.net.netif = ifindex;
4637         ad.u.net.family = family;
4638         if (selinux_parse_skb(skb, &ad, &addrp, 0, &proto))
4639                 return NF_DROP;
4640
4641         if (selinux_secmark_enabled())
4642                 if (avc_has_perm(sksec->sid, skb->secmark,
4643                                  SECCLASS_PACKET, PACKET__SEND, &ad))
4644                         return NF_DROP_ERR(-ECONNREFUSED);
4645
4646         if (selinux_xfrm_postroute_last(sksec->sid, skb, &ad, proto))
4647                 return NF_DROP_ERR(-ECONNREFUSED);
4648
4649         return NF_ACCEPT;
4650 }
4651
4652 static unsigned int selinux_ip_postroute(struct sk_buff *skb, int ifindex,
4653                                          u16 family)
4654 {
4655         u32 secmark_perm;
4656         u32 peer_sid;
4657         struct sock *sk;
4658         struct common_audit_data ad;
4659         struct selinux_audit_data sad = {0,};
4660         char *addrp;
4661         u8 secmark_active;
4662         u8 peerlbl_active;
4663
4664         /* If any sort of compatibility mode is enabled then handoff processing
4665          * to the selinux_ip_postroute_compat() function to deal with the
4666          * special handling.  We do this in an attempt to keep this function
4667          * as fast and as clean as possible. */
4668         if (!selinux_policycap_netpeer)
4669                 return selinux_ip_postroute_compat(skb, ifindex, family);
4670 #ifdef CONFIG_XFRM
4671         /* If skb->dst->xfrm is non-NULL then the packet is undergoing an IPsec
4672          * packet transformation so allow the packet to pass without any checks
4673          * since we'll have another chance to perform access control checks
4674          * when the packet is on it's final way out.
4675          * NOTE: there appear to be some IPv6 multicast cases where skb->dst
4676          *       is NULL, in this case go ahead and apply access control. */
4677         if (skb_dst(skb) != NULL && skb_dst(skb)->xfrm != NULL)
4678                 return NF_ACCEPT;
4679 #endif
4680         secmark_active = selinux_secmark_enabled();
4681         peerlbl_active = netlbl_enabled() || selinux_xfrm_enabled();
4682         if (!secmark_active && !peerlbl_active)
4683                 return NF_ACCEPT;
4684
4685         /* if the packet is being forwarded then get the peer label from the
4686          * packet itself; otherwise check to see if it is from a local
4687          * application or the kernel, if from an application get the peer label
4688          * from the sending socket, otherwise use the kernel's sid */
4689         sk = skb->sk;
4690         if (sk == NULL) {
4691                 if (skb->skb_iif) {
4692                         secmark_perm = PACKET__FORWARD_OUT;
4693                         if (selinux_skb_peerlbl_sid(skb, family, &peer_sid))
4694                                 return NF_DROP;
4695                 } else {
4696                         secmark_perm = PACKET__SEND;
4697                         peer_sid = SECINITSID_KERNEL;
4698                 }
4699         } else {
4700                 struct sk_security_struct *sksec = sk->sk_security;
4701                 peer_sid = sksec->sid;
4702                 secmark_perm = PACKET__SEND;
4703         }
4704
4705         COMMON_AUDIT_DATA_INIT(&ad, NET);
4706         ad.selinux_audit_data = &sad;
4707         ad.u.net.netif = ifindex;
4708         ad.u.net.family = family;
4709         if (selinux_parse_skb(skb, &ad, &addrp, 0, NULL))
4710                 return NF_DROP;
4711
4712         if (secmark_active)
4713                 if (avc_has_perm(peer_sid, skb->secmark,
4714                                  SECCLASS_PACKET, secmark_perm, &ad))
4715                         return NF_DROP_ERR(-ECONNREFUSED);
4716
4717         if (peerlbl_active) {
4718                 u32 if_sid;
4719                 u32 node_sid;
4720
4721                 if (sel_netif_sid(ifindex, &if_sid))
4722                         return NF_DROP;
4723                 if (avc_has_perm(peer_sid, if_sid,
4724                                  SECCLASS_NETIF, NETIF__EGRESS, &ad))
4725                         return NF_DROP_ERR(-ECONNREFUSED);
4726
4727                 if (sel_netnode_sid(addrp, family, &node_sid))
4728                         return NF_DROP;
4729                 if (avc_has_perm(peer_sid, node_sid,
4730                                  SECCLASS_NODE, NODE__SENDTO, &ad))
4731                         return NF_DROP_ERR(-ECONNREFUSED);
4732         }
4733
4734         return NF_ACCEPT;
4735 }
4736
4737 static unsigned int selinux_ipv4_postroute(unsigned int hooknum,
4738                                            struct sk_buff *skb,
4739                                            const struct net_device *in,
4740                                            const struct net_device *out,
4741                                            int (*okfn)(struct sk_buff *))
4742 {
4743         return selinux_ip_postroute(skb, out->ifindex, PF_INET);
4744 }
4745
4746 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
4747 static unsigned int selinux_ipv6_postroute(unsigned int hooknum,
4748                                            struct sk_buff *skb,
4749                                            const struct net_device *in,
4750                                            const struct net_device *out,
4751                                            int (*okfn)(struct sk_buff *))
4752 {
4753         return selinux_ip_postroute(skb, out->ifindex, PF_INET6);
4754 }
4755 #endif  /* IPV6 */
4756
4757 #endif  /* CONFIG_NETFILTER */
4758
4759 static int selinux_netlink_send(struct sock *sk, struct sk_buff *skb)
4760 {
4761         int err;
4762
4763         err = cap_netlink_send(sk, skb);
4764         if (err)
4765                 return err;
4766
4767         return selinux_nlmsg_perm(sk, skb);
4768 }
4769
4770 static int ipc_alloc_security(struct task_struct *task,
4771                               struct kern_ipc_perm *perm,
4772                               u16 sclass)
4773 {
4774         struct ipc_security_struct *isec;
4775         u32 sid;
4776
4777         isec = kzalloc(sizeof(struct ipc_security_struct), GFP_KERNEL);
4778         if (!isec)
4779                 return -ENOMEM;
4780
4781         sid = task_sid(task);
4782         isec->sclass = sclass;
4783         isec->sid = sid;
4784         perm->security = isec;
4785
4786         return 0;
4787 }
4788
4789 static void ipc_free_security(struct kern_ipc_perm *perm)
4790 {
4791         struct ipc_security_struct *isec = perm->security;
4792         perm->security = NULL;
4793         kfree(isec);
4794 }
4795
4796 static int msg_msg_alloc_security(struct msg_msg *msg)
4797 {
4798         struct msg_security_struct *msec;
4799
4800         msec = kzalloc(sizeof(struct msg_security_struct), GFP_KERNEL);
4801         if (!msec)
4802                 return -ENOMEM;
4803
4804         msec->sid = SECINITSID_UNLABELED;
4805         msg->security = msec;
4806
4807         return 0;
4808 }
4809
4810 static void msg_msg_free_security(struct msg_msg *msg)
4811 {
4812         struct msg_security_struct *msec = msg->security;
4813
4814         msg->security = NULL;
4815         kfree(msec);
4816 }
4817
4818 static int ipc_has_perm(struct kern_ipc_perm *ipc_perms,
4819                         u32 perms)
4820 {
4821         struct ipc_security_struct *isec;
4822         struct common_audit_data ad;
4823         struct selinux_audit_data sad = {0,};
4824         u32 sid = current_sid();
4825
4826         isec = ipc_perms->security;
4827
4828         COMMON_AUDIT_DATA_INIT(&ad, IPC);
4829         ad.selinux_audit_data = &sad;
4830         ad.u.ipc_id = ipc_perms->key;
4831
4832         return avc_has_perm(sid, isec->sid, isec->sclass, perms, &ad);
4833 }
4834
4835 static int selinux_msg_msg_alloc_security(struct msg_msg *msg)
4836 {
4837         return msg_msg_alloc_security(msg);
4838 }
4839
4840 static void selinux_msg_msg_free_security(struct msg_msg *msg)
4841 {
4842         msg_msg_free_security(msg);
4843 }
4844
4845 /* message queue security operations */
4846 static int selinux_msg_queue_alloc_security(struct msg_queue *msq)
4847 {
4848         struct ipc_security_struct *isec;
4849         struct common_audit_data ad;
4850         struct selinux_audit_data sad = {0,};
4851         u32 sid = current_sid();
4852         int rc;
4853
4854         rc = ipc_alloc_security(current, &msq->q_perm, SECCLASS_MSGQ);
4855         if (rc)
4856                 return rc;
4857
4858         isec = msq->q_perm.security;
4859
4860         COMMON_AUDIT_DATA_INIT(&ad, IPC);
4861         ad.selinux_audit_data = &sad;
4862         ad.u.ipc_id = msq->q_perm.key;
4863
4864         rc = avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
4865                           MSGQ__CREATE, &ad);
4866         if (rc) {
4867                 ipc_free_security(&msq->q_perm);
4868                 return rc;
4869         }
4870         return 0;
4871 }
4872
4873 static void selinux_msg_queue_free_security(struct msg_queue *msq)
4874 {
4875         ipc_free_security(&msq->q_perm);
4876 }
4877
4878 static int selinux_msg_queue_associate(struct msg_queue *msq, int msqflg)
4879 {
4880         struct ipc_security_struct *isec;
4881         struct common_audit_data ad;
4882         struct selinux_audit_data sad = {0,};
4883         u32 sid = current_sid();
4884
4885         isec = msq->q_perm.security;
4886
4887         COMMON_AUDIT_DATA_INIT(&ad, IPC);
4888         ad.selinux_audit_data = &sad;
4889         ad.u.ipc_id = msq->q_perm.key;
4890
4891         return avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
4892                             MSGQ__ASSOCIATE, &ad);
4893 }
4894
4895 static int selinux_msg_queue_msgctl(struct msg_queue *msq, int cmd)
4896 {
4897         int err;
4898         int perms;
4899
4900         switch (cmd) {
4901         case IPC_INFO:
4902         case MSG_INFO:
4903                 /* No specific object, just general system-wide information. */
4904                 return task_has_system(current, SYSTEM__IPC_INFO);
4905         case IPC_STAT:
4906         case MSG_STAT:
4907                 perms = MSGQ__GETATTR | MSGQ__ASSOCIATE;
4908                 break;
4909         case IPC_SET:
4910                 perms = MSGQ__SETATTR;
4911                 break;
4912         case IPC_RMID:
4913                 perms = MSGQ__DESTROY;
4914                 break;
4915         default:
4916                 return 0;
4917         }
4918
4919         err = ipc_has_perm(&msq->q_perm, perms);
4920         return err;
4921 }
4922
4923 static int selinux_msg_queue_msgsnd(struct msg_queue *msq, struct msg_msg *msg, int msqflg)
4924 {
4925         struct ipc_security_struct *isec;
4926         struct msg_security_struct *msec;
4927         struct common_audit_data ad;
4928         struct selinux_audit_data sad = {0,};
4929         u32 sid = current_sid();
4930         int rc;
4931
4932         isec = msq->q_perm.security;
4933         msec = msg->security;
4934
4935         /*
4936          * First time through, need to assign label to the message
4937          */
4938         if (msec->sid == SECINITSID_UNLABELED) {
4939                 /*
4940                  * Compute new sid based on current process and
4941                  * message queue this message will be stored in
4942                  */
4943                 rc = security_transition_sid(sid, isec->sid, SECCLASS_MSG,
4944                                              NULL, &msec->sid);
4945                 if (rc)
4946                         return rc;
4947         }
4948
4949         COMMON_AUDIT_DATA_INIT(&ad, IPC);
4950         ad.selinux_audit_data = &sad;
4951         ad.u.ipc_id = msq->q_perm.key;
4952
4953         /* Can this process write to the queue? */
4954         rc = avc_has_perm(sid, isec->sid, SECCLASS_MSGQ,
4955                           MSGQ__WRITE, &ad);
4956         if (!rc)
4957                 /* Can this process send the message */
4958                 rc = avc_has_perm(sid, msec->sid, SECCLASS_MSG,
4959                                   MSG__SEND, &ad);
4960         if (!rc)
4961                 /* Can the message be put in the queue? */
4962                 rc = avc_has_perm(msec->sid, isec->sid, SECCLASS_MSGQ,
4963                                   MSGQ__ENQUEUE, &ad);
4964
4965         return rc;
4966 }
4967
4968 static int selinux_msg_queue_msgrcv(struct msg_queue *msq, struct msg_msg *msg,
4969                                     struct task_struct *target,
4970                                     long type, int mode)
4971 {
4972         struct ipc_security_struct *isec;
4973         struct msg_security_struct *msec;
4974         struct common_audit_data ad;
4975         struct selinux_audit_data sad = {0,};
4976         u32 sid = task_sid(target);
4977         int rc;
4978
4979         isec = msq->q_perm.security;
4980         msec = msg->security;
4981
4982         COMMON_AUDIT_DATA_INIT(&ad, IPC);
4983         ad.selinux_audit_data = &sad;
4984         ad.u.ipc_id = msq->q_perm.key;
4985
4986         rc = avc_has_perm(sid, isec->sid,
4987                           SECCLASS_MSGQ, MSGQ__READ, &ad);
4988         if (!rc)
4989                 rc = avc_has_perm(sid, msec->sid,
4990                                   SECCLASS_MSG, MSG__RECEIVE, &ad);
4991         return rc;
4992 }
4993
4994 /* Shared Memory security operations */
4995 static int selinux_shm_alloc_security(struct shmid_kernel *shp)
4996 {
4997         struct ipc_security_struct *isec;
4998         struct common_audit_data ad;
4999         struct selinux_audit_data sad = {0,};
5000         u32 sid = current_sid();
5001         int rc;
5002
5003         rc = ipc_alloc_security(current, &shp->shm_perm, SECCLASS_SHM);
5004         if (rc)
5005                 return rc;
5006
5007         isec = shp->shm_perm.security;
5008
5009         COMMON_AUDIT_DATA_INIT(&ad, IPC);
5010         ad.selinux_audit_data = &sad;
5011         ad.u.ipc_id = shp->shm_perm.key;
5012
5013         rc = avc_has_perm(sid, isec->sid, SECCLASS_SHM,
5014                           SHM__CREATE, &ad);
5015         if (rc) {
5016                 ipc_free_security(&shp->shm_perm);
5017                 return rc;
5018         }
5019         return 0;
5020 }
5021
5022 static void selinux_shm_free_security(struct shmid_kernel *shp)
5023 {
5024         ipc_free_security(&shp->shm_perm);
5025 }
5026
5027 static int selinux_shm_associate(struct shmid_kernel *shp, int shmflg)
5028 {
5029         struct ipc_security_struct *isec;
5030         struct common_audit_data ad;
5031         struct selinux_audit_data sad = {0,};
5032         u32 sid = current_sid();
5033
5034         isec = shp->shm_perm.security;
5035
5036         COMMON_AUDIT_DATA_INIT(&ad, IPC);
5037         ad.selinux_audit_data = &sad;
5038         ad.u.ipc_id = shp->shm_perm.key;
5039
5040         return avc_has_perm(sid, isec->sid, SECCLASS_SHM,
5041                             SHM__ASSOCIATE, &ad);
5042 }
5043
5044 /* Note, at this point, shp is locked down */
5045 static int selinux_shm_shmctl(struct shmid_kernel *shp, int cmd)
5046 {
5047         int perms;
5048         int err;
5049
5050         switch (cmd) {
5051         case IPC_INFO:
5052         case SHM_INFO:
5053                 /* No specific object, just general system-wide information. */
5054                 return task_has_system(current, SYSTEM__IPC_INFO);
5055         case IPC_STAT:
5056         case SHM_STAT:
5057                 perms = SHM__GETATTR | SHM__ASSOCIATE;
5058                 break;
5059         case IPC_SET:
5060                 perms = SHM__SETATTR;
5061                 break;
5062         case SHM_LOCK:
5063         case SHM_UNLOCK:
5064                 perms = SHM__LOCK;
5065                 break;
5066         case IPC_RMID:
5067                 perms = SHM__DESTROY;
5068                 break;
5069         default:
5070                 return 0;
5071         }
5072
5073         err = ipc_has_perm(&shp->shm_perm, perms);
5074         return err;
5075 }
5076
5077 static int selinux_shm_shmat(struct shmid_kernel *shp,
5078                              char __user *shmaddr, int shmflg)
5079 {
5080         u32 perms;
5081
5082         if (shmflg & SHM_RDONLY)
5083                 perms = SHM__READ;
5084         else
5085                 perms = SHM__READ | SHM__WRITE;
5086
5087         return ipc_has_perm(&shp->shm_perm, perms);
5088 }
5089
5090 /* Semaphore security operations */
5091 static int selinux_sem_alloc_security(struct sem_array *sma)
5092 {
5093         struct ipc_security_struct *isec;
5094         struct common_audit_data ad;
5095         struct selinux_audit_data sad = {0,};
5096         u32 sid = current_sid();
5097         int rc;
5098
5099         rc = ipc_alloc_security(current, &sma->sem_perm, SECCLASS_SEM);
5100         if (rc)
5101                 return rc;
5102
5103         isec = sma->sem_perm.security;
5104
5105         COMMON_AUDIT_DATA_INIT(&ad, IPC);
5106         ad.selinux_audit_data = &sad;
5107         ad.u.ipc_id = sma->sem_perm.key;
5108
5109         rc = avc_has_perm(sid, isec->sid, SECCLASS_SEM,
5110                           SEM__CREATE, &ad);
5111         if (rc) {
5112                 ipc_free_security(&sma->sem_perm);
5113                 return rc;
5114         }
5115         return 0;
5116 }
5117
5118 static void selinux_sem_free_security(struct sem_array *sma)
5119 {
5120         ipc_free_security(&sma->sem_perm);
5121 }
5122
5123 static int selinux_sem_associate(struct sem_array *sma, int semflg)
5124 {
5125         struct ipc_security_struct *isec;
5126         struct common_audit_data ad;
5127         struct selinux_audit_data sad = {0,};
5128         u32 sid = current_sid();
5129
5130         isec = sma->sem_perm.security;
5131
5132         COMMON_AUDIT_DATA_INIT(&ad, IPC);
5133         ad.selinux_audit_data = &sad;
5134         ad.u.ipc_id = sma->sem_perm.key;
5135
5136         return avc_has_perm(sid, isec->sid, SECCLASS_SEM,
5137                             SEM__ASSOCIATE, &ad);
5138 }
5139
5140 /* Note, at this point, sma is locked down */
5141 static int selinux_sem_semctl(struct sem_array *sma, int cmd)
5142 {
5143         int err;
5144         u32 perms;
5145
5146         switch (cmd) {
5147         case IPC_INFO:
5148         case SEM_INFO:
5149                 /* No specific object, just general system-wide information. */
5150                 return task_has_system(current, SYSTEM__IPC_INFO);
5151         case GETPID:
5152         case GETNCNT:
5153         case GETZCNT:
5154                 perms = SEM__GETATTR;
5155                 break;
5156         case GETVAL:
5157         case GETALL:
5158                 perms = SEM__READ;
5159                 break;
5160         case SETVAL:
5161         case SETALL:
5162                 perms = SEM__WRITE;
5163                 break;
5164         case IPC_RMID:
5165                 perms = SEM__DESTROY;
5166                 break;
5167         case IPC_SET:
5168                 perms = SEM__SETATTR;
5169                 break;
5170         case IPC_STAT:
5171         case SEM_STAT:
5172                 perms = SEM__GETATTR | SEM__ASSOCIATE;
5173                 break;
5174         default:
5175                 return 0;
5176         }
5177
5178         err = ipc_has_perm(&sma->sem_perm, perms);
5179         return err;
5180 }
5181
5182 static int selinux_sem_semop(struct sem_array *sma,
5183                              struct sembuf *sops, unsigned nsops, int alter)
5184 {
5185         u32 perms;
5186
5187         if (alter)
5188                 perms = SEM__READ | SEM__WRITE;
5189         else
5190                 perms = SEM__READ;
5191
5192         return ipc_has_perm(&sma->sem_perm, perms);
5193 }
5194
5195 static int selinux_ipc_permission(struct kern_ipc_perm *ipcp, short flag)
5196 {
5197         u32 av = 0;
5198
5199         av = 0;
5200         if (flag & S_IRUGO)
5201                 av |= IPC__UNIX_READ;
5202         if (flag & S_IWUGO)
5203                 av |= IPC__UNIX_WRITE;
5204
5205         if (av == 0)
5206                 return 0;
5207
5208         return ipc_has_perm(ipcp, av);
5209 }
5210
5211 static void selinux_ipc_getsecid(struct kern_ipc_perm *ipcp, u32 *secid)
5212 {
5213         struct ipc_security_struct *isec = ipcp->security;
5214         *secid = isec->sid;
5215 }
5216
5217 static void selinux_d_instantiate(struct dentry *dentry, struct inode *inode)
5218 {
5219         if (inode)
5220                 inode_doinit_with_dentry(inode, dentry);
5221 }
5222
5223 static int selinux_getprocattr(struct task_struct *p,
5224                                char *name, char **value)
5225 {
5226         const struct task_security_struct *__tsec;
5227         u32 sid;
5228         int error;
5229         unsigned len;
5230
5231         if (current != p) {
5232                 error = current_has_perm(p, PROCESS__GETATTR);
5233                 if (error)
5234                         return error;
5235         }
5236
5237         rcu_read_lock();
5238         __tsec = __task_cred(p)->security;
5239
5240         if (!strcmp(name, "current"))
5241                 sid = __tsec->sid;
5242         else if (!strcmp(name, "prev"))
5243                 sid = __tsec->osid;
5244         else if (!strcmp(name, "exec"))
5245                 sid = __tsec->exec_sid;
5246         else if (!strcmp(name, "fscreate"))
5247                 sid = __tsec->create_sid;
5248         else if (!strcmp(name, "keycreate"))
5249                 sid = __tsec->keycreate_sid;
5250         else if (!strcmp(name, "sockcreate"))
5251                 sid = __tsec->sockcreate_sid;
5252         else
5253                 goto invalid;
5254         rcu_read_unlock();
5255
5256         if (!sid)
5257                 return 0;
5258
5259         error = security_sid_to_context(sid, value, &len);
5260         if (error)
5261                 return error;
5262         return len;
5263
5264 invalid:
5265         rcu_read_unlock();
5266         return -EINVAL;
5267 }
5268
5269 static int selinux_setprocattr(struct task_struct *p,
5270                                char *name, void *value, size_t size)
5271 {
5272         struct task_security_struct *tsec;
5273         struct task_struct *tracer;
5274         struct cred *new;
5275         u32 sid = 0, ptsid;
5276         int error;
5277         char *str = value;
5278
5279         if (current != p) {
5280                 /* SELinux only allows a process to change its own
5281                    security attributes. */
5282                 return -EACCES;
5283         }
5284
5285         /*
5286          * Basic control over ability to set these attributes at all.
5287          * current == p, but we'll pass them separately in case the
5288          * above restriction is ever removed.
5289          */
5290         if (!strcmp(name, "exec"))
5291                 error = current_has_perm(p, PROCESS__SETEXEC);
5292         else if (!strcmp(name, "fscreate"))
5293                 error = current_has_perm(p, PROCESS__SETFSCREATE);
5294         else if (!strcmp(name, "keycreate"))
5295                 error = current_has_perm(p, PROCESS__SETKEYCREATE);
5296         else if (!strcmp(name, "sockcreate"))
5297                 error = current_has_perm(p, PROCESS__SETSOCKCREATE);
5298         else if (!strcmp(name, "current"))
5299                 error = current_has_perm(p, PROCESS__SETCURRENT);
5300         else
5301                 error = -EINVAL;
5302         if (error)
5303                 return error;
5304
5305         /* Obtain a SID for the context, if one was specified. */
5306         if (size && str[1] && str[1] != '\n') {
5307                 if (str[size-1] == '\n') {
5308                         str[size-1] = 0;
5309                         size--;
5310                 }
5311                 error = security_context_to_sid(value, size, &sid);
5312                 if (error == -EINVAL && !strcmp(name, "fscreate")) {
5313                         if (!capable(CAP_MAC_ADMIN))
5314                                 return error;
5315                         error = security_context_to_sid_force(value, size,
5316                                                               &sid);
5317                 }
5318                 if (error)
5319                         return error;
5320         }
5321
5322         new = prepare_creds();
5323         if (!new)
5324                 return -ENOMEM;
5325
5326         /* Permission checking based on the specified context is
5327            performed during the actual operation (execve,
5328            open/mkdir/...), when we know the full context of the
5329            operation.  See selinux_bprm_set_creds for the execve
5330            checks and may_create for the file creation checks. The
5331            operation will then fail if the context is not permitted. */
5332         tsec = new->security;
5333         if (!strcmp(name, "exec")) {
5334                 tsec->exec_sid = sid;
5335         } else if (!strcmp(name, "fscreate")) {
5336                 tsec->create_sid = sid;
5337         } else if (!strcmp(name, "keycreate")) {
5338                 error = may_create_key(sid, p);
5339                 if (error)
5340                         goto abort_change;
5341                 tsec->keycreate_sid = sid;
5342         } else if (!strcmp(name, "sockcreate")) {
5343                 tsec->sockcreate_sid = sid;
5344         } else if (!strcmp(name, "current")) {
5345                 error = -EINVAL;
5346                 if (sid == 0)
5347                         goto abort_change;
5348
5349                 /* Only allow single threaded processes to change context */
5350                 error = -EPERM;
5351                 if (!current_is_single_threaded()) {
5352                         error = security_bounded_transition(tsec->sid, sid);
5353                         if (error)
5354                                 goto abort_change;
5355                 }
5356
5357                 /* Check permissions for the transition. */
5358                 error = avc_has_perm(tsec->sid, sid, SECCLASS_PROCESS,
5359                                      PROCESS__DYNTRANSITION, NULL);
5360                 if (error)
5361                         goto abort_change;
5362
5363                 /* Check for ptracing, and update the task SID if ok.
5364                    Otherwise, leave SID unchanged and fail. */
5365                 ptsid = 0;
5366                 task_lock(p);
5367                 tracer = ptrace_parent(p);
5368                 if (tracer)
5369                         ptsid = task_sid(tracer);
5370                 task_unlock(p);
5371
5372                 if (tracer) {
5373                         error = avc_has_perm(ptsid, sid, SECCLASS_PROCESS,
5374                                              PROCESS__PTRACE, NULL);
5375                         if (error)
5376                                 goto abort_change;
5377                 }
5378
5379                 tsec->sid = sid;
5380         } else {
5381                 error = -EINVAL;
5382                 goto abort_change;
5383         }
5384
5385         commit_creds(new);
5386         return size;
5387
5388 abort_change:
5389         abort_creds(new);
5390         return error;
5391 }
5392
5393 static int selinux_secid_to_secctx(u32 secid, char **secdata, u32 *seclen)
5394 {
5395         return security_sid_to_context(secid, secdata, seclen);
5396 }
5397
5398 static int selinux_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid)
5399 {
5400         return security_context_to_sid(secdata, seclen, secid);
5401 }
5402
5403 static void selinux_release_secctx(char *secdata, u32 seclen)
5404 {
5405         kfree(secdata);
5406 }
5407
5408 /*
5409  *      called with inode->i_mutex locked
5410  */
5411 static int selinux_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen)
5412 {
5413         return selinux_inode_setsecurity(inode, XATTR_SELINUX_SUFFIX, ctx, ctxlen, 0);
5414 }
5415
5416 /*
5417  *      called with inode->i_mutex locked
5418  */
5419 static int selinux_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen)
5420 {
5421         return __vfs_setxattr_noperm(dentry, XATTR_NAME_SELINUX, ctx, ctxlen, 0);
5422 }
5423
5424 static int selinux_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen)
5425 {
5426         int len = 0;
5427         len = selinux_inode_getsecurity(inode, XATTR_SELINUX_SUFFIX,
5428                                                 ctx, true);
5429         if (len < 0)
5430                 return len;
5431         *ctxlen = len;
5432         return 0;
5433 }
5434 #ifdef CONFIG_KEYS
5435
5436 static int selinux_key_alloc(struct key *k, const struct cred *cred,
5437                              unsigned long flags)
5438 {
5439         const struct task_security_struct *tsec;
5440         struct key_security_struct *ksec;
5441
5442         ksec = kzalloc(sizeof(struct key_security_struct), GFP_KERNEL);
5443         if (!ksec)
5444                 return -ENOMEM;
5445
5446         tsec = cred->security;
5447         if (tsec->keycreate_sid)
5448                 ksec->sid = tsec->keycreate_sid;
5449         else
5450                 ksec->sid = tsec->sid;
5451
5452         k->security = ksec;
5453         return 0;
5454 }
5455
5456 static void selinux_key_free(struct key *k)
5457 {
5458         struct key_security_struct *ksec = k->security;
5459
5460         k->security = NULL;
5461         kfree(ksec);
5462 }
5463
5464 static int selinux_key_permission(key_ref_t key_ref,
5465                                   const struct cred *cred,
5466                                   key_perm_t perm)
5467 {
5468         struct key *key;
5469         struct key_security_struct *ksec;
5470         u32 sid;
5471
5472         /* if no specific permissions are requested, we skip the
5473            permission check. No serious, additional covert channels
5474            appear to be created. */
5475         if (perm == 0)
5476                 return 0;
5477
5478         sid = cred_sid(cred);
5479
5480         key = key_ref_to_ptr(key_ref);
5481         ksec = key->security;
5482
5483         return avc_has_perm(sid, ksec->sid, SECCLASS_KEY, perm, NULL);
5484 }
5485
5486 static int selinux_key_getsecurity(struct key *key, char **_buffer)
5487 {
5488         struct key_security_struct *ksec = key->security;
5489         char *context = NULL;
5490         unsigned len;
5491         int rc;
5492
5493         rc = security_sid_to_context(ksec->sid, &context, &len);
5494         if (!rc)
5495                 rc = len;
5496         *_buffer = context;
5497         return rc;
5498 }
5499
5500 #endif
5501
5502 static struct security_operations selinux_ops = {
5503         .name =                         "selinux",
5504
5505         .ptrace_access_check =          selinux_ptrace_access_check,
5506         .ptrace_traceme =               selinux_ptrace_traceme,
5507         .capget =                       selinux_capget,
5508         .capset =                       selinux_capset,
5509         .capable =                      selinux_capable,
5510         .quotactl =                     selinux_quotactl,
5511         .quota_on =                     selinux_quota_on,
5512         .syslog =                       selinux_syslog,
5513         .vm_enough_memory =             selinux_vm_enough_memory,
5514
5515         .netlink_send =                 selinux_netlink_send,
5516
5517         .bprm_set_creds =               selinux_bprm_set_creds,
5518         .bprm_committing_creds =        selinux_bprm_committing_creds,
5519         .bprm_committed_creds =         selinux_bprm_committed_creds,
5520         .bprm_secureexec =              selinux_bprm_secureexec,
5521
5522         .sb_alloc_security =            selinux_sb_alloc_security,
5523         .sb_free_security =             selinux_sb_free_security,
5524         .sb_copy_data =                 selinux_sb_copy_data,
5525         .sb_remount =                   selinux_sb_remount,
5526         .sb_kern_mount =                selinux_sb_kern_mount,
5527         .sb_show_options =              selinux_sb_show_options,
5528         .sb_statfs =                    selinux_sb_statfs,
5529         .sb_mount =                     selinux_mount,
5530         .sb_umount =                    selinux_umount,
5531         .sb_set_mnt_opts =              selinux_set_mnt_opts,
5532         .sb_clone_mnt_opts =            selinux_sb_clone_mnt_opts,
5533         .sb_parse_opts_str =            selinux_parse_opts_str,
5534
5535
5536         .inode_alloc_security =         selinux_inode_alloc_security,
5537         .inode_free_security =          selinux_inode_free_security,
5538         .inode_init_security =          selinux_inode_init_security,
5539         .inode_create =                 selinux_inode_create,
5540         .inode_link =                   selinux_inode_link,
5541         .inode_unlink =                 selinux_inode_unlink,
5542         .inode_symlink =                selinux_inode_symlink,
5543         .inode_mkdir =                  selinux_inode_mkdir,
5544         .inode_rmdir =                  selinux_inode_rmdir,
5545         .inode_mknod =                  selinux_inode_mknod,
5546         .inode_rename =                 selinux_inode_rename,
5547         .inode_readlink =               selinux_inode_readlink,
5548         .inode_follow_link =            selinux_inode_follow_link,
5549         .inode_permission =             selinux_inode_permission,
5550         .inode_setattr =                selinux_inode_setattr,
5551         .inode_getattr =                selinux_inode_getattr,
5552         .inode_setxattr =               selinux_inode_setxattr,
5553         .inode_post_setxattr =          selinux_inode_post_setxattr,
5554         .inode_getxattr =               selinux_inode_getxattr,
5555         .inode_listxattr =              selinux_inode_listxattr,
5556         .inode_removexattr =            selinux_inode_removexattr,
5557         .inode_getsecurity =            selinux_inode_getsecurity,
5558         .inode_setsecurity =            selinux_inode_setsecurity,
5559         .inode_listsecurity =           selinux_inode_listsecurity,
5560         .inode_getsecid =               selinux_inode_getsecid,
5561
5562         .file_permission =              selinux_file_permission,
5563         .file_alloc_security =          selinux_file_alloc_security,
5564         .file_free_security =           selinux_file_free_security,
5565         .file_ioctl =                   selinux_file_ioctl,
5566         .file_mmap =                    selinux_file_mmap,
5567         .file_mprotect =                selinux_file_mprotect,
5568         .file_lock =                    selinux_file_lock,
5569         .file_fcntl =                   selinux_file_fcntl,
5570         .file_set_fowner =              selinux_file_set_fowner,
5571         .file_send_sigiotask =          selinux_file_send_sigiotask,
5572         .file_receive =                 selinux_file_receive,
5573
5574         .dentry_open =                  selinux_dentry_open,
5575
5576         .task_create =                  selinux_task_create,
5577         .cred_alloc_blank =             selinux_cred_alloc_blank,
5578         .cred_free =                    selinux_cred_free,
5579         .cred_prepare =                 selinux_cred_prepare,
5580         .cred_transfer =                selinux_cred_transfer,
5581         .kernel_act_as =                selinux_kernel_act_as,
5582         .kernel_create_files_as =       selinux_kernel_create_files_as,
5583         .kernel_module_request =        selinux_kernel_module_request,
5584         .task_setpgid =                 selinux_task_setpgid,
5585         .task_getpgid =                 selinux_task_getpgid,
5586         .task_getsid =                  selinux_task_getsid,
5587         .task_getsecid =                selinux_task_getsecid,
5588         .task_setnice =                 selinux_task_setnice,
5589         .task_setioprio =               selinux_task_setioprio,
5590         .task_getioprio =               selinux_task_getioprio,
5591         .task_setrlimit =               selinux_task_setrlimit,
5592         .task_setscheduler =            selinux_task_setscheduler,
5593         .task_getscheduler =            selinux_task_getscheduler,
5594         .task_movememory =              selinux_task_movememory,
5595         .task_kill =                    selinux_task_kill,
5596         .task_wait =                    selinux_task_wait,
5597         .task_to_inode =                selinux_task_to_inode,
5598
5599         .ipc_permission =               selinux_ipc_permission,
5600         .ipc_getsecid =                 selinux_ipc_getsecid,
5601
5602         .msg_msg_alloc_security =       selinux_msg_msg_alloc_security,
5603         .msg_msg_free_security =        selinux_msg_msg_free_security,
5604
5605         .msg_queue_alloc_security =     selinux_msg_queue_alloc_security,
5606         .msg_queue_free_security =      selinux_msg_queue_free_security,
5607         .msg_queue_associate =          selinux_msg_queue_associate,
5608         .msg_queue_msgctl =             selinux_msg_queue_msgctl,
5609         .msg_queue_msgsnd =             selinux_msg_queue_msgsnd,
5610         .msg_queue_msgrcv =             selinux_msg_queue_msgrcv,
5611
5612         .shm_alloc_security =           selinux_shm_alloc_security,
5613         .shm_free_security =            selinux_shm_free_security,
5614         .shm_associate =                selinux_shm_associate,
5615         .shm_shmctl =                   selinux_shm_shmctl,
5616         .shm_shmat =                    selinux_shm_shmat,
5617
5618         .sem_alloc_security =           selinux_sem_alloc_security,
5619         .sem_free_security =            selinux_sem_free_security,
5620         .sem_associate =                selinux_sem_associate,
5621         .sem_semctl =                   selinux_sem_semctl,
5622         .sem_semop =                    selinux_sem_semop,
5623
5624         .d_instantiate =                selinux_d_instantiate,
5625
5626         .getprocattr =                  selinux_getprocattr,
5627         .setprocattr =                  selinux_setprocattr,
5628
5629         .secid_to_secctx =              selinux_secid_to_secctx,
5630         .secctx_to_secid =              selinux_secctx_to_secid,
5631         .release_secctx =               selinux_release_secctx,
5632         .inode_notifysecctx =           selinux_inode_notifysecctx,
5633         .inode_setsecctx =              selinux_inode_setsecctx,
5634         .inode_getsecctx =              selinux_inode_getsecctx,
5635
5636         .unix_stream_connect =          selinux_socket_unix_stream_connect,
5637         .unix_may_send =                selinux_socket_unix_may_send,
5638
5639         .socket_create =                selinux_socket_create,
5640         .socket_post_create =           selinux_socket_post_create,
5641         .socket_bind =                  selinux_socket_bind,
5642         .socket_connect =               selinux_socket_connect,
5643         .socket_listen =                selinux_socket_listen,
5644         .socket_accept =                selinux_socket_accept,
5645         .socket_sendmsg =               selinux_socket_sendmsg,
5646         .socket_recvmsg =               selinux_socket_recvmsg,
5647         .socket_getsockname =           selinux_socket_getsockname,
5648         .socket_getpeername =           selinux_socket_getpeername,
5649         .socket_getsockopt =            selinux_socket_getsockopt,
5650         .socket_setsockopt =            selinux_socket_setsockopt,
5651         .socket_shutdown =              selinux_socket_shutdown,
5652         .socket_sock_rcv_skb =          selinux_socket_sock_rcv_skb,
5653         .socket_getpeersec_stream =     selinux_socket_getpeersec_stream,
5654         .socket_getpeersec_dgram =      selinux_socket_getpeersec_dgram,
5655         .sk_alloc_security =            selinux_sk_alloc_security,
5656         .sk_free_security =             selinux_sk_free_security,
5657         .sk_clone_security =            selinux_sk_clone_security,
5658         .sk_getsecid =                  selinux_sk_getsecid,
5659         .sock_graft =                   selinux_sock_graft,
5660         .inet_conn_request =            selinux_inet_conn_request,
5661         .inet_csk_clone =               selinux_inet_csk_clone,
5662         .inet_conn_established =        selinux_inet_conn_established,
5663         .secmark_relabel_packet =       selinux_secmark_relabel_packet,
5664         .secmark_refcount_inc =         selinux_secmark_refcount_inc,
5665         .secmark_refcount_dec =         selinux_secmark_refcount_dec,
5666         .req_classify_flow =            selinux_req_classify_flow,
5667         .tun_dev_create =               selinux_tun_dev_create,
5668         .tun_dev_post_create =          selinux_tun_dev_post_create,
5669         .tun_dev_attach =               selinux_tun_dev_attach,
5670
5671 #ifdef CONFIG_SECURITY_NETWORK_XFRM
5672         .xfrm_policy_alloc_security =   selinux_xfrm_policy_alloc,
5673         .xfrm_policy_clone_security =   selinux_xfrm_policy_clone,
5674         .xfrm_policy_free_security =    selinux_xfrm_policy_free,
5675         .xfrm_policy_delete_security =  selinux_xfrm_policy_delete,
5676         .xfrm_state_alloc_security =    selinux_xfrm_state_alloc,
5677         .xfrm_state_free_security =     selinux_xfrm_state_free,
5678         .xfrm_state_delete_security =   selinux_xfrm_state_delete,
5679         .xfrm_policy_lookup =           selinux_xfrm_policy_lookup,
5680         .xfrm_state_pol_flow_match =    selinux_xfrm_state_pol_flow_match,
5681         .xfrm_decode_session =          selinux_xfrm_decode_session,
5682 #endif
5683
5684 #ifdef CONFIG_KEYS
5685         .key_alloc =                    selinux_key_alloc,
5686         .key_free =                     selinux_key_free,
5687         .key_permission =               selinux_key_permission,
5688         .key_getsecurity =              selinux_key_getsecurity,
5689 #endif
5690
5691 #ifdef CONFIG_AUDIT
5692         .audit_rule_init =              selinux_audit_rule_init,
5693         .audit_rule_known =             selinux_audit_rule_known,
5694         .audit_rule_match =             selinux_audit_rule_match,
5695         .audit_rule_free =              selinux_audit_rule_free,
5696 #endif
5697 };
5698
5699 static __init int selinux_init(void)
5700 {
5701         if (!security_module_enable(&selinux_ops)) {
5702                 selinux_enabled = 0;
5703                 return 0;
5704         }
5705
5706         if (!selinux_enabled) {
5707                 printk(KERN_INFO "SELinux:  Disabled at boot.\n");
5708                 return 0;
5709         }
5710
5711         printk(KERN_INFO "SELinux:  Initializing.\n");
5712
5713         /* Set the security state for the initial task. */
5714         cred_init_security();
5715
5716         default_noexec = !(VM_DATA_DEFAULT_FLAGS & VM_EXEC);
5717
5718         sel_inode_cache = kmem_cache_create("selinux_inode_security",
5719                                             sizeof(struct inode_security_struct),
5720                                             0, SLAB_PANIC, NULL);
5721         avc_init();
5722
5723         if (register_security(&selinux_ops))
5724                 panic("SELinux: Unable to register with kernel.\n");
5725
5726         if (selinux_enforcing)
5727                 printk(KERN_DEBUG "SELinux:  Starting in enforcing mode\n");
5728         else
5729                 printk(KERN_DEBUG "SELinux:  Starting in permissive mode\n");
5730
5731         return 0;
5732 }
5733
5734 static void delayed_superblock_init(struct super_block *sb, void *unused)
5735 {
5736         superblock_doinit(sb, NULL);
5737 }
5738
5739 void selinux_complete_init(void)
5740 {
5741         printk(KERN_DEBUG "SELinux:  Completing initialization.\n");
5742
5743         /* Set up any superblocks initialized prior to the policy load. */
5744         printk(KERN_DEBUG "SELinux:  Setting up existing superblocks.\n");
5745         iterate_supers(delayed_superblock_init, NULL);
5746 }
5747
5748 /* SELinux requires early initialization in order to label
5749    all processes and objects when they are created. */
5750 security_initcall(selinux_init);
5751
5752 #if defined(CONFIG_NETFILTER)
5753
5754 static struct nf_hook_ops selinux_ipv4_ops[] = {
5755         {
5756                 .hook =         selinux_ipv4_postroute,
5757                 .owner =        THIS_MODULE,
5758                 .pf =           PF_INET,
5759                 .hooknum =      NF_INET_POST_ROUTING,
5760                 .priority =     NF_IP_PRI_SELINUX_LAST,
5761         },
5762         {
5763                 .hook =         selinux_ipv4_forward,
5764                 .owner =        THIS_MODULE,
5765                 .pf =           PF_INET,
5766                 .hooknum =      NF_INET_FORWARD,
5767                 .priority =     NF_IP_PRI_SELINUX_FIRST,
5768         },
5769         {
5770                 .hook =         selinux_ipv4_output,
5771                 .owner =        THIS_MODULE,
5772                 .pf =           PF_INET,
5773                 .hooknum =      NF_INET_LOCAL_OUT,
5774                 .priority =     NF_IP_PRI_SELINUX_FIRST,
5775         }
5776 };
5777
5778 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
5779
5780 static struct nf_hook_ops selinux_ipv6_ops[] = {
5781         {
5782                 .hook =         selinux_ipv6_postroute,
5783                 .owner =        THIS_MODULE,
5784                 .pf =           PF_INET6,
5785                 .hooknum =      NF_INET_POST_ROUTING,
5786                 .priority =     NF_IP6_PRI_SELINUX_LAST,
5787         },
5788         {
5789                 .hook =         selinux_ipv6_forward,
5790                 .owner =        THIS_MODULE,
5791                 .pf =           PF_INET6,
5792                 .hooknum =      NF_INET_FORWARD,
5793                 .priority =     NF_IP6_PRI_SELINUX_FIRST,
5794         }
5795 };
5796
5797 #endif  /* IPV6 */
5798
5799 static int __init selinux_nf_ip_init(void)
5800 {
5801         int err = 0;
5802
5803         if (!selinux_enabled)
5804                 goto out;
5805
5806         printk(KERN_DEBUG "SELinux:  Registering netfilter hooks\n");
5807
5808         err = nf_register_hooks(selinux_ipv4_ops, ARRAY_SIZE(selinux_ipv4_ops));
5809         if (err)
5810                 panic("SELinux: nf_register_hooks for IPv4: error %d\n", err);
5811
5812 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
5813         err = nf_register_hooks(selinux_ipv6_ops, ARRAY_SIZE(selinux_ipv6_ops));
5814         if (err)
5815                 panic("SELinux: nf_register_hooks for IPv6: error %d\n", err);
5816 #endif  /* IPV6 */
5817
5818 out:
5819         return err;
5820 }
5821
5822 __initcall(selinux_nf_ip_init);
5823
5824 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
5825 static void selinux_nf_ip_exit(void)
5826 {
5827         printk(KERN_DEBUG "SELinux:  Unregistering netfilter hooks\n");
5828
5829         nf_unregister_hooks(selinux_ipv4_ops, ARRAY_SIZE(selinux_ipv4_ops));
5830 #if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
5831         nf_unregister_hooks(selinux_ipv6_ops, ARRAY_SIZE(selinux_ipv6_ops));
5832 #endif  /* IPV6 */
5833 }
5834 #endif
5835
5836 #else /* CONFIG_NETFILTER */
5837
5838 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
5839 #define selinux_nf_ip_exit()
5840 #endif
5841
5842 #endif /* CONFIG_NETFILTER */
5843
5844 #ifdef CONFIG_SECURITY_SELINUX_DISABLE
5845 static int selinux_disabled;
5846
5847 int selinux_disable(void)
5848 {
5849         if (ss_initialized) {
5850                 /* Not permitted after initial policy load. */
5851                 return -EINVAL;
5852         }
5853
5854         if (selinux_disabled) {
5855                 /* Only do this once. */
5856                 return -EINVAL;
5857         }
5858
5859         printk(KERN_INFO "SELinux:  Disabled at runtime.\n");
5860
5861         selinux_disabled = 1;
5862         selinux_enabled = 0;
5863
5864         reset_security_ops();
5865
5866         /* Try to destroy the avc node cache */
5867         avc_disable();
5868
5869         /* Unregister netfilter hooks. */
5870         selinux_nf_ip_exit();
5871
5872         /* Unregister selinuxfs. */
5873         exit_sel_fs();
5874
5875         return 0;
5876 }
5877 #endif