Pileus Git - ~andy/linux/blob - kernel/auditfilter.c

   1 /* auditfilter.c -- filtering of audit events
   2  *
   3  * Copyright 2003-2004 Red Hat, Inc.
   4  * Copyright 2005 Hewlett-Packard Development Company, L.P.
   5  * Copyright 2005 IBM Corporation
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License as published by
   9  * the Free Software Foundation; either version 2 of the License, or
  10  * (at your option) any later version.
  11  *
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU General Public License
  18  * along with this program; if not, write to the Free Software
  19  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
  20  */
  21
  22 #include <linux/kernel.h>
  23 #include <linux/audit.h>
  24 #include <linux/kthread.h>
  25 #include <linux/mutex.h>
  26 #include <linux/fs.h>
  27 #include <linux/namei.h>
  28 #include <linux/netlink.h>
  29 #include <linux/sched.h>
  30 #include <linux/slab.h>
  31 #include <linux/security.h>
  32 #include "audit.h"
  33
  34 /*
  35  * Locking model:
  36  *
  37  * audit_filter_mutex:
  38  *              Synchronizes writes and blocking reads of audit's filterlist
  39  *              data.  Rcu is used to traverse the filterlist and access
  40  *              contents of structs audit_entry, audit_watch and opaque
  41  *              LSM rules during filtering.  If modified, these structures
  42  *              must be copied and replace their counterparts in the filterlist.
  43  *              An audit_parent struct is not accessed during filtering, so may
  44  *              be written directly provided audit_filter_mutex is held.
  45  */
  46
  47 /* Audit filter lists, defined in <linux/audit.h> */
  48 struct list_head audit_filter_list[AUDIT_NR_FILTERS] = {
  49         LIST_HEAD_INIT(audit_filter_list[0]),
  50         LIST_HEAD_INIT(audit_filter_list[1]),
  51         LIST_HEAD_INIT(audit_filter_list[2]),
  52         LIST_HEAD_INIT(audit_filter_list[3]),
  53         LIST_HEAD_INIT(audit_filter_list[4]),
  54         LIST_HEAD_INIT(audit_filter_list[5]),
  55 #if AUDIT_NR_FILTERS != 6
  56 #error Fix audit_filter_list initialiser
  57 #endif
  58 };
  59 static struct list_head audit_rules_list[AUDIT_NR_FILTERS] = {
  60         LIST_HEAD_INIT(audit_rules_list[0]),
  61         LIST_HEAD_INIT(audit_rules_list[1]),
  62         LIST_HEAD_INIT(audit_rules_list[2]),
  63         LIST_HEAD_INIT(audit_rules_list[3]),
  64         LIST_HEAD_INIT(audit_rules_list[4]),
  65         LIST_HEAD_INIT(audit_rules_list[5]),
  66 };
  67
  68 DEFINE_MUTEX(audit_filter_mutex);
  69
  70 static inline void audit_free_rule(struct audit_entry *e)
  71 {
  72         int i;
  73         struct audit_krule *erule = &e->rule;
  74
  75         /* some rules don't have associated watches */
  76         if (erule->watch)
  77                 audit_put_watch(erule->watch);
  78         if (erule->fields)
  79                 for (i = 0; i < erule->field_count; i++) {
  80                         struct audit_field *f = &erule->fields[i];
  81                         kfree(f->lsm_str);
  82                         security_audit_rule_free(f->lsm_rule);
  83                 }
  84         kfree(erule->fields);
  85         kfree(erule->filterkey);
  86         kfree(e);
  87 }
  88
  89 void audit_free_rule_rcu(struct rcu_head *head)
  90 {
  91         struct audit_entry *e = container_of(head, struct audit_entry, rcu);
  92         audit_free_rule(e);
  93 }
  94
  95 /* Initialize an audit filterlist entry. */
  96 static inline struct audit_entry *audit_init_entry(u32 field_count)
  97 {
  98         struct audit_entry *entry;
  99         struct audit_field *fields;
 100
 101         entry = kzalloc(sizeof(*entry), GFP_KERNEL);
 102         if (unlikely(!entry))
 103                 return NULL;
 104
 105         fields = kzalloc(sizeof(*fields) * field_count, GFP_KERNEL);
 106         if (unlikely(!fields)) {
 107                 kfree(entry);
 108                 return NULL;
 109         }
 110         entry->rule.fields = fields;
 111
 112         return entry;
 113 }
 114
 115 /* Unpack a filter field's string representation from user-space
 116  * buffer. */
 117 char *audit_unpack_string(void **bufp, size_t *remain, size_t len)
 118 {
 119         char *str;
 120
 121         if (!*bufp || (len == 0) || (len > *remain))
 122                 return ERR_PTR(-EINVAL);
 123
 124         /* Of the currently implemented string fields, PATH_MAX
 125          * defines the longest valid length.
 126          */
 127         if (len > PATH_MAX)
 128                 return ERR_PTR(-ENAMETOOLONG);
 129
 130         str = kmalloc(len + 1, GFP_KERNEL);
 131         if (unlikely(!str))
 132                 return ERR_PTR(-ENOMEM);
 133
 134         memcpy(str, *bufp, len);
 135         str[len] = 0;
 136         *bufp += len;
 137         *remain -= len;
 138
 139         return str;
 140 }
 141
 142 /* Translate an inode field to kernel respresentation. */
 143 static inline int audit_to_inode(struct audit_krule *krule,
 144                                  struct audit_field *f)
 145 {
 146         if (krule->listnr != AUDIT_FILTER_EXIT ||
 147             krule->watch || krule->inode_f || krule->tree ||
 148             (f->op != Audit_equal && f->op != Audit_not_equal))
 149                 return -EINVAL;
 150
 151         krule->inode_f = f;
 152         return 0;
 153 }
 154
 155 static __u32 *classes[AUDIT_SYSCALL_CLASSES];
 156
 157 int __init audit_register_class(int class, unsigned *list)
 158 {
 159         __u32 *p = kzalloc(AUDIT_BITMASK_SIZE * sizeof(__u32), GFP_KERNEL);
 160         if (!p)
 161                 return -ENOMEM;
 162         while (*list != ~0U) {
 163                 unsigned n = *list++;
 164                 if (n >= AUDIT_BITMASK_SIZE * 32 - AUDIT_SYSCALL_CLASSES) {
 165                         kfree(p);
 166                         return -EINVAL;
 167                 }
 168                 p[AUDIT_WORD(n)] |= AUDIT_BIT(n);
 169         }
 170         if (class >= AUDIT_SYSCALL_CLASSES || classes[class]) {
 171                 kfree(p);
 172                 return -EINVAL;
 173         }
 174         classes[class] = p;
 175         return 0;
 176 }
 177
 178 int audit_match_class(int class, unsigned syscall)
 179 {
 180         if (unlikely(syscall >= AUDIT_BITMASK_SIZE * 32))
 181                 return 0;
 182         if (unlikely(class >= AUDIT_SYSCALL_CLASSES || !classes[class]))
 183                 return 0;
 184         return classes[class][AUDIT_WORD(syscall)] & AUDIT_BIT(syscall);
 185 }
 186
 187 #ifdef CONFIG_AUDITSYSCALL
 188 static inline int audit_match_class_bits(int class, u32 *mask)
 189 {
 190         int i;
 191
 192         if (classes[class]) {
 193                 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
 194                         if (mask[i] & classes[class][i])
 195                                 return 0;
 196         }
 197         return 1;
 198 }
 199
 200 static int audit_match_signal(struct audit_entry *entry)
 201 {
 202         struct audit_field *arch = entry->rule.arch_f;
 203
 204         if (!arch) {
 205                 /* When arch is unspecified, we must check both masks on biarch
 206                  * as syscall number alone is ambiguous. */
 207                 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL,
 208                                                entry->rule.mask) &&
 209                         audit_match_class_bits(AUDIT_CLASS_SIGNAL_32,
 210                                                entry->rule.mask));
 211         }
 212
 213         switch(audit_classify_arch(arch->val)) {
 214         case 0: /* native */
 215                 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL,
 216                                                entry->rule.mask));
 217         case 1: /* 32bit on biarch */
 218                 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL_32,
 219                                                entry->rule.mask));
 220         default:
 221                 return 1;
 222         }
 223 }
 224 #endif
 225
 226 /* Common user-space to kernel rule translation. */
 227 static inline struct audit_entry *audit_to_entry_common(struct audit_rule *rule)
 228 {
 229         unsigned listnr;
 230         struct audit_entry *entry;
 231         int i, err;
 232
 233         err = -EINVAL;
 234         listnr = rule->flags & ~AUDIT_FILTER_PREPEND;
 235         switch(listnr) {
 236         default:
 237                 goto exit_err;
 238 #ifdef CONFIG_AUDITSYSCALL
 239         case AUDIT_FILTER_ENTRY:
 240                 if (rule->action == AUDIT_ALWAYS)
 241                         goto exit_err;
 242         case AUDIT_FILTER_EXIT:
 243         case AUDIT_FILTER_TASK:
 244 #endif
 245         case AUDIT_FILTER_USER:
 246         case AUDIT_FILTER_TYPE:
 247                 ;
 248         }
 249         if (unlikely(rule->action == AUDIT_POSSIBLE)) {
 250                 printk(KERN_ERR "AUDIT_POSSIBLE is deprecated\n");
 251                 goto exit_err;
 252         }
 253         if (rule->action != AUDIT_NEVER && rule->action != AUDIT_ALWAYS)
 254                 goto exit_err;
 255         if (rule->field_count > AUDIT_MAX_FIELDS)
 256                 goto exit_err;
 257
 258         err = -ENOMEM;
 259         entry = audit_init_entry(rule->field_count);
 260         if (!entry)
 261                 goto exit_err;
 262
 263         entry->rule.flags = rule->flags & AUDIT_FILTER_PREPEND;
 264         entry->rule.listnr = listnr;
 265         entry->rule.action = rule->action;
 266         entry->rule.field_count = rule->field_count;
 267
 268         for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
 269                 entry->rule.mask[i] = rule->mask[i];
 270
 271         for (i = 0; i < AUDIT_SYSCALL_CLASSES; i++) {
 272                 int bit = AUDIT_BITMASK_SIZE * 32 - i - 1;
 273                 __u32 *p = &entry->rule.mask[AUDIT_WORD(bit)];
 274                 __u32 *class;
 275
 276                 if (!(*p & AUDIT_BIT(bit)))
 277                         continue;
 278                 *p &= ~AUDIT_BIT(bit);
 279                 class = classes[i];
 280                 if (class) {
 281                         int j;
 282                         for (j = 0; j < AUDIT_BITMASK_SIZE; j++)
 283                                 entry->rule.mask[j] |= class[j];
 284                 }
 285         }
 286
 287         return entry;
 288
 289 exit_err:
 290         return ERR_PTR(err);
 291 }
 292
 293 static u32 audit_ops[] =
 294 {
 295         [Audit_equal] = AUDIT_EQUAL,
 296         [Audit_not_equal] = AUDIT_NOT_EQUAL,
 297         [Audit_bitmask] = AUDIT_BIT_MASK,
 298         [Audit_bittest] = AUDIT_BIT_TEST,
 299         [Audit_lt] = AUDIT_LESS_THAN,
 300         [Audit_gt] = AUDIT_GREATER_THAN,
 301         [Audit_le] = AUDIT_LESS_THAN_OR_EQUAL,
 302         [Audit_ge] = AUDIT_GREATER_THAN_OR_EQUAL,
 303 };
 304
 305 static u32 audit_to_op(u32 op)
 306 {
 307         u32 n;
 308         for (n = Audit_equal; n < Audit_bad && audit_ops[n] != op; n++)
 309                 ;
 310         return n;
 311 }
 312
 313 /* check if a field is valid for a given list */
 314 static int audit_field_valid(struct audit_entry *entry, struct audit_field *f)
 315 {
 316         switch(f->type) {
 317         case AUDIT_MSGTYPE:
 318                 if (entry->rule.listnr != AUDIT_FILTER_TYPE &&
 319                     entry->rule.listnr != AUDIT_FILTER_USER)
 320                         return -EINVAL;
 321                 break;
 322         };
 323         return 0;
 324 }
 325
 326 /* Translate struct audit_rule to kernel's rule respresentation.
 327  * Exists for backward compatibility with userspace. */
 328 static struct audit_entry *audit_rule_to_entry(struct audit_rule *rule)
 329 {
 330         struct audit_entry *entry;
 331         int err = 0;
 332         int i;
 333
 334         entry = audit_to_entry_common(rule);
 335         if (IS_ERR(entry))
 336                 goto exit_nofree;
 337
 338         for (i = 0; i < rule->field_count; i++) {
 339                 struct audit_field *f = &entry->rule.fields[i];
 340                 u32 n;
 341
 342                 n = rule->fields[i] & (AUDIT_NEGATE|AUDIT_OPERATORS);
 343
 344                 /* Support for legacy operators where
 345                  * AUDIT_NEGATE bit signifies != and otherwise assumes == */
 346                 if (n & AUDIT_NEGATE)
 347                         f->op = Audit_not_equal;
 348                 else if (!n)
 349                         f->op = Audit_equal;
 350                 else
 351                         f->op = audit_to_op(n);
 352
 353                 entry->rule.vers_ops = (n & AUDIT_OPERATORS) ? 2 : 1;
 354
 355                 f->type = rule->fields[i] & ~(AUDIT_NEGATE|AUDIT_OPERATORS);
 356                 f->val = rule->values[i];
 357                 f->uid = INVALID_UID;
 358                 f->gid = INVALID_GID;
 359
 360                 err = -EINVAL;
 361                 if (f->op == Audit_bad)
 362                         goto exit_free;
 363
 364                 switch(f->type) {
 365                 default:
 366                         goto exit_free;
 367                 case AUDIT_UID:
 368                 case AUDIT_EUID:
 369                 case AUDIT_SUID:
 370                 case AUDIT_FSUID:
 371                 case AUDIT_LOGINUID:
 372                         /* bit ops not implemented for uid comparisons */
 373                         if (f->op == Audit_bitmask || f->op == Audit_bittest)
 374                                 goto exit_free;
 375
 376                         f->uid = make_kuid(current_user_ns(), f->val);
 377                         if (!uid_valid(f->uid))
 378                                 goto exit_free;
 379                         break;
 380                 case AUDIT_GID:
 381                 case AUDIT_EGID:
 382                 case AUDIT_SGID:
 383                 case AUDIT_FSGID:
 384                         /* bit ops not implemented for gid comparisons */
 385                         if (f->op == Audit_bitmask || f->op == Audit_bittest)
 386                                 goto exit_free;
 387
 388                         f->gid = make_kgid(current_user_ns(), f->val);
 389                         if (!gid_valid(f->gid))
 390                                 goto exit_free;
 391                         break;
 392                 case AUDIT_PID:
 393                 case AUDIT_PERS:
 394                 case AUDIT_MSGTYPE:
 395                 case AUDIT_PPID:
 396                 case AUDIT_DEVMAJOR:
 397                 case AUDIT_DEVMINOR:
 398                 case AUDIT_EXIT:
 399                 case AUDIT_SUCCESS:
 400                         /* bit ops are only useful on syscall args */
 401                         if (f->op == Audit_bitmask || f->op == Audit_bittest)
 402                                 goto exit_free;
 403                         break;
 404                 case AUDIT_ARG0:
 405                 case AUDIT_ARG1:
 406                 case AUDIT_ARG2:
 407                 case AUDIT_ARG3:
 408                         break;
 409                 /* arch is only allowed to be = or != */
 410                 case AUDIT_ARCH:
 411                         if (f->op != Audit_not_equal && f->op != Audit_equal)
 412                                 goto exit_free;
 413                         entry->rule.arch_f = f;
 414                         break;
 415                 case AUDIT_PERM:
 416                         if (f->val & ~15)
 417                                 goto exit_free;
 418                         break;
 419                 case AUDIT_FILETYPE:
 420                         if (f->val & ~S_IFMT)
 421                                 goto exit_free;
 422                         break;
 423                 case AUDIT_INODE:
 424                         err = audit_to_inode(&entry->rule, f);
 425                         if (err)
 426                                 goto exit_free;
 427                         break;
 428                 }
 429         }
 430
 431         if (entry->rule.inode_f && entry->rule.inode_f->op == Audit_not_equal)
 432                 entry->rule.inode_f = NULL;
 433
 434 exit_nofree:
 435         return entry;
 436
 437 exit_free:
 438         audit_free_rule(entry);
 439         return ERR_PTR(err);
 440 }
 441
 442 /* Translate struct audit_rule_data to kernel's rule respresentation. */
 443 static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
 444                                                size_t datasz)
 445 {
 446         int err = 0;
 447         struct audit_entry *entry;
 448         void *bufp;
 449         size_t remain = datasz - sizeof(struct audit_rule_data);
 450         int i;
 451         char *str;
 452
 453         entry = audit_to_entry_common((struct audit_rule *)data);
 454         if (IS_ERR(entry))
 455                 goto exit_nofree;
 456
 457         bufp = data->buf;
 458         entry->rule.vers_ops = 2;
 459         for (i = 0; i < data->field_count; i++) {
 460                 struct audit_field *f = &entry->rule.fields[i];
 461
 462                 err = -EINVAL;
 463
 464                 f->op = audit_to_op(data->fieldflags[i]);
 465                 if (f->op == Audit_bad)
 466                         goto exit_free;
 467
 468                 f->type = data->fields[i];
 469                 f->val = data->values[i];
 470                 f->uid = INVALID_UID;
 471                 f->gid = INVALID_GID;
 472                 f->lsm_str = NULL;
 473                 f->lsm_rule = NULL;
 474
 475                 err = audit_field_valid(entry, f);
 476                 if (err)
 477                         goto exit_free;
 478
 479                 err = -EINVAL;
 480
 481                 switch(f->type) {
 482                 case AUDIT_UID:
 483                 case AUDIT_EUID:
 484                 case AUDIT_SUID:
 485                 case AUDIT_FSUID:
 486                 case AUDIT_LOGINUID:
 487                 case AUDIT_OBJ_UID:
 488                         /* bit ops not implemented for uid comparisons */
 489                         if (f->op == Audit_bitmask || f->op == Audit_bittest)
 490                                 goto exit_free;
 491
 492                         f->uid = make_kuid(current_user_ns(), f->val);
 493                         if (!uid_valid(f->uid))
 494                                 goto exit_free;
 495                         break;
 496                 case AUDIT_GID:
 497                 case AUDIT_EGID:
 498                 case AUDIT_SGID:
 499                 case AUDIT_FSGID:
 500                 case AUDIT_OBJ_GID:
 501                         /* bit ops not implemented for gid comparisons */
 502                         if (f->op == Audit_bitmask || f->op == Audit_bittest)
 503                                 goto exit_free;
 504
 505                         f->gid = make_kgid(current_user_ns(), f->val);
 506                         if (!gid_valid(f->gid))
 507                                 goto exit_free;
 508                         break;
 509                 case AUDIT_PID:
 510                 case AUDIT_PERS:
 511                 case AUDIT_MSGTYPE:
 512                 case AUDIT_PPID:
 513                 case AUDIT_DEVMAJOR:
 514                 case AUDIT_DEVMINOR:
 515                 case AUDIT_EXIT:
 516                 case AUDIT_SUCCESS:
 517                 case AUDIT_ARG0:
 518                 case AUDIT_ARG1:
 519                 case AUDIT_ARG2:
 520                 case AUDIT_ARG3:
 521                         break;
 522                 case AUDIT_ARCH:
 523                         entry->rule.arch_f = f;
 524                         break;
 525                 case AUDIT_SUBJ_USER:
 526                 case AUDIT_SUBJ_ROLE:
 527                 case AUDIT_SUBJ_TYPE:
 528                 case AUDIT_SUBJ_SEN:
 529                 case AUDIT_SUBJ_CLR:
 530                 case AUDIT_OBJ_USER:
 531                 case AUDIT_OBJ_ROLE:
 532                 case AUDIT_OBJ_TYPE:
 533                 case AUDIT_OBJ_LEV_LOW:
 534                 case AUDIT_OBJ_LEV_HIGH:
 535                         str = audit_unpack_string(&bufp, &remain, f->val);
 536                         if (IS_ERR(str))
 537                                 goto exit_free;
 538                         entry->rule.buflen += f->val;
 539
 540                         err = security_audit_rule_init(f->type, f->op, str,
 541                                                        (void **)&f->lsm_rule);
 542                         /* Keep currently invalid fields around in case they
 543                          * become valid after a policy reload. */
 544                         if (err == -EINVAL) {
 545                                 printk(KERN_WARNING "audit rule for LSM "
 546                                        "\'%s\' is invalid\n",  str);
 547                                 err = 0;
 548                         }
 549                         if (err) {
 550                                 kfree(str);
 551                                 goto exit_free;
 552                         } else
 553                                 f->lsm_str = str;
 554                         break;
 555                 case AUDIT_WATCH:
 556                         str = audit_unpack_string(&bufp, &remain, f->val);
 557                         if (IS_ERR(str))
 558                                 goto exit_free;
 559                         entry->rule.buflen += f->val;
 560
 561                         err = audit_to_watch(&entry->rule, str, f->val, f->op);
 562                         if (err) {
 563                                 kfree(str);
 564                                 goto exit_free;
 565                         }
 566                         break;
 567                 case AUDIT_DIR:
 568                         str = audit_unpack_string(&bufp, &remain, f->val);
 569                         if (IS_ERR(str))
 570                                 goto exit_free;
 571                         entry->rule.buflen += f->val;
 572
 573                         err = audit_make_tree(&entry->rule, str, f->op);
 574                         kfree(str);
 575                         if (err)
 576                                 goto exit_free;
 577                         break;
 578                 case AUDIT_INODE:
 579                         err = audit_to_inode(&entry->rule, f);
 580                         if (err)
 581                                 goto exit_free;
 582                         break;
 583                 case AUDIT_FILTERKEY:
 584                         if (entry->rule.filterkey || f->val > AUDIT_MAX_KEY_LEN)
 585                                 goto exit_free;
 586                         str = audit_unpack_string(&bufp, &remain, f->val);
 587                         if (IS_ERR(str))
 588                                 goto exit_free;
 589                         entry->rule.buflen += f->val;
 590                         entry->rule.filterkey = str;
 591                         break;
 592                 case AUDIT_PERM:
 593                         if (f->val & ~15)
 594                                 goto exit_free;
 595                         break;
 596                 case AUDIT_FILETYPE:
 597                         if (f->val & ~S_IFMT)
 598                                 goto exit_free;
 599                         break;
 600                 case AUDIT_FIELD_COMPARE:
 601                         if (f->val > AUDIT_MAX_FIELD_COMPARE)
 602                                 goto exit_free;
 603                         break;
 604                 default:
 605                         goto exit_free;
 606                 }
 607         }
 608
 609         if (entry->rule.inode_f && entry->rule.inode_f->op == Audit_not_equal)
 610                 entry->rule.inode_f = NULL;
 611
 612 exit_nofree:
 613         return entry;
 614
 615 exit_free:
 616         audit_free_rule(entry);
 617         return ERR_PTR(err);
 618 }
 619
 620 /* Pack a filter field's string representation into data block. */
 621 static inline size_t audit_pack_string(void **bufp, const char *str)
 622 {
 623         size_t len = strlen(str);
 624
 625         memcpy(*bufp, str, len);
 626         *bufp += len;
 627
 628         return len;
 629 }
 630
 631 /* Translate kernel rule respresentation to struct audit_rule.
 632  * Exists for backward compatibility with userspace. */
 633 static struct audit_rule *audit_krule_to_rule(struct audit_krule *krule)
 634 {
 635         struct audit_rule *rule;
 636         int i;
 637
 638         rule = kzalloc(sizeof(*rule), GFP_KERNEL);
 639         if (unlikely(!rule))
 640                 return NULL;
 641
 642         rule->flags = krule->flags | krule->listnr;
 643         rule->action = krule->action;
 644         rule->field_count = krule->field_count;
 645         for (i = 0; i < rule->field_count; i++) {
 646                 rule->values[i] = krule->fields[i].val;
 647                 rule->fields[i] = krule->fields[i].type;
 648
 649                 if (krule->vers_ops == 1) {
 650                         if (krule->fields[i].op == Audit_not_equal)
 651                                 rule->fields[i] |= AUDIT_NEGATE;
 652                 } else {
 653                         rule->fields[i] |= audit_ops[krule->fields[i].op];
 654                 }
 655         }
 656         for (i = 0; i < AUDIT_BITMASK_SIZE; i++) rule->mask[i] = krule->mask[i];
 657
 658         return rule;
 659 }
 660
 661 /* Translate kernel rule respresentation to struct audit_rule_data. */
 662 static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule)
 663 {
 664         struct audit_rule_data *data;
 665         void *bufp;
 666         int i;
 667
 668         data = kmalloc(sizeof(*data) + krule->buflen, GFP_KERNEL);
 669         if (unlikely(!data))
 670                 return NULL;
 671         memset(data, 0, sizeof(*data));
 672
 673         data->flags = krule->flags | krule->listnr;
 674         data->action = krule->action;
 675         data->field_count = krule->field_count;
 676         bufp = data->buf;
 677         for (i = 0; i < data->field_count; i++) {
 678                 struct audit_field *f = &krule->fields[i];
 679
 680                 data->fields[i] = f->type;
 681                 data->fieldflags[i] = audit_ops[f->op];
 682                 switch(f->type) {
 683                 case AUDIT_SUBJ_USER:
 684                 case AUDIT_SUBJ_ROLE:
 685                 case AUDIT_SUBJ_TYPE:
 686                 case AUDIT_SUBJ_SEN:
 687                 case AUDIT_SUBJ_CLR:
 688                 case AUDIT_OBJ_USER:
 689                 case AUDIT_OBJ_ROLE:
 690                 case AUDIT_OBJ_TYPE:
 691                 case AUDIT_OBJ_LEV_LOW:
 692                 case AUDIT_OBJ_LEV_HIGH:
 693                         data->buflen += data->values[i] =
 694                                 audit_pack_string(&bufp, f->lsm_str);
 695                         break;
 696                 case AUDIT_WATCH:
 697                         data->buflen += data->values[i] =
 698                                 audit_pack_string(&bufp,
 699                                                   audit_watch_path(krule->watch));
 700                         break;
 701                 case AUDIT_DIR:
 702                         data->buflen += data->values[i] =
 703                                 audit_pack_string(&bufp,
 704                                                   audit_tree_path(krule->tree));
 705                         break;
 706                 case AUDIT_FILTERKEY:
 707                         data->buflen += data->values[i] =
 708                                 audit_pack_string(&bufp, krule->filterkey);
 709                         break;
 710                 default:
 711                         data->values[i] = f->val;
 712                 }
 713         }
 714         for (i = 0; i < AUDIT_BITMASK_SIZE; i++) data->mask[i] = krule->mask[i];
 715
 716         return data;
 717 }
 718
 719 /* Compare two rules in kernel format.  Considered success if rules
 720  * don't match. */
 721 static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b)
 722 {
 723         int i;
 724
 725         if (a->flags != b->flags ||
 726             a->listnr != b->listnr ||
 727             a->action != b->action ||
 728             a->field_count != b->field_count)
 729                 return 1;
 730
 731         for (i = 0; i < a->field_count; i++) {
 732                 if (a->fields[i].type != b->fields[i].type ||
 733                     a->fields[i].op != b->fields[i].op)
 734                         return 1;
 735
 736                 switch(a->fields[i].type) {
 737                 case AUDIT_SUBJ_USER:
 738                 case AUDIT_SUBJ_ROLE:
 739                 case AUDIT_SUBJ_TYPE:
 740                 case AUDIT_SUBJ_SEN:
 741                 case AUDIT_SUBJ_CLR:
 742                 case AUDIT_OBJ_USER:
 743                 case AUDIT_OBJ_ROLE:
 744                 case AUDIT_OBJ_TYPE:
 745                 case AUDIT_OBJ_LEV_LOW:
 746                 case AUDIT_OBJ_LEV_HIGH:
 747                         if (strcmp(a->fields[i].lsm_str, b->fields[i].lsm_str))
 748                                 return 1;
 749                         break;
 750                 case AUDIT_WATCH:
 751                         if (strcmp(audit_watch_path(a->watch),
 752                                    audit_watch_path(b->watch)))
 753                                 return 1;
 754                         break;
 755                 case AUDIT_DIR:
 756                         if (strcmp(audit_tree_path(a->tree),
 757                                    audit_tree_path(b->tree)))
 758                                 return 1;
 759                         break;
 760                 case AUDIT_FILTERKEY:
 761                         /* both filterkeys exist based on above type compare */
 762                         if (strcmp(a->filterkey, b->filterkey))
 763                                 return 1;
 764                         break;
 765                 case AUDIT_UID:
 766                 case AUDIT_EUID:
 767                 case AUDIT_SUID:
 768                 case AUDIT_FSUID:
 769                 case AUDIT_LOGINUID:
 770                 case AUDIT_OBJ_UID:
 771                         if (!uid_eq(a->fields[i].uid, b->fields[i].uid))
 772                                 return 1;
 773                         break;
 774                 case AUDIT_GID:
 775                 case AUDIT_EGID:
 776                 case AUDIT_SGID:
 777                 case AUDIT_FSGID:
 778                 case AUDIT_OBJ_GID:
 779                         if (!gid_eq(a->fields[i].gid, b->fields[i].gid))
 780                                 return 1;
 781                         break;
 782                 default:
 783                         if (a->fields[i].val != b->fields[i].val)
 784                                 return 1;
 785                 }
 786         }
 787
 788         for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
 789                 if (a->mask[i] != b->mask[i])
 790                         return 1;
 791
 792         return 0;
 793 }
 794
 795 /* Duplicate LSM field information.  The lsm_rule is opaque, so must be
 796  * re-initialized. */
 797 static inline int audit_dupe_lsm_field(struct audit_field *df,
 798                                            struct audit_field *sf)
 799 {
 800         int ret = 0;
 801         char *lsm_str;
 802
 803         /* our own copy of lsm_str */
 804         lsm_str = kstrdup(sf->lsm_str, GFP_KERNEL);
 805         if (unlikely(!lsm_str))
 806                 return -ENOMEM;
 807         df->lsm_str = lsm_str;
 808
 809         /* our own (refreshed) copy of lsm_rule */
 810         ret = security_audit_rule_init(df->type, df->op, df->lsm_str,
 811                                        (void **)&df->lsm_rule);
 812         /* Keep currently invalid fields around in case they
 813          * become valid after a policy reload. */
 814         if (ret == -EINVAL) {
 815                 printk(KERN_WARNING "audit rule for LSM \'%s\' is "
 816                        "invalid\n", df->lsm_str);
 817                 ret = 0;
 818         }
 819
 820         return ret;
 821 }
 822
 823 /* Duplicate an audit rule.  This will be a deep copy with the exception
 824  * of the watch - that pointer is carried over.  The LSM specific fields
 825  * will be updated in the copy.  The point is to be able to replace the old
 826  * rule with the new rule in the filterlist, then free the old rule.
 827  * The rlist element is undefined; list manipulations are handled apart from
 828  * the initial copy. */
 829 struct audit_entry *audit_dupe_rule(struct audit_krule *old)
 830 {
 831         u32 fcount = old->field_count;
 832         struct audit_entry *entry;
 833         struct audit_krule *new;
 834         char *fk;
 835         int i, err = 0;
 836
 837         entry = audit_init_entry(fcount);
 838         if (unlikely(!entry))
 839                 return ERR_PTR(-ENOMEM);
 840
 841         new = &entry->rule;
 842         new->vers_ops = old->vers_ops;
 843         new->flags = old->flags;
 844         new->listnr = old->listnr;
 845         new->action = old->action;
 846         for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
 847                 new->mask[i] = old->mask[i];
 848         new->prio = old->prio;
 849         new->buflen = old->buflen;
 850         new->inode_f = old->inode_f;
 851         new->field_count = old->field_count;
 852
 853         /*
 854          * note that we are OK with not refcounting here; audit_match_tree()
 855          * never dereferences tree and we can't get false positives there
 856          * since we'd have to have rule gone from the list *and* removed
 857          * before the chunks found by lookup had been allocated, i.e. before
 858          * the beginning of list scan.
 859          */
 860         new->tree = old->tree;
 861         memcpy(new->fields, old->fields, sizeof(struct audit_field) * fcount);
 862
 863         /* deep copy this information, updating the lsm_rule fields, because
 864          * the originals will all be freed when the old rule is freed. */
 865         for (i = 0; i < fcount; i++) {
 866                 switch (new->fields[i].type) {
 867                 case AUDIT_SUBJ_USER:
 868                 case AUDIT_SUBJ_ROLE:
 869                 case AUDIT_SUBJ_TYPE:
 870                 case AUDIT_SUBJ_SEN:
 871                 case AUDIT_SUBJ_CLR:
 872                 case AUDIT_OBJ_USER:
 873                 case AUDIT_OBJ_ROLE:
 874                 case AUDIT_OBJ_TYPE:
 875                 case AUDIT_OBJ_LEV_LOW:
 876                 case AUDIT_OBJ_LEV_HIGH:
 877                         err = audit_dupe_lsm_field(&new->fields[i],
 878                                                        &old->fields[i]);
 879                         break;
 880                 case AUDIT_FILTERKEY:
 881                         fk = kstrdup(old->filterkey, GFP_KERNEL);
 882                         if (unlikely(!fk))
 883                                 err = -ENOMEM;
 884                         else
 885                                 new->filterkey = fk;
 886                 }
 887                 if (err) {
 888                         audit_free_rule(entry);
 889                         return ERR_PTR(err);
 890                 }
 891         }
 892
 893         if (old->watch) {
 894                 audit_get_watch(old->watch);
 895                 new->watch = old->watch;
 896         }
 897
 898         return entry;
 899 }
 900
 901 /* Find an existing audit rule.
 902  * Caller must hold audit_filter_mutex to prevent stale rule data. */
 903 static struct audit_entry *audit_find_rule(struct audit_entry *entry,
 904                                            struct list_head **p)
 905 {
 906         struct audit_entry *e, *found = NULL;
 907         struct list_head *list;
 908         int h;
 909
 910         if (entry->rule.inode_f) {
 911                 h = audit_hash_ino(entry->rule.inode_f->val);
 912                 *p = list = &audit_inode_hash[h];
 913         } else if (entry->rule.watch) {
 914                 /* we don't know the inode number, so must walk entire hash */
 915                 for (h = 0; h < AUDIT_INODE_BUCKETS; h++) {
 916                         list = &audit_inode_hash[h];
 917                         list_for_each_entry(e, list, list)
 918                                 if (!audit_compare_rule(&entry->rule, &e->rule)) {
 919                                         found = e;
 920                                         goto out;
 921                                 }
 922                 }
 923                 goto out;
 924         } else {
 925                 *p = list = &audit_filter_list[entry->rule.listnr];
 926         }
 927
 928         list_for_each_entry(e, list, list)
 929                 if (!audit_compare_rule(&entry->rule, &e->rule)) {
 930                         found = e;
 931                         goto out;
 932                 }
 933
 934 out:
 935         return found;
 936 }
 937
 938 static u64 prio_low = ~0ULL/2;
 939 static u64 prio_high = ~0ULL/2 - 1;
 940
 941 /* Add rule to given filterlist if not a duplicate. */
 942 static inline int audit_add_rule(struct audit_entry *entry)
 943 {
 944         struct audit_entry *e;
 945         struct audit_watch *watch = entry->rule.watch;
 946         struct audit_tree *tree = entry->rule.tree;
 947         struct list_head *list;
 948         int err;
 949 #ifdef CONFIG_AUDITSYSCALL
 950         int dont_count = 0;
 951
 952         /* If either of these, don't count towards total */
 953         if (entry->rule.listnr == AUDIT_FILTER_USER ||
 954                 entry->rule.listnr == AUDIT_FILTER_TYPE)
 955                 dont_count = 1;
 956 #endif
 957
 958         mutex_lock(&audit_filter_mutex);
 959         e = audit_find_rule(entry, &list);
 960         if (e) {
 961                 mutex_unlock(&audit_filter_mutex);
 962                 err = -EEXIST;
 963                 /* normally audit_add_tree_rule() will free it on failure */
 964                 if (tree)
 965                         audit_put_tree(tree);
 966                 goto error;
 967         }
 968
 969         if (watch) {
 970                 /* audit_filter_mutex is dropped and re-taken during this call */
 971                 err = audit_add_watch(&entry->rule, &list);
 972                 if (err) {
 973                         mutex_unlock(&audit_filter_mutex);
 974                         goto error;
 975                 }
 976         }
 977         if (tree) {
 978                 err = audit_add_tree_rule(&entry->rule);
 979                 if (err) {
 980                         mutex_unlock(&audit_filter_mutex);
 981                         goto error;
 982                 }
 983         }
 984
 985         entry->rule.prio = ~0ULL;
 986         if (entry->rule.listnr == AUDIT_FILTER_EXIT) {
 987                 if (entry->rule.flags & AUDIT_FILTER_PREPEND)
 988                         entry->rule.prio = ++prio_high;
 989                 else
 990                         entry->rule.prio = --prio_low;
 991         }
 992
 993         if (entry->rule.flags & AUDIT_FILTER_PREPEND) {
 994                 list_add(&entry->rule.list,
 995                          &audit_rules_list[entry->rule.listnr]);
 996                 list_add_rcu(&entry->list, list);
 997                 entry->rule.flags &= ~AUDIT_FILTER_PREPEND;
 998         } else {
 999                 list_add_tail(&entry->rule.list,
1000                               &audit_rules_list[entry->rule.listnr]);
1001                 list_add_tail_rcu(&entry->list, list);
1002         }
1003 #ifdef CONFIG_AUDITSYSCALL
1004         if (!dont_count)
1005                 audit_n_rules++;
1006
1007         if (!audit_match_signal(entry))
1008                 audit_signals++;
1009 #endif
1010         mutex_unlock(&audit_filter_mutex);
1011
1012         return 0;
1013
1014 error:
1015         if (watch)
1016                 audit_put_watch(watch); /* tmp watch, matches initial get */
1017         return err;
1018 }
1019
1020 /* Remove an existing rule from filterlist. */
1021 static inline int audit_del_rule(struct audit_entry *entry)
1022 {
1023         struct audit_entry  *e;
1024         struct audit_watch *watch = entry->rule.watch;
1025         struct audit_tree *tree = entry->rule.tree;
1026         struct list_head *list;
1027         int ret = 0;
1028 #ifdef CONFIG_AUDITSYSCALL
1029         int dont_count = 0;
1030
1031         /* If either of these, don't count towards total */
1032         if (entry->rule.listnr == AUDIT_FILTER_USER ||
1033                 entry->rule.listnr == AUDIT_FILTER_TYPE)
1034                 dont_count = 1;
1035 #endif
1036
1037         mutex_lock(&audit_filter_mutex);
1038         e = audit_find_rule(entry, &list);
1039         if (!e) {
1040                 mutex_unlock(&audit_filter_mutex);
1041                 ret = -ENOENT;
1042                 goto out;
1043         }
1044
1045         if (e->rule.watch)
1046                 audit_remove_watch_rule(&e->rule);
1047
1048         if (e->rule.tree)
1049                 audit_remove_tree_rule(&e->rule);
1050
1051         list_del_rcu(&e->list);
1052         list_del(&e->rule.list);
1053         call_rcu(&e->rcu, audit_free_rule_rcu);
1054
1055 #ifdef CONFIG_AUDITSYSCALL
1056         if (!dont_count)
1057                 audit_n_rules--;
1058
1059         if (!audit_match_signal(entry))
1060                 audit_signals--;
1061 #endif
1062         mutex_unlock(&audit_filter_mutex);
1063
1064 out:
1065         if (watch)
1066                 audit_put_watch(watch); /* match initial get */
1067         if (tree)
1068                 audit_put_tree(tree);   /* that's the temporary one */
1069
1070         return ret;
1071 }
1072
1073 /* List rules using struct audit_rule.  Exists for backward
1074  * compatibility with userspace. */
1075 static void audit_list(int pid, int seq, struct sk_buff_head *q)
1076 {
1077         struct sk_buff *skb;
1078         struct audit_krule *r;
1079         int i;
1080
1081         /* This is a blocking read, so use audit_filter_mutex instead of rcu
1082          * iterator to sync with list writers. */
1083         for (i=0; i<AUDIT_NR_FILTERS; i++) {
1084                 list_for_each_entry(r, &audit_rules_list[i], list) {
1085                         struct audit_rule *rule;
1086
1087                         rule = audit_krule_to_rule(r);
1088                         if (unlikely(!rule))
1089                                 break;
1090                         skb = audit_make_reply(pid, seq, AUDIT_LIST, 0, 1,
1091                                          rule, sizeof(*rule));
1092                         if (skb)
1093                                 skb_queue_tail(q, skb);
1094                         kfree(rule);
1095                 }
1096         }
1097         skb = audit_make_reply(pid, seq, AUDIT_LIST, 1, 1, NULL, 0);
1098         if (skb)
1099                 skb_queue_tail(q, skb);
1100 }
1101
1102 /* List rules using struct audit_rule_data. */
1103 static void audit_list_rules(int pid, int seq, struct sk_buff_head *q)
1104 {
1105         struct sk_buff *skb;
1106         struct audit_krule *r;
1107         int i;
1108
1109         /* This is a blocking read, so use audit_filter_mutex instead of rcu
1110          * iterator to sync with list writers. */
1111         for (i=0; i<AUDIT_NR_FILTERS; i++) {
1112                 list_for_each_entry(r, &audit_rules_list[i], list) {
1113                         struct audit_rule_data *data;
1114
1115                         data = audit_krule_to_data(r);
1116                         if (unlikely(!data))
1117                                 break;
1118                         skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 0, 1,
1119                                          data, sizeof(*data) + data->buflen);
1120                         if (skb)
1121                                 skb_queue_tail(q, skb);
1122                         kfree(data);
1123                 }
1124         }
1125         skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 1, 1, NULL, 0);
1126         if (skb)
1127                 skb_queue_tail(q, skb);
1128 }
1129
1130 /* Log rule additions and removals */
1131 static void audit_log_rule_change(kuid_t loginuid, u32 sessionid, u32 sid,
1132                                   char *action, struct audit_krule *rule,
1133                                   int res)
1134 {
1135         struct audit_buffer *ab;
1136
1137         if (!audit_enabled)
1138                 return;
1139
1140         ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
1141         if (!ab)
1142                 return;
1143         audit_log_format(ab, "auid=%u ses=%u",
1144                          from_kuid(&init_user_ns, loginuid), sessionid);
1145         if (sid) {
1146                 char *ctx = NULL;
1147                 u32 len;
1148                 if (security_secid_to_secctx(sid, &ctx, &len))
1149                         audit_log_format(ab, " ssid=%u", sid);
1150                 else {
1151                         audit_log_format(ab, " subj=%s", ctx);
1152                         security_release_secctx(ctx, len);
1153                 }
1154         }
1155         audit_log_format(ab, " op=");
1156         audit_log_string(ab, action);
1157         audit_log_key(ab, rule->filterkey);
1158         audit_log_format(ab, " list=%d res=%d", rule->listnr, res);
1159         audit_log_end(ab);
1160 }
1161
1162 /**
1163  * audit_receive_filter - apply all rules to the specified message type
1164  * @type: audit message type
1165  * @pid: target pid for netlink audit messages
1166  * @seq: netlink audit message sequence (serial) number
1167  * @data: payload data
1168  * @datasz: size of payload data
1169  * @loginuid: loginuid of sender
1170  * @sessionid: sessionid for netlink audit message
1171  * @sid: SE Linux Security ID of sender
1172  */
1173 int audit_receive_filter(int type, int pid, int seq, void *data,
1174                          size_t datasz, kuid_t loginuid, u32 sessionid, u32 sid)
1175 {
1176         struct task_struct *tsk;
1177         struct audit_netlink_list *dest;
1178         int err = 0;
1179         struct audit_entry *entry;
1180
1181         switch (type) {
1182         case AUDIT_LIST:
1183         case AUDIT_LIST_RULES:
1184                 /* We can't just spew out the rules here because we might fill
1185                  * the available socket buffer space and deadlock waiting for
1186                  * auditctl to read from it... which isn't ever going to
1187                  * happen if we're actually running in the context of auditctl
1188                  * trying to _send_ the stuff */
1189
1190                 dest = kmalloc(sizeof(struct audit_netlink_list), GFP_KERNEL);
1191                 if (!dest)
1192                         return -ENOMEM;
1193                 dest->pid = pid;
1194                 skb_queue_head_init(&dest->q);
1195
1196                 mutex_lock(&audit_filter_mutex);
1197                 if (type == AUDIT_LIST)
1198                         audit_list(pid, seq, &dest->q);
1199                 else
1200                         audit_list_rules(pid, seq, &dest->q);
1201                 mutex_unlock(&audit_filter_mutex);
1202
1203                 tsk = kthread_run(audit_send_list, dest, "audit_send_list");
1204                 if (IS_ERR(tsk)) {
1205                         skb_queue_purge(&dest->q);
1206                         kfree(dest);
1207                         err = PTR_ERR(tsk);
1208                 }
1209                 break;
1210         case AUDIT_ADD:
1211         case AUDIT_ADD_RULE:
1212                 if (type == AUDIT_ADD)
1213                         entry = audit_rule_to_entry(data);
1214                 else
1215                         entry = audit_data_to_entry(data, datasz);
1216                 if (IS_ERR(entry))
1217                         return PTR_ERR(entry);
1218
1219                 err = audit_add_rule(entry);
1220                 audit_log_rule_change(loginuid, sessionid, sid, "add rule",
1221                                       &entry->rule, !err);
1222
1223                 if (err)
1224                         audit_free_rule(entry);
1225                 break;
1226         case AUDIT_DEL:
1227         case AUDIT_DEL_RULE:
1228                 if (type == AUDIT_DEL)
1229                         entry = audit_rule_to_entry(data);
1230                 else
1231                         entry = audit_data_to_entry(data, datasz);
1232                 if (IS_ERR(entry))
1233                         return PTR_ERR(entry);
1234
1235                 err = audit_del_rule(entry);
1236                 audit_log_rule_change(loginuid, sessionid, sid, "remove rule",
1237                                       &entry->rule, !err);
1238
1239                 audit_free_rule(entry);
1240                 break;
1241         default:
1242                 return -EINVAL;
1243         }
1244
1245         return err;
1246 }
1247
1248 int audit_comparator(u32 left, u32 op, u32 right)
1249 {
1250         switch (op) {
1251         case Audit_equal:
1252                 return (left == right);
1253         case Audit_not_equal:
1254                 return (left != right);
1255         case Audit_lt:
1256                 return (left < right);
1257         case Audit_le:
1258                 return (left <= right);
1259         case Audit_gt:
1260                 return (left > right);
1261         case Audit_ge:
1262                 return (left >= right);
1263         case Audit_bitmask:
1264                 return (left & right);
1265         case Audit_bittest:
1266                 return ((left & right) == right);
1267         default:
1268                 BUG();
1269                 return 0;
1270         }
1271 }
1272
1273 int audit_uid_comparator(kuid_t left, u32 op, kuid_t right)
1274 {
1275         switch (op) {
1276         case Audit_equal:
1277                 return uid_eq(left, right);
1278         case Audit_not_equal:
1279                 return !uid_eq(left, right);
1280         case Audit_lt:
1281                 return uid_lt(left, right);
1282         case Audit_le:
1283                 return uid_lte(left, right);
1284         case Audit_gt:
1285                 return uid_gt(left, right);
1286         case Audit_ge:
1287                 return uid_gte(left, right);
1288         case Audit_bitmask:
1289         case Audit_bittest:
1290         default:
1291                 BUG();
1292                 return 0;
1293         }
1294 }
1295
1296 int audit_gid_comparator(kgid_t left, u32 op, kgid_t right)
1297 {
1298         switch (op) {
1299         case Audit_equal:
1300                 return gid_eq(left, right);
1301         case Audit_not_equal:
1302                 return !gid_eq(left, right);
1303         case Audit_lt:
1304                 return gid_lt(left, right);
1305         case Audit_le:
1306                 return gid_lte(left, right);
1307         case Audit_gt:
1308                 return gid_gt(left, right);
1309         case Audit_ge:
1310                 return gid_gte(left, right);
1311         case Audit_bitmask:
1312         case Audit_bittest:
1313         default:
1314                 BUG();
1315                 return 0;
1316         }
1317 }
1318
1319 /**
1320  * parent_len - find the length of the parent portion of a pathname
1321  * @path: pathname of which to determine length
1322  */
1323 int parent_len(const char *path)
1324 {
1325         int plen;
1326         const char *p;
1327
1328         plen = strlen(path);
1329
1330         if (plen == 0)
1331                 return plen;
1332
1333         /* disregard trailing slashes */
1334         p = path + plen - 1;
1335         while ((*p == '/') && (p > path))
1336                 p--;
1337
1338         /* walk backward until we find the next slash or hit beginning */
1339         while ((*p != '/') && (p > path))
1340                 p--;
1341
1342         /* did we find a slash? Then increment to include it in path */
1343         if (*p == '/')
1344                 p++;
1345
1346         return p - path;
1347 }
1348
1349 /**
1350  * audit_compare_dname_path - compare given dentry name with last component in
1351  *                            given path. Return of 0 indicates a match.
1352  * @dname:      dentry name that we're comparing
1353  * @path:       full pathname that we're comparing
1354  * @parentlen:  length of the parent if known. Passing in AUDIT_NAME_FULL
1355  *              here indicates that we must compute this value.
1356  */
1357 int audit_compare_dname_path(const char *dname, const char *path, int parentlen)
1358 {
1359         int dlen, pathlen;
1360         const char *p;
1361
1362         dlen = strlen(dname);
1363         pathlen = strlen(path);
1364         if (pathlen < dlen)
1365                 return 1;
1366
1367         parentlen = parentlen == AUDIT_NAME_FULL ? parent_len(path) : parentlen;
1368         if (pathlen - parentlen != dlen)
1369                 return 1;
1370
1371         p = path + parentlen;
1372
1373         return strncmp(p, dname, dlen);
1374 }
1375
1376 static int audit_filter_user_rules(struct audit_krule *rule, int type,
1377                                    enum audit_state *state)
1378 {
1379         int i;
1380
1381         for (i = 0; i < rule->field_count; i++) {
1382                 struct audit_field *f = &rule->fields[i];
1383                 int result = 0;
1384                 u32 sid;
1385
1386                 switch (f->type) {
1387                 case AUDIT_PID:
1388                         result = audit_comparator(task_pid_vnr(current), f->op, f->val);
1389                         break;
1390                 case AUDIT_UID:
1391                         result = audit_uid_comparator(current_uid(), f->op, f->uid);
1392                         break;
1393                 case AUDIT_GID:
1394                         result = audit_gid_comparator(current_gid(), f->op, f->gid);
1395                         break;
1396                 case AUDIT_LOGINUID:
1397                         result = audit_uid_comparator(audit_get_loginuid(current),
1398                                                   f->op, f->uid);
1399                         break;
1400                 case AUDIT_MSGTYPE:
1401                         result = audit_comparator(type, f->op, f->val);
1402                         break;
1403                 case AUDIT_SUBJ_USER:
1404                 case AUDIT_SUBJ_ROLE:
1405                 case AUDIT_SUBJ_TYPE:
1406                 case AUDIT_SUBJ_SEN:
1407                 case AUDIT_SUBJ_CLR:
1408                         if (f->lsm_rule) {
1409                                 security_task_getsecid(current, &sid);
1410                                 result = security_audit_rule_match(sid,
1411                                                                    f->type,
1412                                                                    f->op,
1413                                                                    f->lsm_rule,
1414                                                                    NULL);
1415                         }
1416                         break;
1417                 }
1418
1419                 if (!result)
1420                         return 0;
1421         }
1422         switch (rule->action) {
1423         case AUDIT_NEVER:    *state = AUDIT_DISABLED;       break;
1424         case AUDIT_ALWAYS:   *state = AUDIT_RECORD_CONTEXT; break;
1425         }
1426         return 1;
1427 }
1428
1429 int audit_filter_user(int type)
1430 {
1431         enum audit_state state = AUDIT_DISABLED;
1432         struct audit_entry *e;
1433         int ret = 1;
1434
1435         rcu_read_lock();
1436         list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_USER], list) {
1437                 if (audit_filter_user_rules(&e->rule, type, &state)) {
1438                         if (state == AUDIT_DISABLED)
1439                                 ret = 0;
1440                         break;
1441                 }
1442         }
1443         rcu_read_unlock();
1444
1445         return ret; /* Audit by default */
1446 }
1447
1448 int audit_filter_type(int type)
1449 {
1450         struct audit_entry *e;
1451         int result = 0;
1452
1453         rcu_read_lock();
1454         if (list_empty(&audit_filter_list[AUDIT_FILTER_TYPE]))
1455                 goto unlock_and_return;
1456
1457         list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_TYPE],
1458                                 list) {
1459                 int i;
1460                 for (i = 0; i < e->rule.field_count; i++) {
1461                         struct audit_field *f = &e->rule.fields[i];
1462                         if (f->type == AUDIT_MSGTYPE) {
1463                                 result = audit_comparator(type, f->op, f->val);
1464                                 if (!result)
1465                                         break;
1466                         }
1467                 }
1468                 if (result)
1469                         goto unlock_and_return;
1470         }
1471 unlock_and_return:
1472         rcu_read_unlock();
1473         return result;
1474 }
1475
1476 static int update_lsm_rule(struct audit_krule *r)
1477 {
1478         struct audit_entry *entry = container_of(r, struct audit_entry, rule);
1479         struct audit_entry *nentry;
1480         int err = 0;
1481
1482         if (!security_audit_rule_known(r))
1483                 return 0;
1484
1485         nentry = audit_dupe_rule(r);
1486         if (IS_ERR(nentry)) {
1487                 /* save the first error encountered for the
1488                  * return value */
1489                 err = PTR_ERR(nentry);
1490                 audit_panic("error updating LSM filters");
1491                 if (r->watch)
1492                         list_del(&r->rlist);
1493                 list_del_rcu(&entry->list);
1494                 list_del(&r->list);
1495         } else {
1496                 if (r->watch || r->tree)
1497                         list_replace_init(&r->rlist, &nentry->rule.rlist);
1498                 list_replace_rcu(&entry->list, &nentry->list);
1499                 list_replace(&r->list, &nentry->rule.list);
1500         }
1501         call_rcu(&entry->rcu, audit_free_rule_rcu);
1502
1503         return err;
1504 }
1505
1506 /* This function will re-initialize the lsm_rule field of all applicable rules.
1507  * It will traverse the filter lists serarching for rules that contain LSM
1508  * specific filter fields.  When such a rule is found, it is copied, the
1509  * LSM field is re-initialized, and the old rule is replaced with the
1510  * updated rule. */
1511 int audit_update_lsm_rules(void)
1512 {
1513         struct audit_krule *r, *n;
1514         int i, err = 0;
1515
1516         /* audit_filter_mutex synchronizes the writers */
1517         mutex_lock(&audit_filter_mutex);
1518
1519         for (i = 0; i < AUDIT_NR_FILTERS; i++) {
1520                 list_for_each_entry_safe(r, n, &audit_rules_list[i], list) {
1521                         int res = update_lsm_rule(r);
1522                         if (!err)
1523                                 err = res;
1524                 }
1525         }
1526         mutex_unlock(&audit_filter_mutex);
1527
1528         return err;
1529 }