kernel/auditfilter.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /* auditfilter.c -- filtering of audit events
   3  *
   4  * Copyright 2003-2004 Red Hat, Inc.
   5  * Copyright 2005 Hewlett-Packard Development Company, L.P.
   6  * Copyright 2005 IBM Corporation
   7  */
   8
   9 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  10
  11 #include <linux/kernel.h>
  12 #include <linux/audit.h>
  13 #include <linux/kthread.h>
  14 #include <linux/mutex.h>
  15 #include <linux/fs.h>
  16 #include <linux/namei.h>
  17 #include <linux/netlink.h>
  18 #include <linux/sched.h>
  19 #include <linux/slab.h>
  20 #include <linux/security.h>
  21 #include <net/net_namespace.h>
  22 #include <net/sock.h>
  23 #include "audit.h"
  24
  25 /*
  26  * Locking model:
  27  *
  28  * audit_filter_mutex:
  29  *              Synchronizes writes and blocking reads of audit's filterlist
  30  *              data.  Rcu is used to traverse the filterlist and access
  31  *              contents of structs audit_entry, audit_watch and opaque
  32  *              LSM rules during filtering.  If modified, these structures
  33  *              must be copied and replace their counterparts in the filterlist.
  34  *              An audit_parent struct is not accessed during filtering, so may
  35  *              be written directly provided audit_filter_mutex is held.
  36  */
  37
  38 /* Audit filter lists, defined in <linux/audit.h> */
  39 struct list_head audit_filter_list[AUDIT_NR_FILTERS] = {
  40         LIST_HEAD_INIT(audit_filter_list[0]),
  41         LIST_HEAD_INIT(audit_filter_list[1]),
  42         LIST_HEAD_INIT(audit_filter_list[2]),
  43         LIST_HEAD_INIT(audit_filter_list[3]),
  44         LIST_HEAD_INIT(audit_filter_list[4]),
  45         LIST_HEAD_INIT(audit_filter_list[5]),
  46         LIST_HEAD_INIT(audit_filter_list[6]),
  47 #if AUDIT_NR_FILTERS != 7
  48 #error Fix audit_filter_list initialiser
  49 #endif
  50 };
  51 static struct list_head audit_rules_list[AUDIT_NR_FILTERS] = {
  52         LIST_HEAD_INIT(audit_rules_list[0]),
  53         LIST_HEAD_INIT(audit_rules_list[1]),
  54         LIST_HEAD_INIT(audit_rules_list[2]),
  55         LIST_HEAD_INIT(audit_rules_list[3]),
  56         LIST_HEAD_INIT(audit_rules_list[4]),
  57         LIST_HEAD_INIT(audit_rules_list[5]),
  58         LIST_HEAD_INIT(audit_rules_list[6]),
  59 };
  60
  61 DEFINE_MUTEX(audit_filter_mutex);
  62
  63 static void audit_free_lsm_field(struct audit_field *f)
  64 {
  65         switch (f->type) {
  66         case AUDIT_SUBJ_USER:
  67         case AUDIT_SUBJ_ROLE:
  68         case AUDIT_SUBJ_TYPE:
  69         case AUDIT_SUBJ_SEN:
  70         case AUDIT_SUBJ_CLR:
  71         case AUDIT_OBJ_USER:
  72         case AUDIT_OBJ_ROLE:
  73         case AUDIT_OBJ_TYPE:
  74         case AUDIT_OBJ_LEV_LOW:
  75         case AUDIT_OBJ_LEV_HIGH:
  76                 kfree(f->lsm_str);
  77                 security_audit_rule_free(f->lsm_rule);
  78         }
  79 }
  80
  81 static inline void audit_free_rule(struct audit_entry *e)
  82 {
  83         int i;
  84         struct audit_krule *erule = &e->rule;
  85
  86         /* some rules don't have associated watches */
  87         if (erule->watch)
  88                 audit_put_watch(erule->watch);
  89         if (erule->fields)
  90                 for (i = 0; i < erule->field_count; i++)
  91                         audit_free_lsm_field(&erule->fields[i]);
  92         kfree(erule->fields);
  93         kfree(erule->filterkey);
  94         kfree(e);
  95 }
  96
  97 void audit_free_rule_rcu(struct rcu_head *head)
  98 {
  99         struct audit_entry *e = container_of(head, struct audit_entry, rcu);
 100         audit_free_rule(e);
 101 }
 102
 103 /* Initialize an audit filterlist entry. */
 104 static inline struct audit_entry *audit_init_entry(u32 field_count)
 105 {
 106         struct audit_entry *entry;
 107         struct audit_field *fields;
 108
 109         entry = kzalloc(sizeof(*entry), GFP_KERNEL);
 110         if (unlikely(!entry))
 111                 return NULL;
 112
 113         fields = kcalloc(field_count, sizeof(*fields), GFP_KERNEL);
 114         if (unlikely(!fields)) {
 115                 kfree(entry);
 116                 return NULL;
 117         }
 118         entry->rule.fields = fields;
 119
 120         return entry;
 121 }
 122
 123 /* Unpack a filter field's string representation from user-space
 124  * buffer. */
 125 char *audit_unpack_string(void **bufp, size_t *remain, size_t len)
 126 {
 127         char *str;
 128
 129         if (!*bufp || (len == 0) || (len > *remain))
 130                 return ERR_PTR(-EINVAL);
 131
 132         /* Of the currently implemented string fields, PATH_MAX
 133          * defines the longest valid length.
 134          */
 135         if (len > PATH_MAX)
 136                 return ERR_PTR(-ENAMETOOLONG);
 137
 138         str = kmalloc(len + 1, GFP_KERNEL);
 139         if (unlikely(!str))
 140                 return ERR_PTR(-ENOMEM);
 141
 142         memcpy(str, *bufp, len);
 143         str[len] = 0;
 144         *bufp += len;
 145         *remain -= len;
 146
 147         return str;
 148 }
 149
 150 /* Translate an inode field to kernel representation. */
 151 static inline int audit_to_inode(struct audit_krule *krule,
 152                                  struct audit_field *f)
 153 {
 154         if (krule->listnr != AUDIT_FILTER_EXIT ||
 155             krule->inode_f || krule->watch || krule->tree ||
 156             (f->op != Audit_equal && f->op != Audit_not_equal))
 157                 return -EINVAL;
 158
 159         krule->inode_f = f;
 160         return 0;
 161 }
 162
 163 static __u32 *classes[AUDIT_SYSCALL_CLASSES];
 164
 165 int __init audit_register_class(int class, unsigned *list)
 166 {
 167         __u32 *p = kcalloc(AUDIT_BITMASK_SIZE, sizeof(__u32), GFP_KERNEL);
 168         if (!p)
 169                 return -ENOMEM;
 170         while (*list != ~0U) {
 171                 unsigned n = *list++;
 172                 if (n >= AUDIT_BITMASK_SIZE * 32 - AUDIT_SYSCALL_CLASSES) {
 173                         kfree(p);
 174                         return -EINVAL;
 175                 }
 176                 p[AUDIT_WORD(n)] |= AUDIT_BIT(n);
 177         }
 178         if (class >= AUDIT_SYSCALL_CLASSES || classes[class]) {
 179                 kfree(p);
 180                 return -EINVAL;
 181         }
 182         classes[class] = p;
 183         return 0;
 184 }
 185
 186 int audit_match_class(int class, unsigned syscall)
 187 {
 188         if (unlikely(syscall >= AUDIT_BITMASK_SIZE * 32))
 189                 return 0;
 190         if (unlikely(class >= AUDIT_SYSCALL_CLASSES || !classes[class]))
 191                 return 0;
 192         return classes[class][AUDIT_WORD(syscall)] & AUDIT_BIT(syscall);
 193 }
 194
 195 #ifdef CONFIG_AUDITSYSCALL
 196 static inline int audit_match_class_bits(int class, u32 *mask)
 197 {
 198         int i;
 199
 200         if (classes[class]) {
 201                 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
 202                         if (mask[i] & classes[class][i])
 203                                 return 0;
 204         }
 205         return 1;
 206 }
 207
 208 static int audit_match_signal(struct audit_entry *entry)
 209 {
 210         struct audit_field *arch = entry->rule.arch_f;
 211
 212         if (!arch) {
 213                 /* When arch is unspecified, we must check both masks on biarch
 214                  * as syscall number alone is ambiguous. */
 215                 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL,
 216                                                entry->rule.mask) &&
 217                         audit_match_class_bits(AUDIT_CLASS_SIGNAL_32,
 218                                                entry->rule.mask));
 219         }
 220
 221         switch(audit_classify_arch(arch->val)) {
 222         case 0: /* native */
 223                 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL,
 224                                                entry->rule.mask));
 225         case 1: /* 32bit on biarch */
 226                 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL_32,
 227                                                entry->rule.mask));
 228         default:
 229                 return 1;
 230         }
 231 }
 232 #endif
 233
 234 /* Common user-space to kernel rule translation. */
 235 static inline struct audit_entry *audit_to_entry_common(struct audit_rule_data *rule)
 236 {
 237         unsigned listnr;
 238         struct audit_entry *entry;
 239         int i, err;
 240
 241         err = -EINVAL;
 242         listnr = rule->flags & ~AUDIT_FILTER_PREPEND;
 243         switch(listnr) {
 244         default:
 245                 goto exit_err;
 246 #ifdef CONFIG_AUDITSYSCALL
 247         case AUDIT_FILTER_ENTRY:
 248                 pr_err("AUDIT_FILTER_ENTRY is deprecated\n");
 249                 goto exit_err;
 250         case AUDIT_FILTER_EXIT:
 251         case AUDIT_FILTER_TASK:
 252 #endif
 253         case AUDIT_FILTER_USER:
 254         case AUDIT_FILTER_EXCLUDE:
 255         case AUDIT_FILTER_FS:
 256                 ;
 257         }
 258         if (unlikely(rule->action == AUDIT_POSSIBLE)) {
 259                 pr_err("AUDIT_POSSIBLE is deprecated\n");
 260                 goto exit_err;
 261         }
 262         if (rule->action != AUDIT_NEVER && rule->action != AUDIT_ALWAYS)
 263                 goto exit_err;
 264         if (rule->field_count > AUDIT_MAX_FIELDS)
 265                 goto exit_err;
 266
 267         err = -ENOMEM;
 268         entry = audit_init_entry(rule->field_count);
 269         if (!entry)
 270                 goto exit_err;
 271
 272         entry->rule.flags = rule->flags & AUDIT_FILTER_PREPEND;
 273         entry->rule.listnr = listnr;
 274         entry->rule.action = rule->action;
 275         entry->rule.field_count = rule->field_count;
 276
 277         for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
 278                 entry->rule.mask[i] = rule->mask[i];
 279
 280         for (i = 0; i < AUDIT_SYSCALL_CLASSES; i++) {
 281                 int bit = AUDIT_BITMASK_SIZE * 32 - i - 1;
 282                 __u32 *p = &entry->rule.mask[AUDIT_WORD(bit)];
 283                 __u32 *class;
 284
 285                 if (!(*p & AUDIT_BIT(bit)))
 286                         continue;
 287                 *p &= ~AUDIT_BIT(bit);
 288                 class = classes[i];
 289                 if (class) {
 290                         int j;
 291                         for (j = 0; j < AUDIT_BITMASK_SIZE; j++)
 292                                 entry->rule.mask[j] |= class[j];
 293                 }
 294         }
 295
 296         return entry;
 297
 298 exit_err:
 299         return ERR_PTR(err);
 300 }
 301
 302 static u32 audit_ops[] =
 303 {
 304         [Audit_equal] = AUDIT_EQUAL,
 305         [Audit_not_equal] = AUDIT_NOT_EQUAL,
 306         [Audit_bitmask] = AUDIT_BIT_MASK,
 307         [Audit_bittest] = AUDIT_BIT_TEST,
 308         [Audit_lt] = AUDIT_LESS_THAN,
 309         [Audit_gt] = AUDIT_GREATER_THAN,
 310         [Audit_le] = AUDIT_LESS_THAN_OR_EQUAL,
 311         [Audit_ge] = AUDIT_GREATER_THAN_OR_EQUAL,
 312 };
 313
 314 static u32 audit_to_op(u32 op)
 315 {
 316         u32 n;
 317         for (n = Audit_equal; n < Audit_bad && audit_ops[n] != op; n++)
 318                 ;
 319         return n;
 320 }
 321
 322 /* check if an audit field is valid */
 323 static int audit_field_valid(struct audit_entry *entry, struct audit_field *f)
 324 {
 325         switch(f->type) {
 326         case AUDIT_MSGTYPE:
 327                 if (entry->rule.listnr != AUDIT_FILTER_EXCLUDE &&
 328                     entry->rule.listnr != AUDIT_FILTER_USER)
 329                         return -EINVAL;
 330                 break;
 331         case AUDIT_FSTYPE:
 332                 if (entry->rule.listnr != AUDIT_FILTER_FS)
 333                         return -EINVAL;
 334                 break;
 335         }
 336
 337         switch(entry->rule.listnr) {
 338         case AUDIT_FILTER_FS:
 339                 switch(f->type) {
 340                 case AUDIT_FSTYPE:
 341                 case AUDIT_FILTERKEY:
 342                         break;
 343                 default:
 344                         return -EINVAL;
 345                 }
 346         }
 347
 348         switch(f->type) {
 349         default:
 350                 return -EINVAL;
 351         case AUDIT_UID:
 352         case AUDIT_EUID:
 353         case AUDIT_SUID:
 354         case AUDIT_FSUID:
 355         case AUDIT_LOGINUID:
 356         case AUDIT_OBJ_UID:
 357         case AUDIT_GID:
 358         case AUDIT_EGID:
 359         case AUDIT_SGID:
 360         case AUDIT_FSGID:
 361         case AUDIT_OBJ_GID:
 362         case AUDIT_PID:
 363         case AUDIT_PERS:
 364         case AUDIT_MSGTYPE:
 365         case AUDIT_PPID:
 366         case AUDIT_DEVMAJOR:
 367         case AUDIT_DEVMINOR:
 368         case AUDIT_EXIT:
 369         case AUDIT_SUCCESS:
 370         case AUDIT_INODE:
 371         case AUDIT_SESSIONID:
 372                 /* bit ops are only useful on syscall args */
 373                 if (f->op == Audit_bitmask || f->op == Audit_bittest)
 374                         return -EINVAL;
 375                 break;
 376         case AUDIT_ARG0:
 377         case AUDIT_ARG1:
 378         case AUDIT_ARG2:
 379         case AUDIT_ARG3:
 380         case AUDIT_SUBJ_USER:
 381         case AUDIT_SUBJ_ROLE:
 382         case AUDIT_SUBJ_TYPE:
 383         case AUDIT_SUBJ_SEN:
 384         case AUDIT_SUBJ_CLR:
 385         case AUDIT_OBJ_USER:
 386         case AUDIT_OBJ_ROLE:
 387         case AUDIT_OBJ_TYPE:
 388         case AUDIT_OBJ_LEV_LOW:
 389         case AUDIT_OBJ_LEV_HIGH:
 390         case AUDIT_WATCH:
 391         case AUDIT_DIR:
 392         case AUDIT_FILTERKEY:
 393                 break;
 394         case AUDIT_LOGINUID_SET:
 395                 if ((f->val != 0) && (f->val != 1))
 396                         return -EINVAL;
 397         /* FALL THROUGH */
 398         case AUDIT_ARCH:
 399         case AUDIT_FSTYPE:
 400                 if (f->op != Audit_not_equal && f->op != Audit_equal)
 401                         return -EINVAL;
 402                 break;
 403         case AUDIT_PERM:
 404                 if (f->val & ~15)
 405                         return -EINVAL;
 406                 break;
 407         case AUDIT_FILETYPE:
 408                 if (f->val & ~S_IFMT)
 409                         return -EINVAL;
 410                 break;
 411         case AUDIT_FIELD_COMPARE:
 412                 if (f->val > AUDIT_MAX_FIELD_COMPARE)
 413                         return -EINVAL;
 414                 break;
 415         case AUDIT_EXE:
 416                 if (f->op != Audit_not_equal && f->op != Audit_equal)
 417                         return -EINVAL;
 418                 break;
 419         }
 420         return 0;
 421 }
 422
 423 /* Translate struct audit_rule_data to kernel's rule representation. */
 424 static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
 425                                                size_t datasz)
 426 {
 427         int err = 0;
 428         struct audit_entry *entry;
 429         void *bufp;
 430         size_t remain = datasz - sizeof(struct audit_rule_data);
 431         int i;
 432         char *str;
 433         struct audit_fsnotify_mark *audit_mark;
 434
 435         entry = audit_to_entry_common(data);
 436         if (IS_ERR(entry))
 437                 goto exit_nofree;
 438
 439         bufp = data->buf;
 440         for (i = 0; i < data->field_count; i++) {
 441                 struct audit_field *f = &entry->rule.fields[i];
 442
 443                 err = -EINVAL;
 444
 445                 f->op = audit_to_op(data->fieldflags[i]);
 446                 if (f->op == Audit_bad)
 447                         goto exit_free;
 448
 449                 f->type = data->fields[i];
 450                 f->val = data->values[i];
 451
 452                 /* Support legacy tests for a valid loginuid */
 453                 if ((f->type == AUDIT_LOGINUID) && (f->val == AUDIT_UID_UNSET)) {
 454                         f->type = AUDIT_LOGINUID_SET;
 455                         f->val = 0;
 456                         entry->rule.pflags |= AUDIT_LOGINUID_LEGACY;
 457                 }
 458
 459                 err = audit_field_valid(entry, f);
 460                 if (err)
 461                         goto exit_free;
 462
 463                 err = -EINVAL;
 464                 switch (f->type) {
 465                 case AUDIT_LOGINUID:
 466                 case AUDIT_UID:
 467                 case AUDIT_EUID:
 468                 case AUDIT_SUID:
 469                 case AUDIT_FSUID:
 470                 case AUDIT_OBJ_UID:
 471                         f->uid = make_kuid(current_user_ns(), f->val);
 472                         if (!uid_valid(f->uid))
 473                                 goto exit_free;
 474                         break;
 475                 case AUDIT_GID:
 476                 case AUDIT_EGID:
 477                 case AUDIT_SGID:
 478                 case AUDIT_FSGID:
 479                 case AUDIT_OBJ_GID:
 480                         f->gid = make_kgid(current_user_ns(), f->val);
 481                         if (!gid_valid(f->gid))
 482                                 goto exit_free;
 483                         break;
 484                 case AUDIT_ARCH:
 485                         entry->rule.arch_f = f;
 486                         break;
 487                 case AUDIT_SUBJ_USER:
 488                 case AUDIT_SUBJ_ROLE:
 489                 case AUDIT_SUBJ_TYPE:
 490                 case AUDIT_SUBJ_SEN:
 491                 case AUDIT_SUBJ_CLR:
 492                 case AUDIT_OBJ_USER:
 493                 case AUDIT_OBJ_ROLE:
 494                 case AUDIT_OBJ_TYPE:
 495                 case AUDIT_OBJ_LEV_LOW:
 496                 case AUDIT_OBJ_LEV_HIGH:
 497                         str = audit_unpack_string(&bufp, &remain, f->val);
 498                         if (IS_ERR(str))
 499                                 goto exit_free;
 500                         entry->rule.buflen += f->val;
 501
 502                         err = security_audit_rule_init(f->type, f->op, str,
 503                                                        (void **)&f->lsm_rule);
 504                         /* Keep currently invalid fields around in case they
 505                          * become valid after a policy reload. */
 506                         if (err == -EINVAL) {
 507                                 pr_warn("audit rule for LSM \'%s\' is invalid\n",
 508                                         str);
 509                                 err = 0;
 510                         }
 511                         if (err) {
 512                                 kfree(str);
 513                                 goto exit_free;
 514                         } else
 515                                 f->lsm_str = str;
 516                         break;
 517                 case AUDIT_WATCH:
 518                         str = audit_unpack_string(&bufp, &remain, f->val);
 519                         if (IS_ERR(str))
 520                                 goto exit_free;
 521                         entry->rule.buflen += f->val;
 522
 523                         err = audit_to_watch(&entry->rule, str, f->val, f->op);
 524                         if (err) {
 525                                 kfree(str);
 526                                 goto exit_free;
 527                         }
 528                         break;
 529                 case AUDIT_DIR:
 530                         str = audit_unpack_string(&bufp, &remain, f->val);
 531                         if (IS_ERR(str))
 532                                 goto exit_free;
 533                         entry->rule.buflen += f->val;
 534
 535                         err = audit_make_tree(&entry->rule, str, f->op);
 536                         kfree(str);
 537                         if (err)
 538                                 goto exit_free;
 539                         break;
 540                 case AUDIT_INODE:
 541                         err = audit_to_inode(&entry->rule, f);
 542                         if (err)
 543                                 goto exit_free;
 544                         break;
 545                 case AUDIT_FILTERKEY:
 546                         if (entry->rule.filterkey || f->val > AUDIT_MAX_KEY_LEN)
 547                                 goto exit_free;
 548                         str = audit_unpack_string(&bufp, &remain, f->val);
 549                         if (IS_ERR(str))
 550                                 goto exit_free;
 551                         entry->rule.buflen += f->val;
 552                         entry->rule.filterkey = str;
 553                         break;
 554                 case AUDIT_EXE:
 555                         if (entry->rule.exe || f->val > PATH_MAX)
 556                                 goto exit_free;
 557                         str = audit_unpack_string(&bufp, &remain, f->val);
 558                         if (IS_ERR(str)) {
 559                                 err = PTR_ERR(str);
 560                                 goto exit_free;
 561                         }
 562                         entry->rule.buflen += f->val;
 563
 564                         audit_mark = audit_alloc_mark(&entry->rule, str, f->val);
 565                         if (IS_ERR(audit_mark)) {
 566                                 kfree(str);
 567                                 err = PTR_ERR(audit_mark);
 568                                 goto exit_free;
 569                         }
 570                         entry->rule.exe = audit_mark;
 571                         break;
 572                 }
 573         }
 574
 575         if (entry->rule.inode_f && entry->rule.inode_f->op == Audit_not_equal)
 576                 entry->rule.inode_f = NULL;
 577
 578 exit_nofree:
 579         return entry;
 580
 581 exit_free:
 582         if (entry->rule.tree)
 583                 audit_put_tree(entry->rule.tree); /* that's the temporary one */
 584         if (entry->rule.exe)
 585                 audit_remove_mark(entry->rule.exe); /* that's the template one */
 586         audit_free_rule(entry);
 587         return ERR_PTR(err);
 588 }
 589
 590 /* Pack a filter field's string representation into data block. */
 591 static inline size_t audit_pack_string(void **bufp, const char *str)
 592 {
 593         size_t len = strlen(str);
 594
 595         memcpy(*bufp, str, len);
 596         *bufp += len;
 597
 598         return len;
 599 }
 600
 601 /* Translate kernel rule representation to struct audit_rule_data. */
 602 static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule)
 603 {
 604         struct audit_rule_data *data;
 605         void *bufp;
 606         int i;
 607
 608         data = kmalloc(sizeof(*data) + krule->buflen, GFP_KERNEL);
 609         if (unlikely(!data))
 610                 return NULL;
 611         memset(data, 0, sizeof(*data));
 612
 613         data->flags = krule->flags | krule->listnr;
 614         data->action = krule->action;
 615         data->field_count = krule->field_count;
 616         bufp = data->buf;
 617         for (i = 0; i < data->field_count; i++) {
 618                 struct audit_field *f = &krule->fields[i];
 619
 620                 data->fields[i] = f->type;
 621                 data->fieldflags[i] = audit_ops[f->op];
 622                 switch(f->type) {
 623                 case AUDIT_SUBJ_USER:
 624                 case AUDIT_SUBJ_ROLE:
 625                 case AUDIT_SUBJ_TYPE:
 626                 case AUDIT_SUBJ_SEN:
 627                 case AUDIT_SUBJ_CLR:
 628                 case AUDIT_OBJ_USER:
 629                 case AUDIT_OBJ_ROLE:
 630                 case AUDIT_OBJ_TYPE:
 631                 case AUDIT_OBJ_LEV_LOW:
 632                 case AUDIT_OBJ_LEV_HIGH:
 633                         data->buflen += data->values[i] =
 634                                 audit_pack_string(&bufp, f->lsm_str);
 635                         break;
 636                 case AUDIT_WATCH:
 637                         data->buflen += data->values[i] =
 638                                 audit_pack_string(&bufp,
 639                                                   audit_watch_path(krule->watch));
 640                         break;
 641                 case AUDIT_DIR:
 642                         data->buflen += data->values[i] =
 643                                 audit_pack_string(&bufp,
 644                                                   audit_tree_path(krule->tree));
 645                         break;
 646                 case AUDIT_FILTERKEY:
 647                         data->buflen += data->values[i] =
 648                                 audit_pack_string(&bufp, krule->filterkey);
 649                         break;
 650                 case AUDIT_EXE:
 651                         data->buflen += data->values[i] =
 652                                 audit_pack_string(&bufp, audit_mark_path(krule->exe));
 653                         break;
 654                 case AUDIT_LOGINUID_SET:
 655                         if (krule->pflags & AUDIT_LOGINUID_LEGACY && !f->val) {
 656                                 data->fields[i] = AUDIT_LOGINUID;
 657                                 data->values[i] = AUDIT_UID_UNSET;
 658                                 break;
 659                         }
 660                         /* fall through - if set */
 661                 default:
 662                         data->values[i] = f->val;
 663                 }
 664         }
 665         for (i = 0; i < AUDIT_BITMASK_SIZE; i++) data->mask[i] = krule->mask[i];
 666
 667         return data;
 668 }
 669
 670 /* Compare two rules in kernel format.  Considered success if rules
 671  * don't match. */
 672 static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b)
 673 {
 674         int i;
 675
 676         if (a->flags != b->flags ||
 677             a->pflags != b->pflags ||
 678             a->listnr != b->listnr ||
 679             a->action != b->action ||
 680             a->field_count != b->field_count)
 681                 return 1;
 682
 683         for (i = 0; i < a->field_count; i++) {
 684                 if (a->fields[i].type != b->fields[i].type ||
 685                     a->fields[i].op != b->fields[i].op)
 686                         return 1;
 687
 688                 switch(a->fields[i].type) {
 689                 case AUDIT_SUBJ_USER:
 690                 case AUDIT_SUBJ_ROLE:
 691                 case AUDIT_SUBJ_TYPE:
 692                 case AUDIT_SUBJ_SEN:
 693                 case AUDIT_SUBJ_CLR:
 694                 case AUDIT_OBJ_USER:
 695                 case AUDIT_OBJ_ROLE:
 696                 case AUDIT_OBJ_TYPE:
 697                 case AUDIT_OBJ_LEV_LOW:
 698                 case AUDIT_OBJ_LEV_HIGH:
 699                         if (strcmp(a->fields[i].lsm_str, b->fields[i].lsm_str))
 700                                 return 1;
 701                         break;
 702                 case AUDIT_WATCH:
 703                         if (strcmp(audit_watch_path(a->watch),
 704                                    audit_watch_path(b->watch)))
 705                                 return 1;
 706                         break;
 707                 case AUDIT_DIR:
 708                         if (strcmp(audit_tree_path(a->tree),
 709                                    audit_tree_path(b->tree)))
 710                                 return 1;
 711                         break;
 712                 case AUDIT_FILTERKEY:
 713                         /* both filterkeys exist based on above type compare */
 714                         if (strcmp(a->filterkey, b->filterkey))
 715                                 return 1;
 716                         break;
 717                 case AUDIT_EXE:
 718                         /* both paths exist based on above type compare */
 719                         if (strcmp(audit_mark_path(a->exe),
 720                                    audit_mark_path(b->exe)))
 721                                 return 1;
 722                         break;
 723                 case AUDIT_UID:
 724                 case AUDIT_EUID:
 725                 case AUDIT_SUID:
 726                 case AUDIT_FSUID:
 727                 case AUDIT_LOGINUID:
 728                 case AUDIT_OBJ_UID:
 729                         if (!uid_eq(a->fields[i].uid, b->fields[i].uid))
 730                                 return 1;
 731                         break;
 732                 case AUDIT_GID:
 733                 case AUDIT_EGID:
 734                 case AUDIT_SGID:
 735                 case AUDIT_FSGID:
 736                 case AUDIT_OBJ_GID:
 737                         if (!gid_eq(a->fields[i].gid, b->fields[i].gid))
 738                                 return 1;
 739                         break;
 740                 default:
 741                         if (a->fields[i].val != b->fields[i].val)
 742                                 return 1;
 743                 }
 744         }
 745
 746         for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
 747                 if (a->mask[i] != b->mask[i])
 748                         return 1;
 749
 750         return 0;
 751 }
 752
 753 /* Duplicate LSM field information.  The lsm_rule is opaque, so must be
 754  * re-initialized. */
 755 static inline int audit_dupe_lsm_field(struct audit_field *df,
 756                                            struct audit_field *sf)
 757 {
 758         int ret = 0;
 759         char *lsm_str;
 760
 761         /* our own copy of lsm_str */
 762         lsm_str = kstrdup(sf->lsm_str, GFP_KERNEL);
 763         if (unlikely(!lsm_str))
 764                 return -ENOMEM;
 765         df->lsm_str = lsm_str;
 766
 767         /* our own (refreshed) copy of lsm_rule */
 768         ret = security_audit_rule_init(df->type, df->op, df->lsm_str,
 769                                        (void **)&df->lsm_rule);
 770         /* Keep currently invalid fields around in case they
 771          * become valid after a policy reload. */
 772         if (ret == -EINVAL) {
 773                 pr_warn("audit rule for LSM \'%s\' is invalid\n",
 774                         df->lsm_str);
 775                 ret = 0;
 776         }
 777
 778         return ret;
 779 }
 780
 781 /* Duplicate an audit rule.  This will be a deep copy with the exception
 782  * of the watch - that pointer is carried over.  The LSM specific fields
 783  * will be updated in the copy.  The point is to be able to replace the old
 784  * rule with the new rule in the filterlist, then free the old rule.
 785  * The rlist element is undefined; list manipulations are handled apart from
 786  * the initial copy. */
 787 struct audit_entry *audit_dupe_rule(struct audit_krule *old)
 788 {
 789         u32 fcount = old->field_count;
 790         struct audit_entry *entry;
 791         struct audit_krule *new;
 792         char *fk;
 793         int i, err = 0;
 794
 795         entry = audit_init_entry(fcount);
 796         if (unlikely(!entry))
 797                 return ERR_PTR(-ENOMEM);
 798
 799         new = &entry->rule;
 800         new->flags = old->flags;
 801         new->pflags = old->pflags;
 802         new->listnr = old->listnr;
 803         new->action = old->action;
 804         for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
 805                 new->mask[i] = old->mask[i];
 806         new->prio = old->prio;
 807         new->buflen = old->buflen;
 808         new->inode_f = old->inode_f;
 809         new->field_count = old->field_count;
 810
 811         /*
 812          * note that we are OK with not refcounting here; audit_match_tree()
 813          * never dereferences tree and we can't get false positives there
 814          * since we'd have to have rule gone from the list *and* removed
 815          * before the chunks found by lookup had been allocated, i.e. before
 816          * the beginning of list scan.
 817          */
 818         new->tree = old->tree;
 819         memcpy(new->fields, old->fields, sizeof(struct audit_field) * fcount);
 820
 821         /* deep copy this information, updating the lsm_rule fields, because
 822          * the originals will all be freed when the old rule is freed. */
 823         for (i = 0; i < fcount; i++) {
 824                 switch (new->fields[i].type) {
 825                 case AUDIT_SUBJ_USER:
 826                 case AUDIT_SUBJ_ROLE:
 827                 case AUDIT_SUBJ_TYPE:
 828                 case AUDIT_SUBJ_SEN:
 829                 case AUDIT_SUBJ_CLR:
 830                 case AUDIT_OBJ_USER:
 831                 case AUDIT_OBJ_ROLE:
 832                 case AUDIT_OBJ_TYPE:
 833                 case AUDIT_OBJ_LEV_LOW:
 834                 case AUDIT_OBJ_LEV_HIGH:
 835                         err = audit_dupe_lsm_field(&new->fields[i],
 836                                                        &old->fields[i]);
 837                         break;
 838                 case AUDIT_FILTERKEY:
 839                         fk = kstrdup(old->filterkey, GFP_KERNEL);
 840                         if (unlikely(!fk))
 841                                 err = -ENOMEM;
 842                         else
 843                                 new->filterkey = fk;
 844                         break;
 845                 case AUDIT_EXE:
 846                         err = audit_dupe_exe(new, old);
 847                         break;
 848                 }
 849                 if (err) {
 850                         if (new->exe)
 851                                 audit_remove_mark(new->exe);
 852                         audit_free_rule(entry);
 853                         return ERR_PTR(err);
 854                 }
 855         }
 856
 857         if (old->watch) {
 858                 audit_get_watch(old->watch);
 859                 new->watch = old->watch;
 860         }
 861
 862         return entry;
 863 }
 864
 865 /* Find an existing audit rule.
 866  * Caller must hold audit_filter_mutex to prevent stale rule data. */
 867 static struct audit_entry *audit_find_rule(struct audit_entry *entry,
 868                                            struct list_head **p)
 869 {
 870         struct audit_entry *e, *found = NULL;
 871         struct list_head *list;
 872         int h;
 873
 874         if (entry->rule.inode_f) {
 875                 h = audit_hash_ino(entry->rule.inode_f->val);
 876                 *p = list = &audit_inode_hash[h];
 877         } else if (entry->rule.watch) {
 878                 /* we don't know the inode number, so must walk entire hash */
 879                 for (h = 0; h < AUDIT_INODE_BUCKETS; h++) {
 880                         list = &audit_inode_hash[h];
 881                         list_for_each_entry(e, list, list)
 882                                 if (!audit_compare_rule(&entry->rule, &e->rule)) {
 883                                         found = e;
 884                                         goto out;
 885                                 }
 886                 }
 887                 goto out;
 888         } else {
 889                 *p = list = &audit_filter_list[entry->rule.listnr];
 890         }
 891
 892         list_for_each_entry(e, list, list)
 893                 if (!audit_compare_rule(&entry->rule, &e->rule)) {
 894                         found = e;
 895                         goto out;
 896                 }
 897
 898 out:
 899         return found;
 900 }
 901
 902 static u64 prio_low = ~0ULL/2;
 903 static u64 prio_high = ~0ULL/2 - 1;
 904
 905 /* Add rule to given filterlist if not a duplicate. */
 906 static inline int audit_add_rule(struct audit_entry *entry)
 907 {
 908         struct audit_entry *e;
 909         struct audit_watch *watch = entry->rule.watch;
 910         struct audit_tree *tree = entry->rule.tree;
 911         struct list_head *list;
 912         int err = 0;
 913 #ifdef CONFIG_AUDITSYSCALL
 914         int dont_count = 0;
 915
 916         /* If any of these, don't count towards total */
 917         switch(entry->rule.listnr) {
 918         case AUDIT_FILTER_USER:
 919         case AUDIT_FILTER_EXCLUDE:
 920         case AUDIT_FILTER_FS:
 921                 dont_count = 1;
 922         }
 923 #endif
 924
 925         mutex_lock(&audit_filter_mutex);
 926         e = audit_find_rule(entry, &list);
 927         if (e) {
 928                 mutex_unlock(&audit_filter_mutex);
 929                 err = -EEXIST;
 930                 /* normally audit_add_tree_rule() will free it on failure */
 931                 if (tree)
 932                         audit_put_tree(tree);
 933                 return err;
 934         }
 935
 936         if (watch) {
 937                 /* audit_filter_mutex is dropped and re-taken during this call */
 938                 err = audit_add_watch(&entry->rule, &list);
 939                 if (err) {
 940                         mutex_unlock(&audit_filter_mutex);
 941                         /*
 942                          * normally audit_add_tree_rule() will free it
 943                          * on failure
 944                          */
 945                         if (tree)
 946                                 audit_put_tree(tree);
 947                         return err;
 948                 }
 949         }
 950         if (tree) {
 951                 err = audit_add_tree_rule(&entry->rule);
 952                 if (err) {
 953                         mutex_unlock(&audit_filter_mutex);
 954                         return err;
 955                 }
 956         }
 957
 958         entry->rule.prio = ~0ULL;
 959         if (entry->rule.listnr == AUDIT_FILTER_EXIT) {
 960                 if (entry->rule.flags & AUDIT_FILTER_PREPEND)
 961                         entry->rule.prio = ++prio_high;
 962                 else
 963                         entry->rule.prio = --prio_low;
 964         }
 965
 966         if (entry->rule.flags & AUDIT_FILTER_PREPEND) {
 967                 list_add(&entry->rule.list,
 968                          &audit_rules_list[entry->rule.listnr]);
 969                 list_add_rcu(&entry->list, list);
 970                 entry->rule.flags &= ~AUDIT_FILTER_PREPEND;
 971         } else {
 972                 list_add_tail(&entry->rule.list,
 973                               &audit_rules_list[entry->rule.listnr]);
 974                 list_add_tail_rcu(&entry->list, list);
 975         }
 976 #ifdef CONFIG_AUDITSYSCALL
 977         if (!dont_count)
 978                 audit_n_rules++;
 979
 980         if (!audit_match_signal(entry))
 981                 audit_signals++;
 982 #endif
 983         mutex_unlock(&audit_filter_mutex);
 984
 985         return err;
 986 }
 987
 988 /* Remove an existing rule from filterlist. */
 989 int audit_del_rule(struct audit_entry *entry)
 990 {
 991         struct audit_entry  *e;
 992         struct audit_tree *tree = entry->rule.tree;
 993         struct list_head *list;
 994         int ret = 0;
 995 #ifdef CONFIG_AUDITSYSCALL
 996         int dont_count = 0;
 997
 998         /* If any of these, don't count towards total */
 999         switch(entry->rule.listnr) {
1000         case AUDIT_FILTER_USER:
1001         case AUDIT_FILTER_EXCLUDE:
1002         case AUDIT_FILTER_FS:
1003                 dont_count = 1;
1004         }
1005 #endif
1006
1007         mutex_lock(&audit_filter_mutex);
1008         e = audit_find_rule(entry, &list);
1009         if (!e) {
1010                 ret = -ENOENT;
1011                 goto out;
1012         }
1013
1014         if (e->rule.watch)
1015                 audit_remove_watch_rule(&e->rule);
1016
1017         if (e->rule.tree)
1018                 audit_remove_tree_rule(&e->rule);
1019
1020         if (e->rule.exe)
1021                 audit_remove_mark_rule(&e->rule);
1022
1023 #ifdef CONFIG_AUDITSYSCALL
1024         if (!dont_count)
1025                 audit_n_rules--;
1026
1027         if (!audit_match_signal(entry))
1028                 audit_signals--;
1029 #endif
1030
1031         list_del_rcu(&e->list);
1032         list_del(&e->rule.list);
1033         call_rcu(&e->rcu, audit_free_rule_rcu);
1034
1035 out:
1036         mutex_unlock(&audit_filter_mutex);
1037
1038         if (tree)
1039                 audit_put_tree(tree);   /* that's the temporary one */
1040
1041         return ret;
1042 }
1043
1044 /* List rules using struct audit_rule_data. */
1045 static void audit_list_rules(int seq, struct sk_buff_head *q)
1046 {
1047         struct sk_buff *skb;
1048         struct audit_krule *r;
1049         int i;
1050
1051         /* This is a blocking read, so use audit_filter_mutex instead of rcu
1052          * iterator to sync with list writers. */
1053         for (i=0; i<AUDIT_NR_FILTERS; i++) {
1054                 list_for_each_entry(r, &audit_rules_list[i], list) {
1055                         struct audit_rule_data *data;
1056
1057                         data = audit_krule_to_data(r);
1058                         if (unlikely(!data))
1059                                 break;
1060                         skb = audit_make_reply(seq, AUDIT_LIST_RULES, 0, 1,
1061                                                data,
1062                                                sizeof(*data) + data->buflen);
1063                         if (skb)
1064                                 skb_queue_tail(q, skb);
1065                         kfree(data);
1066                 }
1067         }
1068         skb = audit_make_reply(seq, AUDIT_LIST_RULES, 1, 1, NULL, 0);
1069         if (skb)
1070                 skb_queue_tail(q, skb);
1071 }
1072
1073 /* Log rule additions and removals */
1074 static void audit_log_rule_change(char *action, struct audit_krule *rule, int res)
1075 {
1076         struct audit_buffer *ab;
1077
1078         if (!audit_enabled)
1079                 return;
1080
1081         ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_CONFIG_CHANGE);
1082         if (!ab)
1083                 return;
1084         audit_log_session_info(ab);
1085         audit_log_task_context(ab);
1086         audit_log_format(ab, " op=%s", action);
1087         audit_log_key(ab, rule->filterkey);
1088         audit_log_format(ab, " list=%d res=%d", rule->listnr, res);
1089         audit_log_end(ab);
1090 }
1091
1092 /**
1093  * audit_rule_change - apply all rules to the specified message type
1094  * @type: audit message type
1095  * @seq: netlink audit message sequence (serial) number
1096  * @data: payload data
1097  * @datasz: size of payload data
1098  */
1099 int audit_rule_change(int type, int seq, void *data, size_t datasz)
1100 {
1101         int err = 0;
1102         struct audit_entry *entry;
1103
1104         switch (type) {
1105         case AUDIT_ADD_RULE:
1106                 entry = audit_data_to_entry(data, datasz);
1107                 if (IS_ERR(entry))
1108                         return PTR_ERR(entry);
1109                 err = audit_add_rule(entry);
1110                 audit_log_rule_change("add_rule", &entry->rule, !err);
1111                 break;
1112         case AUDIT_DEL_RULE:
1113                 entry = audit_data_to_entry(data, datasz);
1114                 if (IS_ERR(entry))
1115                         return PTR_ERR(entry);
1116                 err = audit_del_rule(entry);
1117                 audit_log_rule_change("remove_rule", &entry->rule, !err);
1118                 break;
1119         default:
1120                 WARN_ON(1);
1121                 return -EINVAL;
1122         }
1123
1124         if (err || type == AUDIT_DEL_RULE) {
1125                 if (entry->rule.exe)
1126                         audit_remove_mark(entry->rule.exe);
1127                 audit_free_rule(entry);
1128         }
1129
1130         return err;
1131 }
1132
1133 /**
1134  * audit_list_rules_send - list the audit rules
1135  * @request_skb: skb of request we are replying to (used to target the reply)
1136  * @seq: netlink audit message sequence (serial) number
1137  */
1138 int audit_list_rules_send(struct sk_buff *request_skb, int seq)
1139 {
1140         u32 portid = NETLINK_CB(request_skb).portid;
1141         struct net *net = sock_net(NETLINK_CB(request_skb).sk);
1142         struct task_struct *tsk;
1143         struct audit_netlink_list *dest;
1144         int err = 0;
1145
1146         /* We can't just spew out the rules here because we might fill
1147          * the available socket buffer space and deadlock waiting for
1148          * auditctl to read from it... which isn't ever going to
1149          * happen if we're actually running in the context of auditctl
1150          * trying to _send_ the stuff */
1151
1152         dest = kmalloc(sizeof(struct audit_netlink_list), GFP_KERNEL);
1153         if (!dest)
1154                 return -ENOMEM;
1155         dest->net = get_net(net);
1156         dest->portid = portid;
1157         skb_queue_head_init(&dest->q);
1158
1159         mutex_lock(&audit_filter_mutex);
1160         audit_list_rules(seq, &dest->q);
1161         mutex_unlock(&audit_filter_mutex);
1162
1163         tsk = kthread_run(audit_send_list, dest, "audit_send_list");
1164         if (IS_ERR(tsk)) {
1165                 skb_queue_purge(&dest->q);
1166                 kfree(dest);
1167                 err = PTR_ERR(tsk);
1168         }
1169
1170         return err;
1171 }
1172
1173 int audit_comparator(u32 left, u32 op, u32 right)
1174 {
1175         switch (op) {
1176         case Audit_equal:
1177                 return (left == right);
1178         case Audit_not_equal:
1179                 return (left != right);
1180         case Audit_lt:
1181                 return (left < right);
1182         case Audit_le:
1183                 return (left <= right);
1184         case Audit_gt:
1185                 return (left > right);
1186         case Audit_ge:
1187                 return (left >= right);
1188         case Audit_bitmask:
1189                 return (left & right);
1190         case Audit_bittest:
1191                 return ((left & right) == right);
1192         default:
1193                 BUG();
1194                 return 0;
1195         }
1196 }
1197
1198 int audit_uid_comparator(kuid_t left, u32 op, kuid_t right)
1199 {
1200         switch (op) {
1201         case Audit_equal:
1202                 return uid_eq(left, right);
1203         case Audit_not_equal:
1204                 return !uid_eq(left, right);
1205         case Audit_lt:
1206                 return uid_lt(left, right);
1207         case Audit_le:
1208                 return uid_lte(left, right);
1209         case Audit_gt:
1210                 return uid_gt(left, right);
1211         case Audit_ge:
1212                 return uid_gte(left, right);
1213         case Audit_bitmask:
1214         case Audit_bittest:
1215         default:
1216                 BUG();
1217                 return 0;
1218         }
1219 }
1220
1221 int audit_gid_comparator(kgid_t left, u32 op, kgid_t right)
1222 {
1223         switch (op) {
1224         case Audit_equal:
1225                 return gid_eq(left, right);
1226         case Audit_not_equal:
1227                 return !gid_eq(left, right);
1228         case Audit_lt:
1229                 return gid_lt(left, right);
1230         case Audit_le:
1231                 return gid_lte(left, right);
1232         case Audit_gt:
1233                 return gid_gt(left, right);
1234         case Audit_ge:
1235                 return gid_gte(left, right);
1236         case Audit_bitmask:
1237         case Audit_bittest:
1238         default:
1239                 BUG();
1240                 return 0;
1241         }
1242 }
1243
1244 /**
1245  * parent_len - find the length of the parent portion of a pathname
1246  * @path: pathname of which to determine length
1247  */
1248 int parent_len(const char *path)
1249 {
1250         int plen;
1251         const char *p;
1252
1253         plen = strlen(path);
1254
1255         if (plen == 0)
1256                 return plen;
1257
1258         /* disregard trailing slashes */
1259         p = path + plen - 1;
1260         while ((*p == '/') && (p > path))
1261                 p--;
1262
1263         /* walk backward until we find the next slash or hit beginning */
1264         while ((*p != '/') && (p > path))
1265                 p--;
1266
1267         /* did we find a slash? Then increment to include it in path */
1268         if (*p == '/')
1269                 p++;
1270
1271         return p - path;
1272 }
1273
1274 /**
1275  * audit_compare_dname_path - compare given dentry name with last component in
1276  *                            given path. Return of 0 indicates a match.
1277  * @dname:      dentry name that we're comparing
1278  * @path:       full pathname that we're comparing
1279  * @parentlen:  length of the parent if known. Passing in AUDIT_NAME_FULL
1280  *              here indicates that we must compute this value.
1281  */
1282 int audit_compare_dname_path(const struct qstr *dname, const char *path, int parentlen)
1283 {
1284         int dlen, pathlen;
1285         const char *p;
1286
1287         dlen = dname->len;
1288         pathlen = strlen(path);
1289         if (pathlen < dlen)
1290                 return 1;
1291
1292         parentlen = parentlen == AUDIT_NAME_FULL ? parent_len(path) : parentlen;
1293         if (pathlen - parentlen != dlen)
1294                 return 1;
1295
1296         p = path + parentlen;
1297
1298         return strncmp(p, dname->name, dlen);
1299 }
1300
1301 int audit_filter(int msgtype, unsigned int listtype)
1302 {
1303         struct audit_entry *e;
1304         int ret = 1; /* Audit by default */
1305
1306         rcu_read_lock();
1307         list_for_each_entry_rcu(e, &audit_filter_list[listtype], list) {
1308                 int i, result = 0;
1309
1310                 for (i = 0; i < e->rule.field_count; i++) {
1311                         struct audit_field *f = &e->rule.fields[i];
1312                         pid_t pid;
1313                         u32 sid;
1314
1315                         switch (f->type) {
1316                         case AUDIT_PID:
1317                                 pid = task_pid_nr(current);
1318                                 result = audit_comparator(pid, f->op, f->val);
1319                                 break;
1320                         case AUDIT_UID:
1321                                 result = audit_uid_comparator(current_uid(), f->op, f->uid);
1322                                 break;
1323                         case AUDIT_GID:
1324                                 result = audit_gid_comparator(current_gid(), f->op, f->gid);
1325                                 break;
1326                         case AUDIT_LOGINUID:
1327                                 result = audit_uid_comparator(audit_get_loginuid(current),
1328                                                               f->op, f->uid);
1329                                 break;
1330                         case AUDIT_LOGINUID_SET:
1331                                 result = audit_comparator(audit_loginuid_set(current),
1332                                                           f->op, f->val);
1333                                 break;
1334                         case AUDIT_MSGTYPE:
1335                                 result = audit_comparator(msgtype, f->op, f->val);
1336                                 break;
1337                         case AUDIT_SUBJ_USER:
1338                         case AUDIT_SUBJ_ROLE:
1339                         case AUDIT_SUBJ_TYPE:
1340                         case AUDIT_SUBJ_SEN:
1341                         case AUDIT_SUBJ_CLR:
1342                                 if (f->lsm_rule) {
1343                                         security_task_getsecid(current, &sid);
1344                                         result = security_audit_rule_match(sid,
1345                                                    f->type, f->op, f->lsm_rule);
1346                                 }
1347                                 break;
1348                         case AUDIT_EXE:
1349                                 result = audit_exe_compare(current, e->rule.exe);
1350                                 if (f->op == Audit_not_equal)
1351                                         result = !result;
1352                                 break;
1353                         default:
1354                                 goto unlock_and_return;
1355                         }
1356                         if (result < 0) /* error */
1357                                 goto unlock_and_return;
1358                         if (!result)
1359                                 break;
1360                 }
1361                 if (result > 0) {
1362                         if (e->rule.action == AUDIT_NEVER || listtype == AUDIT_FILTER_EXCLUDE)
1363                                 ret = 0;
1364                         break;
1365                 }
1366         }
1367 unlock_and_return:
1368         rcu_read_unlock();
1369         return ret;
1370 }
1371
1372 static int update_lsm_rule(struct audit_krule *r)
1373 {
1374         struct audit_entry *entry = container_of(r, struct audit_entry, rule);
1375         struct audit_entry *nentry;
1376         int err = 0;
1377
1378         if (!security_audit_rule_known(r))
1379                 return 0;
1380
1381         nentry = audit_dupe_rule(r);
1382         if (entry->rule.exe)
1383                 audit_remove_mark(entry->rule.exe);
1384         if (IS_ERR(nentry)) {
1385                 /* save the first error encountered for the
1386                  * return value */
1387                 err = PTR_ERR(nentry);
1388                 audit_panic("error updating LSM filters");
1389                 if (r->watch)
1390                         list_del(&r->rlist);
1391                 list_del_rcu(&entry->list);
1392                 list_del(&r->list);
1393         } else {
1394                 if (r->watch || r->tree)
1395                         list_replace_init(&r->rlist, &nentry->rule.rlist);
1396                 list_replace_rcu(&entry->list, &nentry->list);
1397                 list_replace(&r->list, &nentry->rule.list);
1398         }
1399         call_rcu(&entry->rcu, audit_free_rule_rcu);
1400
1401         return err;
1402 }
1403
1404 /* This function will re-initialize the lsm_rule field of all applicable rules.
1405  * It will traverse the filter lists serarching for rules that contain LSM
1406  * specific filter fields.  When such a rule is found, it is copied, the
1407  * LSM field is re-initialized, and the old rule is replaced with the
1408  * updated rule. */
1409 int audit_update_lsm_rules(void)
1410 {
1411         struct audit_krule *r, *n;
1412         int i, err = 0;
1413
1414         /* audit_filter_mutex synchronizes the writers */
1415         mutex_lock(&audit_filter_mutex);
1416
1417         for (i = 0; i < AUDIT_NR_FILTERS; i++) {
1418                 list_for_each_entry_safe(r, n, &audit_rules_list[i], list) {
1419                         int res = update_lsm_rule(r);
1420                         if (!err)
1421                                 err = res;
1422                 }
1423         }
1424         mutex_unlock(&audit_filter_mutex);
1425
1426         return err;
1427 }