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