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