kernel/auditfilter.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /* auditfilter.c -- filtering of audit events
   3  *
   4  * Copyright 2003-2004 Red Hat, Inc.
   5  * Copyright 2005 Hewlett-Packard Development Company, L.P.
   6  * Copyright 2005 IBM Corporation
   7  */
   8
   9 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
  10
  11 #include <linux/kernel.h>
  12 #include <linux/audit.h>
  13 #include <linux/kthread.h>
  14 #include <linux/mutex.h>
  15 #include <linux/fs.h>
  16 #include <linux/namei.h>
  17 #include <linux/netlink.h>
  18 #include <linux/sched.h>
  19 #include <linux/slab.h>
  20 #include <linux/security.h>
  21 #include <net/net_namespace.h>
  22 #include <net/sock.h>
  23 #include "audit.h"
  24
  25 /*
  26  * Locking model:
  27  *
  28  * audit_filter_mutex:
  29  *              Synchronizes writes and blocking reads of audit's filterlist
  30  *              data.  Rcu is used to traverse the filterlist and access
  31  *              contents of structs audit_entry, audit_watch and opaque
  32  *              LSM rules during filtering.  If modified, these structures
  33  *              must be copied and replace their counterparts in the filterlist.
  34  *              An audit_parent struct is not accessed during filtering, so may
  35  *              be written directly provided audit_filter_mutex is held.
  36  */
  37
  38 /* Audit filter lists, defined in <linux/audit.h> */
  39 struct list_head audit_filter_list[AUDIT_NR_FILTERS] = {
  40         LIST_HEAD_INIT(audit_filter_list[0]),
  41         LIST_HEAD_INIT(audit_filter_list[1]),
  42         LIST_HEAD_INIT(audit_filter_list[2]),
  43         LIST_HEAD_INIT(audit_filter_list[3]),
  44         LIST_HEAD_INIT(audit_filter_list[4]),
  45         LIST_HEAD_INIT(audit_filter_list[5]),
  46         LIST_HEAD_INIT(audit_filter_list[6]),
  47         LIST_HEAD_INIT(audit_filter_list[7]),
  48 #if AUDIT_NR_FILTERS != 8
  49 #error Fix audit_filter_list initialiser
  50 #endif
  51 };
  52 static struct list_head audit_rules_list[AUDIT_NR_FILTERS] = {
  53         LIST_HEAD_INIT(audit_rules_list[0]),
  54         LIST_HEAD_INIT(audit_rules_list[1]),
  55         LIST_HEAD_INIT(audit_rules_list[2]),
  56         LIST_HEAD_INIT(audit_rules_list[3]),
  57         LIST_HEAD_INIT(audit_rules_list[4]),
  58         LIST_HEAD_INIT(audit_rules_list[5]),
  59         LIST_HEAD_INIT(audit_rules_list[6]),
  60         LIST_HEAD_INIT(audit_rules_list[7]),
  61 };
  62
  63 DEFINE_MUTEX(audit_filter_mutex);
  64
  65 static void audit_free_lsm_field(struct audit_field *f)
  66 {
  67         switch (f->type) {
  68         case AUDIT_SUBJ_USER:
  69         case AUDIT_SUBJ_ROLE:
  70         case AUDIT_SUBJ_TYPE:
  71         case AUDIT_SUBJ_SEN:
  72         case AUDIT_SUBJ_CLR:
  73         case AUDIT_OBJ_USER:
  74         case AUDIT_OBJ_ROLE:
  75         case AUDIT_OBJ_TYPE:
  76         case AUDIT_OBJ_LEV_LOW:
  77         case AUDIT_OBJ_LEV_HIGH:
  78                 kfree(f->lsm_str);
  79                 security_audit_rule_free(f->lsm_rule);
  80         }
  81 }
  82
  83 static inline void audit_free_rule(struct audit_entry *e)
  84 {
  85         int i;
  86         struct audit_krule *erule = &e->rule;
  87
  88         /* some rules don't have associated watches */
  89         if (erule->watch)
  90                 audit_put_watch(erule->watch);
  91         if (erule->fields)
  92                 for (i = 0; i < erule->field_count; i++)
  93                         audit_free_lsm_field(&erule->fields[i]);
  94         kfree(erule->fields);
  95         kfree(erule->filterkey);
  96         kfree(e);
  97 }
  98
  99 void audit_free_rule_rcu(struct rcu_head *head)
 100 {
 101         struct audit_entry *e = container_of(head, struct audit_entry, rcu);
 102         audit_free_rule(e);
 103 }
 104
 105 /* Initialize an audit filterlist entry. */
 106 static inline struct audit_entry *audit_init_entry(u32 field_count)
 107 {
 108         struct audit_entry *entry;
 109         struct audit_field *fields;
 110
 111         entry = kzalloc(sizeof(*entry), GFP_KERNEL);
 112         if (unlikely(!entry))
 113                 return NULL;
 114
 115         fields = kcalloc(field_count, sizeof(*fields), GFP_KERNEL);
 116         if (unlikely(!fields)) {
 117                 kfree(entry);
 118                 return NULL;
 119         }
 120         entry->rule.fields = fields;
 121
 122         return entry;
 123 }
 124
 125 /* Unpack a filter field's string representation from user-space
 126  * buffer. */
 127 char *audit_unpack_string(void **bufp, size_t *remain, size_t len)
 128 {
 129         char *str;
 130
 131         if (!*bufp || (len == 0) || (len > *remain))
 132                 return ERR_PTR(-EINVAL);
 133
 134         /* Of the currently implemented string fields, PATH_MAX
 135          * defines the longest valid length.
 136          */
 137         if (len > PATH_MAX)
 138                 return ERR_PTR(-ENAMETOOLONG);
 139
 140         str = kmalloc(len + 1, GFP_KERNEL);
 141         if (unlikely(!str))
 142                 return ERR_PTR(-ENOMEM);
 143
 144         memcpy(str, *bufp, len);
 145         str[len] = 0;
 146         *bufp += len;
 147         *remain -= len;
 148
 149         return str;
 150 }
 151
 152 /* Translate an inode field to kernel representation. */
 153 static inline int audit_to_inode(struct audit_krule *krule,
 154                                  struct audit_field *f)
 155 {
 156         if ((krule->listnr != AUDIT_FILTER_EXIT &&
 157              krule->listnr != AUDIT_FILTER_URING_EXIT) ||
 158             krule->inode_f || krule->watch || krule->tree ||
 159             (f->op != Audit_equal && f->op != Audit_not_equal))
 160                 return -EINVAL;
 161
 162         krule->inode_f = f;
 163         return 0;
 164 }
 165
 166 static __u32 *classes[AUDIT_SYSCALL_CLASSES];
 167
 168 int __init audit_register_class(int class, unsigned *list)
 169 {
 170         __u32 *p = kcalloc(AUDIT_BITMASK_SIZE, sizeof(__u32), GFP_KERNEL);
 171         if (!p)
 172                 return -ENOMEM;
 173         while (*list != ~0U) {
 174                 unsigned n = *list++;
 175                 if (n >= AUDIT_BITMASK_SIZE * 32 - AUDIT_SYSCALL_CLASSES) {
 176                         kfree(p);
 177                         return -EINVAL;
 178                 }
 179                 p[AUDIT_WORD(n)] |= AUDIT_BIT(n);
 180         }
 181         if (class >= AUDIT_SYSCALL_CLASSES || classes[class]) {
 182                 kfree(p);
 183                 return -EINVAL;
 184         }
 185         classes[class] = p;
 186         return 0;
 187 }
 188
 189 int audit_match_class(int class, unsigned syscall)
 190 {
 191         if (unlikely(syscall >= AUDIT_BITMASK_SIZE * 32))
 192                 return 0;
 193         if (unlikely(class >= AUDIT_SYSCALL_CLASSES || !classes[class]))
 194                 return 0;
 195         return classes[class][AUDIT_WORD(syscall)] & AUDIT_BIT(syscall);
 196 }
 197
 198 #ifdef CONFIG_AUDITSYSCALL
 199 static inline int audit_match_class_bits(int class, u32 *mask)
 200 {
 201         int i;
 202
 203         if (classes[class]) {
 204                 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
 205                         if (mask[i] & classes[class][i])
 206                                 return 0;
 207         }
 208         return 1;
 209 }
 210
 211 static int audit_match_signal(struct audit_entry *entry)
 212 {
 213         struct audit_field *arch = entry->rule.arch_f;
 214
 215         if (!arch) {
 216                 /* When arch is unspecified, we must check both masks on biarch
 217                  * as syscall number alone is ambiguous. */
 218                 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL,
 219                                                entry->rule.mask) &&
 220                         audit_match_class_bits(AUDIT_CLASS_SIGNAL_32,
 221                                                entry->rule.mask));
 222         }
 223
 224         switch (audit_classify_arch(arch->val)) {
 225         case 0: /* native */
 226                 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL,
 227                                                entry->rule.mask));
 228         case 1: /* 32bit on biarch */
 229                 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL_32,
 230                                                entry->rule.mask));
 231         default:
 232                 return 1;
 233         }
 234 }
 235 #endif
 236
 237 /* Common user-space to kernel rule translation. */
 238 static inline struct audit_entry *audit_to_entry_common(struct audit_rule_data *rule)
 239 {
 240         unsigned listnr;
 241         struct audit_entry *entry;
 242         int i, err;
 243
 244         err = -EINVAL;
 245         listnr = rule->flags & ~AUDIT_FILTER_PREPEND;
 246         switch (listnr) {
 247         default:
 248                 goto exit_err;
 249 #ifdef CONFIG_AUDITSYSCALL
 250         case AUDIT_FILTER_ENTRY:
 251                 pr_err("AUDIT_FILTER_ENTRY is deprecated\n");
 252                 goto exit_err;
 253         case AUDIT_FILTER_EXIT:
 254         case AUDIT_FILTER_URING_EXIT:
 255         case AUDIT_FILTER_TASK:
 256 #endif
 257         case AUDIT_FILTER_USER:
 258         case AUDIT_FILTER_EXCLUDE:
 259         case AUDIT_FILTER_FS:
 260                 ;
 261         }
 262         if (unlikely(rule->action == AUDIT_POSSIBLE)) {
 263                 pr_err("AUDIT_POSSIBLE is deprecated\n");
 264                 goto exit_err;
 265         }
 266         if (rule->action != AUDIT_NEVER && rule->action != AUDIT_ALWAYS)
 267                 goto exit_err;
 268         if (rule->field_count > AUDIT_MAX_FIELDS)
 269                 goto exit_err;
 270
 271         err = -ENOMEM;
 272         entry = audit_init_entry(rule->field_count);
 273         if (!entry)
 274                 goto exit_err;
 275
 276         entry->rule.flags = rule->flags & AUDIT_FILTER_PREPEND;
 277         entry->rule.listnr = listnr;
 278         entry->rule.action = rule->action;
 279         entry->rule.field_count = rule->field_count;
 280
 281         for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
 282                 entry->rule.mask[i] = rule->mask[i];
 283
 284         for (i = 0; i < AUDIT_SYSCALL_CLASSES; i++) {
 285                 int bit = AUDIT_BITMASK_SIZE * 32 - i - 1;
 286                 __u32 *p = &entry->rule.mask[AUDIT_WORD(bit)];
 287                 __u32 *class;
 288
 289                 if (!(*p & AUDIT_BIT(bit)))
 290                         continue;
 291                 *p &= ~AUDIT_BIT(bit);
 292                 class = classes[i];
 293                 if (class) {
 294                         int j;
 295                         for (j = 0; j < AUDIT_BITMASK_SIZE; j++)
 296                                 entry->rule.mask[j] |= class[j];
 297                 }
 298         }
 299
 300         return entry;
 301
 302 exit_err:
 303         return ERR_PTR(err);
 304 }
 305
 306 static u32 audit_ops[] =
 307 {
 308         [Audit_equal] = AUDIT_EQUAL,
 309         [Audit_not_equal] = AUDIT_NOT_EQUAL,
 310         [Audit_bitmask] = AUDIT_BIT_MASK,
 311         [Audit_bittest] = AUDIT_BIT_TEST,
 312         [Audit_lt] = AUDIT_LESS_THAN,
 313         [Audit_gt] = AUDIT_GREATER_THAN,
 314         [Audit_le] = AUDIT_LESS_THAN_OR_EQUAL,
 315         [Audit_ge] = AUDIT_GREATER_THAN_OR_EQUAL,
 316 };
 317
 318 static u32 audit_to_op(u32 op)
 319 {
 320         u32 n;
 321         for (n = Audit_equal; n < Audit_bad && audit_ops[n] != op; n++)
 322                 ;
 323         return n;
 324 }
 325
 326 /* check if an audit field is valid */
 327 static int audit_field_valid(struct audit_entry *entry, struct audit_field *f)
 328 {
 329         switch (f->type) {
 330         case AUDIT_MSGTYPE:
 331                 if (entry->rule.listnr != AUDIT_FILTER_EXCLUDE &&
 332                     entry->rule.listnr != AUDIT_FILTER_USER)
 333                         return -EINVAL;
 334                 break;
 335         case AUDIT_FSTYPE:
 336                 if (entry->rule.listnr != AUDIT_FILTER_FS)
 337                         return -EINVAL;
 338                 break;
 339         case AUDIT_PERM:
 340                 if (entry->rule.listnr == AUDIT_FILTER_URING_EXIT)
 341                         return -EINVAL;
 342                 break;
 343         }
 344
 345         switch (entry->rule.listnr) {
 346         case AUDIT_FILTER_FS:
 347                 switch (f->type) {
 348                 case AUDIT_FSTYPE:
 349                 case AUDIT_FILTERKEY:
 350                         break;
 351                 default:
 352                         return -EINVAL;
 353                 }
 354         }
 355
 356         /* Check for valid field type and op */
 357         switch (f->type) {
 358         case AUDIT_ARG0:
 359         case AUDIT_ARG1:
 360         case AUDIT_ARG2:
 361         case AUDIT_ARG3:
 362         case AUDIT_PERS: /* <uapi/linux/personality.h> */
 363         case AUDIT_DEVMINOR:
 364                 /* all ops are valid */
 365                 break;
 366         case AUDIT_UID:
 367         case AUDIT_EUID:
 368         case AUDIT_SUID:
 369         case AUDIT_FSUID:
 370         case AUDIT_LOGINUID:
 371         case AUDIT_OBJ_UID:
 372         case AUDIT_GID:
 373         case AUDIT_EGID:
 374         case AUDIT_SGID:
 375         case AUDIT_FSGID:
 376         case AUDIT_OBJ_GID:
 377         case AUDIT_PID:
 378         case AUDIT_MSGTYPE:
 379         case AUDIT_PPID:
 380         case AUDIT_DEVMAJOR:
 381         case AUDIT_EXIT:
 382         case AUDIT_SUCCESS:
 383         case AUDIT_INODE:
 384         case AUDIT_SESSIONID:
 385         case AUDIT_SUBJ_SEN:
 386         case AUDIT_SUBJ_CLR:
 387         case AUDIT_OBJ_LEV_LOW:
 388         case AUDIT_OBJ_LEV_HIGH:
 389         case AUDIT_SADDR_FAM:
 390                 /* bit ops are only useful on syscall args */
 391                 if (f->op == Audit_bitmask || f->op == Audit_bittest)
 392                         return -EINVAL;
 393                 break;
 394         case AUDIT_SUBJ_USER:
 395         case AUDIT_SUBJ_ROLE:
 396         case AUDIT_SUBJ_TYPE:
 397         case AUDIT_OBJ_USER:
 398         case AUDIT_OBJ_ROLE:
 399         case AUDIT_OBJ_TYPE:
 400         case AUDIT_WATCH:
 401         case AUDIT_DIR:
 402         case AUDIT_FILTERKEY:
 403         case AUDIT_LOGINUID_SET:
 404         case AUDIT_ARCH:
 405         case AUDIT_FSTYPE:
 406         case AUDIT_PERM:
 407         case AUDIT_FILETYPE:
 408         case AUDIT_FIELD_COMPARE:
 409         case AUDIT_EXE:
 410                 /* only equal and not equal valid ops */
 411                 if (f->op != Audit_not_equal && f->op != Audit_equal)
 412                         return -EINVAL;
 413                 break;
 414         default:
 415                 /* field not recognized */
 416                 return -EINVAL;
 417         }
 418
 419         /* Check for select valid field values */
 420         switch (f->type) {
 421         case AUDIT_LOGINUID_SET:
 422                 if ((f->val != 0) && (f->val != 1))
 423                         return -EINVAL;
 424                 break;
 425         case AUDIT_PERM:
 426                 if (f->val & ~15)
 427                         return -EINVAL;
 428                 break;
 429         case AUDIT_FILETYPE:
 430                 if (f->val & ~S_IFMT)
 431                         return -EINVAL;
 432                 break;
 433         case AUDIT_FIELD_COMPARE:
 434                 if (f->val > AUDIT_MAX_FIELD_COMPARE)
 435                         return -EINVAL;
 436                 break;
 437         case AUDIT_SADDR_FAM:
 438                 if (f->val >= AF_MAX)
 439                         return -EINVAL;
 440                 break;
 441         default:
 442                 break;
 443         }
 444
 445         return 0;
 446 }
 447
 448 /* Translate struct audit_rule_data to kernel's rule representation. */
 449 static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
 450                                                size_t datasz)
 451 {
 452         int err = 0;
 453         struct audit_entry *entry;
 454         void *bufp;
 455         size_t remain = datasz - sizeof(struct audit_rule_data);
 456         int i;
 457         char *str;
 458         struct audit_fsnotify_mark *audit_mark;
 459
 460         entry = audit_to_entry_common(data);
 461         if (IS_ERR(entry))
 462                 goto exit_nofree;
 463
 464         bufp = data->buf;
 465         for (i = 0; i < data->field_count; i++) {
 466                 struct audit_field *f = &entry->rule.fields[i];
 467                 u32 f_val;
 468
 469                 err = -EINVAL;
 470
 471                 f->op = audit_to_op(data->fieldflags[i]);
 472                 if (f->op == Audit_bad)
 473                         goto exit_free;
 474
 475                 f->type = data->fields[i];
 476                 f_val = data->values[i];
 477
 478                 /* Support legacy tests for a valid loginuid */
 479                 if ((f->type == AUDIT_LOGINUID) && (f_val == AUDIT_UID_UNSET)) {
 480                         f->type = AUDIT_LOGINUID_SET;
 481                         f_val = 0;
 482                         entry->rule.pflags |= AUDIT_LOGINUID_LEGACY;
 483                 }
 484
 485                 err = audit_field_valid(entry, f);
 486                 if (err)
 487                         goto exit_free;
 488
 489                 err = -EINVAL;
 490                 switch (f->type) {
 491                 case AUDIT_LOGINUID:
 492                 case AUDIT_UID:
 493                 case AUDIT_EUID:
 494                 case AUDIT_SUID:
 495                 case AUDIT_FSUID:
 496                 case AUDIT_OBJ_UID:
 497                         f->uid = make_kuid(current_user_ns(), f_val);
 498                         if (!uid_valid(f->uid))
 499                                 goto exit_free;
 500                         break;
 501                 case AUDIT_GID:
 502                 case AUDIT_EGID:
 503                 case AUDIT_SGID:
 504                 case AUDIT_FSGID:
 505                 case AUDIT_OBJ_GID:
 506                         f->gid = make_kgid(current_user_ns(), f_val);
 507                         if (!gid_valid(f->gid))
 508                                 goto exit_free;
 509                         break;
 510                 case AUDIT_ARCH:
 511                         f->val = f_val;
 512                         entry->rule.arch_f = f;
 513                         break;
 514                 case AUDIT_SUBJ_USER:
 515                 case AUDIT_SUBJ_ROLE:
 516                 case AUDIT_SUBJ_TYPE:
 517                 case AUDIT_SUBJ_SEN:
 518                 case AUDIT_SUBJ_CLR:
 519                 case AUDIT_OBJ_USER:
 520                 case AUDIT_OBJ_ROLE:
 521                 case AUDIT_OBJ_TYPE:
 522                 case AUDIT_OBJ_LEV_LOW:
 523                 case AUDIT_OBJ_LEV_HIGH:
 524                         str = audit_unpack_string(&bufp, &remain, f_val);
 525                         if (IS_ERR(str)) {
 526                                 err = PTR_ERR(str);
 527                                 goto exit_free;
 528                         }
 529                         entry->rule.buflen += f_val;
 530                         f->lsm_str = str;
 531                         err = security_audit_rule_init(f->type, f->op, str,
 532                                                        (void **)&f->lsm_rule,
 533                                                        GFP_KERNEL);
 534                         /* Keep currently invalid fields around in case they
 535                          * become valid after a policy reload. */
 536                         if (err == -EINVAL) {
 537                                 pr_warn("audit rule for LSM \'%s\' is invalid\n",
 538                                         str);
 539                                 err = 0;
 540                         } else if (err)
 541                                 goto exit_free;
 542                         break;
 543                 case AUDIT_WATCH:
 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_to_watch(&entry->rule, str, f_val, f->op);
 550                         if (err) {
 551                                 kfree(str);
 552                                 goto exit_free;
 553                         }
 554                         entry->rule.buflen += f_val;
 555                         break;
 556                 case AUDIT_DIR:
 557                         str = audit_unpack_string(&bufp, &remain, f_val);
 558                         if (IS_ERR(str)) {
 559                                 err = PTR_ERR(str);
 560                                 goto exit_free;
 561                         }
 562                         err = audit_make_tree(&entry->rule, str, f->op);
 563                         kfree(str);
 564                         if (err)
 565                                 goto exit_free;
 566                         entry->rule.buflen += f_val;
 567                         break;
 568                 case AUDIT_INODE:
 569                         f->val = f_val;
 570                         err = audit_to_inode(&entry->rule, f);
 571                         if (err)
 572                                 goto exit_free;
 573                         break;
 574                 case AUDIT_FILTERKEY:
 575                         if (entry->rule.filterkey || f_val > AUDIT_MAX_KEY_LEN)
 576                                 goto exit_free;
 577                         str = audit_unpack_string(&bufp, &remain, f_val);
 578                         if (IS_ERR(str)) {
 579                                 err = PTR_ERR(str);
 580                                 goto exit_free;
 581                         }
 582                         entry->rule.buflen += f_val;
 583                         entry->rule.filterkey = str;
 584                         break;
 585                 case AUDIT_EXE:
 586                         if (entry->rule.exe || f_val > PATH_MAX)
 587                                 goto exit_free;
 588                         str = audit_unpack_string(&bufp, &remain, f_val);
 589                         if (IS_ERR(str)) {
 590                                 err = PTR_ERR(str);
 591                                 goto exit_free;
 592                         }
 593                         audit_mark = audit_alloc_mark(&entry->rule, str, f_val);
 594                         if (IS_ERR(audit_mark)) {
 595                                 kfree(str);
 596                                 err = PTR_ERR(audit_mark);
 597                                 goto exit_free;
 598                         }
 599                         entry->rule.buflen += f_val;
 600                         entry->rule.exe = audit_mark;
 601                         break;
 602                 default:
 603                         f->val = f_val;
 604                         break;
 605                 }
 606         }
 607
 608         if (entry->rule.inode_f && entry->rule.inode_f->op == Audit_not_equal)
 609                 entry->rule.inode_f = NULL;
 610
 611 exit_nofree:
 612         return entry;
 613
 614 exit_free:
 615         if (entry->rule.tree)
 616                 audit_put_tree(entry->rule.tree); /* that's the temporary one */
 617         if (entry->rule.exe)
 618                 audit_remove_mark(entry->rule.exe); /* that's the template one */
 619         audit_free_rule(entry);
 620         return ERR_PTR(err);
 621 }
 622
 623 /* Pack a filter field's string representation into data block. */
 624 static inline size_t audit_pack_string(void **bufp, const char *str)
 625 {
 626         size_t len = strlen(str);
 627
 628         memcpy(*bufp, str, len);
 629         *bufp += len;
 630
 631         return len;
 632 }
 633
 634 /* Translate kernel rule representation to struct audit_rule_data. */
 635 static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule)
 636 {
 637         struct audit_rule_data *data;
 638         void *bufp;
 639         int i;
 640
 641         data = kmalloc(struct_size(data, buf, krule->buflen), GFP_KERNEL);
 642         if (unlikely(!data))
 643                 return NULL;
 644         memset(data, 0, sizeof(*data));
 645
 646         data->flags = krule->flags | krule->listnr;
 647         data->action = krule->action;
 648         data->field_count = krule->field_count;
 649         bufp = data->buf;
 650         for (i = 0; i < data->field_count; i++) {
 651                 struct audit_field *f = &krule->fields[i];
 652
 653                 data->fields[i] = f->type;
 654                 data->fieldflags[i] = audit_ops[f->op];
 655                 switch (f->type) {
 656                 case AUDIT_SUBJ_USER:
 657                 case AUDIT_SUBJ_ROLE:
 658                 case AUDIT_SUBJ_TYPE:
 659                 case AUDIT_SUBJ_SEN:
 660                 case AUDIT_SUBJ_CLR:
 661                 case AUDIT_OBJ_USER:
 662                 case AUDIT_OBJ_ROLE:
 663                 case AUDIT_OBJ_TYPE:
 664                 case AUDIT_OBJ_LEV_LOW:
 665                 case AUDIT_OBJ_LEV_HIGH:
 666                         data->buflen += data->values[i] =
 667                                 audit_pack_string(&bufp, f->lsm_str);
 668                         break;
 669                 case AUDIT_WATCH:
 670                         data->buflen += data->values[i] =
 671                                 audit_pack_string(&bufp,
 672                                                   audit_watch_path(krule->watch));
 673                         break;
 674                 case AUDIT_DIR:
 675                         data->buflen += data->values[i] =
 676                                 audit_pack_string(&bufp,
 677                                                   audit_tree_path(krule->tree));
 678                         break;
 679                 case AUDIT_FILTERKEY:
 680                         data->buflen += data->values[i] =
 681                                 audit_pack_string(&bufp, krule->filterkey);
 682                         break;
 683                 case AUDIT_EXE:
 684                         data->buflen += data->values[i] =
 685                                 audit_pack_string(&bufp, audit_mark_path(krule->exe));
 686                         break;
 687                 case AUDIT_LOGINUID_SET:
 688                         if (krule->pflags & AUDIT_LOGINUID_LEGACY && !f->val) {
 689                                 data->fields[i] = AUDIT_LOGINUID;
 690                                 data->values[i] = AUDIT_UID_UNSET;
 691                                 break;
 692                         }
 693                         fallthrough;    /* if set */
 694                 default:
 695                         data->values[i] = f->val;
 696                 }
 697         }
 698         for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
 699                 data->mask[i] = krule->mask[i];
 700
 701         return data;
 702 }
 703
 704 /* Compare two rules in kernel format.  Considered success if rules
 705  * don't match. */
 706 static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b)
 707 {
 708         int i;
 709
 710         if (a->flags != b->flags ||
 711             a->pflags != b->pflags ||
 712             a->listnr != b->listnr ||
 713             a->action != b->action ||
 714             a->field_count != b->field_count)
 715                 return 1;
 716
 717         for (i = 0; i < a->field_count; i++) {
 718                 if (a->fields[i].type != b->fields[i].type ||
 719                     a->fields[i].op != b->fields[i].op)
 720                         return 1;
 721
 722                 switch (a->fields[i].type) {
 723                 case AUDIT_SUBJ_USER:
 724                 case AUDIT_SUBJ_ROLE:
 725                 case AUDIT_SUBJ_TYPE:
 726                 case AUDIT_SUBJ_SEN:
 727                 case AUDIT_SUBJ_CLR:
 728                 case AUDIT_OBJ_USER:
 729                 case AUDIT_OBJ_ROLE:
 730                 case AUDIT_OBJ_TYPE:
 731                 case AUDIT_OBJ_LEV_LOW:
 732                 case AUDIT_OBJ_LEV_HIGH:
 733                         if (strcmp(a->fields[i].lsm_str, b->fields[i].lsm_str))
 734                                 return 1;
 735                         break;
 736                 case AUDIT_WATCH:
 737                         if (strcmp(audit_watch_path(a->watch),
 738                                    audit_watch_path(b->watch)))
 739                                 return 1;
 740                         break;
 741                 case AUDIT_DIR:
 742                         if (strcmp(audit_tree_path(a->tree),
 743                                    audit_tree_path(b->tree)))
 744                                 return 1;
 745                         break;
 746                 case AUDIT_FILTERKEY:
 747                         /* both filterkeys exist based on above type compare */
 748                         if (strcmp(a->filterkey, b->filterkey))
 749                                 return 1;
 750                         break;
 751                 case AUDIT_EXE:
 752                         /* both paths exist based on above type compare */
 753                         if (strcmp(audit_mark_path(a->exe),
 754                                    audit_mark_path(b->exe)))
 755                                 return 1;
 756                         break;
 757                 case AUDIT_UID:
 758                 case AUDIT_EUID:
 759                 case AUDIT_SUID:
 760                 case AUDIT_FSUID:
 761                 case AUDIT_LOGINUID:
 762                 case AUDIT_OBJ_UID:
 763                         if (!uid_eq(a->fields[i].uid, b->fields[i].uid))
 764                                 return 1;
 765                         break;
 766                 case AUDIT_GID:
 767                 case AUDIT_EGID:
 768                 case AUDIT_SGID:
 769                 case AUDIT_FSGID:
 770                 case AUDIT_OBJ_GID:
 771                         if (!gid_eq(a->fields[i].gid, b->fields[i].gid))
 772                                 return 1;
 773                         break;
 774                 default:
 775                         if (a->fields[i].val != b->fields[i].val)
 776                                 return 1;
 777                 }
 778         }
 779
 780         for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
 781                 if (a->mask[i] != b->mask[i])
 782                         return 1;
 783
 784         return 0;
 785 }
 786
 787 /* Duplicate LSM field information.  The lsm_rule is opaque, so must be
 788  * re-initialized. */
 789 static inline int audit_dupe_lsm_field(struct audit_field *df,
 790                                            struct audit_field *sf)
 791 {
 792         int ret;
 793         char *lsm_str;
 794
 795         /* our own copy of lsm_str */
 796         lsm_str = kstrdup(sf->lsm_str, GFP_KERNEL);
 797         if (unlikely(!lsm_str))
 798                 return -ENOMEM;
 799         df->lsm_str = lsm_str;
 800
 801         /* our own (refreshed) copy of lsm_rule */
 802         ret = security_audit_rule_init(df->type, df->op, df->lsm_str,
 803                                        (void **)&df->lsm_rule, GFP_KERNEL);
 804         /* Keep currently invalid fields around in case they
 805          * become valid after a policy reload. */
 806         if (ret == -EINVAL) {
 807                 pr_warn("audit rule for LSM \'%s\' is invalid\n",
 808                         df->lsm_str);
 809                 ret = 0;
 810         }
 811
 812         return ret;
 813 }
 814
 815 /* Duplicate an audit rule.  This will be a deep copy with the exception
 816  * of the watch - that pointer is carried over.  The LSM specific fields
 817  * will be updated in the copy.  The point is to be able to replace the old
 818  * rule with the new rule in the filterlist, then free the old rule.
 819  * The rlist element is undefined; list manipulations are handled apart from
 820  * the initial copy. */
 821 struct audit_entry *audit_dupe_rule(struct audit_krule *old)
 822 {
 823         u32 fcount = old->field_count;
 824         struct audit_entry *entry;
 825         struct audit_krule *new;
 826         char *fk;
 827         int i, err = 0;
 828
 829         entry = audit_init_entry(fcount);
 830         if (unlikely(!entry))
 831                 return ERR_PTR(-ENOMEM);
 832
 833         new = &entry->rule;
 834         new->flags = old->flags;
 835         new->pflags = old->pflags;
 836         new->listnr = old->listnr;
 837         new->action = old->action;
 838         for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
 839                 new->mask[i] = old->mask[i];
 840         new->prio = old->prio;
 841         new->buflen = old->buflen;
 842         new->inode_f = old->inode_f;
 843         new->field_count = old->field_count;
 844
 845         /*
 846          * note that we are OK with not refcounting here; audit_match_tree()
 847          * never dereferences tree and we can't get false positives there
 848          * since we'd have to have rule gone from the list *and* removed
 849          * before the chunks found by lookup had been allocated, i.e. before
 850          * the beginning of list scan.
 851          */
 852         new->tree = old->tree;
 853         memcpy(new->fields, old->fields, sizeof(struct audit_field) * fcount);
 854
 855         /* deep copy this information, updating the lsm_rule fields, because
 856          * the originals will all be freed when the old rule is freed. */
 857         for (i = 0; i < fcount; i++) {
 858                 switch (new->fields[i].type) {
 859                 case AUDIT_SUBJ_USER:
 860                 case AUDIT_SUBJ_ROLE:
 861                 case AUDIT_SUBJ_TYPE:
 862                 case AUDIT_SUBJ_SEN:
 863                 case AUDIT_SUBJ_CLR:
 864                 case AUDIT_OBJ_USER:
 865                 case AUDIT_OBJ_ROLE:
 866                 case AUDIT_OBJ_TYPE:
 867                 case AUDIT_OBJ_LEV_LOW:
 868                 case AUDIT_OBJ_LEV_HIGH:
 869                         err = audit_dupe_lsm_field(&new->fields[i],
 870                                                        &old->fields[i]);
 871                         break;
 872                 case AUDIT_FILTERKEY:
 873                         fk = kstrdup(old->filterkey, GFP_KERNEL);
 874                         if (unlikely(!fk))
 875                                 err = -ENOMEM;
 876                         else
 877                                 new->filterkey = fk;
 878                         break;
 879                 case AUDIT_EXE:
 880                         err = audit_dupe_exe(new, old);
 881                         break;
 882                 }
 883                 if (err) {
 884                         if (new->exe)
 885                                 audit_remove_mark(new->exe);
 886                         audit_free_rule(entry);
 887                         return ERR_PTR(err);
 888                 }
 889         }
 890
 891         if (old->watch) {
 892                 audit_get_watch(old->watch);
 893                 new->watch = old->watch;
 894         }
 895
 896         return entry;
 897 }
 898
 899 /* Find an existing audit rule.
 900  * Caller must hold audit_filter_mutex to prevent stale rule data. */
 901 static struct audit_entry *audit_find_rule(struct audit_entry *entry,
 902                                            struct list_head **p)
 903 {
 904         struct audit_entry *e, *found = NULL;
 905         struct list_head *list;
 906         int h;
 907
 908         if (entry->rule.inode_f) {
 909                 h = audit_hash_ino(entry->rule.inode_f->val);
 910                 *p = list = &audit_inode_hash[h];
 911         } else if (entry->rule.watch) {
 912                 /* we don't know the inode number, so must walk entire hash */
 913                 for (h = 0; h < AUDIT_INODE_BUCKETS; h++) {
 914                         list = &audit_inode_hash[h];
 915                         list_for_each_entry(e, list, list)
 916                                 if (!audit_compare_rule(&entry->rule, &e->rule)) {
 917                                         found = e;
 918                                         goto out;
 919                                 }
 920                 }
 921                 goto out;
 922         } else {
 923                 *p = list = &audit_filter_list[entry->rule.listnr];
 924         }
 925
 926         list_for_each_entry(e, list, list)
 927                 if (!audit_compare_rule(&entry->rule, &e->rule)) {
 928                         found = e;
 929                         goto out;
 930                 }
 931
 932 out:
 933         return found;
 934 }
 935
 936 static u64 prio_low = ~0ULL/2;
 937 static u64 prio_high = ~0ULL/2 - 1;
 938
 939 /* Add rule to given filterlist if not a duplicate. */
 940 static inline int audit_add_rule(struct audit_entry *entry)
 941 {
 942         struct audit_entry *e;
 943         struct audit_watch *watch = entry->rule.watch;
 944         struct audit_tree *tree = entry->rule.tree;
 945         struct list_head *list;
 946         int err = 0;
 947 #ifdef CONFIG_AUDITSYSCALL
 948         int dont_count = 0;
 949
 950         /* If any of these, don't count towards total */
 951         switch (entry->rule.listnr) {
 952         case AUDIT_FILTER_USER:
 953         case AUDIT_FILTER_EXCLUDE:
 954         case AUDIT_FILTER_FS:
 955                 dont_count = 1;
 956         }
 957 #endif
 958
 959         mutex_lock(&audit_filter_mutex);
 960         e = audit_find_rule(entry, &list);
 961         if (e) {
 962                 mutex_unlock(&audit_filter_mutex);
 963                 err = -EEXIST;
 964                 /* normally audit_add_tree_rule() will free it on failure */
 965                 if (tree)
 966                         audit_put_tree(tree);
 967                 return err;
 968         }
 969
 970         if (watch) {
 971                 /* audit_filter_mutex is dropped and re-taken during this call */
 972                 err = audit_add_watch(&entry->rule, &list);
 973                 if (err) {
 974                         mutex_unlock(&audit_filter_mutex);
 975                         /*
 976                          * normally audit_add_tree_rule() will free it
 977                          * on failure
 978                          */
 979                         if (tree)
 980                                 audit_put_tree(tree);
 981                         return err;
 982                 }
 983         }
 984         if (tree) {
 985                 err = audit_add_tree_rule(&entry->rule);
 986                 if (err) {
 987                         mutex_unlock(&audit_filter_mutex);
 988                         return err;
 989                 }
 990         }
 991
 992         entry->rule.prio = ~0ULL;
 993         if (entry->rule.listnr == AUDIT_FILTER_EXIT ||
 994             entry->rule.listnr == AUDIT_FILTER_URING_EXIT) {
 995                 if (entry->rule.flags & AUDIT_FILTER_PREPEND)
 996                         entry->rule.prio = ++prio_high;
 997                 else
 998                         entry->rule.prio = --prio_low;
 999         }
1000
1001         if (entry->rule.flags & AUDIT_FILTER_PREPEND) {
1002                 list_add(&entry->rule.list,
1003                          &audit_rules_list[entry->rule.listnr]);
1004                 list_add_rcu(&entry->list, list);
1005                 entry->rule.flags &= ~AUDIT_FILTER_PREPEND;
1006         } else {
1007                 list_add_tail(&entry->rule.list,
1008                               &audit_rules_list[entry->rule.listnr]);
1009                 list_add_tail_rcu(&entry->list, list);
1010         }
1011 #ifdef CONFIG_AUDITSYSCALL
1012         if (!dont_count)
1013                 audit_n_rules++;
1014
1015         if (!audit_match_signal(entry))
1016                 audit_signals++;
1017 #endif
1018         mutex_unlock(&audit_filter_mutex);
1019
1020         return err;
1021 }
1022
1023 /* Remove an existing rule from filterlist. */
1024 int audit_del_rule(struct audit_entry *entry)
1025 {
1026         struct audit_entry  *e;
1027         struct audit_tree *tree = entry->rule.tree;
1028         struct list_head *list;
1029         int ret = 0;
1030 #ifdef CONFIG_AUDITSYSCALL
1031         int dont_count = 0;
1032
1033         /* If any of these, don't count towards total */
1034         switch (entry->rule.listnr) {
1035         case AUDIT_FILTER_USER:
1036         case AUDIT_FILTER_EXCLUDE:
1037         case AUDIT_FILTER_FS:
1038                 dont_count = 1;
1039         }
1040 #endif
1041
1042         mutex_lock(&audit_filter_mutex);
1043         e = audit_find_rule(entry, &list);
1044         if (!e) {
1045                 ret = -ENOENT;
1046                 goto out;
1047         }
1048
1049         if (e->rule.watch)
1050                 audit_remove_watch_rule(&e->rule);
1051
1052         if (e->rule.tree)
1053                 audit_remove_tree_rule(&e->rule);
1054
1055         if (e->rule.exe)
1056                 audit_remove_mark_rule(&e->rule);
1057
1058 #ifdef CONFIG_AUDITSYSCALL
1059         if (!dont_count)
1060                 audit_n_rules--;
1061
1062         if (!audit_match_signal(entry))
1063                 audit_signals--;
1064 #endif
1065
1066         list_del_rcu(&e->list);
1067         list_del(&e->rule.list);
1068         call_rcu(&e->rcu, audit_free_rule_rcu);
1069
1070 out:
1071         mutex_unlock(&audit_filter_mutex);
1072
1073         if (tree)
1074                 audit_put_tree(tree);   /* that's the temporary one */
1075
1076         return ret;
1077 }
1078
1079 /* List rules using struct audit_rule_data. */
1080 static void audit_list_rules(int seq, struct sk_buff_head *q)
1081 {
1082         struct sk_buff *skb;
1083         struct audit_krule *r;
1084         int i;
1085
1086         /* This is a blocking read, so use audit_filter_mutex instead of rcu
1087          * iterator to sync with list writers. */
1088         for (i = 0; i < AUDIT_NR_FILTERS; i++) {
1089                 list_for_each_entry(r, &audit_rules_list[i], list) {
1090                         struct audit_rule_data *data;
1091
1092                         data = audit_krule_to_data(r);
1093                         if (unlikely(!data))
1094                                 break;
1095                         skb = audit_make_reply(seq, AUDIT_LIST_RULES, 0, 1,
1096                                                data,
1097                                                struct_size(data, buf, data->buflen));
1098                         if (skb)
1099                                 skb_queue_tail(q, skb);
1100                         kfree(data);
1101                 }
1102         }
1103         skb = audit_make_reply(seq, AUDIT_LIST_RULES, 1, 1, NULL, 0);
1104         if (skb)
1105                 skb_queue_tail(q, skb);
1106 }
1107
1108 /* Log rule additions and removals */
1109 static void audit_log_rule_change(char *action, struct audit_krule *rule, int res)
1110 {
1111         struct audit_buffer *ab;
1112
1113         if (!audit_enabled)
1114                 return;
1115
1116         ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_CONFIG_CHANGE);
1117         if (!ab)
1118                 return;
1119         audit_log_session_info(ab);
1120         audit_log_task_context(ab);
1121         audit_log_format(ab, " op=%s", action);
1122         audit_log_key(ab, rule->filterkey);
1123         audit_log_format(ab, " list=%d res=%d", rule->listnr, res);
1124         audit_log_end(ab);
1125 }
1126
1127 /**
1128  * audit_rule_change - apply all rules to the specified message type
1129  * @type: audit message type
1130  * @seq: netlink audit message sequence (serial) number
1131  * @data: payload data
1132  * @datasz: size of payload data
1133  */
1134 int audit_rule_change(int type, int seq, void *data, size_t datasz)
1135 {
1136         int err = 0;
1137         struct audit_entry *entry;
1138
1139         switch (type) {
1140         case AUDIT_ADD_RULE:
1141                 entry = audit_data_to_entry(data, datasz);
1142                 if (IS_ERR(entry))
1143                         return PTR_ERR(entry);
1144                 err = audit_add_rule(entry);
1145                 audit_log_rule_change("add_rule", &entry->rule, !err);
1146                 break;
1147         case AUDIT_DEL_RULE:
1148                 entry = audit_data_to_entry(data, datasz);
1149                 if (IS_ERR(entry))
1150                         return PTR_ERR(entry);
1151                 err = audit_del_rule(entry);
1152                 audit_log_rule_change("remove_rule", &entry->rule, !err);
1153                 break;
1154         default:
1155                 WARN_ON(1);
1156                 return -EINVAL;
1157         }
1158
1159         if (err || type == AUDIT_DEL_RULE) {
1160                 if (entry->rule.exe)
1161                         audit_remove_mark(entry->rule.exe);
1162                 audit_free_rule(entry);
1163         }
1164
1165         return err;
1166 }
1167
1168 /**
1169  * audit_list_rules_send - list the audit rules
1170  * @request_skb: skb of request we are replying to (used to target the reply)
1171  * @seq: netlink audit message sequence (serial) number
1172  */
1173 int audit_list_rules_send(struct sk_buff *request_skb, int seq)
1174 {
1175         struct task_struct *tsk;
1176         struct audit_netlink_list *dest;
1177
1178         /* We can't just spew out the rules here because we might fill
1179          * the available socket buffer space and deadlock waiting for
1180          * auditctl to read from it... which isn't ever going to
1181          * happen if we're actually running in the context of auditctl
1182          * trying to _send_ the stuff */
1183
1184         dest = kmalloc(sizeof(*dest), GFP_KERNEL);
1185         if (!dest)
1186                 return -ENOMEM;
1187         dest->net = get_net(sock_net(NETLINK_CB(request_skb).sk));
1188         dest->portid = NETLINK_CB(request_skb).portid;
1189         skb_queue_head_init(&dest->q);
1190
1191         mutex_lock(&audit_filter_mutex);
1192         audit_list_rules(seq, &dest->q);
1193         mutex_unlock(&audit_filter_mutex);
1194
1195         tsk = kthread_run(audit_send_list_thread, dest, "audit_send_list");
1196         if (IS_ERR(tsk)) {
1197                 skb_queue_purge(&dest->q);
1198                 put_net(dest->net);
1199                 kfree(dest);
1200                 return PTR_ERR(tsk);
1201         }
1202
1203         return 0;
1204 }
1205
1206 int audit_comparator(u32 left, u32 op, u32 right)
1207 {
1208         switch (op) {
1209         case Audit_equal:
1210                 return (left == right);
1211         case Audit_not_equal:
1212                 return (left != right);
1213         case Audit_lt:
1214                 return (left < right);
1215         case Audit_le:
1216                 return (left <= right);
1217         case Audit_gt:
1218                 return (left > right);
1219         case Audit_ge:
1220                 return (left >= right);
1221         case Audit_bitmask:
1222                 return (left & right);
1223         case Audit_bittest:
1224                 return ((left & right) == right);
1225         default:
1226                 return 0;
1227         }
1228 }
1229
1230 int audit_uid_comparator(kuid_t left, u32 op, kuid_t right)
1231 {
1232         switch (op) {
1233         case Audit_equal:
1234                 return uid_eq(left, right);
1235         case Audit_not_equal:
1236                 return !uid_eq(left, right);
1237         case Audit_lt:
1238                 return uid_lt(left, right);
1239         case Audit_le:
1240                 return uid_lte(left, right);
1241         case Audit_gt:
1242                 return uid_gt(left, right);
1243         case Audit_ge:
1244                 return uid_gte(left, right);
1245         case Audit_bitmask:
1246         case Audit_bittest:
1247         default:
1248                 return 0;
1249         }
1250 }
1251
1252 int audit_gid_comparator(kgid_t left, u32 op, kgid_t right)
1253 {
1254         switch (op) {
1255         case Audit_equal:
1256                 return gid_eq(left, right);
1257         case Audit_not_equal:
1258                 return !gid_eq(left, right);
1259         case Audit_lt:
1260                 return gid_lt(left, right);
1261         case Audit_le:
1262                 return gid_lte(left, right);
1263         case Audit_gt:
1264                 return gid_gt(left, right);
1265         case Audit_ge:
1266                 return gid_gte(left, right);
1267         case Audit_bitmask:
1268         case Audit_bittest:
1269         default:
1270                 return 0;
1271         }
1272 }
1273
1274 /**
1275  * parent_len - find the length of the parent portion of a pathname
1276  * @path: pathname of which to determine length
1277  */
1278 int parent_len(const char *path)
1279 {
1280         int plen;
1281         const char *p;
1282
1283         plen = strlen(path);
1284
1285         if (plen == 0)
1286                 return plen;
1287
1288         /* disregard trailing slashes */
1289         p = path + plen - 1;
1290         while ((*p == '/') && (p > path))
1291                 p--;
1292
1293         /* walk backward until we find the next slash or hit beginning */
1294         while ((*p != '/') && (p > path))
1295                 p--;
1296
1297         /* did we find a slash? Then increment to include it in path */
1298         if (*p == '/')
1299                 p++;
1300
1301         return p - path;
1302 }
1303
1304 /**
1305  * audit_compare_dname_path - compare given dentry name with last component in
1306  *                            given path. Return of 0 indicates a match.
1307  * @dname:      dentry name that we're comparing
1308  * @path:       full pathname that we're comparing
1309  * @parentlen:  length of the parent if known. Passing in AUDIT_NAME_FULL
1310  *              here indicates that we must compute this value.
1311  */
1312 int audit_compare_dname_path(const struct qstr *dname, const char *path, int parentlen)
1313 {
1314         int dlen, pathlen;
1315         const char *p;
1316
1317         dlen = dname->len;
1318         pathlen = strlen(path);
1319         if (pathlen < dlen)
1320                 return 1;
1321
1322         parentlen = parentlen == AUDIT_NAME_FULL ? parent_len(path) : parentlen;
1323         if (pathlen - parentlen != dlen)
1324                 return 1;
1325
1326         p = path + parentlen;
1327
1328         return strncmp(p, dname->name, dlen);
1329 }
1330
1331 int audit_filter(int msgtype, unsigned int listtype)
1332 {
1333         struct audit_entry *e;
1334         int ret = 1; /* Audit by default */
1335
1336         rcu_read_lock();
1337         list_for_each_entry_rcu(e, &audit_filter_list[listtype], list) {
1338                 int i, result = 0;
1339
1340                 for (i = 0; i < e->rule.field_count; i++) {
1341                         struct audit_field *f = &e->rule.fields[i];
1342                         pid_t pid;
1343                         u32 sid;
1344
1345                         switch (f->type) {
1346                         case AUDIT_PID:
1347                                 pid = task_pid_nr(current);
1348                                 result = audit_comparator(pid, f->op, f->val);
1349                                 break;
1350                         case AUDIT_UID:
1351                                 result = audit_uid_comparator(current_uid(), f->op, f->uid);
1352                                 break;
1353                         case AUDIT_GID:
1354                                 result = audit_gid_comparator(current_gid(), f->op, f->gid);
1355                                 break;
1356                         case AUDIT_LOGINUID:
1357                                 result = audit_uid_comparator(audit_get_loginuid(current),
1358                                                               f->op, f->uid);
1359                                 break;
1360                         case AUDIT_LOGINUID_SET:
1361                                 result = audit_comparator(audit_loginuid_set(current),
1362                                                           f->op, f->val);
1363                                 break;
1364                         case AUDIT_MSGTYPE:
1365                                 result = audit_comparator(msgtype, f->op, f->val);
1366                                 break;
1367                         case AUDIT_SUBJ_USER:
1368                         case AUDIT_SUBJ_ROLE:
1369                         case AUDIT_SUBJ_TYPE:
1370                         case AUDIT_SUBJ_SEN:
1371                         case AUDIT_SUBJ_CLR:
1372                                 if (f->lsm_rule) {
1373                                         security_current_getsecid_subj(&sid);
1374                                         result = security_audit_rule_match(sid,
1375                                                    f->type, f->op, f->lsm_rule);
1376                                 }
1377                                 break;
1378                         case AUDIT_EXE:
1379                                 result = audit_exe_compare(current, e->rule.exe);
1380                                 if (f->op == Audit_not_equal)
1381                                         result = !result;
1382                                 break;
1383                         default:
1384                                 goto unlock_and_return;
1385                         }
1386                         if (result < 0) /* error */
1387                                 goto unlock_and_return;
1388                         if (!result)
1389                                 break;
1390                 }
1391                 if (result > 0) {
1392                         if (e->rule.action == AUDIT_NEVER || listtype == AUDIT_FILTER_EXCLUDE)
1393                                 ret = 0;
1394                         break;
1395                 }
1396         }
1397 unlock_and_return:
1398         rcu_read_unlock();
1399         return ret;
1400 }
1401
1402 static int update_lsm_rule(struct audit_krule *r)
1403 {
1404         struct audit_entry *entry = container_of(r, struct audit_entry, rule);
1405         struct audit_entry *nentry;
1406         int err = 0;
1407
1408         if (!security_audit_rule_known(r))
1409                 return 0;
1410
1411         nentry = audit_dupe_rule(r);
1412         if (entry->rule.exe)
1413                 audit_remove_mark(entry->rule.exe);
1414         if (IS_ERR(nentry)) {
1415                 /* save the first error encountered for the
1416                  * return value */
1417                 err = PTR_ERR(nentry);
1418                 audit_panic("error updating LSM filters");
1419                 if (r->watch)
1420                         list_del(&r->rlist);
1421                 list_del_rcu(&entry->list);
1422                 list_del(&r->list);
1423         } else {
1424                 if (r->watch || r->tree)
1425                         list_replace_init(&r->rlist, &nentry->rule.rlist);
1426                 list_replace_rcu(&entry->list, &nentry->list);
1427                 list_replace(&r->list, &nentry->rule.list);
1428         }
1429         call_rcu(&entry->rcu, audit_free_rule_rcu);
1430
1431         return err;
1432 }
1433
1434 /* This function will re-initialize the lsm_rule field of all applicable rules.
1435  * It will traverse the filter lists serarching for rules that contain LSM
1436  * specific filter fields.  When such a rule is found, it is copied, the
1437  * LSM field is re-initialized, and the old rule is replaced with the
1438  * updated rule. */
1439 int audit_update_lsm_rules(void)
1440 {
1441         struct audit_krule *r, *n;
1442         int i, err = 0;
1443
1444         /* audit_filter_mutex synchronizes the writers */
1445         mutex_lock(&audit_filter_mutex);
1446
1447         for (i = 0; i < AUDIT_NR_FILTERS; i++) {
1448                 list_for_each_entry_safe(r, n, &audit_rules_list[i], list) {
1449                         int res = update_lsm_rule(r);
1450                         if (!err)
1451                                 err = res;
1452                 }
1453         }
1454         mutex_unlock(&audit_filter_mutex);
1455
1456         return err;
1457 }