| 1 | /* auditfilter.c -- filtering of audit events |
| 2 | * |
| 3 | * Copyright 2003-2004 Red Hat, Inc. |
| 4 | * Copyright 2005 Hewlett-Packard Development Company, L.P. |
| 5 | * Copyright 2005 IBM Corporation |
| 6 | * |
| 7 | * This program is free software; you can redistribute it and/or modify |
| 8 | * it under the terms of the GNU General Public License as published by |
| 9 | * the Free Software Foundation; either version 2 of the License, or |
| 10 | * (at your option) any later version. |
| 11 | * |
| 12 | * This program is distributed in the hope that it will be useful, |
| 13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 15 | * GNU General Public License for more details. |
| 16 | * |
| 17 | * You should have received a copy of the GNU General Public License |
| 18 | * along with this program; if not, write to the Free Software |
| 19 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| 20 | */ |
| 21 | |
| 22 | #include <linux/kernel.h> |
| 23 | #include <linux/audit.h> |
| 24 | #include <linux/kthread.h> |
| 25 | #include <linux/mutex.h> |
| 26 | #include <linux/fs.h> |
| 27 | #include <linux/namei.h> |
| 28 | #include <linux/netlink.h> |
| 29 | #include <linux/sched.h> |
| 30 | #include <linux/inotify.h> |
| 31 | #include <linux/selinux.h> |
| 32 | #include "audit.h" |
| 33 | |
| 34 | /* |
| 35 | * Locking model: |
| 36 | * |
| 37 | * audit_filter_mutex: |
| 38 | * Synchronizes writes and blocking reads of audit's filterlist |
| 39 | * data. Rcu is used to traverse the filterlist and access |
| 40 | * contents of structs audit_entry, audit_watch and opaque |
| 41 | * selinux rules during filtering. If modified, these structures |
| 42 | * must be copied and replace their counterparts in the filterlist. |
| 43 | * An audit_parent struct is not accessed during filtering, so may |
| 44 | * be written directly provided audit_filter_mutex is held. |
| 45 | */ |
| 46 | |
| 47 | /* |
| 48 | * Reference counting: |
| 49 | * |
| 50 | * audit_parent: lifetime is from audit_init_parent() to receipt of an IN_IGNORED |
| 51 | * event. Each audit_watch holds a reference to its associated parent. |
| 52 | * |
| 53 | * audit_watch: if added to lists, lifetime is from audit_init_watch() to |
| 54 | * audit_remove_watch(). Additionally, an audit_watch may exist |
| 55 | * temporarily to assist in searching existing filter data. Each |
| 56 | * audit_krule holds a reference to its associated watch. |
| 57 | */ |
| 58 | |
| 59 | struct audit_parent { |
| 60 | struct list_head ilist; /* entry in inotify registration list */ |
| 61 | struct list_head watches; /* associated watches */ |
| 62 | struct inotify_watch wdata; /* inotify watch data */ |
| 63 | unsigned flags; /* status flags */ |
| 64 | }; |
| 65 | |
| 66 | /* |
| 67 | * audit_parent status flags: |
| 68 | * |
| 69 | * AUDIT_PARENT_INVALID - set anytime rules/watches are auto-removed due to |
| 70 | * a filesystem event to ensure we're adding audit watches to a valid parent. |
| 71 | * Technically not needed for IN_DELETE_SELF or IN_UNMOUNT events, as we cannot |
| 72 | * receive them while we have nameidata, but must be used for IN_MOVE_SELF which |
| 73 | * we can receive while holding nameidata. |
| 74 | */ |
| 75 | #define AUDIT_PARENT_INVALID 0x001 |
| 76 | |
| 77 | /* Audit filter lists, defined in <linux/audit.h> */ |
| 78 | struct list_head audit_filter_list[AUDIT_NR_FILTERS] = { |
| 79 | LIST_HEAD_INIT(audit_filter_list[0]), |
| 80 | LIST_HEAD_INIT(audit_filter_list[1]), |
| 81 | LIST_HEAD_INIT(audit_filter_list[2]), |
| 82 | LIST_HEAD_INIT(audit_filter_list[3]), |
| 83 | LIST_HEAD_INIT(audit_filter_list[4]), |
| 84 | LIST_HEAD_INIT(audit_filter_list[5]), |
| 85 | #if AUDIT_NR_FILTERS != 6 |
| 86 | #error Fix audit_filter_list initialiser |
| 87 | #endif |
| 88 | }; |
| 89 | |
| 90 | static DEFINE_MUTEX(audit_filter_mutex); |
| 91 | |
| 92 | /* Inotify handle */ |
| 93 | extern struct inotify_handle *audit_ih; |
| 94 | |
| 95 | /* Inotify events we care about. */ |
| 96 | #define AUDIT_IN_WATCH IN_MOVE|IN_CREATE|IN_DELETE|IN_DELETE_SELF|IN_MOVE_SELF |
| 97 | |
| 98 | void audit_free_parent(struct inotify_watch *i_watch) |
| 99 | { |
| 100 | struct audit_parent *parent; |
| 101 | |
| 102 | parent = container_of(i_watch, struct audit_parent, wdata); |
| 103 | WARN_ON(!list_empty(&parent->watches)); |
| 104 | kfree(parent); |
| 105 | } |
| 106 | |
| 107 | static inline void audit_get_watch(struct audit_watch *watch) |
| 108 | { |
| 109 | atomic_inc(&watch->count); |
| 110 | } |
| 111 | |
| 112 | static void audit_put_watch(struct audit_watch *watch) |
| 113 | { |
| 114 | if (atomic_dec_and_test(&watch->count)) { |
| 115 | WARN_ON(watch->parent); |
| 116 | WARN_ON(!list_empty(&watch->rules)); |
| 117 | kfree(watch->path); |
| 118 | kfree(watch); |
| 119 | } |
| 120 | } |
| 121 | |
| 122 | static void audit_remove_watch(struct audit_watch *watch) |
| 123 | { |
| 124 | list_del(&watch->wlist); |
| 125 | put_inotify_watch(&watch->parent->wdata); |
| 126 | watch->parent = NULL; |
| 127 | audit_put_watch(watch); /* match initial get */ |
| 128 | } |
| 129 | |
| 130 | static inline void audit_free_rule(struct audit_entry *e) |
| 131 | { |
| 132 | int i; |
| 133 | |
| 134 | /* some rules don't have associated watches */ |
| 135 | if (e->rule.watch) |
| 136 | audit_put_watch(e->rule.watch); |
| 137 | if (e->rule.fields) |
| 138 | for (i = 0; i < e->rule.field_count; i++) { |
| 139 | struct audit_field *f = &e->rule.fields[i]; |
| 140 | kfree(f->se_str); |
| 141 | selinux_audit_rule_free(f->se_rule); |
| 142 | } |
| 143 | kfree(e->rule.fields); |
| 144 | kfree(e->rule.filterkey); |
| 145 | kfree(e); |
| 146 | } |
| 147 | |
| 148 | static inline void audit_free_rule_rcu(struct rcu_head *head) |
| 149 | { |
| 150 | struct audit_entry *e = container_of(head, struct audit_entry, rcu); |
| 151 | audit_free_rule(e); |
| 152 | } |
| 153 | |
| 154 | /* Initialize a parent watch entry. */ |
| 155 | static struct audit_parent *audit_init_parent(struct nameidata *ndp) |
| 156 | { |
| 157 | struct audit_parent *parent; |
| 158 | s32 wd; |
| 159 | |
| 160 | parent = kzalloc(sizeof(*parent), GFP_KERNEL); |
| 161 | if (unlikely(!parent)) |
| 162 | return ERR_PTR(-ENOMEM); |
| 163 | |
| 164 | INIT_LIST_HEAD(&parent->watches); |
| 165 | parent->flags = 0; |
| 166 | |
| 167 | inotify_init_watch(&parent->wdata); |
| 168 | /* grab a ref so inotify watch hangs around until we take audit_filter_mutex */ |
| 169 | get_inotify_watch(&parent->wdata); |
| 170 | wd = inotify_add_watch(audit_ih, &parent->wdata, ndp->dentry->d_inode, |
| 171 | AUDIT_IN_WATCH); |
| 172 | if (wd < 0) { |
| 173 | audit_free_parent(&parent->wdata); |
| 174 | return ERR_PTR(wd); |
| 175 | } |
| 176 | |
| 177 | return parent; |
| 178 | } |
| 179 | |
| 180 | /* Initialize a watch entry. */ |
| 181 | static struct audit_watch *audit_init_watch(char *path) |
| 182 | { |
| 183 | struct audit_watch *watch; |
| 184 | |
| 185 | watch = kzalloc(sizeof(*watch), GFP_KERNEL); |
| 186 | if (unlikely(!watch)) |
| 187 | return ERR_PTR(-ENOMEM); |
| 188 | |
| 189 | INIT_LIST_HEAD(&watch->rules); |
| 190 | atomic_set(&watch->count, 1); |
| 191 | watch->path = path; |
| 192 | watch->dev = (dev_t)-1; |
| 193 | watch->ino = (unsigned long)-1; |
| 194 | |
| 195 | return watch; |
| 196 | } |
| 197 | |
| 198 | /* Initialize an audit filterlist entry. */ |
| 199 | static inline struct audit_entry *audit_init_entry(u32 field_count) |
| 200 | { |
| 201 | struct audit_entry *entry; |
| 202 | struct audit_field *fields; |
| 203 | |
| 204 | entry = kzalloc(sizeof(*entry), GFP_KERNEL); |
| 205 | if (unlikely(!entry)) |
| 206 | return NULL; |
| 207 | |
| 208 | fields = kzalloc(sizeof(*fields) * field_count, GFP_KERNEL); |
| 209 | if (unlikely(!fields)) { |
| 210 | kfree(entry); |
| 211 | return NULL; |
| 212 | } |
| 213 | entry->rule.fields = fields; |
| 214 | |
| 215 | return entry; |
| 216 | } |
| 217 | |
| 218 | /* Unpack a filter field's string representation from user-space |
| 219 | * buffer. */ |
| 220 | static char *audit_unpack_string(void **bufp, size_t *remain, size_t len) |
| 221 | { |
| 222 | char *str; |
| 223 | |
| 224 | if (!*bufp || (len == 0) || (len > *remain)) |
| 225 | return ERR_PTR(-EINVAL); |
| 226 | |
| 227 | /* Of the currently implemented string fields, PATH_MAX |
| 228 | * defines the longest valid length. |
| 229 | */ |
| 230 | if (len > PATH_MAX) |
| 231 | return ERR_PTR(-ENAMETOOLONG); |
| 232 | |
| 233 | str = kmalloc(len + 1, GFP_KERNEL); |
| 234 | if (unlikely(!str)) |
| 235 | return ERR_PTR(-ENOMEM); |
| 236 | |
| 237 | memcpy(str, *bufp, len); |
| 238 | str[len] = 0; |
| 239 | *bufp += len; |
| 240 | *remain -= len; |
| 241 | |
| 242 | return str; |
| 243 | } |
| 244 | |
| 245 | /* Translate an inode field to kernel respresentation. */ |
| 246 | static inline int audit_to_inode(struct audit_krule *krule, |
| 247 | struct audit_field *f) |
| 248 | { |
| 249 | if (krule->listnr != AUDIT_FILTER_EXIT || |
| 250 | krule->watch || krule->inode_f) |
| 251 | return -EINVAL; |
| 252 | |
| 253 | krule->inode_f = f; |
| 254 | return 0; |
| 255 | } |
| 256 | |
| 257 | /* Translate a watch string to kernel respresentation. */ |
| 258 | static int audit_to_watch(struct audit_krule *krule, char *path, int len, |
| 259 | u32 op) |
| 260 | { |
| 261 | struct audit_watch *watch; |
| 262 | |
| 263 | if (!audit_ih) |
| 264 | return -EOPNOTSUPP; |
| 265 | |
| 266 | if (path[0] != '/' || path[len-1] == '/' || |
| 267 | krule->listnr != AUDIT_FILTER_EXIT || |
| 268 | op & ~AUDIT_EQUAL || |
| 269 | krule->inode_f || krule->watch) /* 1 inode # per rule, for hash */ |
| 270 | return -EINVAL; |
| 271 | |
| 272 | watch = audit_init_watch(path); |
| 273 | if (unlikely(IS_ERR(watch))) |
| 274 | return PTR_ERR(watch); |
| 275 | |
| 276 | audit_get_watch(watch); |
| 277 | krule->watch = watch; |
| 278 | |
| 279 | return 0; |
| 280 | } |
| 281 | |
| 282 | static __u32 *classes[AUDIT_SYSCALL_CLASSES]; |
| 283 | |
| 284 | int __init audit_register_class(int class, unsigned *list) |
| 285 | { |
| 286 | __u32 *p = kzalloc(AUDIT_BITMASK_SIZE * sizeof(__u32), GFP_KERNEL); |
| 287 | if (!p) |
| 288 | return -ENOMEM; |
| 289 | while (*list != ~0U) { |
| 290 | unsigned n = *list++; |
| 291 | if (n >= AUDIT_BITMASK_SIZE * 32 - AUDIT_SYSCALL_CLASSES) { |
| 292 | kfree(p); |
| 293 | return -EINVAL; |
| 294 | } |
| 295 | p[AUDIT_WORD(n)] |= AUDIT_BIT(n); |
| 296 | } |
| 297 | if (class >= AUDIT_SYSCALL_CLASSES || classes[class]) { |
| 298 | kfree(p); |
| 299 | return -EINVAL; |
| 300 | } |
| 301 | classes[class] = p; |
| 302 | return 0; |
| 303 | } |
| 304 | |
| 305 | int audit_match_class(int class, unsigned syscall) |
| 306 | { |
| 307 | if (unlikely(syscall >= AUDIT_BITMASK_SIZE * sizeof(__u32))) |
| 308 | return 0; |
| 309 | if (unlikely(class >= AUDIT_SYSCALL_CLASSES || !classes[class])) |
| 310 | return 0; |
| 311 | return classes[class][AUDIT_WORD(syscall)] & AUDIT_BIT(syscall); |
| 312 | } |
| 313 | |
| 314 | #ifdef CONFIG_AUDITSYSCALL |
| 315 | static inline int audit_match_class_bits(int class, u32 *mask) |
| 316 | { |
| 317 | int i; |
| 318 | |
| 319 | if (classes[class]) { |
| 320 | for (i = 0; i < AUDIT_BITMASK_SIZE; i++) |
| 321 | if (mask[i] & classes[class][i]) |
| 322 | return 0; |
| 323 | } |
| 324 | return 1; |
| 325 | } |
| 326 | |
| 327 | static int audit_match_signal(struct audit_entry *entry) |
| 328 | { |
| 329 | struct audit_field *arch = entry->rule.arch_f; |
| 330 | |
| 331 | if (!arch) { |
| 332 | /* When arch is unspecified, we must check both masks on biarch |
| 333 | * as syscall number alone is ambiguous. */ |
| 334 | return (audit_match_class_bits(AUDIT_CLASS_SIGNAL, |
| 335 | entry->rule.mask) && |
| 336 | audit_match_class_bits(AUDIT_CLASS_SIGNAL_32, |
| 337 | entry->rule.mask)); |
| 338 | } |
| 339 | |
| 340 | switch(audit_classify_arch(arch->val)) { |
| 341 | case 0: /* native */ |
| 342 | return (audit_match_class_bits(AUDIT_CLASS_SIGNAL, |
| 343 | entry->rule.mask)); |
| 344 | case 1: /* 32bit on biarch */ |
| 345 | return (audit_match_class_bits(AUDIT_CLASS_SIGNAL_32, |
| 346 | entry->rule.mask)); |
| 347 | default: |
| 348 | return 1; |
| 349 | } |
| 350 | } |
| 351 | #endif |
| 352 | |
| 353 | /* Common user-space to kernel rule translation. */ |
| 354 | static inline struct audit_entry *audit_to_entry_common(struct audit_rule *rule) |
| 355 | { |
| 356 | unsigned listnr; |
| 357 | struct audit_entry *entry; |
| 358 | int i, err; |
| 359 | |
| 360 | err = -EINVAL; |
| 361 | listnr = rule->flags & ~AUDIT_FILTER_PREPEND; |
| 362 | switch(listnr) { |
| 363 | default: |
| 364 | goto exit_err; |
| 365 | case AUDIT_FILTER_USER: |
| 366 | case AUDIT_FILTER_TYPE: |
| 367 | #ifdef CONFIG_AUDITSYSCALL |
| 368 | case AUDIT_FILTER_ENTRY: |
| 369 | case AUDIT_FILTER_EXIT: |
| 370 | case AUDIT_FILTER_TASK: |
| 371 | #endif |
| 372 | ; |
| 373 | } |
| 374 | if (unlikely(rule->action == AUDIT_POSSIBLE)) { |
| 375 | printk(KERN_ERR "AUDIT_POSSIBLE is deprecated\n"); |
| 376 | goto exit_err; |
| 377 | } |
| 378 | if (rule->action != AUDIT_NEVER && rule->action != AUDIT_ALWAYS) |
| 379 | goto exit_err; |
| 380 | if (rule->field_count > AUDIT_MAX_FIELDS) |
| 381 | goto exit_err; |
| 382 | |
| 383 | err = -ENOMEM; |
| 384 | entry = audit_init_entry(rule->field_count); |
| 385 | if (!entry) |
| 386 | goto exit_err; |
| 387 | |
| 388 | entry->rule.flags = rule->flags & AUDIT_FILTER_PREPEND; |
| 389 | entry->rule.listnr = listnr; |
| 390 | entry->rule.action = rule->action; |
| 391 | entry->rule.field_count = rule->field_count; |
| 392 | |
| 393 | for (i = 0; i < AUDIT_BITMASK_SIZE; i++) |
| 394 | entry->rule.mask[i] = rule->mask[i]; |
| 395 | |
| 396 | for (i = 0; i < AUDIT_SYSCALL_CLASSES; i++) { |
| 397 | int bit = AUDIT_BITMASK_SIZE * 32 - i - 1; |
| 398 | __u32 *p = &entry->rule.mask[AUDIT_WORD(bit)]; |
| 399 | __u32 *class; |
| 400 | |
| 401 | if (!(*p & AUDIT_BIT(bit))) |
| 402 | continue; |
| 403 | *p &= ~AUDIT_BIT(bit); |
| 404 | class = classes[i]; |
| 405 | if (class) { |
| 406 | int j; |
| 407 | for (j = 0; j < AUDIT_BITMASK_SIZE; j++) |
| 408 | entry->rule.mask[j] |= class[j]; |
| 409 | } |
| 410 | } |
| 411 | |
| 412 | return entry; |
| 413 | |
| 414 | exit_err: |
| 415 | return ERR_PTR(err); |
| 416 | } |
| 417 | |
| 418 | /* Translate struct audit_rule to kernel's rule respresentation. |
| 419 | * Exists for backward compatibility with userspace. */ |
| 420 | static struct audit_entry *audit_rule_to_entry(struct audit_rule *rule) |
| 421 | { |
| 422 | struct audit_entry *entry; |
| 423 | struct audit_field *f; |
| 424 | int err = 0; |
| 425 | int i; |
| 426 | |
| 427 | entry = audit_to_entry_common(rule); |
| 428 | if (IS_ERR(entry)) |
| 429 | goto exit_nofree; |
| 430 | |
| 431 | for (i = 0; i < rule->field_count; i++) { |
| 432 | struct audit_field *f = &entry->rule.fields[i]; |
| 433 | |
| 434 | f->op = rule->fields[i] & (AUDIT_NEGATE|AUDIT_OPERATORS); |
| 435 | f->type = rule->fields[i] & ~(AUDIT_NEGATE|AUDIT_OPERATORS); |
| 436 | f->val = rule->values[i]; |
| 437 | |
| 438 | err = -EINVAL; |
| 439 | switch(f->type) { |
| 440 | default: |
| 441 | goto exit_free; |
| 442 | case AUDIT_PID: |
| 443 | case AUDIT_UID: |
| 444 | case AUDIT_EUID: |
| 445 | case AUDIT_SUID: |
| 446 | case AUDIT_FSUID: |
| 447 | case AUDIT_GID: |
| 448 | case AUDIT_EGID: |
| 449 | case AUDIT_SGID: |
| 450 | case AUDIT_FSGID: |
| 451 | case AUDIT_LOGINUID: |
| 452 | case AUDIT_PERS: |
| 453 | case AUDIT_MSGTYPE: |
| 454 | case AUDIT_PPID: |
| 455 | case AUDIT_DEVMAJOR: |
| 456 | case AUDIT_DEVMINOR: |
| 457 | case AUDIT_EXIT: |
| 458 | case AUDIT_SUCCESS: |
| 459 | case AUDIT_ARG0: |
| 460 | case AUDIT_ARG1: |
| 461 | case AUDIT_ARG2: |
| 462 | case AUDIT_ARG3: |
| 463 | break; |
| 464 | /* arch is only allowed to be = or != */ |
| 465 | case AUDIT_ARCH: |
| 466 | if ((f->op != AUDIT_NOT_EQUAL) && (f->op != AUDIT_EQUAL) |
| 467 | && (f->op != AUDIT_NEGATE) && (f->op)) { |
| 468 | err = -EINVAL; |
| 469 | goto exit_free; |
| 470 | } |
| 471 | entry->rule.arch_f = f; |
| 472 | break; |
| 473 | case AUDIT_PERM: |
| 474 | if (f->val & ~15) |
| 475 | goto exit_free; |
| 476 | break; |
| 477 | case AUDIT_INODE: |
| 478 | err = audit_to_inode(&entry->rule, f); |
| 479 | if (err) |
| 480 | goto exit_free; |
| 481 | break; |
| 482 | } |
| 483 | |
| 484 | entry->rule.vers_ops = (f->op & AUDIT_OPERATORS) ? 2 : 1; |
| 485 | |
| 486 | /* Support for legacy operators where |
| 487 | * AUDIT_NEGATE bit signifies != and otherwise assumes == */ |
| 488 | if (f->op & AUDIT_NEGATE) |
| 489 | f->op = AUDIT_NOT_EQUAL; |
| 490 | else if (!f->op) |
| 491 | f->op = AUDIT_EQUAL; |
| 492 | else if (f->op == AUDIT_OPERATORS) { |
| 493 | err = -EINVAL; |
| 494 | goto exit_free; |
| 495 | } |
| 496 | } |
| 497 | |
| 498 | f = entry->rule.inode_f; |
| 499 | if (f) { |
| 500 | switch(f->op) { |
| 501 | case AUDIT_NOT_EQUAL: |
| 502 | entry->rule.inode_f = NULL; |
| 503 | case AUDIT_EQUAL: |
| 504 | break; |
| 505 | default: |
| 506 | err = -EINVAL; |
| 507 | goto exit_free; |
| 508 | } |
| 509 | } |
| 510 | |
| 511 | exit_nofree: |
| 512 | return entry; |
| 513 | |
| 514 | exit_free: |
| 515 | audit_free_rule(entry); |
| 516 | return ERR_PTR(err); |
| 517 | } |
| 518 | |
| 519 | /* Translate struct audit_rule_data to kernel's rule respresentation. */ |
| 520 | static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data, |
| 521 | size_t datasz) |
| 522 | { |
| 523 | int err = 0; |
| 524 | struct audit_entry *entry; |
| 525 | struct audit_field *f; |
| 526 | void *bufp; |
| 527 | size_t remain = datasz - sizeof(struct audit_rule_data); |
| 528 | int i; |
| 529 | char *str; |
| 530 | |
| 531 | entry = audit_to_entry_common((struct audit_rule *)data); |
| 532 | if (IS_ERR(entry)) |
| 533 | goto exit_nofree; |
| 534 | |
| 535 | bufp = data->buf; |
| 536 | entry->rule.vers_ops = 2; |
| 537 | for (i = 0; i < data->field_count; i++) { |
| 538 | struct audit_field *f = &entry->rule.fields[i]; |
| 539 | |
| 540 | err = -EINVAL; |
| 541 | if (!(data->fieldflags[i] & AUDIT_OPERATORS) || |
| 542 | data->fieldflags[i] & ~AUDIT_OPERATORS) |
| 543 | goto exit_free; |
| 544 | |
| 545 | f->op = data->fieldflags[i] & AUDIT_OPERATORS; |
| 546 | f->type = data->fields[i]; |
| 547 | f->val = data->values[i]; |
| 548 | f->se_str = NULL; |
| 549 | f->se_rule = NULL; |
| 550 | switch(f->type) { |
| 551 | case AUDIT_PID: |
| 552 | case AUDIT_UID: |
| 553 | case AUDIT_EUID: |
| 554 | case AUDIT_SUID: |
| 555 | case AUDIT_FSUID: |
| 556 | case AUDIT_GID: |
| 557 | case AUDIT_EGID: |
| 558 | case AUDIT_SGID: |
| 559 | case AUDIT_FSGID: |
| 560 | case AUDIT_LOGINUID: |
| 561 | case AUDIT_PERS: |
| 562 | case AUDIT_MSGTYPE: |
| 563 | case AUDIT_PPID: |
| 564 | case AUDIT_DEVMAJOR: |
| 565 | case AUDIT_DEVMINOR: |
| 566 | case AUDIT_EXIT: |
| 567 | case AUDIT_SUCCESS: |
| 568 | case AUDIT_ARG0: |
| 569 | case AUDIT_ARG1: |
| 570 | case AUDIT_ARG2: |
| 571 | case AUDIT_ARG3: |
| 572 | break; |
| 573 | case AUDIT_ARCH: |
| 574 | entry->rule.arch_f = f; |
| 575 | break; |
| 576 | case AUDIT_SUBJ_USER: |
| 577 | case AUDIT_SUBJ_ROLE: |
| 578 | case AUDIT_SUBJ_TYPE: |
| 579 | case AUDIT_SUBJ_SEN: |
| 580 | case AUDIT_SUBJ_CLR: |
| 581 | case AUDIT_OBJ_USER: |
| 582 | case AUDIT_OBJ_ROLE: |
| 583 | case AUDIT_OBJ_TYPE: |
| 584 | case AUDIT_OBJ_LEV_LOW: |
| 585 | case AUDIT_OBJ_LEV_HIGH: |
| 586 | str = audit_unpack_string(&bufp, &remain, f->val); |
| 587 | if (IS_ERR(str)) |
| 588 | goto exit_free; |
| 589 | entry->rule.buflen += f->val; |
| 590 | |
| 591 | err = selinux_audit_rule_init(f->type, f->op, str, |
| 592 | &f->se_rule); |
| 593 | /* Keep currently invalid fields around in case they |
| 594 | * become valid after a policy reload. */ |
| 595 | if (err == -EINVAL) { |
| 596 | printk(KERN_WARNING "audit rule for selinux " |
| 597 | "\'%s\' is invalid\n", str); |
| 598 | err = 0; |
| 599 | } |
| 600 | if (err) { |
| 601 | kfree(str); |
| 602 | goto exit_free; |
| 603 | } else |
| 604 | f->se_str = str; |
| 605 | break; |
| 606 | case AUDIT_WATCH: |
| 607 | str = audit_unpack_string(&bufp, &remain, f->val); |
| 608 | if (IS_ERR(str)) |
| 609 | goto exit_free; |
| 610 | entry->rule.buflen += f->val; |
| 611 | |
| 612 | err = audit_to_watch(&entry->rule, str, f->val, f->op); |
| 613 | if (err) { |
| 614 | kfree(str); |
| 615 | goto exit_free; |
| 616 | } |
| 617 | break; |
| 618 | case AUDIT_INODE: |
| 619 | err = audit_to_inode(&entry->rule, f); |
| 620 | if (err) |
| 621 | goto exit_free; |
| 622 | break; |
| 623 | case AUDIT_FILTERKEY: |
| 624 | err = -EINVAL; |
| 625 | if (entry->rule.filterkey || f->val > AUDIT_MAX_KEY_LEN) |
| 626 | goto exit_free; |
| 627 | str = audit_unpack_string(&bufp, &remain, f->val); |
| 628 | if (IS_ERR(str)) |
| 629 | goto exit_free; |
| 630 | entry->rule.buflen += f->val; |
| 631 | entry->rule.filterkey = str; |
| 632 | break; |
| 633 | case AUDIT_PERM: |
| 634 | if (f->val & ~15) |
| 635 | goto exit_free; |
| 636 | break; |
| 637 | default: |
| 638 | goto exit_free; |
| 639 | } |
| 640 | } |
| 641 | |
| 642 | f = entry->rule.inode_f; |
| 643 | if (f) { |
| 644 | switch(f->op) { |
| 645 | case AUDIT_NOT_EQUAL: |
| 646 | entry->rule.inode_f = NULL; |
| 647 | case AUDIT_EQUAL: |
| 648 | break; |
| 649 | default: |
| 650 | err = -EINVAL; |
| 651 | goto exit_free; |
| 652 | } |
| 653 | } |
| 654 | |
| 655 | exit_nofree: |
| 656 | return entry; |
| 657 | |
| 658 | exit_free: |
| 659 | audit_free_rule(entry); |
| 660 | return ERR_PTR(err); |
| 661 | } |
| 662 | |
| 663 | /* Pack a filter field's string representation into data block. */ |
| 664 | static inline size_t audit_pack_string(void **bufp, char *str) |
| 665 | { |
| 666 | size_t len = strlen(str); |
| 667 | |
| 668 | memcpy(*bufp, str, len); |
| 669 | *bufp += len; |
| 670 | |
| 671 | return len; |
| 672 | } |
| 673 | |
| 674 | /* Translate kernel rule respresentation to struct audit_rule. |
| 675 | * Exists for backward compatibility with userspace. */ |
| 676 | static struct audit_rule *audit_krule_to_rule(struct audit_krule *krule) |
| 677 | { |
| 678 | struct audit_rule *rule; |
| 679 | int i; |
| 680 | |
| 681 | rule = kzalloc(sizeof(*rule), GFP_KERNEL); |
| 682 | if (unlikely(!rule)) |
| 683 | return NULL; |
| 684 | |
| 685 | rule->flags = krule->flags | krule->listnr; |
| 686 | rule->action = krule->action; |
| 687 | rule->field_count = krule->field_count; |
| 688 | for (i = 0; i < rule->field_count; i++) { |
| 689 | rule->values[i] = krule->fields[i].val; |
| 690 | rule->fields[i] = krule->fields[i].type; |
| 691 | |
| 692 | if (krule->vers_ops == 1) { |
| 693 | if (krule->fields[i].op & AUDIT_NOT_EQUAL) |
| 694 | rule->fields[i] |= AUDIT_NEGATE; |
| 695 | } else { |
| 696 | rule->fields[i] |= krule->fields[i].op; |
| 697 | } |
| 698 | } |
| 699 | for (i = 0; i < AUDIT_BITMASK_SIZE; i++) rule->mask[i] = krule->mask[i]; |
| 700 | |
| 701 | return rule; |
| 702 | } |
| 703 | |
| 704 | /* Translate kernel rule respresentation to struct audit_rule_data. */ |
| 705 | static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule) |
| 706 | { |
| 707 | struct audit_rule_data *data; |
| 708 | void *bufp; |
| 709 | int i; |
| 710 | |
| 711 | data = kmalloc(sizeof(*data) + krule->buflen, GFP_KERNEL); |
| 712 | if (unlikely(!data)) |
| 713 | return NULL; |
| 714 | memset(data, 0, sizeof(*data)); |
| 715 | |
| 716 | data->flags = krule->flags | krule->listnr; |
| 717 | data->action = krule->action; |
| 718 | data->field_count = krule->field_count; |
| 719 | bufp = data->buf; |
| 720 | for (i = 0; i < data->field_count; i++) { |
| 721 | struct audit_field *f = &krule->fields[i]; |
| 722 | |
| 723 | data->fields[i] = f->type; |
| 724 | data->fieldflags[i] = f->op; |
| 725 | switch(f->type) { |
| 726 | case AUDIT_SUBJ_USER: |
| 727 | case AUDIT_SUBJ_ROLE: |
| 728 | case AUDIT_SUBJ_TYPE: |
| 729 | case AUDIT_SUBJ_SEN: |
| 730 | case AUDIT_SUBJ_CLR: |
| 731 | case AUDIT_OBJ_USER: |
| 732 | case AUDIT_OBJ_ROLE: |
| 733 | case AUDIT_OBJ_TYPE: |
| 734 | case AUDIT_OBJ_LEV_LOW: |
| 735 | case AUDIT_OBJ_LEV_HIGH: |
| 736 | data->buflen += data->values[i] = |
| 737 | audit_pack_string(&bufp, f->se_str); |
| 738 | break; |
| 739 | case AUDIT_WATCH: |
| 740 | data->buflen += data->values[i] = |
| 741 | audit_pack_string(&bufp, krule->watch->path); |
| 742 | break; |
| 743 | case AUDIT_FILTERKEY: |
| 744 | data->buflen += data->values[i] = |
| 745 | audit_pack_string(&bufp, krule->filterkey); |
| 746 | break; |
| 747 | default: |
| 748 | data->values[i] = f->val; |
| 749 | } |
| 750 | } |
| 751 | for (i = 0; i < AUDIT_BITMASK_SIZE; i++) data->mask[i] = krule->mask[i]; |
| 752 | |
| 753 | return data; |
| 754 | } |
| 755 | |
| 756 | /* Compare two rules in kernel format. Considered success if rules |
| 757 | * don't match. */ |
| 758 | static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b) |
| 759 | { |
| 760 | int i; |
| 761 | |
| 762 | if (a->flags != b->flags || |
| 763 | a->listnr != b->listnr || |
| 764 | a->action != b->action || |
| 765 | a->field_count != b->field_count) |
| 766 | return 1; |
| 767 | |
| 768 | for (i = 0; i < a->field_count; i++) { |
| 769 | if (a->fields[i].type != b->fields[i].type || |
| 770 | a->fields[i].op != b->fields[i].op) |
| 771 | return 1; |
| 772 | |
| 773 | switch(a->fields[i].type) { |
| 774 | case AUDIT_SUBJ_USER: |
| 775 | case AUDIT_SUBJ_ROLE: |
| 776 | case AUDIT_SUBJ_TYPE: |
| 777 | case AUDIT_SUBJ_SEN: |
| 778 | case AUDIT_SUBJ_CLR: |
| 779 | case AUDIT_OBJ_USER: |
| 780 | case AUDIT_OBJ_ROLE: |
| 781 | case AUDIT_OBJ_TYPE: |
| 782 | case AUDIT_OBJ_LEV_LOW: |
| 783 | case AUDIT_OBJ_LEV_HIGH: |
| 784 | if (strcmp(a->fields[i].se_str, b->fields[i].se_str)) |
| 785 | return 1; |
| 786 | break; |
| 787 | case AUDIT_WATCH: |
| 788 | if (strcmp(a->watch->path, b->watch->path)) |
| 789 | return 1; |
| 790 | break; |
| 791 | case AUDIT_FILTERKEY: |
| 792 | /* both filterkeys exist based on above type compare */ |
| 793 | if (strcmp(a->filterkey, b->filterkey)) |
| 794 | return 1; |
| 795 | break; |
| 796 | default: |
| 797 | if (a->fields[i].val != b->fields[i].val) |
| 798 | return 1; |
| 799 | } |
| 800 | } |
| 801 | |
| 802 | for (i = 0; i < AUDIT_BITMASK_SIZE; i++) |
| 803 | if (a->mask[i] != b->mask[i]) |
| 804 | return 1; |
| 805 | |
| 806 | return 0; |
| 807 | } |
| 808 | |
| 809 | /* Duplicate the given audit watch. The new watch's rules list is initialized |
| 810 | * to an empty list and wlist is undefined. */ |
| 811 | static struct audit_watch *audit_dupe_watch(struct audit_watch *old) |
| 812 | { |
| 813 | char *path; |
| 814 | struct audit_watch *new; |
| 815 | |
| 816 | path = kstrdup(old->path, GFP_KERNEL); |
| 817 | if (unlikely(!path)) |
| 818 | return ERR_PTR(-ENOMEM); |
| 819 | |
| 820 | new = audit_init_watch(path); |
| 821 | if (unlikely(IS_ERR(new))) { |
| 822 | kfree(path); |
| 823 | goto out; |
| 824 | } |
| 825 | |
| 826 | new->dev = old->dev; |
| 827 | new->ino = old->ino; |
| 828 | get_inotify_watch(&old->parent->wdata); |
| 829 | new->parent = old->parent; |
| 830 | |
| 831 | out: |
| 832 | return new; |
| 833 | } |
| 834 | |
| 835 | /* Duplicate selinux field information. The se_rule is opaque, so must be |
| 836 | * re-initialized. */ |
| 837 | static inline int audit_dupe_selinux_field(struct audit_field *df, |
| 838 | struct audit_field *sf) |
| 839 | { |
| 840 | int ret = 0; |
| 841 | char *se_str; |
| 842 | |
| 843 | /* our own copy of se_str */ |
| 844 | se_str = kstrdup(sf->se_str, GFP_KERNEL); |
| 845 | if (unlikely(!se_str)) |
| 846 | return -ENOMEM; |
| 847 | df->se_str = se_str; |
| 848 | |
| 849 | /* our own (refreshed) copy of se_rule */ |
| 850 | ret = selinux_audit_rule_init(df->type, df->op, df->se_str, |
| 851 | &df->se_rule); |
| 852 | /* Keep currently invalid fields around in case they |
| 853 | * become valid after a policy reload. */ |
| 854 | if (ret == -EINVAL) { |
| 855 | printk(KERN_WARNING "audit rule for selinux \'%s\' is " |
| 856 | "invalid\n", df->se_str); |
| 857 | ret = 0; |
| 858 | } |
| 859 | |
| 860 | return ret; |
| 861 | } |
| 862 | |
| 863 | /* Duplicate an audit rule. This will be a deep copy with the exception |
| 864 | * of the watch - that pointer is carried over. The selinux specific fields |
| 865 | * will be updated in the copy. The point is to be able to replace the old |
| 866 | * rule with the new rule in the filterlist, then free the old rule. |
| 867 | * The rlist element is undefined; list manipulations are handled apart from |
| 868 | * the initial copy. */ |
| 869 | static struct audit_entry *audit_dupe_rule(struct audit_krule *old, |
| 870 | struct audit_watch *watch) |
| 871 | { |
| 872 | u32 fcount = old->field_count; |
| 873 | struct audit_entry *entry; |
| 874 | struct audit_krule *new; |
| 875 | char *fk; |
| 876 | int i, err = 0; |
| 877 | |
| 878 | entry = audit_init_entry(fcount); |
| 879 | if (unlikely(!entry)) |
| 880 | return ERR_PTR(-ENOMEM); |
| 881 | |
| 882 | new = &entry->rule; |
| 883 | new->vers_ops = old->vers_ops; |
| 884 | new->flags = old->flags; |
| 885 | new->listnr = old->listnr; |
| 886 | new->action = old->action; |
| 887 | for (i = 0; i < AUDIT_BITMASK_SIZE; i++) |
| 888 | new->mask[i] = old->mask[i]; |
| 889 | new->buflen = old->buflen; |
| 890 | new->inode_f = old->inode_f; |
| 891 | new->watch = NULL; |
| 892 | new->field_count = old->field_count; |
| 893 | memcpy(new->fields, old->fields, sizeof(struct audit_field) * fcount); |
| 894 | |
| 895 | /* deep copy this information, updating the se_rule fields, because |
| 896 | * the originals will all be freed when the old rule is freed. */ |
| 897 | for (i = 0; i < fcount; i++) { |
| 898 | switch (new->fields[i].type) { |
| 899 | case AUDIT_SUBJ_USER: |
| 900 | case AUDIT_SUBJ_ROLE: |
| 901 | case AUDIT_SUBJ_TYPE: |
| 902 | case AUDIT_SUBJ_SEN: |
| 903 | case AUDIT_SUBJ_CLR: |
| 904 | case AUDIT_OBJ_USER: |
| 905 | case AUDIT_OBJ_ROLE: |
| 906 | case AUDIT_OBJ_TYPE: |
| 907 | case AUDIT_OBJ_LEV_LOW: |
| 908 | case AUDIT_OBJ_LEV_HIGH: |
| 909 | err = audit_dupe_selinux_field(&new->fields[i], |
| 910 | &old->fields[i]); |
| 911 | break; |
| 912 | case AUDIT_FILTERKEY: |
| 913 | fk = kstrdup(old->filterkey, GFP_KERNEL); |
| 914 | if (unlikely(!fk)) |
| 915 | err = -ENOMEM; |
| 916 | else |
| 917 | new->filterkey = fk; |
| 918 | } |
| 919 | if (err) { |
| 920 | audit_free_rule(entry); |
| 921 | return ERR_PTR(err); |
| 922 | } |
| 923 | } |
| 924 | |
| 925 | if (watch) { |
| 926 | audit_get_watch(watch); |
| 927 | new->watch = watch; |
| 928 | } |
| 929 | |
| 930 | return entry; |
| 931 | } |
| 932 | |
| 933 | /* Update inode info in audit rules based on filesystem event. */ |
| 934 | static void audit_update_watch(struct audit_parent *parent, |
| 935 | const char *dname, dev_t dev, |
| 936 | unsigned long ino, unsigned invalidating) |
| 937 | { |
| 938 | struct audit_watch *owatch, *nwatch, *nextw; |
| 939 | struct audit_krule *r, *nextr; |
| 940 | struct audit_entry *oentry, *nentry; |
| 941 | struct audit_buffer *ab; |
| 942 | |
| 943 | mutex_lock(&audit_filter_mutex); |
| 944 | list_for_each_entry_safe(owatch, nextw, &parent->watches, wlist) { |
| 945 | if (audit_compare_dname_path(dname, owatch->path, NULL)) |
| 946 | continue; |
| 947 | |
| 948 | /* If the update involves invalidating rules, do the inode-based |
| 949 | * filtering now, so we don't omit records. */ |
| 950 | if (invalidating && current->audit_context && |
| 951 | audit_filter_inodes(current, current->audit_context) == AUDIT_RECORD_CONTEXT) |
| 952 | audit_set_auditable(current->audit_context); |
| 953 | |
| 954 | nwatch = audit_dupe_watch(owatch); |
| 955 | if (unlikely(IS_ERR(nwatch))) { |
| 956 | mutex_unlock(&audit_filter_mutex); |
| 957 | audit_panic("error updating watch, skipping"); |
| 958 | return; |
| 959 | } |
| 960 | nwatch->dev = dev; |
| 961 | nwatch->ino = ino; |
| 962 | |
| 963 | list_for_each_entry_safe(r, nextr, &owatch->rules, rlist) { |
| 964 | |
| 965 | oentry = container_of(r, struct audit_entry, rule); |
| 966 | list_del(&oentry->rule.rlist); |
| 967 | list_del_rcu(&oentry->list); |
| 968 | |
| 969 | nentry = audit_dupe_rule(&oentry->rule, nwatch); |
| 970 | if (unlikely(IS_ERR(nentry))) |
| 971 | audit_panic("error updating watch, removing"); |
| 972 | else { |
| 973 | int h = audit_hash_ino((u32)ino); |
| 974 | list_add(&nentry->rule.rlist, &nwatch->rules); |
| 975 | list_add_rcu(&nentry->list, &audit_inode_hash[h]); |
| 976 | } |
| 977 | |
| 978 | call_rcu(&oentry->rcu, audit_free_rule_rcu); |
| 979 | } |
| 980 | |
| 981 | ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE); |
| 982 | audit_log_format(ab, "op=updated rules specifying path="); |
| 983 | audit_log_untrustedstring(ab, owatch->path); |
| 984 | audit_log_format(ab, " with dev=%u ino=%lu\n", dev, ino); |
| 985 | audit_log_format(ab, " list=%d res=1", r->listnr); |
| 986 | audit_log_end(ab); |
| 987 | |
| 988 | audit_remove_watch(owatch); |
| 989 | goto add_watch_to_parent; /* event applies to a single watch */ |
| 990 | } |
| 991 | mutex_unlock(&audit_filter_mutex); |
| 992 | return; |
| 993 | |
| 994 | add_watch_to_parent: |
| 995 | list_add(&nwatch->wlist, &parent->watches); |
| 996 | mutex_unlock(&audit_filter_mutex); |
| 997 | return; |
| 998 | } |
| 999 | |
| 1000 | /* Remove all watches & rules associated with a parent that is going away. */ |
| 1001 | static void audit_remove_parent_watches(struct audit_parent *parent) |
| 1002 | { |
| 1003 | struct audit_watch *w, *nextw; |
| 1004 | struct audit_krule *r, *nextr; |
| 1005 | struct audit_entry *e; |
| 1006 | struct audit_buffer *ab; |
| 1007 | |
| 1008 | mutex_lock(&audit_filter_mutex); |
| 1009 | parent->flags |= AUDIT_PARENT_INVALID; |
| 1010 | list_for_each_entry_safe(w, nextw, &parent->watches, wlist) { |
| 1011 | list_for_each_entry_safe(r, nextr, &w->rules, rlist) { |
| 1012 | e = container_of(r, struct audit_entry, rule); |
| 1013 | |
| 1014 | ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE); |
| 1015 | audit_log_format(ab, "op=remove rule path="); |
| 1016 | audit_log_untrustedstring(ab, w->path); |
| 1017 | if (r->filterkey) { |
| 1018 | audit_log_format(ab, " key="); |
| 1019 | audit_log_untrustedstring(ab, r->filterkey); |
| 1020 | } else |
| 1021 | audit_log_format(ab, " key=(null)"); |
| 1022 | audit_log_format(ab, " list=%d res=1", r->listnr); |
| 1023 | audit_log_end(ab); |
| 1024 | |
| 1025 | list_del(&r->rlist); |
| 1026 | list_del_rcu(&e->list); |
| 1027 | call_rcu(&e->rcu, audit_free_rule_rcu); |
| 1028 | } |
| 1029 | audit_remove_watch(w); |
| 1030 | } |
| 1031 | mutex_unlock(&audit_filter_mutex); |
| 1032 | } |
| 1033 | |
| 1034 | /* Unregister inotify watches for parents on in_list. |
| 1035 | * Generates an IN_IGNORED event. */ |
| 1036 | static void audit_inotify_unregister(struct list_head *in_list) |
| 1037 | { |
| 1038 | struct audit_parent *p, *n; |
| 1039 | |
| 1040 | list_for_each_entry_safe(p, n, in_list, ilist) { |
| 1041 | list_del(&p->ilist); |
| 1042 | inotify_rm_watch(audit_ih, &p->wdata); |
| 1043 | /* the put matching the get in audit_do_del_rule() */ |
| 1044 | put_inotify_watch(&p->wdata); |
| 1045 | } |
| 1046 | } |
| 1047 | |
| 1048 | /* Find an existing audit rule. |
| 1049 | * Caller must hold audit_filter_mutex to prevent stale rule data. */ |
| 1050 | static struct audit_entry *audit_find_rule(struct audit_entry *entry, |
| 1051 | struct list_head *list) |
| 1052 | { |
| 1053 | struct audit_entry *e, *found = NULL; |
| 1054 | int h; |
| 1055 | |
| 1056 | if (entry->rule.watch) { |
| 1057 | /* we don't know the inode number, so must walk entire hash */ |
| 1058 | for (h = 0; h < AUDIT_INODE_BUCKETS; h++) { |
| 1059 | list = &audit_inode_hash[h]; |
| 1060 | list_for_each_entry(e, list, list) |
| 1061 | if (!audit_compare_rule(&entry->rule, &e->rule)) { |
| 1062 | found = e; |
| 1063 | goto out; |
| 1064 | } |
| 1065 | } |
| 1066 | goto out; |
| 1067 | } |
| 1068 | |
| 1069 | list_for_each_entry(e, list, list) |
| 1070 | if (!audit_compare_rule(&entry->rule, &e->rule)) { |
| 1071 | found = e; |
| 1072 | goto out; |
| 1073 | } |
| 1074 | |
| 1075 | out: |
| 1076 | return found; |
| 1077 | } |
| 1078 | |
| 1079 | /* Get path information necessary for adding watches. */ |
| 1080 | static int audit_get_nd(char *path, struct nameidata **ndp, |
| 1081 | struct nameidata **ndw) |
| 1082 | { |
| 1083 | struct nameidata *ndparent, *ndwatch; |
| 1084 | int err; |
| 1085 | |
| 1086 | ndparent = kmalloc(sizeof(*ndparent), GFP_KERNEL); |
| 1087 | if (unlikely(!ndparent)) |
| 1088 | return -ENOMEM; |
| 1089 | |
| 1090 | ndwatch = kmalloc(sizeof(*ndwatch), GFP_KERNEL); |
| 1091 | if (unlikely(!ndwatch)) { |
| 1092 | kfree(ndparent); |
| 1093 | return -ENOMEM; |
| 1094 | } |
| 1095 | |
| 1096 | err = path_lookup(path, LOOKUP_PARENT, ndparent); |
| 1097 | if (err) { |
| 1098 | kfree(ndparent); |
| 1099 | kfree(ndwatch); |
| 1100 | return err; |
| 1101 | } |
| 1102 | |
| 1103 | err = path_lookup(path, 0, ndwatch); |
| 1104 | if (err) { |
| 1105 | kfree(ndwatch); |
| 1106 | ndwatch = NULL; |
| 1107 | } |
| 1108 | |
| 1109 | *ndp = ndparent; |
| 1110 | *ndw = ndwatch; |
| 1111 | |
| 1112 | return 0; |
| 1113 | } |
| 1114 | |
| 1115 | /* Release resources used for watch path information. */ |
| 1116 | static void audit_put_nd(struct nameidata *ndp, struct nameidata *ndw) |
| 1117 | { |
| 1118 | if (ndp) { |
| 1119 | path_release(ndp); |
| 1120 | kfree(ndp); |
| 1121 | } |
| 1122 | if (ndw) { |
| 1123 | path_release(ndw); |
| 1124 | kfree(ndw); |
| 1125 | } |
| 1126 | } |
| 1127 | |
| 1128 | /* Associate the given rule with an existing parent inotify_watch. |
| 1129 | * Caller must hold audit_filter_mutex. */ |
| 1130 | static void audit_add_to_parent(struct audit_krule *krule, |
| 1131 | struct audit_parent *parent) |
| 1132 | { |
| 1133 | struct audit_watch *w, *watch = krule->watch; |
| 1134 | int watch_found = 0; |
| 1135 | |
| 1136 | list_for_each_entry(w, &parent->watches, wlist) { |
| 1137 | if (strcmp(watch->path, w->path)) |
| 1138 | continue; |
| 1139 | |
| 1140 | watch_found = 1; |
| 1141 | |
| 1142 | /* put krule's and initial refs to temporary watch */ |
| 1143 | audit_put_watch(watch); |
| 1144 | audit_put_watch(watch); |
| 1145 | |
| 1146 | audit_get_watch(w); |
| 1147 | krule->watch = watch = w; |
| 1148 | break; |
| 1149 | } |
| 1150 | |
| 1151 | if (!watch_found) { |
| 1152 | get_inotify_watch(&parent->wdata); |
| 1153 | watch->parent = parent; |
| 1154 | |
| 1155 | list_add(&watch->wlist, &parent->watches); |
| 1156 | } |
| 1157 | list_add(&krule->rlist, &watch->rules); |
| 1158 | } |
| 1159 | |
| 1160 | /* Find a matching watch entry, or add this one. |
| 1161 | * Caller must hold audit_filter_mutex. */ |
| 1162 | static int audit_add_watch(struct audit_krule *krule, struct nameidata *ndp, |
| 1163 | struct nameidata *ndw) |
| 1164 | { |
| 1165 | struct audit_watch *watch = krule->watch; |
| 1166 | struct inotify_watch *i_watch; |
| 1167 | struct audit_parent *parent; |
| 1168 | int ret = 0; |
| 1169 | |
| 1170 | /* update watch filter fields */ |
| 1171 | if (ndw) { |
| 1172 | watch->dev = ndw->dentry->d_inode->i_sb->s_dev; |
| 1173 | watch->ino = ndw->dentry->d_inode->i_ino; |
| 1174 | } |
| 1175 | |
| 1176 | /* The audit_filter_mutex must not be held during inotify calls because |
| 1177 | * we hold it during inotify event callback processing. If an existing |
| 1178 | * inotify watch is found, inotify_find_watch() grabs a reference before |
| 1179 | * returning. |
| 1180 | */ |
| 1181 | mutex_unlock(&audit_filter_mutex); |
| 1182 | |
| 1183 | if (inotify_find_watch(audit_ih, ndp->dentry->d_inode, &i_watch) < 0) { |
| 1184 | parent = audit_init_parent(ndp); |
| 1185 | if (IS_ERR(parent)) { |
| 1186 | /* caller expects mutex locked */ |
| 1187 | mutex_lock(&audit_filter_mutex); |
| 1188 | return PTR_ERR(parent); |
| 1189 | } |
| 1190 | } else |
| 1191 | parent = container_of(i_watch, struct audit_parent, wdata); |
| 1192 | |
| 1193 | mutex_lock(&audit_filter_mutex); |
| 1194 | |
| 1195 | /* parent was moved before we took audit_filter_mutex */ |
| 1196 | if (parent->flags & AUDIT_PARENT_INVALID) |
| 1197 | ret = -ENOENT; |
| 1198 | else |
| 1199 | audit_add_to_parent(krule, parent); |
| 1200 | |
| 1201 | /* match get in audit_init_parent or inotify_find_watch */ |
| 1202 | put_inotify_watch(&parent->wdata); |
| 1203 | return ret; |
| 1204 | } |
| 1205 | |
| 1206 | /* Add rule to given filterlist if not a duplicate. */ |
| 1207 | static inline int audit_add_rule(struct audit_entry *entry, |
| 1208 | struct list_head *list) |
| 1209 | { |
| 1210 | struct audit_entry *e; |
| 1211 | struct audit_field *inode_f = entry->rule.inode_f; |
| 1212 | struct audit_watch *watch = entry->rule.watch; |
| 1213 | struct nameidata *ndp = NULL, *ndw = NULL; |
| 1214 | int h, err; |
| 1215 | #ifdef CONFIG_AUDITSYSCALL |
| 1216 | int dont_count = 0; |
| 1217 | |
| 1218 | /* If either of these, don't count towards total */ |
| 1219 | if (entry->rule.listnr == AUDIT_FILTER_USER || |
| 1220 | entry->rule.listnr == AUDIT_FILTER_TYPE) |
| 1221 | dont_count = 1; |
| 1222 | #endif |
| 1223 | |
| 1224 | if (inode_f) { |
| 1225 | h = audit_hash_ino(inode_f->val); |
| 1226 | list = &audit_inode_hash[h]; |
| 1227 | } |
| 1228 | |
| 1229 | mutex_lock(&audit_filter_mutex); |
| 1230 | e = audit_find_rule(entry, list); |
| 1231 | mutex_unlock(&audit_filter_mutex); |
| 1232 | if (e) { |
| 1233 | err = -EEXIST; |
| 1234 | goto error; |
| 1235 | } |
| 1236 | |
| 1237 | /* Avoid calling path_lookup under audit_filter_mutex. */ |
| 1238 | if (watch) { |
| 1239 | err = audit_get_nd(watch->path, &ndp, &ndw); |
| 1240 | if (err) |
| 1241 | goto error; |
| 1242 | } |
| 1243 | |
| 1244 | mutex_lock(&audit_filter_mutex); |
| 1245 | if (watch) { |
| 1246 | /* audit_filter_mutex is dropped and re-taken during this call */ |
| 1247 | err = audit_add_watch(&entry->rule, ndp, ndw); |
| 1248 | if (err) { |
| 1249 | mutex_unlock(&audit_filter_mutex); |
| 1250 | goto error; |
| 1251 | } |
| 1252 | h = audit_hash_ino((u32)watch->ino); |
| 1253 | list = &audit_inode_hash[h]; |
| 1254 | } |
| 1255 | |
| 1256 | if (entry->rule.flags & AUDIT_FILTER_PREPEND) { |
| 1257 | list_add_rcu(&entry->list, list); |
| 1258 | entry->rule.flags &= ~AUDIT_FILTER_PREPEND; |
| 1259 | } else { |
| 1260 | list_add_tail_rcu(&entry->list, list); |
| 1261 | } |
| 1262 | #ifdef CONFIG_AUDITSYSCALL |
| 1263 | if (!dont_count) |
| 1264 | audit_n_rules++; |
| 1265 | |
| 1266 | if (!audit_match_signal(entry)) |
| 1267 | audit_signals++; |
| 1268 | #endif |
| 1269 | mutex_unlock(&audit_filter_mutex); |
| 1270 | |
| 1271 | audit_put_nd(ndp, ndw); /* NULL args OK */ |
| 1272 | return 0; |
| 1273 | |
| 1274 | error: |
| 1275 | audit_put_nd(ndp, ndw); /* NULL args OK */ |
| 1276 | if (watch) |
| 1277 | audit_put_watch(watch); /* tmp watch, matches initial get */ |
| 1278 | return err; |
| 1279 | } |
| 1280 | |
| 1281 | /* Remove an existing rule from filterlist. */ |
| 1282 | static inline int audit_del_rule(struct audit_entry *entry, |
| 1283 | struct list_head *list) |
| 1284 | { |
| 1285 | struct audit_entry *e; |
| 1286 | struct audit_field *inode_f = entry->rule.inode_f; |
| 1287 | struct audit_watch *watch, *tmp_watch = entry->rule.watch; |
| 1288 | LIST_HEAD(inotify_list); |
| 1289 | int h, ret = 0; |
| 1290 | #ifdef CONFIG_AUDITSYSCALL |
| 1291 | int dont_count = 0; |
| 1292 | |
| 1293 | /* If either of these, don't count towards total */ |
| 1294 | if (entry->rule.listnr == AUDIT_FILTER_USER || |
| 1295 | entry->rule.listnr == AUDIT_FILTER_TYPE) |
| 1296 | dont_count = 1; |
| 1297 | #endif |
| 1298 | |
| 1299 | if (inode_f) { |
| 1300 | h = audit_hash_ino(inode_f->val); |
| 1301 | list = &audit_inode_hash[h]; |
| 1302 | } |
| 1303 | |
| 1304 | mutex_lock(&audit_filter_mutex); |
| 1305 | e = audit_find_rule(entry, list); |
| 1306 | if (!e) { |
| 1307 | mutex_unlock(&audit_filter_mutex); |
| 1308 | ret = -ENOENT; |
| 1309 | goto out; |
| 1310 | } |
| 1311 | |
| 1312 | watch = e->rule.watch; |
| 1313 | if (watch) { |
| 1314 | struct audit_parent *parent = watch->parent; |
| 1315 | |
| 1316 | list_del(&e->rule.rlist); |
| 1317 | |
| 1318 | if (list_empty(&watch->rules)) { |
| 1319 | audit_remove_watch(watch); |
| 1320 | |
| 1321 | if (list_empty(&parent->watches)) { |
| 1322 | /* Put parent on the inotify un-registration |
| 1323 | * list. Grab a reference before releasing |
| 1324 | * audit_filter_mutex, to be released in |
| 1325 | * audit_inotify_unregister(). */ |
| 1326 | list_add(&parent->ilist, &inotify_list); |
| 1327 | get_inotify_watch(&parent->wdata); |
| 1328 | } |
| 1329 | } |
| 1330 | } |
| 1331 | |
| 1332 | list_del_rcu(&e->list); |
| 1333 | call_rcu(&e->rcu, audit_free_rule_rcu); |
| 1334 | |
| 1335 | #ifdef CONFIG_AUDITSYSCALL |
| 1336 | if (!dont_count) |
| 1337 | audit_n_rules--; |
| 1338 | |
| 1339 | if (!audit_match_signal(entry)) |
| 1340 | audit_signals--; |
| 1341 | #endif |
| 1342 | mutex_unlock(&audit_filter_mutex); |
| 1343 | |
| 1344 | if (!list_empty(&inotify_list)) |
| 1345 | audit_inotify_unregister(&inotify_list); |
| 1346 | |
| 1347 | out: |
| 1348 | if (tmp_watch) |
| 1349 | audit_put_watch(tmp_watch); /* match initial get */ |
| 1350 | |
| 1351 | return ret; |
| 1352 | } |
| 1353 | |
| 1354 | /* List rules using struct audit_rule. Exists for backward |
| 1355 | * compatibility with userspace. */ |
| 1356 | static void audit_list(int pid, int seq, struct sk_buff_head *q) |
| 1357 | { |
| 1358 | struct sk_buff *skb; |
| 1359 | struct audit_entry *entry; |
| 1360 | int i; |
| 1361 | |
| 1362 | /* This is a blocking read, so use audit_filter_mutex instead of rcu |
| 1363 | * iterator to sync with list writers. */ |
| 1364 | for (i=0; i<AUDIT_NR_FILTERS; i++) { |
| 1365 | list_for_each_entry(entry, &audit_filter_list[i], list) { |
| 1366 | struct audit_rule *rule; |
| 1367 | |
| 1368 | rule = audit_krule_to_rule(&entry->rule); |
| 1369 | if (unlikely(!rule)) |
| 1370 | break; |
| 1371 | skb = audit_make_reply(pid, seq, AUDIT_LIST, 0, 1, |
| 1372 | rule, sizeof(*rule)); |
| 1373 | if (skb) |
| 1374 | skb_queue_tail(q, skb); |
| 1375 | kfree(rule); |
| 1376 | } |
| 1377 | } |
| 1378 | for (i = 0; i < AUDIT_INODE_BUCKETS; i++) { |
| 1379 | list_for_each_entry(entry, &audit_inode_hash[i], list) { |
| 1380 | struct audit_rule *rule; |
| 1381 | |
| 1382 | rule = audit_krule_to_rule(&entry->rule); |
| 1383 | if (unlikely(!rule)) |
| 1384 | break; |
| 1385 | skb = audit_make_reply(pid, seq, AUDIT_LIST, 0, 1, |
| 1386 | rule, sizeof(*rule)); |
| 1387 | if (skb) |
| 1388 | skb_queue_tail(q, skb); |
| 1389 | kfree(rule); |
| 1390 | } |
| 1391 | } |
| 1392 | skb = audit_make_reply(pid, seq, AUDIT_LIST, 1, 1, NULL, 0); |
| 1393 | if (skb) |
| 1394 | skb_queue_tail(q, skb); |
| 1395 | } |
| 1396 | |
| 1397 | /* List rules using struct audit_rule_data. */ |
| 1398 | static void audit_list_rules(int pid, int seq, struct sk_buff_head *q) |
| 1399 | { |
| 1400 | struct sk_buff *skb; |
| 1401 | struct audit_entry *e; |
| 1402 | int i; |
| 1403 | |
| 1404 | /* This is a blocking read, so use audit_filter_mutex instead of rcu |
| 1405 | * iterator to sync with list writers. */ |
| 1406 | for (i=0; i<AUDIT_NR_FILTERS; i++) { |
| 1407 | list_for_each_entry(e, &audit_filter_list[i], list) { |
| 1408 | struct audit_rule_data *data; |
| 1409 | |
| 1410 | data = audit_krule_to_data(&e->rule); |
| 1411 | if (unlikely(!data)) |
| 1412 | break; |
| 1413 | skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 0, 1, |
| 1414 | data, sizeof(*data) + data->buflen); |
| 1415 | if (skb) |
| 1416 | skb_queue_tail(q, skb); |
| 1417 | kfree(data); |
| 1418 | } |
| 1419 | } |
| 1420 | for (i=0; i< AUDIT_INODE_BUCKETS; i++) { |
| 1421 | list_for_each_entry(e, &audit_inode_hash[i], list) { |
| 1422 | struct audit_rule_data *data; |
| 1423 | |
| 1424 | data = audit_krule_to_data(&e->rule); |
| 1425 | if (unlikely(!data)) |
| 1426 | break; |
| 1427 | skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 0, 1, |
| 1428 | data, sizeof(*data) + data->buflen); |
| 1429 | if (skb) |
| 1430 | skb_queue_tail(q, skb); |
| 1431 | kfree(data); |
| 1432 | } |
| 1433 | } |
| 1434 | skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 1, 1, NULL, 0); |
| 1435 | if (skb) |
| 1436 | skb_queue_tail(q, skb); |
| 1437 | } |
| 1438 | |
| 1439 | /* Log rule additions and removals */ |
| 1440 | static void audit_log_rule_change(uid_t loginuid, u32 sid, char *action, |
| 1441 | struct audit_krule *rule, int res) |
| 1442 | { |
| 1443 | struct audit_buffer *ab; |
| 1444 | |
| 1445 | ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE); |
| 1446 | if (!ab) |
| 1447 | return; |
| 1448 | audit_log_format(ab, "auid=%u", loginuid); |
| 1449 | if (sid) { |
| 1450 | char *ctx = NULL; |
| 1451 | u32 len; |
| 1452 | if (selinux_sid_to_string(sid, &ctx, &len)) |
| 1453 | audit_log_format(ab, " ssid=%u", sid); |
| 1454 | else |
| 1455 | audit_log_format(ab, " subj=%s", ctx); |
| 1456 | kfree(ctx); |
| 1457 | } |
| 1458 | audit_log_format(ab, " op=%s rule key=", action); |
| 1459 | if (rule->filterkey) |
| 1460 | audit_log_untrustedstring(ab, rule->filterkey); |
| 1461 | else |
| 1462 | audit_log_format(ab, "(null)"); |
| 1463 | audit_log_format(ab, " list=%d res=%d", rule->listnr, res); |
| 1464 | audit_log_end(ab); |
| 1465 | } |
| 1466 | |
| 1467 | /** |
| 1468 | * audit_receive_filter - apply all rules to the specified message type |
| 1469 | * @type: audit message type |
| 1470 | * @pid: target pid for netlink audit messages |
| 1471 | * @uid: target uid for netlink audit messages |
| 1472 | * @seq: netlink audit message sequence (serial) number |
| 1473 | * @data: payload data |
| 1474 | * @datasz: size of payload data |
| 1475 | * @loginuid: loginuid of sender |
| 1476 | * @sid: SE Linux Security ID of sender |
| 1477 | */ |
| 1478 | int audit_receive_filter(int type, int pid, int uid, int seq, void *data, |
| 1479 | size_t datasz, uid_t loginuid, u32 sid) |
| 1480 | { |
| 1481 | struct task_struct *tsk; |
| 1482 | struct audit_netlink_list *dest; |
| 1483 | int err = 0; |
| 1484 | struct audit_entry *entry; |
| 1485 | |
| 1486 | switch (type) { |
| 1487 | case AUDIT_LIST: |
| 1488 | case AUDIT_LIST_RULES: |
| 1489 | /* We can't just spew out the rules here because we might fill |
| 1490 | * the available socket buffer space and deadlock waiting for |
| 1491 | * auditctl to read from it... which isn't ever going to |
| 1492 | * happen if we're actually running in the context of auditctl |
| 1493 | * trying to _send_ the stuff */ |
| 1494 | |
| 1495 | dest = kmalloc(sizeof(struct audit_netlink_list), GFP_KERNEL); |
| 1496 | if (!dest) |
| 1497 | return -ENOMEM; |
| 1498 | dest->pid = pid; |
| 1499 | skb_queue_head_init(&dest->q); |
| 1500 | |
| 1501 | mutex_lock(&audit_filter_mutex); |
| 1502 | if (type == AUDIT_LIST) |
| 1503 | audit_list(pid, seq, &dest->q); |
| 1504 | else |
| 1505 | audit_list_rules(pid, seq, &dest->q); |
| 1506 | mutex_unlock(&audit_filter_mutex); |
| 1507 | |
| 1508 | tsk = kthread_run(audit_send_list, dest, "audit_send_list"); |
| 1509 | if (IS_ERR(tsk)) { |
| 1510 | skb_queue_purge(&dest->q); |
| 1511 | kfree(dest); |
| 1512 | err = PTR_ERR(tsk); |
| 1513 | } |
| 1514 | break; |
| 1515 | case AUDIT_ADD: |
| 1516 | case AUDIT_ADD_RULE: |
| 1517 | if (type == AUDIT_ADD) |
| 1518 | entry = audit_rule_to_entry(data); |
| 1519 | else |
| 1520 | entry = audit_data_to_entry(data, datasz); |
| 1521 | if (IS_ERR(entry)) |
| 1522 | return PTR_ERR(entry); |
| 1523 | |
| 1524 | err = audit_add_rule(entry, |
| 1525 | &audit_filter_list[entry->rule.listnr]); |
| 1526 | audit_log_rule_change(loginuid, sid, "add", &entry->rule, !err); |
| 1527 | |
| 1528 | if (err) |
| 1529 | audit_free_rule(entry); |
| 1530 | break; |
| 1531 | case AUDIT_DEL: |
| 1532 | case AUDIT_DEL_RULE: |
| 1533 | if (type == AUDIT_DEL) |
| 1534 | entry = audit_rule_to_entry(data); |
| 1535 | else |
| 1536 | entry = audit_data_to_entry(data, datasz); |
| 1537 | if (IS_ERR(entry)) |
| 1538 | return PTR_ERR(entry); |
| 1539 | |
| 1540 | err = audit_del_rule(entry, |
| 1541 | &audit_filter_list[entry->rule.listnr]); |
| 1542 | audit_log_rule_change(loginuid, sid, "remove", &entry->rule, |
| 1543 | !err); |
| 1544 | |
| 1545 | audit_free_rule(entry); |
| 1546 | break; |
| 1547 | default: |
| 1548 | return -EINVAL; |
| 1549 | } |
| 1550 | |
| 1551 | return err; |
| 1552 | } |
| 1553 | |
| 1554 | int audit_comparator(const u32 left, const u32 op, const u32 right) |
| 1555 | { |
| 1556 | switch (op) { |
| 1557 | case AUDIT_EQUAL: |
| 1558 | return (left == right); |
| 1559 | case AUDIT_NOT_EQUAL: |
| 1560 | return (left != right); |
| 1561 | case AUDIT_LESS_THAN: |
| 1562 | return (left < right); |
| 1563 | case AUDIT_LESS_THAN_OR_EQUAL: |
| 1564 | return (left <= right); |
| 1565 | case AUDIT_GREATER_THAN: |
| 1566 | return (left > right); |
| 1567 | case AUDIT_GREATER_THAN_OR_EQUAL: |
| 1568 | return (left >= right); |
| 1569 | } |
| 1570 | BUG(); |
| 1571 | return 0; |
| 1572 | } |
| 1573 | |
| 1574 | /* Compare given dentry name with last component in given path, |
| 1575 | * return of 0 indicates a match. */ |
| 1576 | int audit_compare_dname_path(const char *dname, const char *path, |
| 1577 | int *dirlen) |
| 1578 | { |
| 1579 | int dlen, plen; |
| 1580 | const char *p; |
| 1581 | |
| 1582 | if (!dname || !path) |
| 1583 | return 1; |
| 1584 | |
| 1585 | dlen = strlen(dname); |
| 1586 | plen = strlen(path); |
| 1587 | if (plen < dlen) |
| 1588 | return 1; |
| 1589 | |
| 1590 | /* disregard trailing slashes */ |
| 1591 | p = path + plen - 1; |
| 1592 | while ((*p == '/') && (p > path)) |
| 1593 | p--; |
| 1594 | |
| 1595 | /* find last path component */ |
| 1596 | p = p - dlen + 1; |
| 1597 | if (p < path) |
| 1598 | return 1; |
| 1599 | else if (p > path) { |
| 1600 | if (*--p != '/') |
| 1601 | return 1; |
| 1602 | else |
| 1603 | p++; |
| 1604 | } |
| 1605 | |
| 1606 | /* return length of path's directory component */ |
| 1607 | if (dirlen) |
| 1608 | *dirlen = p - path; |
| 1609 | return strncmp(p, dname, dlen); |
| 1610 | } |
| 1611 | |
| 1612 | static int audit_filter_user_rules(struct netlink_skb_parms *cb, |
| 1613 | struct audit_krule *rule, |
| 1614 | enum audit_state *state) |
| 1615 | { |
| 1616 | int i; |
| 1617 | |
| 1618 | for (i = 0; i < rule->field_count; i++) { |
| 1619 | struct audit_field *f = &rule->fields[i]; |
| 1620 | int result = 0; |
| 1621 | |
| 1622 | switch (f->type) { |
| 1623 | case AUDIT_PID: |
| 1624 | result = audit_comparator(cb->creds.pid, f->op, f->val); |
| 1625 | break; |
| 1626 | case AUDIT_UID: |
| 1627 | result = audit_comparator(cb->creds.uid, f->op, f->val); |
| 1628 | break; |
| 1629 | case AUDIT_GID: |
| 1630 | result = audit_comparator(cb->creds.gid, f->op, f->val); |
| 1631 | break; |
| 1632 | case AUDIT_LOGINUID: |
| 1633 | result = audit_comparator(cb->loginuid, f->op, f->val); |
| 1634 | break; |
| 1635 | } |
| 1636 | |
| 1637 | if (!result) |
| 1638 | return 0; |
| 1639 | } |
| 1640 | switch (rule->action) { |
| 1641 | case AUDIT_NEVER: *state = AUDIT_DISABLED; break; |
| 1642 | case AUDIT_ALWAYS: *state = AUDIT_RECORD_CONTEXT; break; |
| 1643 | } |
| 1644 | return 1; |
| 1645 | } |
| 1646 | |
| 1647 | int audit_filter_user(struct netlink_skb_parms *cb, int type) |
| 1648 | { |
| 1649 | enum audit_state state = AUDIT_DISABLED; |
| 1650 | struct audit_entry *e; |
| 1651 | int ret = 1; |
| 1652 | |
| 1653 | rcu_read_lock(); |
| 1654 | list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_USER], list) { |
| 1655 | if (audit_filter_user_rules(cb, &e->rule, &state)) { |
| 1656 | if (state == AUDIT_DISABLED) |
| 1657 | ret = 0; |
| 1658 | break; |
| 1659 | } |
| 1660 | } |
| 1661 | rcu_read_unlock(); |
| 1662 | |
| 1663 | return ret; /* Audit by default */ |
| 1664 | } |
| 1665 | |
| 1666 | int audit_filter_type(int type) |
| 1667 | { |
| 1668 | struct audit_entry *e; |
| 1669 | int result = 0; |
| 1670 | |
| 1671 | rcu_read_lock(); |
| 1672 | if (list_empty(&audit_filter_list[AUDIT_FILTER_TYPE])) |
| 1673 | goto unlock_and_return; |
| 1674 | |
| 1675 | list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_TYPE], |
| 1676 | list) { |
| 1677 | int i; |
| 1678 | for (i = 0; i < e->rule.field_count; i++) { |
| 1679 | struct audit_field *f = &e->rule.fields[i]; |
| 1680 | if (f->type == AUDIT_MSGTYPE) { |
| 1681 | result = audit_comparator(type, f->op, f->val); |
| 1682 | if (!result) |
| 1683 | break; |
| 1684 | } |
| 1685 | } |
| 1686 | if (result) |
| 1687 | goto unlock_and_return; |
| 1688 | } |
| 1689 | unlock_and_return: |
| 1690 | rcu_read_unlock(); |
| 1691 | return result; |
| 1692 | } |
| 1693 | |
| 1694 | /* Check to see if the rule contains any selinux fields. Returns 1 if there |
| 1695 | are selinux fields specified in the rule, 0 otherwise. */ |
| 1696 | static inline int audit_rule_has_selinux(struct audit_krule *rule) |
| 1697 | { |
| 1698 | int i; |
| 1699 | |
| 1700 | for (i = 0; i < rule->field_count; i++) { |
| 1701 | struct audit_field *f = &rule->fields[i]; |
| 1702 | switch (f->type) { |
| 1703 | case AUDIT_SUBJ_USER: |
| 1704 | case AUDIT_SUBJ_ROLE: |
| 1705 | case AUDIT_SUBJ_TYPE: |
| 1706 | case AUDIT_SUBJ_SEN: |
| 1707 | case AUDIT_SUBJ_CLR: |
| 1708 | case AUDIT_OBJ_USER: |
| 1709 | case AUDIT_OBJ_ROLE: |
| 1710 | case AUDIT_OBJ_TYPE: |
| 1711 | case AUDIT_OBJ_LEV_LOW: |
| 1712 | case AUDIT_OBJ_LEV_HIGH: |
| 1713 | return 1; |
| 1714 | } |
| 1715 | } |
| 1716 | |
| 1717 | return 0; |
| 1718 | } |
| 1719 | |
| 1720 | /* This function will re-initialize the se_rule field of all applicable rules. |
| 1721 | * It will traverse the filter lists serarching for rules that contain selinux |
| 1722 | * specific filter fields. When such a rule is found, it is copied, the |
| 1723 | * selinux field is re-initialized, and the old rule is replaced with the |
| 1724 | * updated rule. */ |
| 1725 | int selinux_audit_rule_update(void) |
| 1726 | { |
| 1727 | struct audit_entry *entry, *n, *nentry; |
| 1728 | struct audit_watch *watch; |
| 1729 | int i, err = 0; |
| 1730 | |
| 1731 | /* audit_filter_mutex synchronizes the writers */ |
| 1732 | mutex_lock(&audit_filter_mutex); |
| 1733 | |
| 1734 | for (i = 0; i < AUDIT_NR_FILTERS; i++) { |
| 1735 | list_for_each_entry_safe(entry, n, &audit_filter_list[i], list) { |
| 1736 | if (!audit_rule_has_selinux(&entry->rule)) |
| 1737 | continue; |
| 1738 | |
| 1739 | watch = entry->rule.watch; |
| 1740 | nentry = audit_dupe_rule(&entry->rule, watch); |
| 1741 | if (unlikely(IS_ERR(nentry))) { |
| 1742 | /* save the first error encountered for the |
| 1743 | * return value */ |
| 1744 | if (!err) |
| 1745 | err = PTR_ERR(nentry); |
| 1746 | audit_panic("error updating selinux filters"); |
| 1747 | if (watch) |
| 1748 | list_del(&entry->rule.rlist); |
| 1749 | list_del_rcu(&entry->list); |
| 1750 | } else { |
| 1751 | if (watch) { |
| 1752 | list_add(&nentry->rule.rlist, |
| 1753 | &watch->rules); |
| 1754 | list_del(&entry->rule.rlist); |
| 1755 | } |
| 1756 | list_replace_rcu(&entry->list, &nentry->list); |
| 1757 | } |
| 1758 | call_rcu(&entry->rcu, audit_free_rule_rcu); |
| 1759 | } |
| 1760 | } |
| 1761 | |
| 1762 | mutex_unlock(&audit_filter_mutex); |
| 1763 | |
| 1764 | return err; |
| 1765 | } |
| 1766 | |
| 1767 | /* Update watch data in audit rules based on inotify events. */ |
| 1768 | void audit_handle_ievent(struct inotify_watch *i_watch, u32 wd, u32 mask, |
| 1769 | u32 cookie, const char *dname, struct inode *inode) |
| 1770 | { |
| 1771 | struct audit_parent *parent; |
| 1772 | |
| 1773 | parent = container_of(i_watch, struct audit_parent, wdata); |
| 1774 | |
| 1775 | if (mask & (IN_CREATE|IN_MOVED_TO) && inode) |
| 1776 | audit_update_watch(parent, dname, inode->i_sb->s_dev, |
| 1777 | inode->i_ino, 0); |
| 1778 | else if (mask & (IN_DELETE|IN_MOVED_FROM)) |
| 1779 | audit_update_watch(parent, dname, (dev_t)-1, (unsigned long)-1, 1); |
| 1780 | /* inotify automatically removes the watch and sends IN_IGNORED */ |
| 1781 | else if (mask & (IN_DELETE_SELF|IN_UNMOUNT)) |
| 1782 | audit_remove_parent_watches(parent); |
| 1783 | /* inotify does not remove the watch, so remove it manually */ |
| 1784 | else if(mask & IN_MOVE_SELF) { |
| 1785 | audit_remove_parent_watches(parent); |
| 1786 | inotify_remove_watch_locked(audit_ih, i_watch); |
| 1787 | } else if (mask & IN_IGNORED) |
| 1788 | put_inotify_watch(i_watch); |
| 1789 | } |