1 /* auditfilter.c -- filtering of audit events
2 *
3 * Copyright 2003-2004 Red Hat, Inc.
4 * Copyright 2005 Hewlett-Packard Development Company, L.P.
5 * Copyright 2005 IBM Corporation
6 *
7 * This program is free software; you can redistribute it and/or modify
8 * it under the terms of the GNU General Public License as published by
9 * the Free Software Foundation; either version 2 of the License, or
10 * (at your option) any later version.
11 *
12 * This program is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 * GNU General Public License for more details.
16 *
17 * You should have received a copy of the GNU General Public License
18 * along with this program; if not, write to the Free Software
19 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
20 */
21
22 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
23
24 #include <linux/kernel.h>
25 #include <linux/audit.h>
26 #include <linux/kthread.h>
27 #include <linux/mutex.h>
28 #include <linux/fs.h>
29 #include <linux/namei.h>
30 #include <linux/netlink.h>
31 #include <linux/sched.h>
32 #include <linux/slab.h>
33 #include <linux/security.h>
34 #include <net/net_namespace.h>
35 #include <net/sock.h>
36 #include "audit.h"
37
38 /*
39 * Locking model:
40 *
41 * audit_filter_mutex:
42 * Synchronizes writes and blocking reads of audit's filterlist
43 * data. Rcu is used to traverse the filterlist and access
44 * contents of structs audit_entry, audit_watch and opaque
45 * LSM rules during filtering. If modified, these structures
46 * must be copied and replace their counterparts in the filterlist.
47 * An audit_parent struct is not accessed during filtering, so may
48 * be written directly provided audit_filter_mutex is held.
49 */
50
51 /* Audit filter lists, defined in <linux/audit.h> */
52 struct list_head audit_filter_list[AUDIT_NR_FILTERS] = {
53 LIST_HEAD_INIT(audit_filter_list[0]),
54 LIST_HEAD_INIT(audit_filter_list[1]),
55 LIST_HEAD_INIT(audit_filter_list[2]),
56 LIST_HEAD_INIT(audit_filter_list[3]),
57 LIST_HEAD_INIT(audit_filter_list[4]),
58 LIST_HEAD_INIT(audit_filter_list[5]),
59 #if AUDIT_NR_FILTERS != 6
60 #error Fix audit_filter_list initialiser
61 #endif
62 };
63 static struct list_head audit_rules_list[AUDIT_NR_FILTERS] = {
64 LIST_HEAD_INIT(audit_rules_list[0]),
65 LIST_HEAD_INIT(audit_rules_list[1]),
66 LIST_HEAD_INIT(audit_rules_list[2]),
67 LIST_HEAD_INIT(audit_rules_list[3]),
68 LIST_HEAD_INIT(audit_rules_list[4]),
69 LIST_HEAD_INIT(audit_rules_list[5]),
70 };
71
72 DEFINE_MUTEX(audit_filter_mutex);
73
audit_free_lsm_field(struct audit_field * f)74 static void audit_free_lsm_field(struct audit_field *f)
75 {
76 switch (f->type) {
77 case AUDIT_SUBJ_USER:
78 case AUDIT_SUBJ_ROLE:
79 case AUDIT_SUBJ_TYPE:
80 case AUDIT_SUBJ_SEN:
81 case AUDIT_SUBJ_CLR:
82 case AUDIT_OBJ_USER:
83 case AUDIT_OBJ_ROLE:
84 case AUDIT_OBJ_TYPE:
85 case AUDIT_OBJ_LEV_LOW:
86 case AUDIT_OBJ_LEV_HIGH:
87 kfree(f->lsm_str);
88 security_audit_rule_free(f->lsm_rule);
89 }
90 }
91
audit_free_rule(struct audit_entry * e)92 static inline void audit_free_rule(struct audit_entry *e)
93 {
94 int i;
95 struct audit_krule *erule = &e->rule;
96
97 /* some rules don't have associated watches */
98 if (erule->watch)
99 audit_put_watch(erule->watch);
100 if (erule->fields)
101 for (i = 0; i < erule->field_count; i++)
102 audit_free_lsm_field(&erule->fields[i]);
103 kfree(erule->fields);
104 kfree(erule->filterkey);
105 kfree(e);
106 }
107
audit_free_rule_rcu(struct rcu_head * head)108 void audit_free_rule_rcu(struct rcu_head *head)
109 {
110 struct audit_entry *e = container_of(head, struct audit_entry, rcu);
111 audit_free_rule(e);
112 }
113
114 /* Initialize an audit filterlist entry. */
audit_init_entry(u32 field_count)115 static inline struct audit_entry *audit_init_entry(u32 field_count)
116 {
117 struct audit_entry *entry;
118 struct audit_field *fields;
119
120 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
121 if (unlikely(!entry))
122 return NULL;
123
124 fields = kcalloc(field_count, sizeof(*fields), GFP_KERNEL);
125 if (unlikely(!fields)) {
126 kfree(entry);
127 return NULL;
128 }
129 entry->rule.fields = fields;
130
131 return entry;
132 }
133
134 /* Unpack a filter field's string representation from user-space
135 * buffer. */
audit_unpack_string(void ** bufp,size_t * remain,size_t len)136 char *audit_unpack_string(void **bufp, size_t *remain, size_t len)
137 {
138 char *str;
139
140 if (!*bufp || (len == 0) || (len > *remain))
141 return ERR_PTR(-EINVAL);
142
143 /* Of the currently implemented string fields, PATH_MAX
144 * defines the longest valid length.
145 */
146 if (len > PATH_MAX)
147 return ERR_PTR(-ENAMETOOLONG);
148
149 str = kmalloc(len + 1, GFP_KERNEL);
150 if (unlikely(!str))
151 return ERR_PTR(-ENOMEM);
152
153 memcpy(str, *bufp, len);
154 str[len] = 0;
155 *bufp += len;
156 *remain -= len;
157
158 return str;
159 }
160
161 /* Translate an inode field to kernel representation. */
audit_to_inode(struct audit_krule * krule,struct audit_field * f)162 static inline int audit_to_inode(struct audit_krule *krule,
163 struct audit_field *f)
164 {
165 if (krule->listnr != AUDIT_FILTER_EXIT ||
166 krule->inode_f || krule->watch || krule->tree ||
167 (f->op != Audit_equal && f->op != Audit_not_equal))
168 return -EINVAL;
169
170 krule->inode_f = f;
171 return 0;
172 }
173
174 static __u32 *classes[AUDIT_SYSCALL_CLASSES];
175
audit_register_class(int class,unsigned * list)176 int __init audit_register_class(int class, unsigned *list)
177 {
178 __u32 *p = kcalloc(AUDIT_BITMASK_SIZE, sizeof(__u32), GFP_KERNEL);
179 if (!p)
180 return -ENOMEM;
181 while (*list != ~0U) {
182 unsigned n = *list++;
183 if (n >= AUDIT_BITMASK_SIZE * 32 - AUDIT_SYSCALL_CLASSES) {
184 kfree(p);
185 return -EINVAL;
186 }
187 p[AUDIT_WORD(n)] |= AUDIT_BIT(n);
188 }
189 if (class >= AUDIT_SYSCALL_CLASSES || classes[class]) {
190 kfree(p);
191 return -EINVAL;
192 }
193 classes[class] = p;
194 return 0;
195 }
196
audit_match_class(int class,unsigned syscall)197 int audit_match_class(int class, unsigned syscall)
198 {
199 if (unlikely(syscall >= AUDIT_BITMASK_SIZE * 32))
200 return 0;
201 if (unlikely(class >= AUDIT_SYSCALL_CLASSES || !classes[class]))
202 return 0;
203 return classes[class][AUDIT_WORD(syscall)] & AUDIT_BIT(syscall);
204 }
205
206 #ifdef CONFIG_AUDITSYSCALL
audit_match_class_bits(int class,u32 * mask)207 static inline int audit_match_class_bits(int class, u32 *mask)
208 {
209 int i;
210
211 if (classes[class]) {
212 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
213 if (mask[i] & classes[class][i])
214 return 0;
215 }
216 return 1;
217 }
218
audit_match_signal(struct audit_entry * entry)219 static int audit_match_signal(struct audit_entry *entry)
220 {
221 struct audit_field *arch = entry->rule.arch_f;
222
223 if (!arch) {
224 /* When arch is unspecified, we must check both masks on biarch
225 * as syscall number alone is ambiguous. */
226 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL,
227 entry->rule.mask) &&
228 audit_match_class_bits(AUDIT_CLASS_SIGNAL_32,
229 entry->rule.mask));
230 }
231
232 switch(audit_classify_arch(arch->val)) {
233 case 0: /* native */
234 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL,
235 entry->rule.mask));
236 case 1: /* 32bit on biarch */
237 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL_32,
238 entry->rule.mask));
239 default:
240 return 1;
241 }
242 }
243 #endif
244
245 /* Common user-space to kernel rule translation. */
audit_to_entry_common(struct audit_rule_data * rule)246 static inline struct audit_entry *audit_to_entry_common(struct audit_rule_data *rule)
247 {
248 unsigned listnr;
249 struct audit_entry *entry;
250 int i, err;
251
252 err = -EINVAL;
253 listnr = rule->flags & ~AUDIT_FILTER_PREPEND;
254 switch(listnr) {
255 default:
256 goto exit_err;
257 #ifdef CONFIG_AUDITSYSCALL
258 case AUDIT_FILTER_ENTRY:
259 if (rule->action == AUDIT_ALWAYS)
260 goto exit_err;
261 case AUDIT_FILTER_EXIT:
262 case AUDIT_FILTER_TASK:
263 #endif
264 case AUDIT_FILTER_USER:
265 case AUDIT_FILTER_TYPE:
266 ;
267 }
268 if (unlikely(rule->action == AUDIT_POSSIBLE)) {
269 pr_err("AUDIT_POSSIBLE is deprecated\n");
270 goto exit_err;
271 }
272 if (rule->action != AUDIT_NEVER && rule->action != AUDIT_ALWAYS)
273 goto exit_err;
274 if (rule->field_count > AUDIT_MAX_FIELDS)
275 goto exit_err;
276
277 err = -ENOMEM;
278 entry = audit_init_entry(rule->field_count);
279 if (!entry)
280 goto exit_err;
281
282 entry->rule.flags = rule->flags & AUDIT_FILTER_PREPEND;
283 entry->rule.listnr = listnr;
284 entry->rule.action = rule->action;
285 entry->rule.field_count = rule->field_count;
286
287 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
288 entry->rule.mask[i] = rule->mask[i];
289
290 for (i = 0; i < AUDIT_SYSCALL_CLASSES; i++) {
291 int bit = AUDIT_BITMASK_SIZE * 32 - i - 1;
292 __u32 *p = &entry->rule.mask[AUDIT_WORD(bit)];
293 __u32 *class;
294
295 if (!(*p & AUDIT_BIT(bit)))
296 continue;
297 *p &= ~AUDIT_BIT(bit);
298 class = classes[i];
299 if (class) {
300 int j;
301 for (j = 0; j < AUDIT_BITMASK_SIZE; j++)
302 entry->rule.mask[j] |= class[j];
303 }
304 }
305
306 return entry;
307
308 exit_err:
309 return ERR_PTR(err);
310 }
311
312 static u32 audit_ops[] =
313 {
314 [Audit_equal] = AUDIT_EQUAL,
315 [Audit_not_equal] = AUDIT_NOT_EQUAL,
316 [Audit_bitmask] = AUDIT_BIT_MASK,
317 [Audit_bittest] = AUDIT_BIT_TEST,
318 [Audit_lt] = AUDIT_LESS_THAN,
319 [Audit_gt] = AUDIT_GREATER_THAN,
320 [Audit_le] = AUDIT_LESS_THAN_OR_EQUAL,
321 [Audit_ge] = AUDIT_GREATER_THAN_OR_EQUAL,
322 };
323
audit_to_op(u32 op)324 static u32 audit_to_op(u32 op)
325 {
326 u32 n;
327 for (n = Audit_equal; n < Audit_bad && audit_ops[n] != op; n++)
328 ;
329 return n;
330 }
331
332 /* check if an audit field is valid */
audit_field_valid(struct audit_entry * entry,struct audit_field * f)333 static int audit_field_valid(struct audit_entry *entry, struct audit_field *f)
334 {
335 switch(f->type) {
336 case AUDIT_MSGTYPE:
337 if (entry->rule.listnr != AUDIT_FILTER_TYPE &&
338 entry->rule.listnr != AUDIT_FILTER_USER)
339 return -EINVAL;
340 break;
341 }
342
343 switch(f->type) {
344 default:
345 return -EINVAL;
346 case AUDIT_UID:
347 case AUDIT_EUID:
348 case AUDIT_SUID:
349 case AUDIT_FSUID:
350 case AUDIT_LOGINUID:
351 case AUDIT_OBJ_UID:
352 case AUDIT_GID:
353 case AUDIT_EGID:
354 case AUDIT_SGID:
355 case AUDIT_FSGID:
356 case AUDIT_OBJ_GID:
357 case AUDIT_PID:
358 case AUDIT_PERS:
359 case AUDIT_MSGTYPE:
360 case AUDIT_PPID:
361 case AUDIT_DEVMAJOR:
362 case AUDIT_DEVMINOR:
363 case AUDIT_EXIT:
364 case AUDIT_SUCCESS:
365 case AUDIT_INODE:
366 case AUDIT_SESSIONID:
367 /* bit ops are only useful on syscall args */
368 if (f->op == Audit_bitmask || f->op == Audit_bittest)
369 return -EINVAL;
370 break;
371 case AUDIT_ARG0:
372 case AUDIT_ARG1:
373 case AUDIT_ARG2:
374 case AUDIT_ARG3:
375 case AUDIT_SUBJ_USER:
376 case AUDIT_SUBJ_ROLE:
377 case AUDIT_SUBJ_TYPE:
378 case AUDIT_SUBJ_SEN:
379 case AUDIT_SUBJ_CLR:
380 case AUDIT_OBJ_USER:
381 case AUDIT_OBJ_ROLE:
382 case AUDIT_OBJ_TYPE:
383 case AUDIT_OBJ_LEV_LOW:
384 case AUDIT_OBJ_LEV_HIGH:
385 case AUDIT_WATCH:
386 case AUDIT_DIR:
387 case AUDIT_FILTERKEY:
388 break;
389 case AUDIT_LOGINUID_SET:
390 if ((f->val != 0) && (f->val != 1))
391 return -EINVAL;
392 /* FALL THROUGH */
393 case AUDIT_ARCH:
394 if (f->op != Audit_not_equal && f->op != Audit_equal)
395 return -EINVAL;
396 break;
397 case AUDIT_PERM:
398 if (f->val & ~15)
399 return -EINVAL;
400 break;
401 case AUDIT_FILETYPE:
402 if (f->val & ~S_IFMT)
403 return -EINVAL;
404 break;
405 case AUDIT_FIELD_COMPARE:
406 if (f->val > AUDIT_MAX_FIELD_COMPARE)
407 return -EINVAL;
408 break;
409 case AUDIT_EXE:
410 if (f->op != Audit_not_equal && f->op != Audit_equal)
411 return -EINVAL;
412 if (entry->rule.listnr != AUDIT_FILTER_EXIT)
413 return -EINVAL;
414 break;
415 }
416 return 0;
417 }
418
419 /* Translate struct audit_rule_data to kernel's rule representation. */
audit_data_to_entry(struct audit_rule_data * data,size_t datasz)420 static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
421 size_t datasz)
422 {
423 int err = 0;
424 struct audit_entry *entry;
425 void *bufp;
426 size_t remain = datasz - sizeof(struct audit_rule_data);
427 int i;
428 char *str;
429 struct audit_fsnotify_mark *audit_mark;
430
431 entry = audit_to_entry_common(data);
432 if (IS_ERR(entry))
433 goto exit_nofree;
434
435 bufp = data->buf;
436 for (i = 0; i < data->field_count; i++) {
437 struct audit_field *f = &entry->rule.fields[i];
438 u32 f_val;
439
440 err = -EINVAL;
441
442 f->op = audit_to_op(data->fieldflags[i]);
443 if (f->op == Audit_bad)
444 goto exit_free;
445
446 f->type = data->fields[i];
447 f_val = data->values[i];
448
449 /* Support legacy tests for a valid loginuid */
450 if ((f->type == AUDIT_LOGINUID) && (f_val == AUDIT_UID_UNSET)) {
451 f->type = AUDIT_LOGINUID_SET;
452 f_val = 0;
453 entry->rule.pflags |= AUDIT_LOGINUID_LEGACY;
454 }
455
456 err = audit_field_valid(entry, f);
457 if (err)
458 goto exit_free;
459
460 err = -EINVAL;
461 switch (f->type) {
462 case AUDIT_LOGINUID:
463 case AUDIT_UID:
464 case AUDIT_EUID:
465 case AUDIT_SUID:
466 case AUDIT_FSUID:
467 case AUDIT_OBJ_UID:
468 f->uid = make_kuid(current_user_ns(), f_val);
469 if (!uid_valid(f->uid))
470 goto exit_free;
471 break;
472 case AUDIT_GID:
473 case AUDIT_EGID:
474 case AUDIT_SGID:
475 case AUDIT_FSGID:
476 case AUDIT_OBJ_GID:
477 f->gid = make_kgid(current_user_ns(), f_val);
478 if (!gid_valid(f->gid))
479 goto exit_free;
480 break;
481 case AUDIT_SESSIONID:
482 case AUDIT_ARCH:
483 f->val = f_val;
484 entry->rule.arch_f = f;
485 break;
486 case AUDIT_SUBJ_USER:
487 case AUDIT_SUBJ_ROLE:
488 case AUDIT_SUBJ_TYPE:
489 case AUDIT_SUBJ_SEN:
490 case AUDIT_SUBJ_CLR:
491 case AUDIT_OBJ_USER:
492 case AUDIT_OBJ_ROLE:
493 case AUDIT_OBJ_TYPE:
494 case AUDIT_OBJ_LEV_LOW:
495 case AUDIT_OBJ_LEV_HIGH:
496 str = audit_unpack_string(&bufp, &remain, f_val);
497 if (IS_ERR(str)) {
498 err = PTR_ERR(str);
499 goto exit_free;
500 }
501 entry->rule.buflen += f_val;
502 f->lsm_str = str;
503 err = security_audit_rule_init(f->type, f->op, str,
504 (void **)&f->lsm_rule);
505 /* Keep currently invalid fields around in case they
506 * become valid after a policy reload. */
507 if (err == -EINVAL) {
508 pr_warn("audit rule for LSM \'%s\' is invalid\n",
509 str);
510 err = 0;
511 } else if (err)
512 goto exit_free;
513 break;
514 case AUDIT_WATCH:
515 str = audit_unpack_string(&bufp, &remain, f_val);
516 if (IS_ERR(str)) {
517 err = PTR_ERR(str);
518 goto exit_free;
519 }
520 err = audit_to_watch(&entry->rule, str, f_val, f->op);
521 if (err) {
522 kfree(str);
523 goto exit_free;
524 }
525 entry->rule.buflen += f_val;
526 break;
527 case AUDIT_DIR:
528 str = audit_unpack_string(&bufp, &remain, f_val);
529 if (IS_ERR(str)) {
530 err = PTR_ERR(str);
531 goto exit_free;
532 }
533 err = audit_make_tree(&entry->rule, str, f->op);
534 kfree(str);
535 if (err)
536 goto exit_free;
537 entry->rule.buflen += f_val;
538 break;
539 case AUDIT_INODE:
540 f->val = f_val;
541 err = audit_to_inode(&entry->rule, f);
542 if (err)
543 goto exit_free;
544 break;
545 case AUDIT_FILTERKEY:
546 if (entry->rule.filterkey || f_val > AUDIT_MAX_KEY_LEN)
547 goto exit_free;
548 str = audit_unpack_string(&bufp, &remain, f_val);
549 if (IS_ERR(str)) {
550 err = PTR_ERR(str);
551 goto exit_free;
552 }
553 entry->rule.buflen += f_val;
554 entry->rule.filterkey = str;
555 break;
556 case AUDIT_EXE:
557 if (entry->rule.exe || f_val > PATH_MAX)
558 goto exit_free;
559 str = audit_unpack_string(&bufp, &remain, f_val);
560 if (IS_ERR(str)) {
561 err = PTR_ERR(str);
562 goto exit_free;
563 }
564 audit_mark = audit_alloc_mark(&entry->rule, str, f_val);
565 if (IS_ERR(audit_mark)) {
566 kfree(str);
567 err = PTR_ERR(audit_mark);
568 goto exit_free;
569 }
570 entry->rule.buflen += f_val;
571 entry->rule.exe = audit_mark;
572 break;
573 default:
574 f->val = f_val;
575 break;
576 }
577 }
578
579 if (entry->rule.inode_f && entry->rule.inode_f->op == Audit_not_equal)
580 entry->rule.inode_f = NULL;
581
582 exit_nofree:
583 return entry;
584
585 exit_free:
586 if (entry->rule.tree)
587 audit_put_tree(entry->rule.tree); /* that's the temporary one */
588 if (entry->rule.exe)
589 audit_remove_mark(entry->rule.exe); /* that's the template one */
590 audit_free_rule(entry);
591 return ERR_PTR(err);
592 }
593
594 /* Pack a filter field's string representation into data block. */
audit_pack_string(void ** bufp,const char * str)595 static inline size_t audit_pack_string(void **bufp, const char *str)
596 {
597 size_t len = strlen(str);
598
599 memcpy(*bufp, str, len);
600 *bufp += len;
601
602 return len;
603 }
604
605 /* Translate kernel rule representation to struct audit_rule_data. */
audit_krule_to_data(struct audit_krule * krule)606 static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule)
607 {
608 struct audit_rule_data *data;
609 void *bufp;
610 int i;
611
612 data = kmalloc(sizeof(*data) + krule->buflen, GFP_KERNEL);
613 if (unlikely(!data))
614 return NULL;
615 memset(data, 0, sizeof(*data));
616
617 data->flags = krule->flags | krule->listnr;
618 data->action = krule->action;
619 data->field_count = krule->field_count;
620 bufp = data->buf;
621 for (i = 0; i < data->field_count; i++) {
622 struct audit_field *f = &krule->fields[i];
623
624 data->fields[i] = f->type;
625 data->fieldflags[i] = audit_ops[f->op];
626 switch(f->type) {
627 case AUDIT_SUBJ_USER:
628 case AUDIT_SUBJ_ROLE:
629 case AUDIT_SUBJ_TYPE:
630 case AUDIT_SUBJ_SEN:
631 case AUDIT_SUBJ_CLR:
632 case AUDIT_OBJ_USER:
633 case AUDIT_OBJ_ROLE:
634 case AUDIT_OBJ_TYPE:
635 case AUDIT_OBJ_LEV_LOW:
636 case AUDIT_OBJ_LEV_HIGH:
637 data->buflen += data->values[i] =
638 audit_pack_string(&bufp, f->lsm_str);
639 break;
640 case AUDIT_WATCH:
641 data->buflen += data->values[i] =
642 audit_pack_string(&bufp,
643 audit_watch_path(krule->watch));
644 break;
645 case AUDIT_DIR:
646 data->buflen += data->values[i] =
647 audit_pack_string(&bufp,
648 audit_tree_path(krule->tree));
649 break;
650 case AUDIT_FILTERKEY:
651 data->buflen += data->values[i] =
652 audit_pack_string(&bufp, krule->filterkey);
653 break;
654 case AUDIT_EXE:
655 data->buflen += data->values[i] =
656 audit_pack_string(&bufp, audit_mark_path(krule->exe));
657 break;
658 case AUDIT_LOGINUID_SET:
659 if (krule->pflags & AUDIT_LOGINUID_LEGACY && !f->val) {
660 data->fields[i] = AUDIT_LOGINUID;
661 data->values[i] = AUDIT_UID_UNSET;
662 break;
663 }
664 /* fallthrough if set */
665 default:
666 data->values[i] = f->val;
667 }
668 }
669 for (i = 0; i < AUDIT_BITMASK_SIZE; i++) data->mask[i] = krule->mask[i];
670
671 return data;
672 }
673
674 /* Compare two rules in kernel format. Considered success if rules
675 * don't match. */
audit_compare_rule(struct audit_krule * a,struct audit_krule * b)676 static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b)
677 {
678 int i;
679
680 if (a->flags != b->flags ||
681 a->pflags != b->pflags ||
682 a->listnr != b->listnr ||
683 a->action != b->action ||
684 a->field_count != b->field_count)
685 return 1;
686
687 for (i = 0; i < a->field_count; i++) {
688 if (a->fields[i].type != b->fields[i].type ||
689 a->fields[i].op != b->fields[i].op)
690 return 1;
691
692 switch(a->fields[i].type) {
693 case AUDIT_SUBJ_USER:
694 case AUDIT_SUBJ_ROLE:
695 case AUDIT_SUBJ_TYPE:
696 case AUDIT_SUBJ_SEN:
697 case AUDIT_SUBJ_CLR:
698 case AUDIT_OBJ_USER:
699 case AUDIT_OBJ_ROLE:
700 case AUDIT_OBJ_TYPE:
701 case AUDIT_OBJ_LEV_LOW:
702 case AUDIT_OBJ_LEV_HIGH:
703 if (strcmp(a->fields[i].lsm_str, b->fields[i].lsm_str))
704 return 1;
705 break;
706 case AUDIT_WATCH:
707 if (strcmp(audit_watch_path(a->watch),
708 audit_watch_path(b->watch)))
709 return 1;
710 break;
711 case AUDIT_DIR:
712 if (strcmp(audit_tree_path(a->tree),
713 audit_tree_path(b->tree)))
714 return 1;
715 break;
716 case AUDIT_FILTERKEY:
717 /* both filterkeys exist based on above type compare */
718 if (strcmp(a->filterkey, b->filterkey))
719 return 1;
720 break;
721 case AUDIT_EXE:
722 /* both paths exist based on above type compare */
723 if (strcmp(audit_mark_path(a->exe),
724 audit_mark_path(b->exe)))
725 return 1;
726 break;
727 case AUDIT_UID:
728 case AUDIT_EUID:
729 case AUDIT_SUID:
730 case AUDIT_FSUID:
731 case AUDIT_LOGINUID:
732 case AUDIT_OBJ_UID:
733 if (!uid_eq(a->fields[i].uid, b->fields[i].uid))
734 return 1;
735 break;
736 case AUDIT_GID:
737 case AUDIT_EGID:
738 case AUDIT_SGID:
739 case AUDIT_FSGID:
740 case AUDIT_OBJ_GID:
741 if (!gid_eq(a->fields[i].gid, b->fields[i].gid))
742 return 1;
743 break;
744 default:
745 if (a->fields[i].val != b->fields[i].val)
746 return 1;
747 }
748 }
749
750 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
751 if (a->mask[i] != b->mask[i])
752 return 1;
753
754 return 0;
755 }
756
757 /* Duplicate LSM field information. The lsm_rule is opaque, so must be
758 * re-initialized. */
audit_dupe_lsm_field(struct audit_field * df,struct audit_field * sf)759 static inline int audit_dupe_lsm_field(struct audit_field *df,
760 struct audit_field *sf)
761 {
762 int ret = 0;
763 char *lsm_str;
764
765 /* our own copy of lsm_str */
766 lsm_str = kstrdup(sf->lsm_str, GFP_KERNEL);
767 if (unlikely(!lsm_str))
768 return -ENOMEM;
769 df->lsm_str = lsm_str;
770
771 /* our own (refreshed) copy of lsm_rule */
772 ret = security_audit_rule_init(df->type, df->op, df->lsm_str,
773 (void **)&df->lsm_rule);
774 /* Keep currently invalid fields around in case they
775 * become valid after a policy reload. */
776 if (ret == -EINVAL) {
777 pr_warn("audit rule for LSM \'%s\' is invalid\n",
778 df->lsm_str);
779 ret = 0;
780 }
781
782 return ret;
783 }
784
785 /* Duplicate an audit rule. This will be a deep copy with the exception
786 * of the watch - that pointer is carried over. The LSM specific fields
787 * will be updated in the copy. The point is to be able to replace the old
788 * rule with the new rule in the filterlist, then free the old rule.
789 * The rlist element is undefined; list manipulations are handled apart from
790 * the initial copy. */
audit_dupe_rule(struct audit_krule * old)791 struct audit_entry *audit_dupe_rule(struct audit_krule *old)
792 {
793 u32 fcount = old->field_count;
794 struct audit_entry *entry;
795 struct audit_krule *new;
796 char *fk;
797 int i, err = 0;
798
799 entry = audit_init_entry(fcount);
800 if (unlikely(!entry))
801 return ERR_PTR(-ENOMEM);
802
803 new = &entry->rule;
804 new->flags = old->flags;
805 new->pflags = old->pflags;
806 new->listnr = old->listnr;
807 new->action = old->action;
808 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
809 new->mask[i] = old->mask[i];
810 new->prio = old->prio;
811 new->buflen = old->buflen;
812 new->inode_f = old->inode_f;
813 new->field_count = old->field_count;
814
815 /*
816 * note that we are OK with not refcounting here; audit_match_tree()
817 * never dereferences tree and we can't get false positives there
818 * since we'd have to have rule gone from the list *and* removed
819 * before the chunks found by lookup had been allocated, i.e. before
820 * the beginning of list scan.
821 */
822 new->tree = old->tree;
823 memcpy(new->fields, old->fields, sizeof(struct audit_field) * fcount);
824
825 /* deep copy this information, updating the lsm_rule fields, because
826 * the originals will all be freed when the old rule is freed. */
827 for (i = 0; i < fcount; i++) {
828 switch (new->fields[i].type) {
829 case AUDIT_SUBJ_USER:
830 case AUDIT_SUBJ_ROLE:
831 case AUDIT_SUBJ_TYPE:
832 case AUDIT_SUBJ_SEN:
833 case AUDIT_SUBJ_CLR:
834 case AUDIT_OBJ_USER:
835 case AUDIT_OBJ_ROLE:
836 case AUDIT_OBJ_TYPE:
837 case AUDIT_OBJ_LEV_LOW:
838 case AUDIT_OBJ_LEV_HIGH:
839 err = audit_dupe_lsm_field(&new->fields[i],
840 &old->fields[i]);
841 break;
842 case AUDIT_FILTERKEY:
843 fk = kstrdup(old->filterkey, GFP_KERNEL);
844 if (unlikely(!fk))
845 err = -ENOMEM;
846 else
847 new->filterkey = fk;
848 break;
849 case AUDIT_EXE:
850 err = audit_dupe_exe(new, old);
851 break;
852 }
853 if (err) {
854 if (new->exe)
855 audit_remove_mark(new->exe);
856 audit_free_rule(entry);
857 return ERR_PTR(err);
858 }
859 }
860
861 if (old->watch) {
862 audit_get_watch(old->watch);
863 new->watch = old->watch;
864 }
865
866 return entry;
867 }
868
869 /* Find an existing audit rule.
870 * Caller must hold audit_filter_mutex to prevent stale rule data. */
audit_find_rule(struct audit_entry * entry,struct list_head ** p)871 static struct audit_entry *audit_find_rule(struct audit_entry *entry,
872 struct list_head **p)
873 {
874 struct audit_entry *e, *found = NULL;
875 struct list_head *list;
876 int h;
877
878 if (entry->rule.inode_f) {
879 h = audit_hash_ino(entry->rule.inode_f->val);
880 *p = list = &audit_inode_hash[h];
881 } else if (entry->rule.watch) {
882 /* we don't know the inode number, so must walk entire hash */
883 for (h = 0; h < AUDIT_INODE_BUCKETS; h++) {
884 list = &audit_inode_hash[h];
885 list_for_each_entry(e, list, list)
886 if (!audit_compare_rule(&entry->rule, &e->rule)) {
887 found = e;
888 goto out;
889 }
890 }
891 goto out;
892 } else {
893 *p = list = &audit_filter_list[entry->rule.listnr];
894 }
895
896 list_for_each_entry(e, list, list)
897 if (!audit_compare_rule(&entry->rule, &e->rule)) {
898 found = e;
899 goto out;
900 }
901
902 out:
903 return found;
904 }
905
906 static u64 prio_low = ~0ULL/2;
907 static u64 prio_high = ~0ULL/2 - 1;
908
909 /* Add rule to given filterlist if not a duplicate. */
audit_add_rule(struct audit_entry * entry)910 static inline int audit_add_rule(struct audit_entry *entry)
911 {
912 struct audit_entry *e;
913 struct audit_watch *watch = entry->rule.watch;
914 struct audit_tree *tree = entry->rule.tree;
915 struct list_head *list;
916 int err = 0;
917 #ifdef CONFIG_AUDITSYSCALL
918 int dont_count = 0;
919
920 /* If either of these, don't count towards total */
921 if (entry->rule.listnr == AUDIT_FILTER_USER ||
922 entry->rule.listnr == AUDIT_FILTER_TYPE)
923 dont_count = 1;
924 #endif
925
926 mutex_lock(&audit_filter_mutex);
927 e = audit_find_rule(entry, &list);
928 if (e) {
929 mutex_unlock(&audit_filter_mutex);
930 err = -EEXIST;
931 /* normally audit_add_tree_rule() will free it on failure */
932 if (tree)
933 audit_put_tree(tree);
934 return err;
935 }
936
937 if (watch) {
938 /* audit_filter_mutex is dropped and re-taken during this call */
939 err = audit_add_watch(&entry->rule, &list);
940 if (err) {
941 mutex_unlock(&audit_filter_mutex);
942 /*
943 * normally audit_add_tree_rule() will free it
944 * on failure
945 */
946 if (tree)
947 audit_put_tree(tree);
948 return err;
949 }
950 }
951 if (tree) {
952 err = audit_add_tree_rule(&entry->rule);
953 if (err) {
954 mutex_unlock(&audit_filter_mutex);
955 return err;
956 }
957 }
958
959 entry->rule.prio = ~0ULL;
960 if (entry->rule.listnr == AUDIT_FILTER_EXIT) {
961 if (entry->rule.flags & AUDIT_FILTER_PREPEND)
962 entry->rule.prio = ++prio_high;
963 else
964 entry->rule.prio = --prio_low;
965 }
966
967 if (entry->rule.flags & AUDIT_FILTER_PREPEND) {
968 list_add(&entry->rule.list,
969 &audit_rules_list[entry->rule.listnr]);
970 list_add_rcu(&entry->list, list);
971 entry->rule.flags &= ~AUDIT_FILTER_PREPEND;
972 } else {
973 list_add_tail(&entry->rule.list,
974 &audit_rules_list[entry->rule.listnr]);
975 list_add_tail_rcu(&entry->list, list);
976 }
977 #ifdef CONFIG_AUDITSYSCALL
978 if (!dont_count)
979 audit_n_rules++;
980
981 if (!audit_match_signal(entry))
982 audit_signals++;
983 #endif
984 mutex_unlock(&audit_filter_mutex);
985
986 return err;
987 }
988
989 /* Remove an existing rule from filterlist. */
audit_del_rule(struct audit_entry * entry)990 int audit_del_rule(struct audit_entry *entry)
991 {
992 struct audit_entry *e;
993 struct audit_tree *tree = entry->rule.tree;
994 struct list_head *list;
995 int ret = 0;
996 #ifdef CONFIG_AUDITSYSCALL
997 int dont_count = 0;
998
999 /* If either of these, don't count towards total */
1000 if (entry->rule.listnr == AUDIT_FILTER_USER ||
1001 entry->rule.listnr == AUDIT_FILTER_TYPE)
1002 dont_count = 1;
1003 #endif
1004
1005 mutex_lock(&audit_filter_mutex);
1006 e = audit_find_rule(entry, &list);
1007 if (!e) {
1008 ret = -ENOENT;
1009 goto out;
1010 }
1011
1012 if (e->rule.watch)
1013 audit_remove_watch_rule(&e->rule);
1014
1015 if (e->rule.tree)
1016 audit_remove_tree_rule(&e->rule);
1017
1018 if (e->rule.exe)
1019 audit_remove_mark_rule(&e->rule);
1020
1021 #ifdef CONFIG_AUDITSYSCALL
1022 if (!dont_count)
1023 audit_n_rules--;
1024
1025 if (!audit_match_signal(entry))
1026 audit_signals--;
1027 #endif
1028
1029 list_del_rcu(&e->list);
1030 list_del(&e->rule.list);
1031 call_rcu(&e->rcu, audit_free_rule_rcu);
1032
1033 out:
1034 mutex_unlock(&audit_filter_mutex);
1035
1036 if (tree)
1037 audit_put_tree(tree); /* that's the temporary one */
1038
1039 return ret;
1040 }
1041
1042 /* List rules using struct audit_rule_data. */
audit_list_rules(int seq,struct sk_buff_head * q)1043 static void audit_list_rules(int seq, struct sk_buff_head *q)
1044 {
1045 struct sk_buff *skb;
1046 struct audit_krule *r;
1047 int i;
1048
1049 /* This is a blocking read, so use audit_filter_mutex instead of rcu
1050 * iterator to sync with list writers. */
1051 for (i=0; i<AUDIT_NR_FILTERS; i++) {
1052 list_for_each_entry(r, &audit_rules_list[i], list) {
1053 struct audit_rule_data *data;
1054
1055 data = audit_krule_to_data(r);
1056 if (unlikely(!data))
1057 break;
1058 skb = audit_make_reply(seq, AUDIT_LIST_RULES, 0, 1,
1059 data,
1060 sizeof(*data) + data->buflen);
1061 if (skb)
1062 skb_queue_tail(q, skb);
1063 kfree(data);
1064 }
1065 }
1066 skb = audit_make_reply(seq, AUDIT_LIST_RULES, 1, 1, NULL, 0);
1067 if (skb)
1068 skb_queue_tail(q, skb);
1069 }
1070
1071 /* Log rule additions and removals */
audit_log_rule_change(char * action,struct audit_krule * rule,int res)1072 static void audit_log_rule_change(char *action, struct audit_krule *rule, int res)
1073 {
1074 struct audit_buffer *ab;
1075 uid_t loginuid = from_kuid(&init_user_ns, audit_get_loginuid(current));
1076 unsigned int sessionid = audit_get_sessionid(current);
1077
1078 if (!audit_enabled)
1079 return;
1080
1081 ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
1082 if (!ab)
1083 return;
1084 audit_log_format(ab, "auid=%u ses=%u" ,loginuid, sessionid);
1085 audit_log_task_context(ab);
1086 audit_log_format(ab, " op=%s", action);
1087 audit_log_key(ab, rule->filterkey);
1088 audit_log_format(ab, " list=%d res=%d", rule->listnr, res);
1089 audit_log_end(ab);
1090 }
1091
1092 /**
1093 * audit_rule_change - apply all rules to the specified message type
1094 * @type: audit message type
1095 * @seq: netlink audit message sequence (serial) number
1096 * @data: payload data
1097 * @datasz: size of payload data
1098 */
audit_rule_change(int type,int seq,void * data,size_t datasz)1099 int audit_rule_change(int type, int seq, void *data, size_t datasz)
1100 {
1101 int err = 0;
1102 struct audit_entry *entry;
1103
1104 switch (type) {
1105 case AUDIT_ADD_RULE:
1106 entry = audit_data_to_entry(data, datasz);
1107 if (IS_ERR(entry))
1108 return PTR_ERR(entry);
1109 err = audit_add_rule(entry);
1110 audit_log_rule_change("add_rule", &entry->rule, !err);
1111 break;
1112 case AUDIT_DEL_RULE:
1113 entry = audit_data_to_entry(data, datasz);
1114 if (IS_ERR(entry))
1115 return PTR_ERR(entry);
1116 err = audit_del_rule(entry);
1117 audit_log_rule_change("remove_rule", &entry->rule, !err);
1118 break;
1119 default:
1120 WARN_ON(1);
1121 return -EINVAL;
1122 }
1123
1124 if (err || type == AUDIT_DEL_RULE) {
1125 if (entry->rule.exe)
1126 audit_remove_mark(entry->rule.exe);
1127 audit_free_rule(entry);
1128 }
1129
1130 return err;
1131 }
1132
1133 /**
1134 * audit_list_rules_send - list the audit rules
1135 * @request_skb: skb of request we are replying to (used to target the reply)
1136 * @seq: netlink audit message sequence (serial) number
1137 */
audit_list_rules_send(struct sk_buff * request_skb,int seq)1138 int audit_list_rules_send(struct sk_buff *request_skb, int seq)
1139 {
1140 u32 portid = NETLINK_CB(request_skb).portid;
1141 struct net *net = sock_net(NETLINK_CB(request_skb).sk);
1142 struct task_struct *tsk;
1143 struct audit_netlink_list *dest;
1144 int err = 0;
1145
1146 /* We can't just spew out the rules here because we might fill
1147 * the available socket buffer space and deadlock waiting for
1148 * auditctl to read from it... which isn't ever going to
1149 * happen if we're actually running in the context of auditctl
1150 * trying to _send_ the stuff */
1151
1152 dest = kmalloc(sizeof(struct audit_netlink_list), GFP_KERNEL);
1153 if (!dest)
1154 return -ENOMEM;
1155 dest->net = get_net(net);
1156 dest->portid = portid;
1157 skb_queue_head_init(&dest->q);
1158
1159 mutex_lock(&audit_filter_mutex);
1160 audit_list_rules(seq, &dest->q);
1161 mutex_unlock(&audit_filter_mutex);
1162
1163 tsk = kthread_run(audit_send_list, dest, "audit_send_list");
1164 if (IS_ERR(tsk)) {
1165 skb_queue_purge(&dest->q);
1166 kfree(dest);
1167 err = PTR_ERR(tsk);
1168 }
1169
1170 return err;
1171 }
1172
audit_comparator(u32 left,u32 op,u32 right)1173 int audit_comparator(u32 left, u32 op, u32 right)
1174 {
1175 switch (op) {
1176 case Audit_equal:
1177 return (left == right);
1178 case Audit_not_equal:
1179 return (left != right);
1180 case Audit_lt:
1181 return (left < right);
1182 case Audit_le:
1183 return (left <= right);
1184 case Audit_gt:
1185 return (left > right);
1186 case Audit_ge:
1187 return (left >= right);
1188 case Audit_bitmask:
1189 return (left & right);
1190 case Audit_bittest:
1191 return ((left & right) == right);
1192 default:
1193 BUG();
1194 return 0;
1195 }
1196 }
1197
audit_uid_comparator(kuid_t left,u32 op,kuid_t right)1198 int audit_uid_comparator(kuid_t left, u32 op, kuid_t right)
1199 {
1200 switch (op) {
1201 case Audit_equal:
1202 return uid_eq(left, right);
1203 case Audit_not_equal:
1204 return !uid_eq(left, right);
1205 case Audit_lt:
1206 return uid_lt(left, right);
1207 case Audit_le:
1208 return uid_lte(left, right);
1209 case Audit_gt:
1210 return uid_gt(left, right);
1211 case Audit_ge:
1212 return uid_gte(left, right);
1213 case Audit_bitmask:
1214 case Audit_bittest:
1215 default:
1216 BUG();
1217 return 0;
1218 }
1219 }
1220
audit_gid_comparator(kgid_t left,u32 op,kgid_t right)1221 int audit_gid_comparator(kgid_t left, u32 op, kgid_t right)
1222 {
1223 switch (op) {
1224 case Audit_equal:
1225 return gid_eq(left, right);
1226 case Audit_not_equal:
1227 return !gid_eq(left, right);
1228 case Audit_lt:
1229 return gid_lt(left, right);
1230 case Audit_le:
1231 return gid_lte(left, right);
1232 case Audit_gt:
1233 return gid_gt(left, right);
1234 case Audit_ge:
1235 return gid_gte(left, right);
1236 case Audit_bitmask:
1237 case Audit_bittest:
1238 default:
1239 BUG();
1240 return 0;
1241 }
1242 }
1243
1244 /**
1245 * parent_len - find the length of the parent portion of a pathname
1246 * @path: pathname of which to determine length
1247 */
parent_len(const char * path)1248 int parent_len(const char *path)
1249 {
1250 int plen;
1251 const char *p;
1252
1253 plen = strlen(path);
1254
1255 if (plen == 0)
1256 return plen;
1257
1258 /* disregard trailing slashes */
1259 p = path + plen - 1;
1260 while ((*p == '/') && (p > path))
1261 p--;
1262
1263 /* walk backward until we find the next slash or hit beginning */
1264 while ((*p != '/') && (p > path))
1265 p--;
1266
1267 /* did we find a slash? Then increment to include it in path */
1268 if (*p == '/')
1269 p++;
1270
1271 return p - path;
1272 }
1273
1274 /**
1275 * audit_compare_dname_path - compare given dentry name with last component in
1276 * given path. Return of 0 indicates a match.
1277 * @dname: dentry name that we're comparing
1278 * @path: full pathname that we're comparing
1279 * @parentlen: length of the parent if known. Passing in AUDIT_NAME_FULL
1280 * here indicates that we must compute this value.
1281 */
audit_compare_dname_path(const char * dname,const char * path,int parentlen)1282 int audit_compare_dname_path(const char *dname, const char *path, int parentlen)
1283 {
1284 int dlen, pathlen;
1285 const char *p;
1286
1287 dlen = strlen(dname);
1288 pathlen = strlen(path);
1289 if (pathlen < dlen)
1290 return 1;
1291
1292 parentlen = parentlen == AUDIT_NAME_FULL ? parent_len(path) : parentlen;
1293 if (pathlen - parentlen != dlen)
1294 return 1;
1295
1296 p = path + parentlen;
1297
1298 return strncmp(p, dname, dlen);
1299 }
1300
audit_filter(int msgtype,unsigned int listtype)1301 int audit_filter(int msgtype, unsigned int listtype)
1302 {
1303 struct audit_entry *e;
1304 int ret = 1; /* Audit by default */
1305
1306 rcu_read_lock();
1307 if (list_empty(&audit_filter_list[listtype]))
1308 goto unlock_and_return;
1309 list_for_each_entry_rcu(e, &audit_filter_list[listtype], list) {
1310 int i, result = 0;
1311
1312 for (i = 0; i < e->rule.field_count; i++) {
1313 struct audit_field *f = &e->rule.fields[i];
1314 pid_t pid;
1315 u32 sid;
1316
1317 switch (f->type) {
1318 case AUDIT_PID:
1319 pid = task_pid_nr(current);
1320 result = audit_comparator(pid, f->op, f->val);
1321 break;
1322 case AUDIT_UID:
1323 result = audit_uid_comparator(current_uid(), f->op, f->uid);
1324 break;
1325 case AUDIT_GID:
1326 result = audit_gid_comparator(current_gid(), f->op, f->gid);
1327 break;
1328 case AUDIT_LOGINUID:
1329 result = audit_uid_comparator(audit_get_loginuid(current),
1330 f->op, f->uid);
1331 break;
1332 case AUDIT_LOGINUID_SET:
1333 result = audit_comparator(audit_loginuid_set(current),
1334 f->op, f->val);
1335 break;
1336 case AUDIT_MSGTYPE:
1337 result = audit_comparator(msgtype, f->op, f->val);
1338 break;
1339 case AUDIT_SUBJ_USER:
1340 case AUDIT_SUBJ_ROLE:
1341 case AUDIT_SUBJ_TYPE:
1342 case AUDIT_SUBJ_SEN:
1343 case AUDIT_SUBJ_CLR:
1344 if (f->lsm_rule) {
1345 security_task_getsecid(current, &sid);
1346 result = security_audit_rule_match(sid,
1347 f->type, f->op, f->lsm_rule, NULL);
1348 }
1349 break;
1350 default:
1351 goto unlock_and_return;
1352 }
1353 if (result < 0) /* error */
1354 goto unlock_and_return;
1355 if (!result)
1356 break;
1357 }
1358 if (result > 0) {
1359 if (e->rule.action == AUDIT_NEVER || listtype == AUDIT_FILTER_TYPE)
1360 ret = 0;
1361 break;
1362 }
1363 }
1364 unlock_and_return:
1365 rcu_read_unlock();
1366 return ret;
1367 }
1368
update_lsm_rule(struct audit_krule * r)1369 static int update_lsm_rule(struct audit_krule *r)
1370 {
1371 struct audit_entry *entry = container_of(r, struct audit_entry, rule);
1372 struct audit_entry *nentry;
1373 int err = 0;
1374
1375 if (!security_audit_rule_known(r))
1376 return 0;
1377
1378 nentry = audit_dupe_rule(r);
1379 if (entry->rule.exe)
1380 audit_remove_mark(entry->rule.exe);
1381 if (IS_ERR(nentry)) {
1382 /* save the first error encountered for the
1383 * return value */
1384 err = PTR_ERR(nentry);
1385 audit_panic("error updating LSM filters");
1386 if (r->watch)
1387 list_del(&r->rlist);
1388 list_del_rcu(&entry->list);
1389 list_del(&r->list);
1390 } else {
1391 if (r->watch || r->tree)
1392 list_replace_init(&r->rlist, &nentry->rule.rlist);
1393 list_replace_rcu(&entry->list, &nentry->list);
1394 list_replace(&r->list, &nentry->rule.list);
1395 }
1396 call_rcu(&entry->rcu, audit_free_rule_rcu);
1397
1398 return err;
1399 }
1400
1401 /* This function will re-initialize the lsm_rule field of all applicable rules.
1402 * It will traverse the filter lists serarching for rules that contain LSM
1403 * specific filter fields. When such a rule is found, it is copied, the
1404 * LSM field is re-initialized, and the old rule is replaced with the
1405 * updated rule. */
audit_update_lsm_rules(void)1406 int audit_update_lsm_rules(void)
1407 {
1408 struct audit_krule *r, *n;
1409 int i, err = 0;
1410
1411 /* audit_filter_mutex synchronizes the writers */
1412 mutex_lock(&audit_filter_mutex);
1413
1414 for (i = 0; i < AUDIT_NR_FILTERS; i++) {
1415 list_for_each_entry_safe(r, n, &audit_rules_list[i], list) {
1416 int res = update_lsm_rule(r);
1417 if (!err)
1418 err = res;
1419 }
1420 }
1421 mutex_unlock(&audit_filter_mutex);
1422
1423 return err;
1424 }
1425