1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* auditfilter.c -- filtering of audit events
3 *
4 * Copyright 2003-2004 Red Hat, Inc.
5 * Copyright 2005 Hewlett-Packard Development Company, L.P.
6 * Copyright 2005 IBM Corporation
7 */
8
9 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
10
11 #include <linux/kernel.h>
12 #include <linux/audit.h>
13 #include <linux/kthread.h>
14 #include <linux/mutex.h>
15 #include <linux/fs.h>
16 #include <linux/namei.h>
17 #include <linux/netlink.h>
18 #include <linux/sched.h>
19 #include <linux/slab.h>
20 #include <linux/security.h>
21 #include <net/net_namespace.h>
22 #include <net/sock.h>
23 #include "audit.h"
24
25 /*
26 * Locking model:
27 *
28 * audit_filter_mutex:
29 * Synchronizes writes and blocking reads of audit's filterlist
30 * data. Rcu is used to traverse the filterlist and access
31 * contents of structs audit_entry, audit_watch and opaque
32 * LSM rules during filtering. If modified, these structures
33 * must be copied and replace their counterparts in the filterlist.
34 * An audit_parent struct is not accessed during filtering, so may
35 * be written directly provided audit_filter_mutex is held.
36 */
37
38 /* Audit filter lists, defined in <linux/audit.h> */
39 struct list_head audit_filter_list[AUDIT_NR_FILTERS] = {
40 LIST_HEAD_INIT(audit_filter_list[0]),
41 LIST_HEAD_INIT(audit_filter_list[1]),
42 LIST_HEAD_INIT(audit_filter_list[2]),
43 LIST_HEAD_INIT(audit_filter_list[3]),
44 LIST_HEAD_INIT(audit_filter_list[4]),
45 LIST_HEAD_INIT(audit_filter_list[5]),
46 LIST_HEAD_INIT(audit_filter_list[6]),
47 #if AUDIT_NR_FILTERS != 7
48 #error Fix audit_filter_list initialiser
49 #endif
50 };
51 static struct list_head audit_rules_list[AUDIT_NR_FILTERS] = {
52 LIST_HEAD_INIT(audit_rules_list[0]),
53 LIST_HEAD_INIT(audit_rules_list[1]),
54 LIST_HEAD_INIT(audit_rules_list[2]),
55 LIST_HEAD_INIT(audit_rules_list[3]),
56 LIST_HEAD_INIT(audit_rules_list[4]),
57 LIST_HEAD_INIT(audit_rules_list[5]),
58 LIST_HEAD_INIT(audit_rules_list[6]),
59 };
60
61 DEFINE_MUTEX(audit_filter_mutex);
62
audit_free_lsm_field(struct audit_field * f)63 static void audit_free_lsm_field(struct audit_field *f)
64 {
65 switch (f->type) {
66 case AUDIT_SUBJ_USER:
67 case AUDIT_SUBJ_ROLE:
68 case AUDIT_SUBJ_TYPE:
69 case AUDIT_SUBJ_SEN:
70 case AUDIT_SUBJ_CLR:
71 case AUDIT_OBJ_USER:
72 case AUDIT_OBJ_ROLE:
73 case AUDIT_OBJ_TYPE:
74 case AUDIT_OBJ_LEV_LOW:
75 case AUDIT_OBJ_LEV_HIGH:
76 kfree(f->lsm_str);
77 security_audit_rule_free(f->lsm_rule);
78 }
79 }
80
audit_free_rule(struct audit_entry * e)81 static inline void audit_free_rule(struct audit_entry *e)
82 {
83 int i;
84 struct audit_krule *erule = &e->rule;
85
86 /* some rules don't have associated watches */
87 if (erule->watch)
88 audit_put_watch(erule->watch);
89 if (erule->fields)
90 for (i = 0; i < erule->field_count; i++)
91 audit_free_lsm_field(&erule->fields[i]);
92 kfree(erule->fields);
93 kfree(erule->filterkey);
94 kfree(e);
95 }
96
audit_free_rule_rcu(struct rcu_head * head)97 void audit_free_rule_rcu(struct rcu_head *head)
98 {
99 struct audit_entry *e = container_of(head, struct audit_entry, rcu);
100 audit_free_rule(e);
101 }
102
103 /* Initialize an audit filterlist entry. */
audit_init_entry(u32 field_count)104 static inline struct audit_entry *audit_init_entry(u32 field_count)
105 {
106 struct audit_entry *entry;
107 struct audit_field *fields;
108
109 entry = kzalloc(sizeof(*entry), GFP_KERNEL);
110 if (unlikely(!entry))
111 return NULL;
112
113 fields = kcalloc(field_count, sizeof(*fields), GFP_KERNEL);
114 if (unlikely(!fields)) {
115 kfree(entry);
116 return NULL;
117 }
118 entry->rule.fields = fields;
119
120 return entry;
121 }
122
123 /* Unpack a filter field's string representation from user-space
124 * buffer. */
audit_unpack_string(void ** bufp,size_t * remain,size_t len)125 char *audit_unpack_string(void **bufp, size_t *remain, size_t len)
126 {
127 char *str;
128
129 if (!*bufp || (len == 0) || (len > *remain))
130 return ERR_PTR(-EINVAL);
131
132 /* Of the currently implemented string fields, PATH_MAX
133 * defines the longest valid length.
134 */
135 if (len > PATH_MAX)
136 return ERR_PTR(-ENAMETOOLONG);
137
138 str = kmalloc(len + 1, GFP_KERNEL);
139 if (unlikely(!str))
140 return ERR_PTR(-ENOMEM);
141
142 memcpy(str, *bufp, len);
143 str[len] = 0;
144 *bufp += len;
145 *remain -= len;
146
147 return str;
148 }
149
150 /* Translate an inode field to kernel representation. */
audit_to_inode(struct audit_krule * krule,struct audit_field * f)151 static inline int audit_to_inode(struct audit_krule *krule,
152 struct audit_field *f)
153 {
154 if (krule->listnr != AUDIT_FILTER_EXIT ||
155 krule->inode_f || krule->watch || krule->tree ||
156 (f->op != Audit_equal && f->op != Audit_not_equal))
157 return -EINVAL;
158
159 krule->inode_f = f;
160 return 0;
161 }
162
163 static __u32 *classes[AUDIT_SYSCALL_CLASSES];
164
audit_register_class(int class,unsigned * list)165 int __init audit_register_class(int class, unsigned *list)
166 {
167 __u32 *p = kcalloc(AUDIT_BITMASK_SIZE, sizeof(__u32), GFP_KERNEL);
168 if (!p)
169 return -ENOMEM;
170 while (*list != ~0U) {
171 unsigned n = *list++;
172 if (n >= AUDIT_BITMASK_SIZE * 32 - AUDIT_SYSCALL_CLASSES) {
173 kfree(p);
174 return -EINVAL;
175 }
176 p[AUDIT_WORD(n)] |= AUDIT_BIT(n);
177 }
178 if (class >= AUDIT_SYSCALL_CLASSES || classes[class]) {
179 kfree(p);
180 return -EINVAL;
181 }
182 classes[class] = p;
183 return 0;
184 }
185
audit_match_class(int class,unsigned syscall)186 int audit_match_class(int class, unsigned syscall)
187 {
188 if (unlikely(syscall >= AUDIT_BITMASK_SIZE * 32))
189 return 0;
190 if (unlikely(class >= AUDIT_SYSCALL_CLASSES || !classes[class]))
191 return 0;
192 return classes[class][AUDIT_WORD(syscall)] & AUDIT_BIT(syscall);
193 }
194
195 #ifdef CONFIG_AUDITSYSCALL
audit_match_class_bits(int class,u32 * mask)196 static inline int audit_match_class_bits(int class, u32 *mask)
197 {
198 int i;
199
200 if (classes[class]) {
201 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
202 if (mask[i] & classes[class][i])
203 return 0;
204 }
205 return 1;
206 }
207
audit_match_signal(struct audit_entry * entry)208 static int audit_match_signal(struct audit_entry *entry)
209 {
210 struct audit_field *arch = entry->rule.arch_f;
211
212 if (!arch) {
213 /* When arch is unspecified, we must check both masks on biarch
214 * as syscall number alone is ambiguous. */
215 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL,
216 entry->rule.mask) &&
217 audit_match_class_bits(AUDIT_CLASS_SIGNAL_32,
218 entry->rule.mask));
219 }
220
221 switch(audit_classify_arch(arch->val)) {
222 case 0: /* native */
223 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL,
224 entry->rule.mask));
225 case 1: /* 32bit on biarch */
226 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL_32,
227 entry->rule.mask));
228 default:
229 return 1;
230 }
231 }
232 #endif
233
234 /* Common user-space to kernel rule translation. */
audit_to_entry_common(struct audit_rule_data * rule)235 static inline struct audit_entry *audit_to_entry_common(struct audit_rule_data *rule)
236 {
237 unsigned listnr;
238 struct audit_entry *entry;
239 int i, err;
240
241 err = -EINVAL;
242 listnr = rule->flags & ~AUDIT_FILTER_PREPEND;
243 switch(listnr) {
244 default:
245 goto exit_err;
246 #ifdef CONFIG_AUDITSYSCALL
247 case AUDIT_FILTER_ENTRY:
248 pr_err("AUDIT_FILTER_ENTRY is deprecated\n");
249 goto exit_err;
250 case AUDIT_FILTER_EXIT:
251 case AUDIT_FILTER_TASK:
252 #endif
253 case AUDIT_FILTER_USER:
254 case AUDIT_FILTER_EXCLUDE:
255 case AUDIT_FILTER_FS:
256 ;
257 }
258 if (unlikely(rule->action == AUDIT_POSSIBLE)) {
259 pr_err("AUDIT_POSSIBLE is deprecated\n");
260 goto exit_err;
261 }
262 if (rule->action != AUDIT_NEVER && rule->action != AUDIT_ALWAYS)
263 goto exit_err;
264 if (rule->field_count > AUDIT_MAX_FIELDS)
265 goto exit_err;
266
267 err = -ENOMEM;
268 entry = audit_init_entry(rule->field_count);
269 if (!entry)
270 goto exit_err;
271
272 entry->rule.flags = rule->flags & AUDIT_FILTER_PREPEND;
273 entry->rule.listnr = listnr;
274 entry->rule.action = rule->action;
275 entry->rule.field_count = rule->field_count;
276
277 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
278 entry->rule.mask[i] = rule->mask[i];
279
280 for (i = 0; i < AUDIT_SYSCALL_CLASSES; i++) {
281 int bit = AUDIT_BITMASK_SIZE * 32 - i - 1;
282 __u32 *p = &entry->rule.mask[AUDIT_WORD(bit)];
283 __u32 *class;
284
285 if (!(*p & AUDIT_BIT(bit)))
286 continue;
287 *p &= ~AUDIT_BIT(bit);
288 class = classes[i];
289 if (class) {
290 int j;
291 for (j = 0; j < AUDIT_BITMASK_SIZE; j++)
292 entry->rule.mask[j] |= class[j];
293 }
294 }
295
296 return entry;
297
298 exit_err:
299 return ERR_PTR(err);
300 }
301
302 static u32 audit_ops[] =
303 {
304 [Audit_equal] = AUDIT_EQUAL,
305 [Audit_not_equal] = AUDIT_NOT_EQUAL,
306 [Audit_bitmask] = AUDIT_BIT_MASK,
307 [Audit_bittest] = AUDIT_BIT_TEST,
308 [Audit_lt] = AUDIT_LESS_THAN,
309 [Audit_gt] = AUDIT_GREATER_THAN,
310 [Audit_le] = AUDIT_LESS_THAN_OR_EQUAL,
311 [Audit_ge] = AUDIT_GREATER_THAN_OR_EQUAL,
312 };
313
audit_to_op(u32 op)314 static u32 audit_to_op(u32 op)
315 {
316 u32 n;
317 for (n = Audit_equal; n < Audit_bad && audit_ops[n] != op; n++)
318 ;
319 return n;
320 }
321
322 /* check if an audit field is valid */
audit_field_valid(struct audit_entry * entry,struct audit_field * f)323 static int audit_field_valid(struct audit_entry *entry, struct audit_field *f)
324 {
325 switch (f->type) {
326 case AUDIT_MSGTYPE:
327 if (entry->rule.listnr != AUDIT_FILTER_EXCLUDE &&
328 entry->rule.listnr != AUDIT_FILTER_USER)
329 return -EINVAL;
330 break;
331 case AUDIT_FSTYPE:
332 if (entry->rule.listnr != AUDIT_FILTER_FS)
333 return -EINVAL;
334 break;
335 }
336
337 switch (entry->rule.listnr) {
338 case AUDIT_FILTER_FS:
339 switch(f->type) {
340 case AUDIT_FSTYPE:
341 case AUDIT_FILTERKEY:
342 break;
343 default:
344 return -EINVAL;
345 }
346 }
347
348 /* Check for valid field type and op */
349 switch (f->type) {
350 case AUDIT_ARG0:
351 case AUDIT_ARG1:
352 case AUDIT_ARG2:
353 case AUDIT_ARG3:
354 case AUDIT_PERS: /* <uapi/linux/personality.h> */
355 case AUDIT_DEVMINOR:
356 /* all ops are valid */
357 break;
358 case AUDIT_UID:
359 case AUDIT_EUID:
360 case AUDIT_SUID:
361 case AUDIT_FSUID:
362 case AUDIT_LOGINUID:
363 case AUDIT_OBJ_UID:
364 case AUDIT_GID:
365 case AUDIT_EGID:
366 case AUDIT_SGID:
367 case AUDIT_FSGID:
368 case AUDIT_OBJ_GID:
369 case AUDIT_PID:
370 case AUDIT_MSGTYPE:
371 case AUDIT_PPID:
372 case AUDIT_DEVMAJOR:
373 case AUDIT_EXIT:
374 case AUDIT_SUCCESS:
375 case AUDIT_INODE:
376 case AUDIT_SESSIONID:
377 case AUDIT_SUBJ_SEN:
378 case AUDIT_SUBJ_CLR:
379 case AUDIT_OBJ_LEV_LOW:
380 case AUDIT_OBJ_LEV_HIGH:
381 case AUDIT_SADDR_FAM:
382 /* bit ops are only useful on syscall args */
383 if (f->op == Audit_bitmask || f->op == Audit_bittest)
384 return -EINVAL;
385 break;
386 case AUDIT_SUBJ_USER:
387 case AUDIT_SUBJ_ROLE:
388 case AUDIT_SUBJ_TYPE:
389 case AUDIT_OBJ_USER:
390 case AUDIT_OBJ_ROLE:
391 case AUDIT_OBJ_TYPE:
392 case AUDIT_WATCH:
393 case AUDIT_DIR:
394 case AUDIT_FILTERKEY:
395 case AUDIT_LOGINUID_SET:
396 case AUDIT_ARCH:
397 case AUDIT_FSTYPE:
398 case AUDIT_PERM:
399 case AUDIT_FILETYPE:
400 case AUDIT_FIELD_COMPARE:
401 case AUDIT_EXE:
402 /* only equal and not equal valid ops */
403 if (f->op != Audit_not_equal && f->op != Audit_equal)
404 return -EINVAL;
405 break;
406 default:
407 /* field not recognized */
408 return -EINVAL;
409 }
410
411 /* Check for select valid field values */
412 switch (f->type) {
413 case AUDIT_LOGINUID_SET:
414 if ((f->val != 0) && (f->val != 1))
415 return -EINVAL;
416 break;
417 case AUDIT_PERM:
418 if (f->val & ~15)
419 return -EINVAL;
420 break;
421 case AUDIT_FILETYPE:
422 if (f->val & ~S_IFMT)
423 return -EINVAL;
424 break;
425 case AUDIT_FIELD_COMPARE:
426 if (f->val > AUDIT_MAX_FIELD_COMPARE)
427 return -EINVAL;
428 break;
429 case AUDIT_SADDR_FAM:
430 if (f->val >= AF_MAX)
431 return -EINVAL;
432 break;
433 default:
434 break;
435 }
436
437 return 0;
438 }
439
440 /* Translate struct audit_rule_data to kernel's rule representation. */
audit_data_to_entry(struct audit_rule_data * data,size_t datasz)441 static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data,
442 size_t datasz)
443 {
444 int err = 0;
445 struct audit_entry *entry;
446 void *bufp;
447 size_t remain = datasz - sizeof(struct audit_rule_data);
448 int i;
449 char *str;
450 struct audit_fsnotify_mark *audit_mark;
451
452 entry = audit_to_entry_common(data);
453 if (IS_ERR(entry))
454 goto exit_nofree;
455
456 bufp = data->buf;
457 for (i = 0; i < data->field_count; i++) {
458 struct audit_field *f = &entry->rule.fields[i];
459
460 err = -EINVAL;
461
462 f->op = audit_to_op(data->fieldflags[i]);
463 if (f->op == Audit_bad)
464 goto exit_free;
465
466 f->type = data->fields[i];
467 f->val = data->values[i];
468
469 /* Support legacy tests for a valid loginuid */
470 if ((f->type == AUDIT_LOGINUID) && (f->val == AUDIT_UID_UNSET)) {
471 f->type = AUDIT_LOGINUID_SET;
472 f->val = 0;
473 entry->rule.pflags |= AUDIT_LOGINUID_LEGACY;
474 }
475
476 err = audit_field_valid(entry, f);
477 if (err)
478 goto exit_free;
479
480 err = -EINVAL;
481 switch (f->type) {
482 case AUDIT_LOGINUID:
483 case AUDIT_UID:
484 case AUDIT_EUID:
485 case AUDIT_SUID:
486 case AUDIT_FSUID:
487 case AUDIT_OBJ_UID:
488 f->uid = make_kuid(current_user_ns(), f->val);
489 if (!uid_valid(f->uid))
490 goto exit_free;
491 break;
492 case AUDIT_GID:
493 case AUDIT_EGID:
494 case AUDIT_SGID:
495 case AUDIT_FSGID:
496 case AUDIT_OBJ_GID:
497 f->gid = make_kgid(current_user_ns(), f->val);
498 if (!gid_valid(f->gid))
499 goto exit_free;
500 break;
501 case AUDIT_ARCH:
502 entry->rule.arch_f = f;
503 break;
504 case AUDIT_SUBJ_USER:
505 case AUDIT_SUBJ_ROLE:
506 case AUDIT_SUBJ_TYPE:
507 case AUDIT_SUBJ_SEN:
508 case AUDIT_SUBJ_CLR:
509 case AUDIT_OBJ_USER:
510 case AUDIT_OBJ_ROLE:
511 case AUDIT_OBJ_TYPE:
512 case AUDIT_OBJ_LEV_LOW:
513 case AUDIT_OBJ_LEV_HIGH:
514 str = audit_unpack_string(&bufp, &remain, f->val);
515 if (IS_ERR(str))
516 goto exit_free;
517 entry->rule.buflen += f->val;
518
519 err = security_audit_rule_init(f->type, f->op, str,
520 (void **)&f->lsm_rule);
521 /* Keep currently invalid fields around in case they
522 * become valid after a policy reload. */
523 if (err == -EINVAL) {
524 pr_warn("audit rule for LSM \'%s\' is invalid\n",
525 str);
526 err = 0;
527 }
528 if (err) {
529 kfree(str);
530 goto exit_free;
531 } else
532 f->lsm_str = str;
533 break;
534 case AUDIT_WATCH:
535 str = audit_unpack_string(&bufp, &remain, f->val);
536 if (IS_ERR(str))
537 goto exit_free;
538 entry->rule.buflen += f->val;
539
540 err = audit_to_watch(&entry->rule, str, f->val, f->op);
541 if (err) {
542 kfree(str);
543 goto exit_free;
544 }
545 break;
546 case AUDIT_DIR:
547 str = audit_unpack_string(&bufp, &remain, f->val);
548 if (IS_ERR(str))
549 goto exit_free;
550 entry->rule.buflen += f->val;
551
552 err = audit_make_tree(&entry->rule, str, f->op);
553 kfree(str);
554 if (err)
555 goto exit_free;
556 break;
557 case AUDIT_INODE:
558 err = audit_to_inode(&entry->rule, f);
559 if (err)
560 goto exit_free;
561 break;
562 case AUDIT_FILTERKEY:
563 if (entry->rule.filterkey || f->val > AUDIT_MAX_KEY_LEN)
564 goto exit_free;
565 str = audit_unpack_string(&bufp, &remain, f->val);
566 if (IS_ERR(str))
567 goto exit_free;
568 entry->rule.buflen += f->val;
569 entry->rule.filterkey = str;
570 break;
571 case AUDIT_EXE:
572 if (entry->rule.exe || f->val > PATH_MAX)
573 goto exit_free;
574 str = audit_unpack_string(&bufp, &remain, f->val);
575 if (IS_ERR(str)) {
576 err = PTR_ERR(str);
577 goto exit_free;
578 }
579 entry->rule.buflen += f->val;
580
581 audit_mark = audit_alloc_mark(&entry->rule, str, f->val);
582 if (IS_ERR(audit_mark)) {
583 kfree(str);
584 err = PTR_ERR(audit_mark);
585 goto exit_free;
586 }
587 entry->rule.exe = audit_mark;
588 break;
589 }
590 }
591
592 if (entry->rule.inode_f && entry->rule.inode_f->op == Audit_not_equal)
593 entry->rule.inode_f = NULL;
594
595 exit_nofree:
596 return entry;
597
598 exit_free:
599 if (entry->rule.tree)
600 audit_put_tree(entry->rule.tree); /* that's the temporary one */
601 if (entry->rule.exe)
602 audit_remove_mark(entry->rule.exe); /* that's the template one */
603 audit_free_rule(entry);
604 return ERR_PTR(err);
605 }
606
607 /* Pack a filter field's string representation into data block. */
audit_pack_string(void ** bufp,const char * str)608 static inline size_t audit_pack_string(void **bufp, const char *str)
609 {
610 size_t len = strlen(str);
611
612 memcpy(*bufp, str, len);
613 *bufp += len;
614
615 return len;
616 }
617
618 /* Translate kernel rule representation to struct audit_rule_data. */
audit_krule_to_data(struct audit_krule * krule)619 static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule)
620 {
621 struct audit_rule_data *data;
622 void *bufp;
623 int i;
624
625 data = kmalloc(sizeof(*data) + krule->buflen, GFP_KERNEL);
626 if (unlikely(!data))
627 return NULL;
628 memset(data, 0, sizeof(*data));
629
630 data->flags = krule->flags | krule->listnr;
631 data->action = krule->action;
632 data->field_count = krule->field_count;
633 bufp = data->buf;
634 for (i = 0; i < data->field_count; i++) {
635 struct audit_field *f = &krule->fields[i];
636
637 data->fields[i] = f->type;
638 data->fieldflags[i] = audit_ops[f->op];
639 switch(f->type) {
640 case AUDIT_SUBJ_USER:
641 case AUDIT_SUBJ_ROLE:
642 case AUDIT_SUBJ_TYPE:
643 case AUDIT_SUBJ_SEN:
644 case AUDIT_SUBJ_CLR:
645 case AUDIT_OBJ_USER:
646 case AUDIT_OBJ_ROLE:
647 case AUDIT_OBJ_TYPE:
648 case AUDIT_OBJ_LEV_LOW:
649 case AUDIT_OBJ_LEV_HIGH:
650 data->buflen += data->values[i] =
651 audit_pack_string(&bufp, f->lsm_str);
652 break;
653 case AUDIT_WATCH:
654 data->buflen += data->values[i] =
655 audit_pack_string(&bufp,
656 audit_watch_path(krule->watch));
657 break;
658 case AUDIT_DIR:
659 data->buflen += data->values[i] =
660 audit_pack_string(&bufp,
661 audit_tree_path(krule->tree));
662 break;
663 case AUDIT_FILTERKEY:
664 data->buflen += data->values[i] =
665 audit_pack_string(&bufp, krule->filterkey);
666 break;
667 case AUDIT_EXE:
668 data->buflen += data->values[i] =
669 audit_pack_string(&bufp, audit_mark_path(krule->exe));
670 break;
671 case AUDIT_LOGINUID_SET:
672 if (krule->pflags & AUDIT_LOGINUID_LEGACY && !f->val) {
673 data->fields[i] = AUDIT_LOGINUID;
674 data->values[i] = AUDIT_UID_UNSET;
675 break;
676 }
677 /* fall through - if set */
678 default:
679 data->values[i] = f->val;
680 }
681 }
682 for (i = 0; i < AUDIT_BITMASK_SIZE; i++) data->mask[i] = krule->mask[i];
683
684 return data;
685 }
686
687 /* Compare two rules in kernel format. Considered success if rules
688 * don't match. */
audit_compare_rule(struct audit_krule * a,struct audit_krule * b)689 static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b)
690 {
691 int i;
692
693 if (a->flags != b->flags ||
694 a->pflags != b->pflags ||
695 a->listnr != b->listnr ||
696 a->action != b->action ||
697 a->field_count != b->field_count)
698 return 1;
699
700 for (i = 0; i < a->field_count; i++) {
701 if (a->fields[i].type != b->fields[i].type ||
702 a->fields[i].op != b->fields[i].op)
703 return 1;
704
705 switch(a->fields[i].type) {
706 case AUDIT_SUBJ_USER:
707 case AUDIT_SUBJ_ROLE:
708 case AUDIT_SUBJ_TYPE:
709 case AUDIT_SUBJ_SEN:
710 case AUDIT_SUBJ_CLR:
711 case AUDIT_OBJ_USER:
712 case AUDIT_OBJ_ROLE:
713 case AUDIT_OBJ_TYPE:
714 case AUDIT_OBJ_LEV_LOW:
715 case AUDIT_OBJ_LEV_HIGH:
716 if (strcmp(a->fields[i].lsm_str, b->fields[i].lsm_str))
717 return 1;
718 break;
719 case AUDIT_WATCH:
720 if (strcmp(audit_watch_path(a->watch),
721 audit_watch_path(b->watch)))
722 return 1;
723 break;
724 case AUDIT_DIR:
725 if (strcmp(audit_tree_path(a->tree),
726 audit_tree_path(b->tree)))
727 return 1;
728 break;
729 case AUDIT_FILTERKEY:
730 /* both filterkeys exist based on above type compare */
731 if (strcmp(a->filterkey, b->filterkey))
732 return 1;
733 break;
734 case AUDIT_EXE:
735 /* both paths exist based on above type compare */
736 if (strcmp(audit_mark_path(a->exe),
737 audit_mark_path(b->exe)))
738 return 1;
739 break;
740 case AUDIT_UID:
741 case AUDIT_EUID:
742 case AUDIT_SUID:
743 case AUDIT_FSUID:
744 case AUDIT_LOGINUID:
745 case AUDIT_OBJ_UID:
746 if (!uid_eq(a->fields[i].uid, b->fields[i].uid))
747 return 1;
748 break;
749 case AUDIT_GID:
750 case AUDIT_EGID:
751 case AUDIT_SGID:
752 case AUDIT_FSGID:
753 case AUDIT_OBJ_GID:
754 if (!gid_eq(a->fields[i].gid, b->fields[i].gid))
755 return 1;
756 break;
757 default:
758 if (a->fields[i].val != b->fields[i].val)
759 return 1;
760 }
761 }
762
763 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
764 if (a->mask[i] != b->mask[i])
765 return 1;
766
767 return 0;
768 }
769
770 /* Duplicate LSM field information. The lsm_rule is opaque, so must be
771 * re-initialized. */
audit_dupe_lsm_field(struct audit_field * df,struct audit_field * sf)772 static inline int audit_dupe_lsm_field(struct audit_field *df,
773 struct audit_field *sf)
774 {
775 int ret = 0;
776 char *lsm_str;
777
778 /* our own copy of lsm_str */
779 lsm_str = kstrdup(sf->lsm_str, GFP_KERNEL);
780 if (unlikely(!lsm_str))
781 return -ENOMEM;
782 df->lsm_str = lsm_str;
783
784 /* our own (refreshed) copy of lsm_rule */
785 ret = security_audit_rule_init(df->type, df->op, df->lsm_str,
786 (void **)&df->lsm_rule);
787 /* Keep currently invalid fields around in case they
788 * become valid after a policy reload. */
789 if (ret == -EINVAL) {
790 pr_warn("audit rule for LSM \'%s\' is invalid\n",
791 df->lsm_str);
792 ret = 0;
793 }
794
795 return ret;
796 }
797
798 /* Duplicate an audit rule. This will be a deep copy with the exception
799 * of the watch - that pointer is carried over. The LSM specific fields
800 * will be updated in the copy. The point is to be able to replace the old
801 * rule with the new rule in the filterlist, then free the old rule.
802 * The rlist element is undefined; list manipulations are handled apart from
803 * the initial copy. */
audit_dupe_rule(struct audit_krule * old)804 struct audit_entry *audit_dupe_rule(struct audit_krule *old)
805 {
806 u32 fcount = old->field_count;
807 struct audit_entry *entry;
808 struct audit_krule *new;
809 char *fk;
810 int i, err = 0;
811
812 entry = audit_init_entry(fcount);
813 if (unlikely(!entry))
814 return ERR_PTR(-ENOMEM);
815
816 new = &entry->rule;
817 new->flags = old->flags;
818 new->pflags = old->pflags;
819 new->listnr = old->listnr;
820 new->action = old->action;
821 for (i = 0; i < AUDIT_BITMASK_SIZE; i++)
822 new->mask[i] = old->mask[i];
823 new->prio = old->prio;
824 new->buflen = old->buflen;
825 new->inode_f = old->inode_f;
826 new->field_count = old->field_count;
827
828 /*
829 * note that we are OK with not refcounting here; audit_match_tree()
830 * never dereferences tree and we can't get false positives there
831 * since we'd have to have rule gone from the list *and* removed
832 * before the chunks found by lookup had been allocated, i.e. before
833 * the beginning of list scan.
834 */
835 new->tree = old->tree;
836 memcpy(new->fields, old->fields, sizeof(struct audit_field) * fcount);
837
838 /* deep copy this information, updating the lsm_rule fields, because
839 * the originals will all be freed when the old rule is freed. */
840 for (i = 0; i < fcount; i++) {
841 switch (new->fields[i].type) {
842 case AUDIT_SUBJ_USER:
843 case AUDIT_SUBJ_ROLE:
844 case AUDIT_SUBJ_TYPE:
845 case AUDIT_SUBJ_SEN:
846 case AUDIT_SUBJ_CLR:
847 case AUDIT_OBJ_USER:
848 case AUDIT_OBJ_ROLE:
849 case AUDIT_OBJ_TYPE:
850 case AUDIT_OBJ_LEV_LOW:
851 case AUDIT_OBJ_LEV_HIGH:
852 err = audit_dupe_lsm_field(&new->fields[i],
853 &old->fields[i]);
854 break;
855 case AUDIT_FILTERKEY:
856 fk = kstrdup(old->filterkey, GFP_KERNEL);
857 if (unlikely(!fk))
858 err = -ENOMEM;
859 else
860 new->filterkey = fk;
861 break;
862 case AUDIT_EXE:
863 err = audit_dupe_exe(new, old);
864 break;
865 }
866 if (err) {
867 if (new->exe)
868 audit_remove_mark(new->exe);
869 audit_free_rule(entry);
870 return ERR_PTR(err);
871 }
872 }
873
874 if (old->watch) {
875 audit_get_watch(old->watch);
876 new->watch = old->watch;
877 }
878
879 return entry;
880 }
881
882 /* Find an existing audit rule.
883 * Caller must hold audit_filter_mutex to prevent stale rule data. */
audit_find_rule(struct audit_entry * entry,struct list_head ** p)884 static struct audit_entry *audit_find_rule(struct audit_entry *entry,
885 struct list_head **p)
886 {
887 struct audit_entry *e, *found = NULL;
888 struct list_head *list;
889 int h;
890
891 if (entry->rule.inode_f) {
892 h = audit_hash_ino(entry->rule.inode_f->val);
893 *p = list = &audit_inode_hash[h];
894 } else if (entry->rule.watch) {
895 /* we don't know the inode number, so must walk entire hash */
896 for (h = 0; h < AUDIT_INODE_BUCKETS; h++) {
897 list = &audit_inode_hash[h];
898 list_for_each_entry(e, list, list)
899 if (!audit_compare_rule(&entry->rule, &e->rule)) {
900 found = e;
901 goto out;
902 }
903 }
904 goto out;
905 } else {
906 *p = list = &audit_filter_list[entry->rule.listnr];
907 }
908
909 list_for_each_entry(e, list, list)
910 if (!audit_compare_rule(&entry->rule, &e->rule)) {
911 found = e;
912 goto out;
913 }
914
915 out:
916 return found;
917 }
918
919 static u64 prio_low = ~0ULL/2;
920 static u64 prio_high = ~0ULL/2 - 1;
921
922 /* Add rule to given filterlist if not a duplicate. */
audit_add_rule(struct audit_entry * entry)923 static inline int audit_add_rule(struct audit_entry *entry)
924 {
925 struct audit_entry *e;
926 struct audit_watch *watch = entry->rule.watch;
927 struct audit_tree *tree = entry->rule.tree;
928 struct list_head *list;
929 int err = 0;
930 #ifdef CONFIG_AUDITSYSCALL
931 int dont_count = 0;
932
933 /* If any of these, don't count towards total */
934 switch(entry->rule.listnr) {
935 case AUDIT_FILTER_USER:
936 case AUDIT_FILTER_EXCLUDE:
937 case AUDIT_FILTER_FS:
938 dont_count = 1;
939 }
940 #endif
941
942 mutex_lock(&audit_filter_mutex);
943 e = audit_find_rule(entry, &list);
944 if (e) {
945 mutex_unlock(&audit_filter_mutex);
946 err = -EEXIST;
947 /* normally audit_add_tree_rule() will free it on failure */
948 if (tree)
949 audit_put_tree(tree);
950 return err;
951 }
952
953 if (watch) {
954 /* audit_filter_mutex is dropped and re-taken during this call */
955 err = audit_add_watch(&entry->rule, &list);
956 if (err) {
957 mutex_unlock(&audit_filter_mutex);
958 /*
959 * normally audit_add_tree_rule() will free it
960 * on failure
961 */
962 if (tree)
963 audit_put_tree(tree);
964 return err;
965 }
966 }
967 if (tree) {
968 err = audit_add_tree_rule(&entry->rule);
969 if (err) {
970 mutex_unlock(&audit_filter_mutex);
971 return err;
972 }
973 }
974
975 entry->rule.prio = ~0ULL;
976 if (entry->rule.listnr == AUDIT_FILTER_EXIT) {
977 if (entry->rule.flags & AUDIT_FILTER_PREPEND)
978 entry->rule.prio = ++prio_high;
979 else
980 entry->rule.prio = --prio_low;
981 }
982
983 if (entry->rule.flags & AUDIT_FILTER_PREPEND) {
984 list_add(&entry->rule.list,
985 &audit_rules_list[entry->rule.listnr]);
986 list_add_rcu(&entry->list, list);
987 entry->rule.flags &= ~AUDIT_FILTER_PREPEND;
988 } else {
989 list_add_tail(&entry->rule.list,
990 &audit_rules_list[entry->rule.listnr]);
991 list_add_tail_rcu(&entry->list, list);
992 }
993 #ifdef CONFIG_AUDITSYSCALL
994 if (!dont_count)
995 audit_n_rules++;
996
997 if (!audit_match_signal(entry))
998 audit_signals++;
999 #endif
1000 mutex_unlock(&audit_filter_mutex);
1001
1002 return err;
1003 }
1004
1005 /* Remove an existing rule from filterlist. */
audit_del_rule(struct audit_entry * entry)1006 int audit_del_rule(struct audit_entry *entry)
1007 {
1008 struct audit_entry *e;
1009 struct audit_tree *tree = entry->rule.tree;
1010 struct list_head *list;
1011 int ret = 0;
1012 #ifdef CONFIG_AUDITSYSCALL
1013 int dont_count = 0;
1014
1015 /* If any of these, don't count towards total */
1016 switch(entry->rule.listnr) {
1017 case AUDIT_FILTER_USER:
1018 case AUDIT_FILTER_EXCLUDE:
1019 case AUDIT_FILTER_FS:
1020 dont_count = 1;
1021 }
1022 #endif
1023
1024 mutex_lock(&audit_filter_mutex);
1025 e = audit_find_rule(entry, &list);
1026 if (!e) {
1027 ret = -ENOENT;
1028 goto out;
1029 }
1030
1031 if (e->rule.watch)
1032 audit_remove_watch_rule(&e->rule);
1033
1034 if (e->rule.tree)
1035 audit_remove_tree_rule(&e->rule);
1036
1037 if (e->rule.exe)
1038 audit_remove_mark_rule(&e->rule);
1039
1040 #ifdef CONFIG_AUDITSYSCALL
1041 if (!dont_count)
1042 audit_n_rules--;
1043
1044 if (!audit_match_signal(entry))
1045 audit_signals--;
1046 #endif
1047
1048 list_del_rcu(&e->list);
1049 list_del(&e->rule.list);
1050 call_rcu(&e->rcu, audit_free_rule_rcu);
1051
1052 out:
1053 mutex_unlock(&audit_filter_mutex);
1054
1055 if (tree)
1056 audit_put_tree(tree); /* that's the temporary one */
1057
1058 return ret;
1059 }
1060
1061 /* List rules using struct audit_rule_data. */
audit_list_rules(int seq,struct sk_buff_head * q)1062 static void audit_list_rules(int seq, struct sk_buff_head *q)
1063 {
1064 struct sk_buff *skb;
1065 struct audit_krule *r;
1066 int i;
1067
1068 /* This is a blocking read, so use audit_filter_mutex instead of rcu
1069 * iterator to sync with list writers. */
1070 for (i=0; i<AUDIT_NR_FILTERS; i++) {
1071 list_for_each_entry(r, &audit_rules_list[i], list) {
1072 struct audit_rule_data *data;
1073
1074 data = audit_krule_to_data(r);
1075 if (unlikely(!data))
1076 break;
1077 skb = audit_make_reply(seq, AUDIT_LIST_RULES, 0, 1,
1078 data,
1079 sizeof(*data) + data->buflen);
1080 if (skb)
1081 skb_queue_tail(q, skb);
1082 kfree(data);
1083 }
1084 }
1085 skb = audit_make_reply(seq, AUDIT_LIST_RULES, 1, 1, NULL, 0);
1086 if (skb)
1087 skb_queue_tail(q, skb);
1088 }
1089
1090 /* Log rule additions and removals */
audit_log_rule_change(char * action,struct audit_krule * rule,int res)1091 static void audit_log_rule_change(char *action, struct audit_krule *rule, int res)
1092 {
1093 struct audit_buffer *ab;
1094
1095 if (!audit_enabled)
1096 return;
1097
1098 ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_CONFIG_CHANGE);
1099 if (!ab)
1100 return;
1101 audit_log_session_info(ab);
1102 audit_log_task_context(ab);
1103 audit_log_format(ab, " op=%s", action);
1104 audit_log_key(ab, rule->filterkey);
1105 audit_log_format(ab, " list=%d res=%d", rule->listnr, res);
1106 audit_log_end(ab);
1107 }
1108
1109 /**
1110 * audit_rule_change - apply all rules to the specified message type
1111 * @type: audit message type
1112 * @seq: netlink audit message sequence (serial) number
1113 * @data: payload data
1114 * @datasz: size of payload data
1115 */
audit_rule_change(int type,int seq,void * data,size_t datasz)1116 int audit_rule_change(int type, int seq, void *data, size_t datasz)
1117 {
1118 int err = 0;
1119 struct audit_entry *entry;
1120
1121 switch (type) {
1122 case AUDIT_ADD_RULE:
1123 entry = audit_data_to_entry(data, datasz);
1124 if (IS_ERR(entry))
1125 return PTR_ERR(entry);
1126 err = audit_add_rule(entry);
1127 audit_log_rule_change("add_rule", &entry->rule, !err);
1128 break;
1129 case AUDIT_DEL_RULE:
1130 entry = audit_data_to_entry(data, datasz);
1131 if (IS_ERR(entry))
1132 return PTR_ERR(entry);
1133 err = audit_del_rule(entry);
1134 audit_log_rule_change("remove_rule", &entry->rule, !err);
1135 break;
1136 default:
1137 WARN_ON(1);
1138 return -EINVAL;
1139 }
1140
1141 if (err || type == AUDIT_DEL_RULE) {
1142 if (entry->rule.exe)
1143 audit_remove_mark(entry->rule.exe);
1144 audit_free_rule(entry);
1145 }
1146
1147 return err;
1148 }
1149
1150 /**
1151 * audit_list_rules_send - list the audit rules
1152 * @request_skb: skb of request we are replying to (used to target the reply)
1153 * @seq: netlink audit message sequence (serial) number
1154 */
audit_list_rules_send(struct sk_buff * request_skb,int seq)1155 int audit_list_rules_send(struct sk_buff *request_skb, int seq)
1156 {
1157 u32 portid = NETLINK_CB(request_skb).portid;
1158 struct net *net = sock_net(NETLINK_CB(request_skb).sk);
1159 struct task_struct *tsk;
1160 struct audit_netlink_list *dest;
1161 int err = 0;
1162
1163 /* We can't just spew out the rules here because we might fill
1164 * the available socket buffer space and deadlock waiting for
1165 * auditctl to read from it... which isn't ever going to
1166 * happen if we're actually running in the context of auditctl
1167 * trying to _send_ the stuff */
1168
1169 dest = kmalloc(sizeof(struct audit_netlink_list), GFP_KERNEL);
1170 if (!dest)
1171 return -ENOMEM;
1172 dest->net = get_net(net);
1173 dest->portid = portid;
1174 skb_queue_head_init(&dest->q);
1175
1176 mutex_lock(&audit_filter_mutex);
1177 audit_list_rules(seq, &dest->q);
1178 mutex_unlock(&audit_filter_mutex);
1179
1180 tsk = kthread_run(audit_send_list, dest, "audit_send_list");
1181 if (IS_ERR(tsk)) {
1182 skb_queue_purge(&dest->q);
1183 kfree(dest);
1184 err = PTR_ERR(tsk);
1185 }
1186
1187 return err;
1188 }
1189
audit_comparator(u32 left,u32 op,u32 right)1190 int audit_comparator(u32 left, u32 op, u32 right)
1191 {
1192 switch (op) {
1193 case Audit_equal:
1194 return (left == right);
1195 case Audit_not_equal:
1196 return (left != right);
1197 case Audit_lt:
1198 return (left < right);
1199 case Audit_le:
1200 return (left <= right);
1201 case Audit_gt:
1202 return (left > right);
1203 case Audit_ge:
1204 return (left >= right);
1205 case Audit_bitmask:
1206 return (left & right);
1207 case Audit_bittest:
1208 return ((left & right) == right);
1209 default:
1210 return 0;
1211 }
1212 }
1213
audit_uid_comparator(kuid_t left,u32 op,kuid_t right)1214 int audit_uid_comparator(kuid_t left, u32 op, kuid_t right)
1215 {
1216 switch (op) {
1217 case Audit_equal:
1218 return uid_eq(left, right);
1219 case Audit_not_equal:
1220 return !uid_eq(left, right);
1221 case Audit_lt:
1222 return uid_lt(left, right);
1223 case Audit_le:
1224 return uid_lte(left, right);
1225 case Audit_gt:
1226 return uid_gt(left, right);
1227 case Audit_ge:
1228 return uid_gte(left, right);
1229 case Audit_bitmask:
1230 case Audit_bittest:
1231 default:
1232 return 0;
1233 }
1234 }
1235
audit_gid_comparator(kgid_t left,u32 op,kgid_t right)1236 int audit_gid_comparator(kgid_t left, u32 op, kgid_t right)
1237 {
1238 switch (op) {
1239 case Audit_equal:
1240 return gid_eq(left, right);
1241 case Audit_not_equal:
1242 return !gid_eq(left, right);
1243 case Audit_lt:
1244 return gid_lt(left, right);
1245 case Audit_le:
1246 return gid_lte(left, right);
1247 case Audit_gt:
1248 return gid_gt(left, right);
1249 case Audit_ge:
1250 return gid_gte(left, right);
1251 case Audit_bitmask:
1252 case Audit_bittest:
1253 default:
1254 return 0;
1255 }
1256 }
1257
1258 /**
1259 * parent_len - find the length of the parent portion of a pathname
1260 * @path: pathname of which to determine length
1261 */
parent_len(const char * path)1262 int parent_len(const char *path)
1263 {
1264 int plen;
1265 const char *p;
1266
1267 plen = strlen(path);
1268
1269 if (plen == 0)
1270 return plen;
1271
1272 /* disregard trailing slashes */
1273 p = path + plen - 1;
1274 while ((*p == '/') && (p > path))
1275 p--;
1276
1277 /* walk backward until we find the next slash or hit beginning */
1278 while ((*p != '/') && (p > path))
1279 p--;
1280
1281 /* did we find a slash? Then increment to include it in path */
1282 if (*p == '/')
1283 p++;
1284
1285 return p - path;
1286 }
1287
1288 /**
1289 * audit_compare_dname_path - compare given dentry name with last component in
1290 * given path. Return of 0 indicates a match.
1291 * @dname: dentry name that we're comparing
1292 * @path: full pathname that we're comparing
1293 * @parentlen: length of the parent if known. Passing in AUDIT_NAME_FULL
1294 * here indicates that we must compute this value.
1295 */
audit_compare_dname_path(const struct qstr * dname,const char * path,int parentlen)1296 int audit_compare_dname_path(const struct qstr *dname, const char *path, int parentlen)
1297 {
1298 int dlen, pathlen;
1299 const char *p;
1300
1301 dlen = dname->len;
1302 pathlen = strlen(path);
1303 if (pathlen < dlen)
1304 return 1;
1305
1306 parentlen = parentlen == AUDIT_NAME_FULL ? parent_len(path) : parentlen;
1307 if (pathlen - parentlen != dlen)
1308 return 1;
1309
1310 p = path + parentlen;
1311
1312 return strncmp(p, dname->name, dlen);
1313 }
1314
audit_filter(int msgtype,unsigned int listtype)1315 int audit_filter(int msgtype, unsigned int listtype)
1316 {
1317 struct audit_entry *e;
1318 int ret = 1; /* Audit by default */
1319
1320 rcu_read_lock();
1321 list_for_each_entry_rcu(e, &audit_filter_list[listtype], list) {
1322 int i, result = 0;
1323
1324 for (i = 0; i < e->rule.field_count; i++) {
1325 struct audit_field *f = &e->rule.fields[i];
1326 pid_t pid;
1327 u32 sid;
1328
1329 switch (f->type) {
1330 case AUDIT_PID:
1331 pid = task_pid_nr(current);
1332 result = audit_comparator(pid, f->op, f->val);
1333 break;
1334 case AUDIT_UID:
1335 result = audit_uid_comparator(current_uid(), f->op, f->uid);
1336 break;
1337 case AUDIT_GID:
1338 result = audit_gid_comparator(current_gid(), f->op, f->gid);
1339 break;
1340 case AUDIT_LOGINUID:
1341 result = audit_uid_comparator(audit_get_loginuid(current),
1342 f->op, f->uid);
1343 break;
1344 case AUDIT_LOGINUID_SET:
1345 result = audit_comparator(audit_loginuid_set(current),
1346 f->op, f->val);
1347 break;
1348 case AUDIT_MSGTYPE:
1349 result = audit_comparator(msgtype, f->op, f->val);
1350 break;
1351 case AUDIT_SUBJ_USER:
1352 case AUDIT_SUBJ_ROLE:
1353 case AUDIT_SUBJ_TYPE:
1354 case AUDIT_SUBJ_SEN:
1355 case AUDIT_SUBJ_CLR:
1356 if (f->lsm_rule) {
1357 security_task_getsecid(current, &sid);
1358 result = security_audit_rule_match(sid,
1359 f->type, f->op, f->lsm_rule);
1360 }
1361 break;
1362 case AUDIT_EXE:
1363 result = audit_exe_compare(current, e->rule.exe);
1364 if (f->op == Audit_not_equal)
1365 result = !result;
1366 break;
1367 default:
1368 goto unlock_and_return;
1369 }
1370 if (result < 0) /* error */
1371 goto unlock_and_return;
1372 if (!result)
1373 break;
1374 }
1375 if (result > 0) {
1376 if (e->rule.action == AUDIT_NEVER || listtype == AUDIT_FILTER_EXCLUDE)
1377 ret = 0;
1378 break;
1379 }
1380 }
1381 unlock_and_return:
1382 rcu_read_unlock();
1383 return ret;
1384 }
1385
update_lsm_rule(struct audit_krule * r)1386 static int update_lsm_rule(struct audit_krule *r)
1387 {
1388 struct audit_entry *entry = container_of(r, struct audit_entry, rule);
1389 struct audit_entry *nentry;
1390 int err = 0;
1391
1392 if (!security_audit_rule_known(r))
1393 return 0;
1394
1395 nentry = audit_dupe_rule(r);
1396 if (entry->rule.exe)
1397 audit_remove_mark(entry->rule.exe);
1398 if (IS_ERR(nentry)) {
1399 /* save the first error encountered for the
1400 * return value */
1401 err = PTR_ERR(nentry);
1402 audit_panic("error updating LSM filters");
1403 if (r->watch)
1404 list_del(&r->rlist);
1405 list_del_rcu(&entry->list);
1406 list_del(&r->list);
1407 } else {
1408 if (r->watch || r->tree)
1409 list_replace_init(&r->rlist, &nentry->rule.rlist);
1410 list_replace_rcu(&entry->list, &nentry->list);
1411 list_replace(&r->list, &nentry->rule.list);
1412 }
1413 call_rcu(&entry->rcu, audit_free_rule_rcu);
1414
1415 return err;
1416 }
1417
1418 /* This function will re-initialize the lsm_rule field of all applicable rules.
1419 * It will traverse the filter lists serarching for rules that contain LSM
1420 * specific filter fields. When such a rule is found, it is copied, the
1421 * LSM field is re-initialized, and the old rule is replaced with the
1422 * updated rule. */
audit_update_lsm_rules(void)1423 int audit_update_lsm_rules(void)
1424 {
1425 struct audit_krule *r, *n;
1426 int i, err = 0;
1427
1428 /* audit_filter_mutex synchronizes the writers */
1429 mutex_lock(&audit_filter_mutex);
1430
1431 for (i = 0; i < AUDIT_NR_FILTERS; i++) {
1432 list_for_each_entry_safe(r, n, &audit_rules_list[i], list) {
1433 int res = update_lsm_rule(r);
1434 if (!err)
1435 err = res;
1436 }
1437 }
1438 mutex_unlock(&audit_filter_mutex);
1439
1440 return err;
1441 }
1442