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