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1 | /* auditfilter.c -- filtering of audit events |
2 | * |
3 | * Copyright 2003-2004 Red Hat, Inc. |
4 | * Copyright 2005 Hewlett-Packard Development Company, L.P. |
5 | * Copyright 2005 IBM Corporation |
6 | * |
7 | * This program is free software; you can redistribute it and/or modify |
8 | * it under the terms of the GNU General Public License as published by |
9 | * the Free Software Foundation; either version 2 of the License, or |
10 | * (at your option) any later version. |
11 | * |
12 | * This program is distributed in the hope that it will be useful, |
13 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
14 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
15 | * GNU General Public License for more details. |
16 | * |
17 | * You should have received a copy of the GNU General Public License |
18 | * along with this program; if not, write to the Free Software |
19 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
20 | */ |
21 | |
22 | #include <linux/kernel.h> |
23 | #include <linux/audit.h> |
24 | #include <linux/kthread.h> |
25 | #include <linux/mutex.h> |
26 | #include <linux/fs.h> |
27 | #include <linux/namei.h> |
28 | #include <linux/netlink.h> |
29 | #include <linux/sched.h> |
30 | #include <linux/slab.h> |
31 | #include <linux/security.h> |
32 | #include "audit.h" |
33 | |
34 | /* |
35 | * Locking model: |
36 | * |
37 | * audit_filter_mutex: |
38 | * Synchronizes writes and blocking reads of audit's filterlist |
39 | * data. Rcu is used to traverse the filterlist and access |
40 | * contents of structs audit_entry, audit_watch and opaque |
41 | * LSM rules during filtering. If modified, these structures |
42 | * must be copied and replace their counterparts in the filterlist. |
43 | * An audit_parent struct is not accessed during filtering, so may |
44 | * be written directly provided audit_filter_mutex is held. |
45 | */ |
46 | |
47 | /* Audit filter lists, defined in <linux/audit.h> */ |
48 | struct list_head audit_filter_list[AUDIT_NR_FILTERS] = { |
49 | LIST_HEAD_INIT(audit_filter_list[0]), |
50 | LIST_HEAD_INIT(audit_filter_list[1]), |
51 | LIST_HEAD_INIT(audit_filter_list[2]), |
52 | LIST_HEAD_INIT(audit_filter_list[3]), |
53 | LIST_HEAD_INIT(audit_filter_list[4]), |
54 | LIST_HEAD_INIT(audit_filter_list[5]), |
55 | #if AUDIT_NR_FILTERS != 6 |
56 | #error Fix audit_filter_list initialiser |
57 | #endif |
58 | }; |
59 | static struct list_head audit_rules_list[AUDIT_NR_FILTERS] = { |
60 | LIST_HEAD_INIT(audit_rules_list[0]), |
61 | LIST_HEAD_INIT(audit_rules_list[1]), |
62 | LIST_HEAD_INIT(audit_rules_list[2]), |
63 | LIST_HEAD_INIT(audit_rules_list[3]), |
64 | LIST_HEAD_INIT(audit_rules_list[4]), |
65 | LIST_HEAD_INIT(audit_rules_list[5]), |
66 | }; |
67 | |
68 | DEFINE_MUTEX(audit_filter_mutex); |
69 | |
70 | static inline void audit_free_rule(struct audit_entry *e) |
71 | { |
72 | int i; |
73 | struct audit_krule *erule = &e->rule; |
74 | /* some rules don't have associated watches */ |
75 | if (erule->watch) |
76 | audit_put_watch(erule->watch); |
77 | if (erule->fields) |
78 | for (i = 0; i < erule->field_count; i++) { |
79 | struct audit_field *f = &erule->fields[i]; |
80 | kfree(f->lsm_str); |
81 | security_audit_rule_free(f->lsm_rule); |
82 | } |
83 | kfree(erule->fields); |
84 | kfree(erule->filterkey); |
85 | kfree(e); |
86 | } |
87 | |
88 | void audit_free_rule_rcu(struct rcu_head *head) |
89 | { |
90 | struct audit_entry *e = container_of(head, struct audit_entry, rcu); |
91 | audit_free_rule(e); |
92 | } |
93 | |
94 | /* Initialize an audit filterlist entry. */ |
95 | static inline struct audit_entry *audit_init_entry(u32 field_count) |
96 | { |
97 | struct audit_entry *entry; |
98 | struct audit_field *fields; |
99 | |
100 | entry = kzalloc(sizeof(*entry), GFP_KERNEL); |
101 | if (unlikely(!entry)) |
102 | return NULL; |
103 | |
104 | fields = kzalloc(sizeof(*fields) * field_count, GFP_KERNEL); |
105 | if (unlikely(!fields)) { |
106 | kfree(entry); |
107 | return NULL; |
108 | } |
109 | entry->rule.fields = fields; |
110 | |
111 | return entry; |
112 | } |
113 | |
114 | /* Unpack a filter field's string representation from user-space |
115 | * buffer. */ |
116 | char *audit_unpack_string(void **bufp, size_t *remain, size_t len) |
117 | { |
118 | char *str; |
119 | |
120 | if (!*bufp || (len == 0) || (len > *remain)) |
121 | return ERR_PTR(-EINVAL); |
122 | |
123 | /* Of the currently implemented string fields, PATH_MAX |
124 | * defines the longest valid length. |
125 | */ |
126 | if (len > PATH_MAX) |
127 | return ERR_PTR(-ENAMETOOLONG); |
128 | |
129 | str = kmalloc(len + 1, GFP_KERNEL); |
130 | if (unlikely(!str)) |
131 | return ERR_PTR(-ENOMEM); |
132 | |
133 | memcpy(str, *bufp, len); |
134 | str[len] = 0; |
135 | *bufp += len; |
136 | *remain -= len; |
137 | |
138 | return str; |
139 | } |
140 | |
141 | /* Translate an inode field to kernel respresentation. */ |
142 | static inline int audit_to_inode(struct audit_krule *krule, |
143 | struct audit_field *f) |
144 | { |
145 | if (krule->listnr != AUDIT_FILTER_EXIT || |
146 | krule->watch || krule->inode_f || krule->tree || |
147 | (f->op != Audit_equal && f->op != Audit_not_equal)) |
148 | return -EINVAL; |
149 | |
150 | krule->inode_f = f; |
151 | return 0; |
152 | } |
153 | |
154 | static __u32 *classes[AUDIT_SYSCALL_CLASSES]; |
155 | |
156 | int __init audit_register_class(int class, unsigned *list) |
157 | { |
158 | __u32 *p = kzalloc(AUDIT_BITMASK_SIZE * sizeof(__u32), GFP_KERNEL); |
159 | if (!p) |
160 | return -ENOMEM; |
161 | while (*list != ~0U) { |
162 | unsigned n = *list++; |
163 | if (n >= AUDIT_BITMASK_SIZE * 32 - AUDIT_SYSCALL_CLASSES) { |
164 | kfree(p); |
165 | return -EINVAL; |
166 | } |
167 | p[AUDIT_WORD(n)] |= AUDIT_BIT(n); |
168 | } |
169 | if (class >= AUDIT_SYSCALL_CLASSES || classes[class]) { |
170 | kfree(p); |
171 | return -EINVAL; |
172 | } |
173 | classes[class] = p; |
174 | return 0; |
175 | } |
176 | |
177 | int audit_match_class(int class, unsigned syscall) |
178 | { |
179 | if (unlikely(syscall >= AUDIT_BITMASK_SIZE * 32)) |
180 | return 0; |
181 | if (unlikely(class >= AUDIT_SYSCALL_CLASSES || !classes[class])) |
182 | return 0; |
183 | return classes[class][AUDIT_WORD(syscall)] & AUDIT_BIT(syscall); |
184 | } |
185 | |
186 | #ifdef CONFIG_AUDITSYSCALL |
187 | static inline int audit_match_class_bits(int class, u32 *mask) |
188 | { |
189 | int i; |
190 | |
191 | if (classes[class]) { |
192 | for (i = 0; i < AUDIT_BITMASK_SIZE; i++) |
193 | if (mask[i] & classes[class][i]) |
194 | return 0; |
195 | } |
196 | return 1; |
197 | } |
198 | |
199 | static int audit_match_signal(struct audit_entry *entry) |
200 | { |
201 | struct audit_field *arch = entry->rule.arch_f; |
202 | |
203 | if (!arch) { |
204 | /* When arch is unspecified, we must check both masks on biarch |
205 | * as syscall number alone is ambiguous. */ |
206 | return (audit_match_class_bits(AUDIT_CLASS_SIGNAL, |
207 | entry->rule.mask) && |
208 | audit_match_class_bits(AUDIT_CLASS_SIGNAL_32, |
209 | entry->rule.mask)); |
210 | } |
211 | |
212 | switch(audit_classify_arch(arch->val)) { |
213 | case 0: /* native */ |
214 | return (audit_match_class_bits(AUDIT_CLASS_SIGNAL, |
215 | entry->rule.mask)); |
216 | case 1: /* 32bit on biarch */ |
217 | return (audit_match_class_bits(AUDIT_CLASS_SIGNAL_32, |
218 | entry->rule.mask)); |
219 | default: |
220 | return 1; |
221 | } |
222 | } |
223 | #endif |
224 | |
225 | /* Common user-space to kernel rule translation. */ |
226 | static inline struct audit_entry *audit_to_entry_common(struct audit_rule *rule) |
227 | { |
228 | unsigned listnr; |
229 | struct audit_entry *entry; |
230 | int i, err; |
231 | |
232 | err = -EINVAL; |
233 | listnr = rule->flags & ~AUDIT_FILTER_PREPEND; |
234 | switch(listnr) { |
235 | default: |
236 | goto exit_err; |
237 | case AUDIT_FILTER_USER: |
238 | case AUDIT_FILTER_TYPE: |
239 | #ifdef CONFIG_AUDITSYSCALL |
240 | case AUDIT_FILTER_ENTRY: |
241 | case AUDIT_FILTER_EXIT: |
242 | case AUDIT_FILTER_TASK: |
243 | #endif |
244 | ; |
245 | } |
246 | if (unlikely(rule->action == AUDIT_POSSIBLE)) { |
247 | printk(KERN_ERR "AUDIT_POSSIBLE is deprecated\n"); |
248 | goto exit_err; |
249 | } |
250 | if (rule->action != AUDIT_NEVER && rule->action != AUDIT_ALWAYS) |
251 | goto exit_err; |
252 | if (rule->field_count > AUDIT_MAX_FIELDS) |
253 | goto exit_err; |
254 | |
255 | err = -ENOMEM; |
256 | entry = audit_init_entry(rule->field_count); |
257 | if (!entry) |
258 | goto exit_err; |
259 | |
260 | entry->rule.flags = rule->flags & AUDIT_FILTER_PREPEND; |
261 | entry->rule.listnr = listnr; |
262 | entry->rule.action = rule->action; |
263 | entry->rule.field_count = rule->field_count; |
264 | |
265 | for (i = 0; i < AUDIT_BITMASK_SIZE; i++) |
266 | entry->rule.mask[i] = rule->mask[i]; |
267 | |
268 | for (i = 0; i < AUDIT_SYSCALL_CLASSES; i++) { |
269 | int bit = AUDIT_BITMASK_SIZE * 32 - i - 1; |
270 | __u32 *p = &entry->rule.mask[AUDIT_WORD(bit)]; |
271 | __u32 *class; |
272 | |
273 | if (!(*p & AUDIT_BIT(bit))) |
274 | continue; |
275 | *p &= ~AUDIT_BIT(bit); |
276 | class = classes[i]; |
277 | if (class) { |
278 | int j; |
279 | for (j = 0; j < AUDIT_BITMASK_SIZE; j++) |
280 | entry->rule.mask[j] |= class[j]; |
281 | } |
282 | } |
283 | |
284 | return entry; |
285 | |
286 | exit_err: |
287 | return ERR_PTR(err); |
288 | } |
289 | |
290 | static u32 audit_ops[] = |
291 | { |
292 | [Audit_equal] = AUDIT_EQUAL, |
293 | [Audit_not_equal] = AUDIT_NOT_EQUAL, |
294 | [Audit_bitmask] = AUDIT_BIT_MASK, |
295 | [Audit_bittest] = AUDIT_BIT_TEST, |
296 | [Audit_lt] = AUDIT_LESS_THAN, |
297 | [Audit_gt] = AUDIT_GREATER_THAN, |
298 | [Audit_le] = AUDIT_LESS_THAN_OR_EQUAL, |
299 | [Audit_ge] = AUDIT_GREATER_THAN_OR_EQUAL, |
300 | }; |
301 | |
302 | static u32 audit_to_op(u32 op) |
303 | { |
304 | u32 n; |
305 | for (n = Audit_equal; n < Audit_bad && audit_ops[n] != op; n++) |
306 | ; |
307 | return n; |
308 | } |
309 | |
310 | |
311 | /* Translate struct audit_rule to kernel's rule respresentation. |
312 | * Exists for backward compatibility with userspace. */ |
313 | static struct audit_entry *audit_rule_to_entry(struct audit_rule *rule) |
314 | { |
315 | struct audit_entry *entry; |
316 | int err = 0; |
317 | int i; |
318 | |
319 | entry = audit_to_entry_common(rule); |
320 | if (IS_ERR(entry)) |
321 | goto exit_nofree; |
322 | |
323 | for (i = 0; i < rule->field_count; i++) { |
324 | struct audit_field *f = &entry->rule.fields[i]; |
325 | u32 n; |
326 | |
327 | n = rule->fields[i] & (AUDIT_NEGATE|AUDIT_OPERATORS); |
328 | |
329 | /* Support for legacy operators where |
330 | * AUDIT_NEGATE bit signifies != and otherwise assumes == */ |
331 | if (n & AUDIT_NEGATE) |
332 | f->op = Audit_not_equal; |
333 | else if (!n) |
334 | f->op = Audit_equal; |
335 | else |
336 | f->op = audit_to_op(n); |
337 | |
338 | entry->rule.vers_ops = (n & AUDIT_OPERATORS) ? 2 : 1; |
339 | |
340 | f->type = rule->fields[i] & ~(AUDIT_NEGATE|AUDIT_OPERATORS); |
341 | f->val = rule->values[i]; |
342 | |
343 | err = -EINVAL; |
344 | if (f->op == Audit_bad) |
345 | goto exit_free; |
346 | |
347 | switch(f->type) { |
348 | default: |
349 | goto exit_free; |
350 | case AUDIT_PID: |
351 | case AUDIT_UID: |
352 | case AUDIT_EUID: |
353 | case AUDIT_SUID: |
354 | case AUDIT_FSUID: |
355 | case AUDIT_GID: |
356 | case AUDIT_EGID: |
357 | case AUDIT_SGID: |
358 | case AUDIT_FSGID: |
359 | case AUDIT_LOGINUID: |
360 | case AUDIT_PERS: |
361 | case AUDIT_MSGTYPE: |
362 | case AUDIT_PPID: |
363 | case AUDIT_DEVMAJOR: |
364 | case AUDIT_DEVMINOR: |
365 | case AUDIT_EXIT: |
366 | case AUDIT_SUCCESS: |
367 | /* bit ops are only useful on syscall args */ |
368 | if (f->op == Audit_bitmask || f->op == Audit_bittest) |
369 | goto exit_free; |
370 | break; |
371 | case AUDIT_ARG0: |
372 | case AUDIT_ARG1: |
373 | case AUDIT_ARG2: |
374 | case AUDIT_ARG3: |
375 | break; |
376 | /* arch is only allowed to be = or != */ |
377 | case AUDIT_ARCH: |
378 | if (f->op != Audit_not_equal && f->op != Audit_equal) |
379 | goto exit_free; |
380 | entry->rule.arch_f = f; |
381 | break; |
382 | case AUDIT_PERM: |
383 | if (f->val & ~15) |
384 | goto exit_free; |
385 | break; |
386 | case AUDIT_FILETYPE: |
387 | if ((f->val & ~S_IFMT) > S_IFMT) |
388 | goto exit_free; |
389 | break; |
390 | case AUDIT_INODE: |
391 | err = audit_to_inode(&entry->rule, f); |
392 | if (err) |
393 | goto exit_free; |
394 | break; |
395 | } |
396 | } |
397 | |
398 | if (entry->rule.inode_f && entry->rule.inode_f->op == Audit_not_equal) |
399 | entry->rule.inode_f = NULL; |
400 | |
401 | exit_nofree: |
402 | return entry; |
403 | |
404 | exit_free: |
405 | audit_free_rule(entry); |
406 | return ERR_PTR(err); |
407 | } |
408 | |
409 | /* Translate struct audit_rule_data to kernel's rule respresentation. */ |
410 | static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data, |
411 | size_t datasz) |
412 | { |
413 | int err = 0; |
414 | struct audit_entry *entry; |
415 | void *bufp; |
416 | size_t remain = datasz - sizeof(struct audit_rule_data); |
417 | int i; |
418 | char *str; |
419 | |
420 | entry = audit_to_entry_common((struct audit_rule *)data); |
421 | if (IS_ERR(entry)) |
422 | goto exit_nofree; |
423 | |
424 | bufp = data->buf; |
425 | entry->rule.vers_ops = 2; |
426 | for (i = 0; i < data->field_count; i++) { |
427 | struct audit_field *f = &entry->rule.fields[i]; |
428 | |
429 | err = -EINVAL; |
430 | |
431 | f->op = audit_to_op(data->fieldflags[i]); |
432 | if (f->op == Audit_bad) |
433 | goto exit_free; |
434 | |
435 | f->type = data->fields[i]; |
436 | f->val = data->values[i]; |
437 | f->lsm_str = NULL; |
438 | f->lsm_rule = NULL; |
439 | switch(f->type) { |
440 | case AUDIT_PID: |
441 | case AUDIT_UID: |
442 | case AUDIT_EUID: |
443 | case AUDIT_SUID: |
444 | case AUDIT_FSUID: |
445 | case AUDIT_GID: |
446 | case AUDIT_EGID: |
447 | case AUDIT_SGID: |
448 | case AUDIT_FSGID: |
449 | case AUDIT_LOGINUID: |
450 | case AUDIT_PERS: |
451 | case AUDIT_MSGTYPE: |
452 | case AUDIT_PPID: |
453 | case AUDIT_DEVMAJOR: |
454 | case AUDIT_DEVMINOR: |
455 | case AUDIT_EXIT: |
456 | case AUDIT_SUCCESS: |
457 | case AUDIT_ARG0: |
458 | case AUDIT_ARG1: |
459 | case AUDIT_ARG2: |
460 | case AUDIT_ARG3: |
461 | break; |
462 | case AUDIT_ARCH: |
463 | entry->rule.arch_f = f; |
464 | break; |
465 | case AUDIT_SUBJ_USER: |
466 | case AUDIT_SUBJ_ROLE: |
467 | case AUDIT_SUBJ_TYPE: |
468 | case AUDIT_SUBJ_SEN: |
469 | case AUDIT_SUBJ_CLR: |
470 | case AUDIT_OBJ_USER: |
471 | case AUDIT_OBJ_ROLE: |
472 | case AUDIT_OBJ_TYPE: |
473 | case AUDIT_OBJ_LEV_LOW: |
474 | case AUDIT_OBJ_LEV_HIGH: |
475 | str = audit_unpack_string(&bufp, &remain, f->val); |
476 | if (IS_ERR(str)) |
477 | goto exit_free; |
478 | entry->rule.buflen += f->val; |
479 | |
480 | err = security_audit_rule_init(f->type, f->op, str, |
481 | (void **)&f->lsm_rule); |
482 | /* Keep currently invalid fields around in case they |
483 | * become valid after a policy reload. */ |
484 | if (err == -EINVAL) { |
485 | printk(KERN_WARNING "audit rule for LSM " |
486 | "\'%s\' is invalid\n", str); |
487 | err = 0; |
488 | } |
489 | if (err) { |
490 | kfree(str); |
491 | goto exit_free; |
492 | } else |
493 | f->lsm_str = str; |
494 | break; |
495 | case AUDIT_WATCH: |
496 | str = audit_unpack_string(&bufp, &remain, f->val); |
497 | if (IS_ERR(str)) |
498 | goto exit_free; |
499 | entry->rule.buflen += f->val; |
500 | |
501 | err = audit_to_watch(&entry->rule, str, f->val, f->op); |
502 | if (err) { |
503 | kfree(str); |
504 | goto exit_free; |
505 | } |
506 | break; |
507 | case AUDIT_DIR: |
508 | str = audit_unpack_string(&bufp, &remain, f->val); |
509 | if (IS_ERR(str)) |
510 | goto exit_free; |
511 | entry->rule.buflen += f->val; |
512 | |
513 | err = audit_make_tree(&entry->rule, str, f->op); |
514 | kfree(str); |
515 | if (err) |
516 | goto exit_free; |
517 | break; |
518 | case AUDIT_INODE: |
519 | err = audit_to_inode(&entry->rule, f); |
520 | if (err) |
521 | goto exit_free; |
522 | break; |
523 | case AUDIT_FILTERKEY: |
524 | err = -EINVAL; |
525 | if (entry->rule.filterkey || f->val > AUDIT_MAX_KEY_LEN) |
526 | goto exit_free; |
527 | str = audit_unpack_string(&bufp, &remain, f->val); |
528 | if (IS_ERR(str)) |
529 | goto exit_free; |
530 | entry->rule.buflen += f->val; |
531 | entry->rule.filterkey = str; |
532 | break; |
533 | case AUDIT_PERM: |
534 | if (f->val & ~15) |
535 | goto exit_free; |
536 | break; |
537 | case AUDIT_FILETYPE: |
538 | if ((f->val & ~S_IFMT) > S_IFMT) |
539 | goto exit_free; |
540 | break; |
541 | default: |
542 | goto exit_free; |
543 | } |
544 | } |
545 | |
546 | if (entry->rule.inode_f && entry->rule.inode_f->op == Audit_not_equal) |
547 | entry->rule.inode_f = NULL; |
548 | |
549 | exit_nofree: |
550 | return entry; |
551 | |
552 | exit_free: |
553 | audit_free_rule(entry); |
554 | return ERR_PTR(err); |
555 | } |
556 | |
557 | /* Pack a filter field's string representation into data block. */ |
558 | static inline size_t audit_pack_string(void **bufp, const char *str) |
559 | { |
560 | size_t len = strlen(str); |
561 | |
562 | memcpy(*bufp, str, len); |
563 | *bufp += len; |
564 | |
565 | return len; |
566 | } |
567 | |
568 | /* Translate kernel rule respresentation to struct audit_rule. |
569 | * Exists for backward compatibility with userspace. */ |
570 | static struct audit_rule *audit_krule_to_rule(struct audit_krule *krule) |
571 | { |
572 | struct audit_rule *rule; |
573 | int i; |
574 | |
575 | rule = kzalloc(sizeof(*rule), GFP_KERNEL); |
576 | if (unlikely(!rule)) |
577 | return NULL; |
578 | |
579 | rule->flags = krule->flags | krule->listnr; |
580 | rule->action = krule->action; |
581 | rule->field_count = krule->field_count; |
582 | for (i = 0; i < rule->field_count; i++) { |
583 | rule->values[i] = krule->fields[i].val; |
584 | rule->fields[i] = krule->fields[i].type; |
585 | |
586 | if (krule->vers_ops == 1) { |
587 | if (krule->fields[i].op == Audit_not_equal) |
588 | rule->fields[i] |= AUDIT_NEGATE; |
589 | } else { |
590 | rule->fields[i] |= audit_ops[krule->fields[i].op]; |
591 | } |
592 | } |
593 | for (i = 0; i < AUDIT_BITMASK_SIZE; i++) rule->mask[i] = krule->mask[i]; |
594 | |
595 | return rule; |
596 | } |
597 | |
598 | /* Translate kernel rule respresentation to struct audit_rule_data. */ |
599 | static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule) |
600 | { |
601 | struct audit_rule_data *data; |
602 | void *bufp; |
603 | int i; |
604 | |
605 | data = kmalloc(sizeof(*data) + krule->buflen, GFP_KERNEL); |
606 | if (unlikely(!data)) |
607 | return NULL; |
608 | memset(data, 0, sizeof(*data)); |
609 | |
610 | data->flags = krule->flags | krule->listnr; |
611 | data->action = krule->action; |
612 | data->field_count = krule->field_count; |
613 | bufp = data->buf; |
614 | for (i = 0; i < data->field_count; i++) { |
615 | struct audit_field *f = &krule->fields[i]; |
616 | |
617 | data->fields[i] = f->type; |
618 | data->fieldflags[i] = audit_ops[f->op]; |
619 | switch(f->type) { |
620 | case AUDIT_SUBJ_USER: |
621 | case AUDIT_SUBJ_ROLE: |
622 | case AUDIT_SUBJ_TYPE: |
623 | case AUDIT_SUBJ_SEN: |
624 | case AUDIT_SUBJ_CLR: |
625 | case AUDIT_OBJ_USER: |
626 | case AUDIT_OBJ_ROLE: |
627 | case AUDIT_OBJ_TYPE: |
628 | case AUDIT_OBJ_LEV_LOW: |
629 | case AUDIT_OBJ_LEV_HIGH: |
630 | data->buflen += data->values[i] = |
631 | audit_pack_string(&bufp, f->lsm_str); |
632 | break; |
633 | case AUDIT_WATCH: |
634 | data->buflen += data->values[i] = |
635 | audit_pack_string(&bufp, |
636 | audit_watch_path(krule->watch)); |
637 | break; |
638 | case AUDIT_DIR: |
639 | data->buflen += data->values[i] = |
640 | audit_pack_string(&bufp, |
641 | audit_tree_path(krule->tree)); |
642 | break; |
643 | case AUDIT_FILTERKEY: |
644 | data->buflen += data->values[i] = |
645 | audit_pack_string(&bufp, krule->filterkey); |
646 | break; |
647 | default: |
648 | data->values[i] = f->val; |
649 | } |
650 | } |
651 | for (i = 0; i < AUDIT_BITMASK_SIZE; i++) data->mask[i] = krule->mask[i]; |
652 | |
653 | return data; |
654 | } |
655 | |
656 | /* Compare two rules in kernel format. Considered success if rules |
657 | * don't match. */ |
658 | static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b) |
659 | { |
660 | int i; |
661 | |
662 | if (a->flags != b->flags || |
663 | a->listnr != b->listnr || |
664 | a->action != b->action || |
665 | a->field_count != b->field_count) |
666 | return 1; |
667 | |
668 | for (i = 0; i < a->field_count; i++) { |
669 | if (a->fields[i].type != b->fields[i].type || |
670 | a->fields[i].op != b->fields[i].op) |
671 | return 1; |
672 | |
673 | switch(a->fields[i].type) { |
674 | case AUDIT_SUBJ_USER: |
675 | case AUDIT_SUBJ_ROLE: |
676 | case AUDIT_SUBJ_TYPE: |
677 | case AUDIT_SUBJ_SEN: |
678 | case AUDIT_SUBJ_CLR: |
679 | case AUDIT_OBJ_USER: |
680 | case AUDIT_OBJ_ROLE: |
681 | case AUDIT_OBJ_TYPE: |
682 | case AUDIT_OBJ_LEV_LOW: |
683 | case AUDIT_OBJ_LEV_HIGH: |
684 | if (strcmp(a->fields[i].lsm_str, b->fields[i].lsm_str)) |
685 | return 1; |
686 | break; |
687 | case AUDIT_WATCH: |
688 | if (strcmp(audit_watch_path(a->watch), |
689 | audit_watch_path(b->watch))) |
690 | return 1; |
691 | break; |
692 | case AUDIT_DIR: |
693 | if (strcmp(audit_tree_path(a->tree), |
694 | audit_tree_path(b->tree))) |
695 | return 1; |
696 | break; |
697 | case AUDIT_FILTERKEY: |
698 | /* both filterkeys exist based on above type compare */ |
699 | if (strcmp(a->filterkey, b->filterkey)) |
700 | return 1; |
701 | break; |
702 | default: |
703 | if (a->fields[i].val != b->fields[i].val) |
704 | return 1; |
705 | } |
706 | } |
707 | |
708 | for (i = 0; i < AUDIT_BITMASK_SIZE; i++) |
709 | if (a->mask[i] != b->mask[i]) |
710 | return 1; |
711 | |
712 | return 0; |
713 | } |
714 | |
715 | /* Duplicate LSM field information. The lsm_rule is opaque, so must be |
716 | * re-initialized. */ |
717 | static inline int audit_dupe_lsm_field(struct audit_field *df, |
718 | struct audit_field *sf) |
719 | { |
720 | int ret = 0; |
721 | char *lsm_str; |
722 | |
723 | /* our own copy of lsm_str */ |
724 | lsm_str = kstrdup(sf->lsm_str, GFP_KERNEL); |
725 | if (unlikely(!lsm_str)) |
726 | return -ENOMEM; |
727 | df->lsm_str = lsm_str; |
728 | |
729 | /* our own (refreshed) copy of lsm_rule */ |
730 | ret = security_audit_rule_init(df->type, df->op, df->lsm_str, |
731 | (void **)&df->lsm_rule); |
732 | /* Keep currently invalid fields around in case they |
733 | * become valid after a policy reload. */ |
734 | if (ret == -EINVAL) { |
735 | printk(KERN_WARNING "audit rule for LSM \'%s\' is " |
736 | "invalid\n", df->lsm_str); |
737 | ret = 0; |
738 | } |
739 | |
740 | return ret; |
741 | } |
742 | |
743 | /* Duplicate an audit rule. This will be a deep copy with the exception |
744 | * of the watch - that pointer is carried over. The LSM specific fields |
745 | * will be updated in the copy. The point is to be able to replace the old |
746 | * rule with the new rule in the filterlist, then free the old rule. |
747 | * The rlist element is undefined; list manipulations are handled apart from |
748 | * the initial copy. */ |
749 | struct audit_entry *audit_dupe_rule(struct audit_krule *old, |
750 | struct audit_watch *watch) |
751 | { |
752 | u32 fcount = old->field_count; |
753 | struct audit_entry *entry; |
754 | struct audit_krule *new; |
755 | char *fk; |
756 | int i, err = 0; |
757 | |
758 | entry = audit_init_entry(fcount); |
759 | if (unlikely(!entry)) |
760 | return ERR_PTR(-ENOMEM); |
761 | |
762 | new = &entry->rule; |
763 | new->vers_ops = old->vers_ops; |
764 | new->flags = old->flags; |
765 | new->listnr = old->listnr; |
766 | new->action = old->action; |
767 | for (i = 0; i < AUDIT_BITMASK_SIZE; i++) |
768 | new->mask[i] = old->mask[i]; |
769 | new->prio = old->prio; |
770 | new->buflen = old->buflen; |
771 | new->inode_f = old->inode_f; |
772 | new->watch = NULL; |
773 | new->field_count = old->field_count; |
774 | /* |
775 | * note that we are OK with not refcounting here; audit_match_tree() |
776 | * never dereferences tree and we can't get false positives there |
777 | * since we'd have to have rule gone from the list *and* removed |
778 | * before the chunks found by lookup had been allocated, i.e. before |
779 | * the beginning of list scan. |
780 | */ |
781 | new->tree = old->tree; |
782 | memcpy(new->fields, old->fields, sizeof(struct audit_field) * fcount); |
783 | |
784 | /* deep copy this information, updating the lsm_rule fields, because |
785 | * the originals will all be freed when the old rule is freed. */ |
786 | for (i = 0; i < fcount; i++) { |
787 | switch (new->fields[i].type) { |
788 | case AUDIT_SUBJ_USER: |
789 | case AUDIT_SUBJ_ROLE: |
790 | case AUDIT_SUBJ_TYPE: |
791 | case AUDIT_SUBJ_SEN: |
792 | case AUDIT_SUBJ_CLR: |
793 | case AUDIT_OBJ_USER: |
794 | case AUDIT_OBJ_ROLE: |
795 | case AUDIT_OBJ_TYPE: |
796 | case AUDIT_OBJ_LEV_LOW: |
797 | case AUDIT_OBJ_LEV_HIGH: |
798 | err = audit_dupe_lsm_field(&new->fields[i], |
799 | &old->fields[i]); |
800 | break; |
801 | case AUDIT_FILTERKEY: |
802 | fk = kstrdup(old->filterkey, GFP_KERNEL); |
803 | if (unlikely(!fk)) |
804 | err = -ENOMEM; |
805 | else |
806 | new->filterkey = fk; |
807 | } |
808 | if (err) { |
809 | audit_free_rule(entry); |
810 | return ERR_PTR(err); |
811 | } |
812 | } |
813 | |
814 | if (watch) { |
815 | audit_get_watch(watch); |
816 | new->watch = watch; |
817 | } |
818 | |
819 | return entry; |
820 | } |
821 | |
822 | /* Find an existing audit rule. |
823 | * Caller must hold audit_filter_mutex to prevent stale rule data. */ |
824 | static struct audit_entry *audit_find_rule(struct audit_entry *entry, |
825 | struct list_head **p) |
826 | { |
827 | struct audit_entry *e, *found = NULL; |
828 | struct list_head *list; |
829 | int h; |
830 | |
831 | if (entry->rule.inode_f) { |
832 | h = audit_hash_ino(entry->rule.inode_f->val); |
833 | *p = list = &audit_inode_hash[h]; |
834 | } else if (entry->rule.watch) { |
835 | /* we don't know the inode number, so must walk entire hash */ |
836 | for (h = 0; h < AUDIT_INODE_BUCKETS; h++) { |
837 | list = &audit_inode_hash[h]; |
838 | list_for_each_entry(e, list, list) |
839 | if (!audit_compare_rule(&entry->rule, &e->rule)) { |
840 | found = e; |
841 | goto out; |
842 | } |
843 | } |
844 | goto out; |
845 | } else { |
846 | *p = list = &audit_filter_list[entry->rule.listnr]; |
847 | } |
848 | |
849 | list_for_each_entry(e, list, list) |
850 | if (!audit_compare_rule(&entry->rule, &e->rule)) { |
851 | found = e; |
852 | goto out; |
853 | } |
854 | |
855 | out: |
856 | return found; |
857 | } |
858 | |
859 | static u64 prio_low = ~0ULL/2; |
860 | static u64 prio_high = ~0ULL/2 - 1; |
861 | |
862 | /* Add rule to given filterlist if not a duplicate. */ |
863 | static inline int audit_add_rule(struct audit_entry *entry) |
864 | { |
865 | struct audit_entry *e; |
866 | struct audit_watch *watch = entry->rule.watch; |
867 | struct audit_tree *tree = entry->rule.tree; |
868 | struct list_head *list; |
869 | int h, err; |
870 | #ifdef CONFIG_AUDITSYSCALL |
871 | int dont_count = 0; |
872 | |
873 | /* If either of these, don't count towards total */ |
874 | if (entry->rule.listnr == AUDIT_FILTER_USER || |
875 | entry->rule.listnr == AUDIT_FILTER_TYPE) |
876 | dont_count = 1; |
877 | #endif |
878 | |
879 | mutex_lock(&audit_filter_mutex); |
880 | e = audit_find_rule(entry, &list); |
881 | if (e) { |
882 | mutex_unlock(&audit_filter_mutex); |
883 | err = -EEXIST; |
884 | /* normally audit_add_tree_rule() will free it on failure */ |
885 | if (tree) |
886 | audit_put_tree(tree); |
887 | goto error; |
888 | } |
889 | |
890 | if (watch) { |
891 | /* audit_filter_mutex is dropped and re-taken during this call */ |
892 | err = audit_add_watch(&entry->rule); |
893 | if (err) { |
894 | mutex_unlock(&audit_filter_mutex); |
895 | goto error; |
896 | } |
897 | /* entry->rule.watch may have changed during audit_add_watch() */ |
898 | watch = entry->rule.watch; |
899 | h = audit_hash_ino((u32)audit_watch_inode(watch)); |
900 | list = &audit_inode_hash[h]; |
901 | } |
902 | if (tree) { |
903 | err = audit_add_tree_rule(&entry->rule); |
904 | if (err) { |
905 | mutex_unlock(&audit_filter_mutex); |
906 | goto error; |
907 | } |
908 | } |
909 | |
910 | entry->rule.prio = ~0ULL; |
911 | if (entry->rule.listnr == AUDIT_FILTER_EXIT) { |
912 | if (entry->rule.flags & AUDIT_FILTER_PREPEND) |
913 | entry->rule.prio = ++prio_high; |
914 | else |
915 | entry->rule.prio = --prio_low; |
916 | } |
917 | |
918 | if (entry->rule.flags & AUDIT_FILTER_PREPEND) { |
919 | list_add(&entry->rule.list, |
920 | &audit_rules_list[entry->rule.listnr]); |
921 | list_add_rcu(&entry->list, list); |
922 | entry->rule.flags &= ~AUDIT_FILTER_PREPEND; |
923 | } else { |
924 | list_add_tail(&entry->rule.list, |
925 | &audit_rules_list[entry->rule.listnr]); |
926 | list_add_tail_rcu(&entry->list, list); |
927 | } |
928 | #ifdef CONFIG_AUDITSYSCALL |
929 | if (!dont_count) |
930 | audit_n_rules++; |
931 | |
932 | if (!audit_match_signal(entry)) |
933 | audit_signals++; |
934 | #endif |
935 | mutex_unlock(&audit_filter_mutex); |
936 | |
937 | return 0; |
938 | |
939 | error: |
940 | if (watch) |
941 | audit_put_watch(watch); /* tmp watch, matches initial get */ |
942 | return err; |
943 | } |
944 | |
945 | /* Remove an existing rule from filterlist. */ |
946 | static inline int audit_del_rule(struct audit_entry *entry) |
947 | { |
948 | struct audit_entry *e; |
949 | struct audit_watch *watch = entry->rule.watch; |
950 | struct audit_tree *tree = entry->rule.tree; |
951 | struct list_head *list; |
952 | LIST_HEAD(inotify_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 | mutex_lock(&audit_filter_mutex); |
964 | e = audit_find_rule(entry, &list); |
965 | if (!e) { |
966 | mutex_unlock(&audit_filter_mutex); |
967 | ret = -ENOENT; |
968 | goto out; |
969 | } |
970 | |
971 | if (e->rule.watch) |
972 | audit_remove_watch_rule(&e->rule, &inotify_list); |
973 | |
974 | 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 | 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 | mutex_unlock(&audit_filter_mutex); |
989 | |
990 | if (!list_empty(&inotify_list)) |
991 | audit_inotify_unregister(&inotify_list); |
992 | |
993 | out: |
994 | if (watch) |
995 | audit_put_watch(watch); /* match initial get */ |
996 | if (tree) |
997 | audit_put_tree(tree); /* that's the temporary one */ |
998 | |
999 | return ret; |
1000 | } |
1001 | |
1002 | /* List rules using struct audit_rule. Exists for backward |
1003 | * compatibility with userspace. */ |
1004 | static void audit_list(int pid, int seq, struct sk_buff_head *q) |
1005 | { |
1006 | struct sk_buff *skb; |
1007 | struct audit_krule *r; |
1008 | int i; |
1009 | |
1010 | /* This is a blocking read, so use audit_filter_mutex instead of rcu |
1011 | * iterator to sync with list writers. */ |
1012 | for (i=0; i<AUDIT_NR_FILTERS; i++) { |
1013 | list_for_each_entry(r, &audit_rules_list[i], list) { |
1014 | struct audit_rule *rule; |
1015 | |
1016 | rule = audit_krule_to_rule(r); |
1017 | if (unlikely(!rule)) |
1018 | break; |
1019 | skb = audit_make_reply(pid, seq, AUDIT_LIST, 0, 1, |
1020 | rule, sizeof(*rule)); |
1021 | if (skb) |
1022 | skb_queue_tail(q, skb); |
1023 | kfree(rule); |
1024 | } |
1025 | } |
1026 | skb = audit_make_reply(pid, seq, AUDIT_LIST, 1, 1, NULL, 0); |
1027 | if (skb) |
1028 | skb_queue_tail(q, skb); |
1029 | } |
1030 | |
1031 | /* List rules using struct audit_rule_data. */ |
1032 | static void audit_list_rules(int pid, int seq, struct sk_buff_head *q) |
1033 | { |
1034 | struct sk_buff *skb; |
1035 | struct audit_krule *r; |
1036 | int i; |
1037 | |
1038 | /* This is a blocking read, so use audit_filter_mutex instead of rcu |
1039 | * iterator to sync with list writers. */ |
1040 | for (i=0; i<AUDIT_NR_FILTERS; i++) { |
1041 | list_for_each_entry(r, &audit_rules_list[i], list) { |
1042 | struct audit_rule_data *data; |
1043 | |
1044 | data = audit_krule_to_data(r); |
1045 | if (unlikely(!data)) |
1046 | break; |
1047 | skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 0, 1, |
1048 | data, sizeof(*data) + data->buflen); |
1049 | if (skb) |
1050 | skb_queue_tail(q, skb); |
1051 | kfree(data); |
1052 | } |
1053 | } |
1054 | skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 1, 1, NULL, 0); |
1055 | if (skb) |
1056 | skb_queue_tail(q, skb); |
1057 | } |
1058 | |
1059 | /* Log rule additions and removals */ |
1060 | static void audit_log_rule_change(uid_t loginuid, u32 sessionid, u32 sid, |
1061 | char *action, struct audit_krule *rule, |
1062 | int res) |
1063 | { |
1064 | struct audit_buffer *ab; |
1065 | |
1066 | if (!audit_enabled) |
1067 | return; |
1068 | |
1069 | ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE); |
1070 | if (!ab) |
1071 | return; |
1072 | audit_log_format(ab, "auid=%u ses=%u", loginuid, sessionid); |
1073 | if (sid) { |
1074 | char *ctx = NULL; |
1075 | u32 len; |
1076 | if (security_secid_to_secctx(sid, &ctx, &len)) |
1077 | audit_log_format(ab, " ssid=%u", sid); |
1078 | else { |
1079 | audit_log_format(ab, " subj=%s", ctx); |
1080 | security_release_secctx(ctx, len); |
1081 | } |
1082 | } |
1083 | audit_log_format(ab, " op="); |
1084 | audit_log_string(ab, action); |
1085 | audit_log_key(ab, rule->filterkey); |
1086 | audit_log_format(ab, " list=%d res=%d", rule->listnr, res); |
1087 | audit_log_end(ab); |
1088 | } |
1089 | |
1090 | /** |
1091 | * audit_receive_filter - apply all rules to the specified message type |
1092 | * @type: audit message type |
1093 | * @pid: target pid for netlink audit messages |
1094 | * @uid: target uid for netlink audit messages |
1095 | * @seq: netlink audit message sequence (serial) number |
1096 | * @data: payload data |
1097 | * @datasz: size of payload data |
1098 | * @loginuid: loginuid of sender |
1099 | * @sessionid: sessionid for netlink audit message |
1100 | * @sid: SE Linux Security ID of sender |
1101 | */ |
1102 | int audit_receive_filter(int type, int pid, int uid, int seq, void *data, |
1103 | size_t datasz, uid_t loginuid, u32 sessionid, u32 sid) |
1104 | { |
1105 | struct task_struct *tsk; |
1106 | struct audit_netlink_list *dest; |
1107 | int err = 0; |
1108 | struct audit_entry *entry; |
1109 | |
1110 | switch (type) { |
1111 | case AUDIT_LIST: |
1112 | case AUDIT_LIST_RULES: |
1113 | /* We can't just spew out the rules here because we might fill |
1114 | * the available socket buffer space and deadlock waiting for |
1115 | * auditctl to read from it... which isn't ever going to |
1116 | * happen if we're actually running in the context of auditctl |
1117 | * trying to _send_ the stuff */ |
1118 | |
1119 | dest = kmalloc(sizeof(struct audit_netlink_list), GFP_KERNEL); |
1120 | if (!dest) |
1121 | return -ENOMEM; |
1122 | dest->pid = pid; |
1123 | skb_queue_head_init(&dest->q); |
1124 | |
1125 | mutex_lock(&audit_filter_mutex); |
1126 | if (type == AUDIT_LIST) |
1127 | audit_list(pid, seq, &dest->q); |
1128 | else |
1129 | audit_list_rules(pid, seq, &dest->q); |
1130 | mutex_unlock(&audit_filter_mutex); |
1131 | |
1132 | tsk = kthread_run(audit_send_list, dest, "audit_send_list"); |
1133 | if (IS_ERR(tsk)) { |
1134 | skb_queue_purge(&dest->q); |
1135 | kfree(dest); |
1136 | err = PTR_ERR(tsk); |
1137 | } |
1138 | break; |
1139 | case AUDIT_ADD: |
1140 | case AUDIT_ADD_RULE: |
1141 | if (type == AUDIT_ADD) |
1142 | entry = audit_rule_to_entry(data); |
1143 | else |
1144 | entry = audit_data_to_entry(data, datasz); |
1145 | if (IS_ERR(entry)) |
1146 | return PTR_ERR(entry); |
1147 | |
1148 | err = audit_add_rule(entry); |
1149 | audit_log_rule_change(loginuid, sessionid, sid, "add rule", |
1150 | &entry->rule, !err); |
1151 | |
1152 | if (err) |
1153 | audit_free_rule(entry); |
1154 | break; |
1155 | case AUDIT_DEL: |
1156 | case AUDIT_DEL_RULE: |
1157 | if (type == AUDIT_DEL) |
1158 | entry = audit_rule_to_entry(data); |
1159 | else |
1160 | entry = audit_data_to_entry(data, datasz); |
1161 | if (IS_ERR(entry)) |
1162 | return PTR_ERR(entry); |
1163 | |
1164 | err = audit_del_rule(entry); |
1165 | audit_log_rule_change(loginuid, sessionid, sid, "remove rule", |
1166 | &entry->rule, !err); |
1167 | |
1168 | audit_free_rule(entry); |
1169 | break; |
1170 | default: |
1171 | return -EINVAL; |
1172 | } |
1173 | |
1174 | return err; |
1175 | } |
1176 | |
1177 | int audit_comparator(u32 left, u32 op, u32 right) |
1178 | { |
1179 | switch (op) { |
1180 | case Audit_equal: |
1181 | return (left == right); |
1182 | case Audit_not_equal: |
1183 | return (left != right); |
1184 | case Audit_lt: |
1185 | return (left < right); |
1186 | case Audit_le: |
1187 | return (left <= right); |
1188 | case Audit_gt: |
1189 | return (left > right); |
1190 | case Audit_ge: |
1191 | return (left >= right); |
1192 | case Audit_bitmask: |
1193 | return (left & right); |
1194 | case Audit_bittest: |
1195 | return ((left & right) == right); |
1196 | default: |
1197 | BUG(); |
1198 | return 0; |
1199 | } |
1200 | } |
1201 | |
1202 | /* Compare given dentry name with last component in given path, |
1203 | * return of 0 indicates a match. */ |
1204 | int audit_compare_dname_path(const char *dname, const char *path, |
1205 | int *dirlen) |
1206 | { |
1207 | int dlen, plen; |
1208 | const char *p; |
1209 | |
1210 | if (!dname || !path) |
1211 | return 1; |
1212 | |
1213 | dlen = strlen(dname); |
1214 | plen = strlen(path); |
1215 | if (plen < dlen) |
1216 | return 1; |
1217 | |
1218 | /* disregard trailing slashes */ |
1219 | p = path + plen - 1; |
1220 | while ((*p == '/') && (p > path)) |
1221 | p--; |
1222 | |
1223 | /* find last path component */ |
1224 | p = p - dlen + 1; |
1225 | if (p < path) |
1226 | return 1; |
1227 | else if (p > path) { |
1228 | if (*--p != '/') |
1229 | return 1; |
1230 | else |
1231 | p++; |
1232 | } |
1233 | |
1234 | /* return length of path's directory component */ |
1235 | if (dirlen) |
1236 | *dirlen = p - path; |
1237 | return strncmp(p, dname, dlen); |
1238 | } |
1239 | |
1240 | static int audit_filter_user_rules(struct netlink_skb_parms *cb, |
1241 | struct audit_krule *rule, |
1242 | enum audit_state *state) |
1243 | { |
1244 | int i; |
1245 | |
1246 | for (i = 0; i < rule->field_count; i++) { |
1247 | struct audit_field *f = &rule->fields[i]; |
1248 | int result = 0; |
1249 | |
1250 | switch (f->type) { |
1251 | case AUDIT_PID: |
1252 | result = audit_comparator(cb->creds.pid, f->op, f->val); |
1253 | break; |
1254 | case AUDIT_UID: |
1255 | result = audit_comparator(cb->creds.uid, f->op, f->val); |
1256 | break; |
1257 | case AUDIT_GID: |
1258 | result = audit_comparator(cb->creds.gid, f->op, f->val); |
1259 | break; |
1260 | case AUDIT_LOGINUID: |
1261 | result = audit_comparator(cb->loginuid, f->op, f->val); |
1262 | break; |
1263 | } |
1264 | |
1265 | if (!result) |
1266 | return 0; |
1267 | } |
1268 | switch (rule->action) { |
1269 | case AUDIT_NEVER: *state = AUDIT_DISABLED; break; |
1270 | case AUDIT_ALWAYS: *state = AUDIT_RECORD_CONTEXT; break; |
1271 | } |
1272 | return 1; |
1273 | } |
1274 | |
1275 | int audit_filter_user(struct netlink_skb_parms *cb) |
1276 | { |
1277 | enum audit_state state = AUDIT_DISABLED; |
1278 | struct audit_entry *e; |
1279 | int ret = 1; |
1280 | |
1281 | rcu_read_lock(); |
1282 | list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_USER], list) { |
1283 | if (audit_filter_user_rules(cb, &e->rule, &state)) { |
1284 | if (state == AUDIT_DISABLED) |
1285 | ret = 0; |
1286 | break; |
1287 | } |
1288 | } |
1289 | rcu_read_unlock(); |
1290 | |
1291 | return ret; /* Audit by default */ |
1292 | } |
1293 | |
1294 | int audit_filter_type(int type) |
1295 | { |
1296 | struct audit_entry *e; |
1297 | int result = 0; |
1298 | |
1299 | rcu_read_lock(); |
1300 | if (list_empty(&audit_filter_list[AUDIT_FILTER_TYPE])) |
1301 | goto unlock_and_return; |
1302 | |
1303 | list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_TYPE], |
1304 | list) { |
1305 | int i; |
1306 | for (i = 0; i < e->rule.field_count; i++) { |
1307 | struct audit_field *f = &e->rule.fields[i]; |
1308 | if (f->type == AUDIT_MSGTYPE) { |
1309 | result = audit_comparator(type, f->op, f->val); |
1310 | if (!result) |
1311 | break; |
1312 | } |
1313 | } |
1314 | if (result) |
1315 | goto unlock_and_return; |
1316 | } |
1317 | unlock_and_return: |
1318 | rcu_read_unlock(); |
1319 | return result; |
1320 | } |
1321 | |
1322 | static int update_lsm_rule(struct audit_krule *r) |
1323 | { |
1324 | struct audit_entry *entry = container_of(r, struct audit_entry, rule); |
1325 | struct audit_entry *nentry; |
1326 | struct audit_watch *watch; |
1327 | struct audit_tree *tree; |
1328 | int err = 0; |
1329 | |
1330 | if (!security_audit_rule_known(r)) |
1331 | return 0; |
1332 | |
1333 | watch = r->watch; |
1334 | tree = r->tree; |
1335 | nentry = audit_dupe_rule(r, watch); |
1336 | if (IS_ERR(nentry)) { |
1337 | /* save the first error encountered for the |
1338 | * return value */ |
1339 | err = PTR_ERR(nentry); |
1340 | audit_panic("error updating LSM filters"); |
1341 | if (watch) |
1342 | list_del(&r->rlist); |
1343 | list_del_rcu(&entry->list); |
1344 | list_del(&r->list); |
1345 | } else { |
1346 | if (watch) { |
1347 | list_add(&nentry->rule.rlist, audit_watch_rules(watch)); |
1348 | list_del(&r->rlist); |
1349 | } else if (tree) |
1350 | list_replace_init(&r->rlist, &nentry->rule.rlist); |
1351 | list_replace_rcu(&entry->list, &nentry->list); |
1352 | list_replace(&r->list, &nentry->rule.list); |
1353 | } |
1354 | call_rcu(&entry->rcu, audit_free_rule_rcu); |
1355 | |
1356 | return err; |
1357 | } |
1358 | |
1359 | /* This function will re-initialize the lsm_rule field of all applicable rules. |
1360 | * It will traverse the filter lists serarching for rules that contain LSM |
1361 | * specific filter fields. When such a rule is found, it is copied, the |
1362 | * LSM field is re-initialized, and the old rule is replaced with the |
1363 | * updated rule. */ |
1364 | int audit_update_lsm_rules(void) |
1365 | { |
1366 | struct audit_krule *r, *n; |
1367 | int i, err = 0; |
1368 | |
1369 | /* audit_filter_mutex synchronizes the writers */ |
1370 | mutex_lock(&audit_filter_mutex); |
1371 | |
1372 | for (i = 0; i < AUDIT_NR_FILTERS; i++) { |
1373 | list_for_each_entry_safe(r, n, &audit_rules_list[i], list) { |
1374 | int res = update_lsm_rule(r); |
1375 | if (!err) |
1376 | err = res; |
1377 | } |
1378 | } |
1379 | mutex_unlock(&audit_filter_mutex); |
1380 | |
1381 | return err; |
1382 | } |
1383 |
Branches:
ben-wpan
ben-wpan-stefan
javiroman/ks7010
jz-2.6.34
jz-2.6.34-rc5
jz-2.6.34-rc6
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jz-3.9-rc8
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jz47xx-2.6.38
master
Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9