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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 | |
75 | /* some rules don't have associated watches */ |
76 | if (erule->watch) |
77 | audit_put_watch(erule->watch); |
78 | if (erule->fields) |
79 | for (i = 0; i < erule->field_count; i++) { |
80 | struct audit_field *f = &erule->fields[i]; |
81 | kfree(f->lsm_str); |
82 | security_audit_rule_free(f->lsm_rule); |
83 | } |
84 | kfree(erule->fields); |
85 | kfree(erule->filterkey); |
86 | kfree(e); |
87 | } |
88 | |
89 | void audit_free_rule_rcu(struct rcu_head *head) |
90 | { |
91 | struct audit_entry *e = container_of(head, struct audit_entry, rcu); |
92 | audit_free_rule(e); |
93 | } |
94 | |
95 | /* Initialize an audit filterlist entry. */ |
96 | static inline struct audit_entry *audit_init_entry(u32 field_count) |
97 | { |
98 | struct audit_entry *entry; |
99 | struct audit_field *fields; |
100 | |
101 | entry = kzalloc(sizeof(*entry), GFP_KERNEL); |
102 | if (unlikely(!entry)) |
103 | return NULL; |
104 | |
105 | fields = kzalloc(sizeof(*fields) * field_count, GFP_KERNEL); |
106 | if (unlikely(!fields)) { |
107 | kfree(entry); |
108 | return NULL; |
109 | } |
110 | entry->rule.fields = fields; |
111 | |
112 | return entry; |
113 | } |
114 | |
115 | /* Unpack a filter field's string representation from user-space |
116 | * buffer. */ |
117 | char *audit_unpack_string(void **bufp, size_t *remain, size_t len) |
118 | { |
119 | char *str; |
120 | |
121 | if (!*bufp || (len == 0) || (len > *remain)) |
122 | return ERR_PTR(-EINVAL); |
123 | |
124 | /* Of the currently implemented string fields, PATH_MAX |
125 | * defines the longest valid length. |
126 | */ |
127 | if (len > PATH_MAX) |
128 | return ERR_PTR(-ENAMETOOLONG); |
129 | |
130 | str = kmalloc(len + 1, GFP_KERNEL); |
131 | if (unlikely(!str)) |
132 | return ERR_PTR(-ENOMEM); |
133 | |
134 | memcpy(str, *bufp, len); |
135 | str[len] = 0; |
136 | *bufp += len; |
137 | *remain -= len; |
138 | |
139 | return str; |
140 | } |
141 | |
142 | /* Translate an inode field to kernel respresentation. */ |
143 | static inline int audit_to_inode(struct audit_krule *krule, |
144 | struct audit_field *f) |
145 | { |
146 | if (krule->listnr != AUDIT_FILTER_EXIT || |
147 | krule->watch || krule->inode_f || krule->tree || |
148 | (f->op != Audit_equal && f->op != Audit_not_equal)) |
149 | return -EINVAL; |
150 | |
151 | krule->inode_f = f; |
152 | return 0; |
153 | } |
154 | |
155 | static __u32 *classes[AUDIT_SYSCALL_CLASSES]; |
156 | |
157 | int __init audit_register_class(int class, unsigned *list) |
158 | { |
159 | __u32 *p = kzalloc(AUDIT_BITMASK_SIZE * sizeof(__u32), GFP_KERNEL); |
160 | if (!p) |
161 | return -ENOMEM; |
162 | while (*list != ~0U) { |
163 | unsigned n = *list++; |
164 | if (n >= AUDIT_BITMASK_SIZE * 32 - AUDIT_SYSCALL_CLASSES) { |
165 | kfree(p); |
166 | return -EINVAL; |
167 | } |
168 | p[AUDIT_WORD(n)] |= AUDIT_BIT(n); |
169 | } |
170 | if (class >= AUDIT_SYSCALL_CLASSES || classes[class]) { |
171 | kfree(p); |
172 | return -EINVAL; |
173 | } |
174 | classes[class] = p; |
175 | return 0; |
176 | } |
177 | |
178 | int audit_match_class(int class, unsigned syscall) |
179 | { |
180 | if (unlikely(syscall >= AUDIT_BITMASK_SIZE * 32)) |
181 | return 0; |
182 | if (unlikely(class >= AUDIT_SYSCALL_CLASSES || !classes[class])) |
183 | return 0; |
184 | return classes[class][AUDIT_WORD(syscall)] & AUDIT_BIT(syscall); |
185 | } |
186 | |
187 | #ifdef CONFIG_AUDITSYSCALL |
188 | static inline int audit_match_class_bits(int class, u32 *mask) |
189 | { |
190 | int i; |
191 | |
192 | if (classes[class]) { |
193 | for (i = 0; i < AUDIT_BITMASK_SIZE; i++) |
194 | if (mask[i] & classes[class][i]) |
195 | return 0; |
196 | } |
197 | return 1; |
198 | } |
199 | |
200 | static int audit_match_signal(struct audit_entry *entry) |
201 | { |
202 | struct audit_field *arch = entry->rule.arch_f; |
203 | |
204 | if (!arch) { |
205 | /* When arch is unspecified, we must check both masks on biarch |
206 | * as syscall number alone is ambiguous. */ |
207 | return (audit_match_class_bits(AUDIT_CLASS_SIGNAL, |
208 | entry->rule.mask) && |
209 | audit_match_class_bits(AUDIT_CLASS_SIGNAL_32, |
210 | entry->rule.mask)); |
211 | } |
212 | |
213 | switch(audit_classify_arch(arch->val)) { |
214 | case 0: /* native */ |
215 | return (audit_match_class_bits(AUDIT_CLASS_SIGNAL, |
216 | entry->rule.mask)); |
217 | case 1: /* 32bit on biarch */ |
218 | return (audit_match_class_bits(AUDIT_CLASS_SIGNAL_32, |
219 | entry->rule.mask)); |
220 | default: |
221 | return 1; |
222 | } |
223 | } |
224 | #endif |
225 | |
226 | /* Common user-space to kernel rule translation. */ |
227 | static inline struct audit_entry *audit_to_entry_common(struct audit_rule *rule) |
228 | { |
229 | unsigned listnr; |
230 | struct audit_entry *entry; |
231 | int i, err; |
232 | |
233 | err = -EINVAL; |
234 | listnr = rule->flags & ~AUDIT_FILTER_PREPEND; |
235 | switch(listnr) { |
236 | default: |
237 | goto exit_err; |
238 | #ifdef CONFIG_AUDITSYSCALL |
239 | case AUDIT_FILTER_ENTRY: |
240 | if (rule->action == AUDIT_ALWAYS) |
241 | goto exit_err; |
242 | case AUDIT_FILTER_EXIT: |
243 | case AUDIT_FILTER_TASK: |
244 | #endif |
245 | case AUDIT_FILTER_USER: |
246 | case AUDIT_FILTER_TYPE: |
247 | ; |
248 | } |
249 | if (unlikely(rule->action == AUDIT_POSSIBLE)) { |
250 | printk(KERN_ERR "AUDIT_POSSIBLE is deprecated\n"); |
251 | goto exit_err; |
252 | } |
253 | if (rule->action != AUDIT_NEVER && rule->action != AUDIT_ALWAYS) |
254 | goto exit_err; |
255 | if (rule->field_count > AUDIT_MAX_FIELDS) |
256 | goto exit_err; |
257 | |
258 | err = -ENOMEM; |
259 | entry = audit_init_entry(rule->field_count); |
260 | if (!entry) |
261 | goto exit_err; |
262 | |
263 | entry->rule.flags = rule->flags & AUDIT_FILTER_PREPEND; |
264 | entry->rule.listnr = listnr; |
265 | entry->rule.action = rule->action; |
266 | entry->rule.field_count = rule->field_count; |
267 | |
268 | for (i = 0; i < AUDIT_BITMASK_SIZE; i++) |
269 | entry->rule.mask[i] = rule->mask[i]; |
270 | |
271 | for (i = 0; i < AUDIT_SYSCALL_CLASSES; i++) { |
272 | int bit = AUDIT_BITMASK_SIZE * 32 - i - 1; |
273 | __u32 *p = &entry->rule.mask[AUDIT_WORD(bit)]; |
274 | __u32 *class; |
275 | |
276 | if (!(*p & AUDIT_BIT(bit))) |
277 | continue; |
278 | *p &= ~AUDIT_BIT(bit); |
279 | class = classes[i]; |
280 | if (class) { |
281 | int j; |
282 | for (j = 0; j < AUDIT_BITMASK_SIZE; j++) |
283 | entry->rule.mask[j] |= class[j]; |
284 | } |
285 | } |
286 | |
287 | return entry; |
288 | |
289 | exit_err: |
290 | return ERR_PTR(err); |
291 | } |
292 | |
293 | static u32 audit_ops[] = |
294 | { |
295 | [Audit_equal] = AUDIT_EQUAL, |
296 | [Audit_not_equal] = AUDIT_NOT_EQUAL, |
297 | [Audit_bitmask] = AUDIT_BIT_MASK, |
298 | [Audit_bittest] = AUDIT_BIT_TEST, |
299 | [Audit_lt] = AUDIT_LESS_THAN, |
300 | [Audit_gt] = AUDIT_GREATER_THAN, |
301 | [Audit_le] = AUDIT_LESS_THAN_OR_EQUAL, |
302 | [Audit_ge] = AUDIT_GREATER_THAN_OR_EQUAL, |
303 | }; |
304 | |
305 | static u32 audit_to_op(u32 op) |
306 | { |
307 | u32 n; |
308 | for (n = Audit_equal; n < Audit_bad && audit_ops[n] != op; n++) |
309 | ; |
310 | return n; |
311 | } |
312 | |
313 | |
314 | /* Translate struct audit_rule to kernel's rule respresentation. |
315 | * Exists for backward compatibility with userspace. */ |
316 | static struct audit_entry *audit_rule_to_entry(struct audit_rule *rule) |
317 | { |
318 | struct audit_entry *entry; |
319 | int err = 0; |
320 | int i; |
321 | |
322 | entry = audit_to_entry_common(rule); |
323 | if (IS_ERR(entry)) |
324 | goto exit_nofree; |
325 | |
326 | for (i = 0; i < rule->field_count; i++) { |
327 | struct audit_field *f = &entry->rule.fields[i]; |
328 | u32 n; |
329 | |
330 | n = rule->fields[i] & (AUDIT_NEGATE|AUDIT_OPERATORS); |
331 | |
332 | /* Support for legacy operators where |
333 | * AUDIT_NEGATE bit signifies != and otherwise assumes == */ |
334 | if (n & AUDIT_NEGATE) |
335 | f->op = Audit_not_equal; |
336 | else if (!n) |
337 | f->op = Audit_equal; |
338 | else |
339 | f->op = audit_to_op(n); |
340 | |
341 | entry->rule.vers_ops = (n & AUDIT_OPERATORS) ? 2 : 1; |
342 | |
343 | f->type = rule->fields[i] & ~(AUDIT_NEGATE|AUDIT_OPERATORS); |
344 | f->val = rule->values[i]; |
345 | |
346 | err = -EINVAL; |
347 | if (f->op == Audit_bad) |
348 | goto exit_free; |
349 | |
350 | switch(f->type) { |
351 | default: |
352 | goto exit_free; |
353 | case AUDIT_PID: |
354 | case AUDIT_UID: |
355 | case AUDIT_EUID: |
356 | case AUDIT_SUID: |
357 | case AUDIT_FSUID: |
358 | case AUDIT_GID: |
359 | case AUDIT_EGID: |
360 | case AUDIT_SGID: |
361 | case AUDIT_FSGID: |
362 | case AUDIT_LOGINUID: |
363 | case AUDIT_PERS: |
364 | case AUDIT_MSGTYPE: |
365 | case AUDIT_PPID: |
366 | case AUDIT_DEVMAJOR: |
367 | case AUDIT_DEVMINOR: |
368 | case AUDIT_EXIT: |
369 | case AUDIT_SUCCESS: |
370 | /* bit ops are only useful on syscall args */ |
371 | if (f->op == Audit_bitmask || f->op == Audit_bittest) |
372 | goto exit_free; |
373 | break; |
374 | case AUDIT_ARG0: |
375 | case AUDIT_ARG1: |
376 | case AUDIT_ARG2: |
377 | case AUDIT_ARG3: |
378 | break; |
379 | /* arch is only allowed to be = or != */ |
380 | case AUDIT_ARCH: |
381 | if (f->op != Audit_not_equal && f->op != Audit_equal) |
382 | goto exit_free; |
383 | entry->rule.arch_f = f; |
384 | break; |
385 | case AUDIT_PERM: |
386 | if (f->val & ~15) |
387 | goto exit_free; |
388 | break; |
389 | case AUDIT_FILETYPE: |
390 | if (f->val & ~S_IFMT) |
391 | goto exit_free; |
392 | break; |
393 | case AUDIT_INODE: |
394 | err = audit_to_inode(&entry->rule, f); |
395 | if (err) |
396 | goto exit_free; |
397 | break; |
398 | } |
399 | } |
400 | |
401 | if (entry->rule.inode_f && entry->rule.inode_f->op == Audit_not_equal) |
402 | entry->rule.inode_f = NULL; |
403 | |
404 | exit_nofree: |
405 | return entry; |
406 | |
407 | exit_free: |
408 | audit_free_rule(entry); |
409 | return ERR_PTR(err); |
410 | } |
411 | |
412 | /* Translate struct audit_rule_data to kernel's rule respresentation. */ |
413 | 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 | size_t remain = datasz - sizeof(struct audit_rule_data); |
420 | int i; |
421 | char *str; |
422 | |
423 | entry = audit_to_entry_common((struct audit_rule *)data); |
424 | if (IS_ERR(entry)) |
425 | goto exit_nofree; |
426 | |
427 | bufp = data->buf; |
428 | entry->rule.vers_ops = 2; |
429 | for (i = 0; i < data->field_count; i++) { |
430 | struct audit_field *f = &entry->rule.fields[i]; |
431 | |
432 | err = -EINVAL; |
433 | |
434 | f->op = audit_to_op(data->fieldflags[i]); |
435 | if (f->op == Audit_bad) |
436 | goto exit_free; |
437 | |
438 | f->type = data->fields[i]; |
439 | f->val = data->values[i]; |
440 | f->lsm_str = NULL; |
441 | f->lsm_rule = NULL; |
442 | switch(f->type) { |
443 | case AUDIT_PID: |
444 | case AUDIT_UID: |
445 | case AUDIT_EUID: |
446 | case AUDIT_SUID: |
447 | case AUDIT_FSUID: |
448 | case AUDIT_GID: |
449 | case AUDIT_EGID: |
450 | case AUDIT_SGID: |
451 | case AUDIT_FSGID: |
452 | case AUDIT_LOGINUID: |
453 | case AUDIT_PERS: |
454 | case AUDIT_MSGTYPE: |
455 | case AUDIT_PPID: |
456 | case AUDIT_DEVMAJOR: |
457 | case AUDIT_DEVMINOR: |
458 | case AUDIT_EXIT: |
459 | case AUDIT_SUCCESS: |
460 | case AUDIT_ARG0: |
461 | case AUDIT_ARG1: |
462 | case AUDIT_ARG2: |
463 | case AUDIT_ARG3: |
464 | case AUDIT_OBJ_UID: |
465 | case AUDIT_OBJ_GID: |
466 | break; |
467 | case AUDIT_ARCH: |
468 | entry->rule.arch_f = f; |
469 | break; |
470 | case AUDIT_SUBJ_USER: |
471 | case AUDIT_SUBJ_ROLE: |
472 | case AUDIT_SUBJ_TYPE: |
473 | case AUDIT_SUBJ_SEN: |
474 | case AUDIT_SUBJ_CLR: |
475 | case AUDIT_OBJ_USER: |
476 | case AUDIT_OBJ_ROLE: |
477 | case AUDIT_OBJ_TYPE: |
478 | case AUDIT_OBJ_LEV_LOW: |
479 | case AUDIT_OBJ_LEV_HIGH: |
480 | str = audit_unpack_string(&bufp, &remain, f->val); |
481 | if (IS_ERR(str)) |
482 | goto exit_free; |
483 | entry->rule.buflen += f->val; |
484 | |
485 | err = security_audit_rule_init(f->type, f->op, str, |
486 | (void **)&f->lsm_rule); |
487 | /* Keep currently invalid fields around in case they |
488 | * become valid after a policy reload. */ |
489 | if (err == -EINVAL) { |
490 | printk(KERN_WARNING "audit rule for LSM " |
491 | "\'%s\' is invalid\n", str); |
492 | err = 0; |
493 | } |
494 | if (err) { |
495 | kfree(str); |
496 | goto exit_free; |
497 | } else |
498 | f->lsm_str = str; |
499 | break; |
500 | case AUDIT_WATCH: |
501 | str = audit_unpack_string(&bufp, &remain, f->val); |
502 | if (IS_ERR(str)) |
503 | goto exit_free; |
504 | entry->rule.buflen += f->val; |
505 | |
506 | err = audit_to_watch(&entry->rule, str, f->val, f->op); |
507 | if (err) { |
508 | kfree(str); |
509 | goto exit_free; |
510 | } |
511 | break; |
512 | case AUDIT_DIR: |
513 | str = audit_unpack_string(&bufp, &remain, f->val); |
514 | if (IS_ERR(str)) |
515 | goto exit_free; |
516 | entry->rule.buflen += f->val; |
517 | |
518 | err = audit_make_tree(&entry->rule, str, f->op); |
519 | kfree(str); |
520 | if (err) |
521 | goto exit_free; |
522 | break; |
523 | case AUDIT_INODE: |
524 | err = audit_to_inode(&entry->rule, f); |
525 | if (err) |
526 | goto exit_free; |
527 | break; |
528 | case AUDIT_FILTERKEY: |
529 | if (entry->rule.filterkey || f->val > AUDIT_MAX_KEY_LEN) |
530 | goto exit_free; |
531 | str = audit_unpack_string(&bufp, &remain, f->val); |
532 | if (IS_ERR(str)) |
533 | goto exit_free; |
534 | entry->rule.buflen += f->val; |
535 | entry->rule.filterkey = str; |
536 | break; |
537 | case AUDIT_PERM: |
538 | if (f->val & ~15) |
539 | goto exit_free; |
540 | break; |
541 | case AUDIT_FILETYPE: |
542 | if (f->val & ~S_IFMT) |
543 | goto exit_free; |
544 | break; |
545 | case AUDIT_FIELD_COMPARE: |
546 | if (f->val > AUDIT_MAX_FIELD_COMPARE) |
547 | goto exit_free; |
548 | break; |
549 | default: |
550 | goto exit_free; |
551 | } |
552 | } |
553 | |
554 | if (entry->rule.inode_f && entry->rule.inode_f->op == Audit_not_equal) |
555 | entry->rule.inode_f = NULL; |
556 | |
557 | exit_nofree: |
558 | return entry; |
559 | |
560 | exit_free: |
561 | audit_free_rule(entry); |
562 | return ERR_PTR(err); |
563 | } |
564 | |
565 | /* Pack a filter field's string representation into data block. */ |
566 | static inline size_t audit_pack_string(void **bufp, const char *str) |
567 | { |
568 | size_t len = strlen(str); |
569 | |
570 | memcpy(*bufp, str, len); |
571 | *bufp += len; |
572 | |
573 | return len; |
574 | } |
575 | |
576 | /* Translate kernel rule respresentation to struct audit_rule. |
577 | * Exists for backward compatibility with userspace. */ |
578 | static struct audit_rule *audit_krule_to_rule(struct audit_krule *krule) |
579 | { |
580 | struct audit_rule *rule; |
581 | int i; |
582 | |
583 | rule = kzalloc(sizeof(*rule), GFP_KERNEL); |
584 | if (unlikely(!rule)) |
585 | return NULL; |
586 | |
587 | rule->flags = krule->flags | krule->listnr; |
588 | rule->action = krule->action; |
589 | rule->field_count = krule->field_count; |
590 | for (i = 0; i < rule->field_count; i++) { |
591 | rule->values[i] = krule->fields[i].val; |
592 | rule->fields[i] = krule->fields[i].type; |
593 | |
594 | if (krule->vers_ops == 1) { |
595 | if (krule->fields[i].op == Audit_not_equal) |
596 | rule->fields[i] |= AUDIT_NEGATE; |
597 | } else { |
598 | rule->fields[i] |= audit_ops[krule->fields[i].op]; |
599 | } |
600 | } |
601 | for (i = 0; i < AUDIT_BITMASK_SIZE; i++) rule->mask[i] = krule->mask[i]; |
602 | |
603 | return rule; |
604 | } |
605 | |
606 | /* Translate kernel rule respresentation to struct audit_rule_data. */ |
607 | static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule) |
608 | { |
609 | struct audit_rule_data *data; |
610 | void *bufp; |
611 | int i; |
612 | |
613 | data = kmalloc(sizeof(*data) + krule->buflen, GFP_KERNEL); |
614 | if (unlikely(!data)) |
615 | return NULL; |
616 | memset(data, 0, sizeof(*data)); |
617 | |
618 | data->flags = krule->flags | krule->listnr; |
619 | data->action = krule->action; |
620 | data->field_count = krule->field_count; |
621 | bufp = data->buf; |
622 | for (i = 0; i < data->field_count; i++) { |
623 | struct audit_field *f = &krule->fields[i]; |
624 | |
625 | data->fields[i] = f->type; |
626 | data->fieldflags[i] = audit_ops[f->op]; |
627 | switch(f->type) { |
628 | case AUDIT_SUBJ_USER: |
629 | case AUDIT_SUBJ_ROLE: |
630 | case AUDIT_SUBJ_TYPE: |
631 | case AUDIT_SUBJ_SEN: |
632 | case AUDIT_SUBJ_CLR: |
633 | case AUDIT_OBJ_USER: |
634 | case AUDIT_OBJ_ROLE: |
635 | case AUDIT_OBJ_TYPE: |
636 | case AUDIT_OBJ_LEV_LOW: |
637 | case AUDIT_OBJ_LEV_HIGH: |
638 | data->buflen += data->values[i] = |
639 | audit_pack_string(&bufp, f->lsm_str); |
640 | break; |
641 | case AUDIT_WATCH: |
642 | data->buflen += data->values[i] = |
643 | audit_pack_string(&bufp, |
644 | audit_watch_path(krule->watch)); |
645 | break; |
646 | case AUDIT_DIR: |
647 | data->buflen += data->values[i] = |
648 | audit_pack_string(&bufp, |
649 | audit_tree_path(krule->tree)); |
650 | break; |
651 | case AUDIT_FILTERKEY: |
652 | data->buflen += data->values[i] = |
653 | audit_pack_string(&bufp, krule->filterkey); |
654 | break; |
655 | default: |
656 | data->values[i] = f->val; |
657 | } |
658 | } |
659 | for (i = 0; i < AUDIT_BITMASK_SIZE; i++) data->mask[i] = krule->mask[i]; |
660 | |
661 | return data; |
662 | } |
663 | |
664 | /* Compare two rules in kernel format. Considered success if rules |
665 | * don't match. */ |
666 | static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b) |
667 | { |
668 | int i; |
669 | |
670 | if (a->flags != b->flags || |
671 | a->listnr != b->listnr || |
672 | a->action != b->action || |
673 | a->field_count != b->field_count) |
674 | return 1; |
675 | |
676 | for (i = 0; i < a->field_count; i++) { |
677 | if (a->fields[i].type != b->fields[i].type || |
678 | a->fields[i].op != b->fields[i].op) |
679 | return 1; |
680 | |
681 | switch(a->fields[i].type) { |
682 | case AUDIT_SUBJ_USER: |
683 | case AUDIT_SUBJ_ROLE: |
684 | case AUDIT_SUBJ_TYPE: |
685 | case AUDIT_SUBJ_SEN: |
686 | case AUDIT_SUBJ_CLR: |
687 | case AUDIT_OBJ_USER: |
688 | case AUDIT_OBJ_ROLE: |
689 | case AUDIT_OBJ_TYPE: |
690 | case AUDIT_OBJ_LEV_LOW: |
691 | case AUDIT_OBJ_LEV_HIGH: |
692 | if (strcmp(a->fields[i].lsm_str, b->fields[i].lsm_str)) |
693 | return 1; |
694 | break; |
695 | case AUDIT_WATCH: |
696 | if (strcmp(audit_watch_path(a->watch), |
697 | audit_watch_path(b->watch))) |
698 | return 1; |
699 | break; |
700 | case AUDIT_DIR: |
701 | if (strcmp(audit_tree_path(a->tree), |
702 | audit_tree_path(b->tree))) |
703 | return 1; |
704 | break; |
705 | case AUDIT_FILTERKEY: |
706 | /* both filterkeys exist based on above type compare */ |
707 | if (strcmp(a->filterkey, b->filterkey)) |
708 | return 1; |
709 | break; |
710 | default: |
711 | if (a->fields[i].val != b->fields[i].val) |
712 | return 1; |
713 | } |
714 | } |
715 | |
716 | for (i = 0; i < AUDIT_BITMASK_SIZE; i++) |
717 | if (a->mask[i] != b->mask[i]) |
718 | return 1; |
719 | |
720 | return 0; |
721 | } |
722 | |
723 | /* Duplicate LSM field information. The lsm_rule is opaque, so must be |
724 | * re-initialized. */ |
725 | static inline int audit_dupe_lsm_field(struct audit_field *df, |
726 | struct audit_field *sf) |
727 | { |
728 | int ret = 0; |
729 | char *lsm_str; |
730 | |
731 | /* our own copy of lsm_str */ |
732 | lsm_str = kstrdup(sf->lsm_str, GFP_KERNEL); |
733 | if (unlikely(!lsm_str)) |
734 | return -ENOMEM; |
735 | df->lsm_str = lsm_str; |
736 | |
737 | /* our own (refreshed) copy of lsm_rule */ |
738 | ret = security_audit_rule_init(df->type, df->op, df->lsm_str, |
739 | (void **)&df->lsm_rule); |
740 | /* Keep currently invalid fields around in case they |
741 | * become valid after a policy reload. */ |
742 | if (ret == -EINVAL) { |
743 | printk(KERN_WARNING "audit rule for LSM \'%s\' is " |
744 | "invalid\n", df->lsm_str); |
745 | ret = 0; |
746 | } |
747 | |
748 | return ret; |
749 | } |
750 | |
751 | /* Duplicate an audit rule. This will be a deep copy with the exception |
752 | * of the watch - that pointer is carried over. The LSM specific fields |
753 | * will be updated in the copy. The point is to be able to replace the old |
754 | * rule with the new rule in the filterlist, then free the old rule. |
755 | * The rlist element is undefined; list manipulations are handled apart from |
756 | * the initial copy. */ |
757 | struct audit_entry *audit_dupe_rule(struct audit_krule *old) |
758 | { |
759 | u32 fcount = old->field_count; |
760 | struct audit_entry *entry; |
761 | struct audit_krule *new; |
762 | char *fk; |
763 | int i, err = 0; |
764 | |
765 | entry = audit_init_entry(fcount); |
766 | if (unlikely(!entry)) |
767 | return ERR_PTR(-ENOMEM); |
768 | |
769 | new = &entry->rule; |
770 | new->vers_ops = old->vers_ops; |
771 | new->flags = old->flags; |
772 | new->listnr = old->listnr; |
773 | new->action = old->action; |
774 | for (i = 0; i < AUDIT_BITMASK_SIZE; i++) |
775 | new->mask[i] = old->mask[i]; |
776 | new->prio = old->prio; |
777 | new->buflen = old->buflen; |
778 | new->inode_f = old->inode_f; |
779 | new->field_count = old->field_count; |
780 | |
781 | /* |
782 | * note that we are OK with not refcounting here; audit_match_tree() |
783 | * never dereferences tree and we can't get false positives there |
784 | * since we'd have to have rule gone from the list *and* removed |
785 | * before the chunks found by lookup had been allocated, i.e. before |
786 | * the beginning of list scan. |
787 | */ |
788 | new->tree = old->tree; |
789 | memcpy(new->fields, old->fields, sizeof(struct audit_field) * fcount); |
790 | |
791 | /* deep copy this information, updating the lsm_rule fields, because |
792 | * the originals will all be freed when the old rule is freed. */ |
793 | for (i = 0; i < fcount; i++) { |
794 | switch (new->fields[i].type) { |
795 | case AUDIT_SUBJ_USER: |
796 | case AUDIT_SUBJ_ROLE: |
797 | case AUDIT_SUBJ_TYPE: |
798 | case AUDIT_SUBJ_SEN: |
799 | case AUDIT_SUBJ_CLR: |
800 | case AUDIT_OBJ_USER: |
801 | case AUDIT_OBJ_ROLE: |
802 | case AUDIT_OBJ_TYPE: |
803 | case AUDIT_OBJ_LEV_LOW: |
804 | case AUDIT_OBJ_LEV_HIGH: |
805 | err = audit_dupe_lsm_field(&new->fields[i], |
806 | &old->fields[i]); |
807 | break; |
808 | case AUDIT_FILTERKEY: |
809 | fk = kstrdup(old->filterkey, GFP_KERNEL); |
810 | if (unlikely(!fk)) |
811 | err = -ENOMEM; |
812 | else |
813 | new->filterkey = fk; |
814 | } |
815 | if (err) { |
816 | audit_free_rule(entry); |
817 | return ERR_PTR(err); |
818 | } |
819 | } |
820 | |
821 | if (old->watch) { |
822 | audit_get_watch(old->watch); |
823 | new->watch = old->watch; |
824 | } |
825 | |
826 | return entry; |
827 | } |
828 | |
829 | /* Find an existing audit rule. |
830 | * Caller must hold audit_filter_mutex to prevent stale rule data. */ |
831 | static struct audit_entry *audit_find_rule(struct audit_entry *entry, |
832 | struct list_head **p) |
833 | { |
834 | struct audit_entry *e, *found = NULL; |
835 | struct list_head *list; |
836 | int h; |
837 | |
838 | if (entry->rule.inode_f) { |
839 | h = audit_hash_ino(entry->rule.inode_f->val); |
840 | *p = list = &audit_inode_hash[h]; |
841 | } else if (entry->rule.watch) { |
842 | /* we don't know the inode number, so must walk entire hash */ |
843 | for (h = 0; h < AUDIT_INODE_BUCKETS; h++) { |
844 | list = &audit_inode_hash[h]; |
845 | list_for_each_entry(e, list, list) |
846 | if (!audit_compare_rule(&entry->rule, &e->rule)) { |
847 | found = e; |
848 | goto out; |
849 | } |
850 | } |
851 | goto out; |
852 | } else { |
853 | *p = list = &audit_filter_list[entry->rule.listnr]; |
854 | } |
855 | |
856 | list_for_each_entry(e, list, list) |
857 | if (!audit_compare_rule(&entry->rule, &e->rule)) { |
858 | found = e; |
859 | goto out; |
860 | } |
861 | |
862 | out: |
863 | return found; |
864 | } |
865 | |
866 | static u64 prio_low = ~0ULL/2; |
867 | static u64 prio_high = ~0ULL/2 - 1; |
868 | |
869 | /* Add rule to given filterlist if not a duplicate. */ |
870 | static inline int audit_add_rule(struct audit_entry *entry) |
871 | { |
872 | struct audit_entry *e; |
873 | struct audit_watch *watch = entry->rule.watch; |
874 | struct audit_tree *tree = entry->rule.tree; |
875 | struct list_head *list; |
876 | int err; |
877 | #ifdef CONFIG_AUDITSYSCALL |
878 | int dont_count = 0; |
879 | |
880 | /* If either of these, don't count towards total */ |
881 | if (entry->rule.listnr == AUDIT_FILTER_USER || |
882 | entry->rule.listnr == AUDIT_FILTER_TYPE) |
883 | dont_count = 1; |
884 | #endif |
885 | |
886 | mutex_lock(&audit_filter_mutex); |
887 | e = audit_find_rule(entry, &list); |
888 | if (e) { |
889 | mutex_unlock(&audit_filter_mutex); |
890 | err = -EEXIST; |
891 | /* normally audit_add_tree_rule() will free it on failure */ |
892 | if (tree) |
893 | audit_put_tree(tree); |
894 | goto error; |
895 | } |
896 | |
897 | if (watch) { |
898 | /* audit_filter_mutex is dropped and re-taken during this call */ |
899 | err = audit_add_watch(&entry->rule, &list); |
900 | if (err) { |
901 | mutex_unlock(&audit_filter_mutex); |
902 | goto error; |
903 | } |
904 | } |
905 | if (tree) { |
906 | err = audit_add_tree_rule(&entry->rule); |
907 | if (err) { |
908 | mutex_unlock(&audit_filter_mutex); |
909 | goto error; |
910 | } |
911 | } |
912 | |
913 | entry->rule.prio = ~0ULL; |
914 | if (entry->rule.listnr == AUDIT_FILTER_EXIT) { |
915 | if (entry->rule.flags & AUDIT_FILTER_PREPEND) |
916 | entry->rule.prio = ++prio_high; |
917 | else |
918 | entry->rule.prio = --prio_low; |
919 | } |
920 | |
921 | if (entry->rule.flags & AUDIT_FILTER_PREPEND) { |
922 | list_add(&entry->rule.list, |
923 | &audit_rules_list[entry->rule.listnr]); |
924 | list_add_rcu(&entry->list, list); |
925 | entry->rule.flags &= ~AUDIT_FILTER_PREPEND; |
926 | } else { |
927 | list_add_tail(&entry->rule.list, |
928 | &audit_rules_list[entry->rule.listnr]); |
929 | list_add_tail_rcu(&entry->list, list); |
930 | } |
931 | #ifdef CONFIG_AUDITSYSCALL |
932 | if (!dont_count) |
933 | audit_n_rules++; |
934 | |
935 | if (!audit_match_signal(entry)) |
936 | audit_signals++; |
937 | #endif |
938 | mutex_unlock(&audit_filter_mutex); |
939 | |
940 | return 0; |
941 | |
942 | error: |
943 | if (watch) |
944 | audit_put_watch(watch); /* tmp watch, matches initial get */ |
945 | return err; |
946 | } |
947 | |
948 | /* Remove an existing rule from filterlist. */ |
949 | static inline int audit_del_rule(struct audit_entry *entry) |
950 | { |
951 | struct audit_entry *e; |
952 | struct audit_watch *watch = entry->rule.watch; |
953 | struct audit_tree *tree = entry->rule.tree; |
954 | struct list_head *list; |
955 | int ret = 0; |
956 | #ifdef CONFIG_AUDITSYSCALL |
957 | int dont_count = 0; |
958 | |
959 | /* If either of these, don't count towards total */ |
960 | if (entry->rule.listnr == AUDIT_FILTER_USER || |
961 | entry->rule.listnr == AUDIT_FILTER_TYPE) |
962 | dont_count = 1; |
963 | #endif |
964 | |
965 | mutex_lock(&audit_filter_mutex); |
966 | e = audit_find_rule(entry, &list); |
967 | if (!e) { |
968 | mutex_unlock(&audit_filter_mutex); |
969 | ret = -ENOENT; |
970 | goto out; |
971 | } |
972 | |
973 | if (e->rule.watch) |
974 | audit_remove_watch_rule(&e->rule); |
975 | |
976 | if (e->rule.tree) |
977 | audit_remove_tree_rule(&e->rule); |
978 | |
979 | list_del_rcu(&e->list); |
980 | list_del(&e->rule.list); |
981 | call_rcu(&e->rcu, audit_free_rule_rcu); |
982 | |
983 | #ifdef CONFIG_AUDITSYSCALL |
984 | if (!dont_count) |
985 | audit_n_rules--; |
986 | |
987 | if (!audit_match_signal(entry)) |
988 | audit_signals--; |
989 | #endif |
990 | mutex_unlock(&audit_filter_mutex); |
991 | |
992 | out: |
993 | if (watch) |
994 | audit_put_watch(watch); /* match initial get */ |
995 | if (tree) |
996 | audit_put_tree(tree); /* that's the temporary one */ |
997 | |
998 | return ret; |
999 | } |
1000 | |
1001 | /* List rules using struct audit_rule. Exists for backward |
1002 | * compatibility with userspace. */ |
1003 | static void audit_list(int pid, int seq, struct sk_buff_head *q) |
1004 | { |
1005 | struct sk_buff *skb; |
1006 | struct audit_krule *r; |
1007 | int i; |
1008 | |
1009 | /* This is a blocking read, so use audit_filter_mutex instead of rcu |
1010 | * iterator to sync with list writers. */ |
1011 | for (i=0; i<AUDIT_NR_FILTERS; i++) { |
1012 | list_for_each_entry(r, &audit_rules_list[i], list) { |
1013 | struct audit_rule *rule; |
1014 | |
1015 | rule = audit_krule_to_rule(r); |
1016 | if (unlikely(!rule)) |
1017 | break; |
1018 | skb = audit_make_reply(pid, seq, AUDIT_LIST, 0, 1, |
1019 | rule, sizeof(*rule)); |
1020 | if (skb) |
1021 | skb_queue_tail(q, skb); |
1022 | kfree(rule); |
1023 | } |
1024 | } |
1025 | skb = audit_make_reply(pid, seq, AUDIT_LIST, 1, 1, NULL, 0); |
1026 | if (skb) |
1027 | skb_queue_tail(q, skb); |
1028 | } |
1029 | |
1030 | /* List rules using struct audit_rule_data. */ |
1031 | static void audit_list_rules(int pid, int seq, struct sk_buff_head *q) |
1032 | { |
1033 | struct sk_buff *skb; |
1034 | struct audit_krule *r; |
1035 | int i; |
1036 | |
1037 | /* This is a blocking read, so use audit_filter_mutex instead of rcu |
1038 | * iterator to sync with list writers. */ |
1039 | for (i=0; i<AUDIT_NR_FILTERS; i++) { |
1040 | list_for_each_entry(r, &audit_rules_list[i], list) { |
1041 | struct audit_rule_data *data; |
1042 | |
1043 | data = audit_krule_to_data(r); |
1044 | if (unlikely(!data)) |
1045 | break; |
1046 | skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 0, 1, |
1047 | data, sizeof(*data) + data->buflen); |
1048 | if (skb) |
1049 | skb_queue_tail(q, skb); |
1050 | kfree(data); |
1051 | } |
1052 | } |
1053 | skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 1, 1, NULL, 0); |
1054 | if (skb) |
1055 | skb_queue_tail(q, skb); |
1056 | } |
1057 | |
1058 | /* Log rule additions and removals */ |
1059 | static void audit_log_rule_change(uid_t loginuid, u32 sessionid, u32 sid, |
1060 | char *action, struct audit_krule *rule, |
1061 | int res) |
1062 | { |
1063 | struct audit_buffer *ab; |
1064 | |
1065 | if (!audit_enabled) |
1066 | return; |
1067 | |
1068 | ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE); |
1069 | if (!ab) |
1070 | return; |
1071 | audit_log_format(ab, "auid=%u ses=%u", loginuid, sessionid); |
1072 | if (sid) { |
1073 | char *ctx = NULL; |
1074 | u32 len; |
1075 | if (security_secid_to_secctx(sid, &ctx, &len)) |
1076 | audit_log_format(ab, " ssid=%u", sid); |
1077 | else { |
1078 | audit_log_format(ab, " subj=%s", ctx); |
1079 | security_release_secctx(ctx, len); |
1080 | } |
1081 | } |
1082 | audit_log_format(ab, " op="); |
1083 | audit_log_string(ab, action); |
1084 | audit_log_key(ab, rule->filterkey); |
1085 | audit_log_format(ab, " list=%d res=%d", rule->listnr, res); |
1086 | audit_log_end(ab); |
1087 | } |
1088 | |
1089 | /** |
1090 | * audit_receive_filter - apply all rules to the specified message type |
1091 | * @type: audit message type |
1092 | * @pid: target pid for netlink audit messages |
1093 | * @uid: target uid for netlink audit messages |
1094 | * @seq: netlink audit message sequence (serial) number |
1095 | * @data: payload data |
1096 | * @datasz: size of payload data |
1097 | * @loginuid: loginuid of sender |
1098 | * @sessionid: sessionid for netlink audit message |
1099 | * @sid: SE Linux Security ID of sender |
1100 | */ |
1101 | int audit_receive_filter(int type, int pid, int uid, int seq, void *data, |
1102 | size_t datasz, uid_t loginuid, u32 sessionid, u32 sid) |
1103 | { |
1104 | struct task_struct *tsk; |
1105 | struct audit_netlink_list *dest; |
1106 | int err = 0; |
1107 | struct audit_entry *entry; |
1108 | |
1109 | switch (type) { |
1110 | case AUDIT_LIST: |
1111 | case AUDIT_LIST_RULES: |
1112 | /* We can't just spew out the rules here because we might fill |
1113 | * the available socket buffer space and deadlock waiting for |
1114 | * auditctl to read from it... which isn't ever going to |
1115 | * happen if we're actually running in the context of auditctl |
1116 | * trying to _send_ the stuff */ |
1117 | |
1118 | dest = kmalloc(sizeof(struct audit_netlink_list), GFP_KERNEL); |
1119 | if (!dest) |
1120 | return -ENOMEM; |
1121 | dest->pid = pid; |
1122 | skb_queue_head_init(&dest->q); |
1123 | |
1124 | mutex_lock(&audit_filter_mutex); |
1125 | if (type == AUDIT_LIST) |
1126 | audit_list(pid, seq, &dest->q); |
1127 | else |
1128 | audit_list_rules(pid, seq, &dest->q); |
1129 | mutex_unlock(&audit_filter_mutex); |
1130 | |
1131 | tsk = kthread_run(audit_send_list, dest, "audit_send_list"); |
1132 | if (IS_ERR(tsk)) { |
1133 | skb_queue_purge(&dest->q); |
1134 | kfree(dest); |
1135 | err = PTR_ERR(tsk); |
1136 | } |
1137 | break; |
1138 | case AUDIT_ADD: |
1139 | case AUDIT_ADD_RULE: |
1140 | if (type == AUDIT_ADD) |
1141 | entry = audit_rule_to_entry(data); |
1142 | else |
1143 | entry = audit_data_to_entry(data, datasz); |
1144 | if (IS_ERR(entry)) |
1145 | return PTR_ERR(entry); |
1146 | |
1147 | err = audit_add_rule(entry); |
1148 | audit_log_rule_change(loginuid, sessionid, sid, "add rule", |
1149 | &entry->rule, !err); |
1150 | |
1151 | if (err) |
1152 | audit_free_rule(entry); |
1153 | break; |
1154 | case AUDIT_DEL: |
1155 | case AUDIT_DEL_RULE: |
1156 | if (type == AUDIT_DEL) |
1157 | entry = audit_rule_to_entry(data); |
1158 | else |
1159 | entry = audit_data_to_entry(data, datasz); |
1160 | if (IS_ERR(entry)) |
1161 | return PTR_ERR(entry); |
1162 | |
1163 | err = audit_del_rule(entry); |
1164 | audit_log_rule_change(loginuid, sessionid, sid, "remove rule", |
1165 | &entry->rule, !err); |
1166 | |
1167 | audit_free_rule(entry); |
1168 | break; |
1169 | default: |
1170 | return -EINVAL; |
1171 | } |
1172 | |
1173 | return err; |
1174 | } |
1175 | |
1176 | int audit_comparator(u32 left, u32 op, u32 right) |
1177 | { |
1178 | switch (op) { |
1179 | case Audit_equal: |
1180 | return (left == right); |
1181 | case Audit_not_equal: |
1182 | return (left != right); |
1183 | case Audit_lt: |
1184 | return (left < right); |
1185 | case Audit_le: |
1186 | return (left <= right); |
1187 | case Audit_gt: |
1188 | return (left > right); |
1189 | case Audit_ge: |
1190 | return (left >= right); |
1191 | case Audit_bitmask: |
1192 | return (left & right); |
1193 | case Audit_bittest: |
1194 | return ((left & right) == right); |
1195 | default: |
1196 | BUG(); |
1197 | return 0; |
1198 | } |
1199 | } |
1200 | |
1201 | /* Compare given dentry name with last component in given path, |
1202 | * return of 0 indicates a match. */ |
1203 | int audit_compare_dname_path(const char *dname, const char *path, |
1204 | int *dirlen) |
1205 | { |
1206 | int dlen, plen; |
1207 | const char *p; |
1208 | |
1209 | if (!dname || !path) |
1210 | return 1; |
1211 | |
1212 | dlen = strlen(dname); |
1213 | plen = strlen(path); |
1214 | if (plen < dlen) |
1215 | return 1; |
1216 | |
1217 | /* disregard trailing slashes */ |
1218 | p = path + plen - 1; |
1219 | while ((*p == '/') && (p > path)) |
1220 | p--; |
1221 | |
1222 | /* find last path component */ |
1223 | p = p - dlen + 1; |
1224 | if (p < path) |
1225 | return 1; |
1226 | else if (p > path) { |
1227 | if (*--p != '/') |
1228 | return 1; |
1229 | else |
1230 | p++; |
1231 | } |
1232 | |
1233 | /* return length of path's directory component */ |
1234 | if (dirlen) |
1235 | *dirlen = p - path; |
1236 | return strncmp(p, dname, dlen); |
1237 | } |
1238 | |
1239 | static int audit_filter_user_rules(struct netlink_skb_parms *cb, |
1240 | struct audit_krule *rule, |
1241 | enum audit_state *state) |
1242 | { |
1243 | int i; |
1244 | |
1245 | for (i = 0; i < rule->field_count; i++) { |
1246 | struct audit_field *f = &rule->fields[i]; |
1247 | int result = 0; |
1248 | u32 sid; |
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(audit_get_loginuid(current), |
1262 | f->op, f->val); |
1263 | break; |
1264 | case AUDIT_SUBJ_USER: |
1265 | case AUDIT_SUBJ_ROLE: |
1266 | case AUDIT_SUBJ_TYPE: |
1267 | case AUDIT_SUBJ_SEN: |
1268 | case AUDIT_SUBJ_CLR: |
1269 | if (f->lsm_rule) { |
1270 | security_task_getsecid(current, &sid); |
1271 | result = security_audit_rule_match(sid, |
1272 | f->type, |
1273 | f->op, |
1274 | f->lsm_rule, |
1275 | NULL); |
1276 | } |
1277 | break; |
1278 | } |
1279 | |
1280 | if (!result) |
1281 | return 0; |
1282 | } |
1283 | switch (rule->action) { |
1284 | case AUDIT_NEVER: *state = AUDIT_DISABLED; break; |
1285 | case AUDIT_ALWAYS: *state = AUDIT_RECORD_CONTEXT; break; |
1286 | } |
1287 | return 1; |
1288 | } |
1289 | |
1290 | int audit_filter_user(struct netlink_skb_parms *cb) |
1291 | { |
1292 | enum audit_state state = AUDIT_DISABLED; |
1293 | struct audit_entry *e; |
1294 | int ret = 1; |
1295 | |
1296 | rcu_read_lock(); |
1297 | list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_USER], list) { |
1298 | if (audit_filter_user_rules(cb, &e->rule, &state)) { |
1299 | if (state == AUDIT_DISABLED) |
1300 | ret = 0; |
1301 | break; |
1302 | } |
1303 | } |
1304 | rcu_read_unlock(); |
1305 | |
1306 | return ret; /* Audit by default */ |
1307 | } |
1308 | |
1309 | int audit_filter_type(int type) |
1310 | { |
1311 | struct audit_entry *e; |
1312 | int result = 0; |
1313 | |
1314 | rcu_read_lock(); |
1315 | if (list_empty(&audit_filter_list[AUDIT_FILTER_TYPE])) |
1316 | goto unlock_and_return; |
1317 | |
1318 | list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_TYPE], |
1319 | list) { |
1320 | int i; |
1321 | for (i = 0; i < e->rule.field_count; i++) { |
1322 | struct audit_field *f = &e->rule.fields[i]; |
1323 | if (f->type == AUDIT_MSGTYPE) { |
1324 | result = audit_comparator(type, f->op, f->val); |
1325 | if (!result) |
1326 | break; |
1327 | } |
1328 | } |
1329 | if (result) |
1330 | goto unlock_and_return; |
1331 | } |
1332 | unlock_and_return: |
1333 | rcu_read_unlock(); |
1334 | return result; |
1335 | } |
1336 | |
1337 | static int update_lsm_rule(struct audit_krule *r) |
1338 | { |
1339 | struct audit_entry *entry = container_of(r, struct audit_entry, rule); |
1340 | struct audit_entry *nentry; |
1341 | int err = 0; |
1342 | |
1343 | if (!security_audit_rule_known(r)) |
1344 | return 0; |
1345 | |
1346 | nentry = audit_dupe_rule(r); |
1347 | if (IS_ERR(nentry)) { |
1348 | /* save the first error encountered for the |
1349 | * return value */ |
1350 | err = PTR_ERR(nentry); |
1351 | audit_panic("error updating LSM filters"); |
1352 | if (r->watch) |
1353 | list_del(&r->rlist); |
1354 | list_del_rcu(&entry->list); |
1355 | list_del(&r->list); |
1356 | } else { |
1357 | if (r->watch || r->tree) |
1358 | list_replace_init(&r->rlist, &nentry->rule.rlist); |
1359 | list_replace_rcu(&entry->list, &nentry->list); |
1360 | list_replace(&r->list, &nentry->rule.list); |
1361 | } |
1362 | call_rcu(&entry->rcu, audit_free_rule_rcu); |
1363 | |
1364 | return err; |
1365 | } |
1366 | |
1367 | /* This function will re-initialize the lsm_rule field of all applicable rules. |
1368 | * It will traverse the filter lists serarching for rules that contain LSM |
1369 | * specific filter fields. When such a rule is found, it is copied, the |
1370 | * LSM field is re-initialized, and the old rule is replaced with the |
1371 | * updated rule. */ |
1372 | int audit_update_lsm_rules(void) |
1373 | { |
1374 | struct audit_krule *r, *n; |
1375 | int i, err = 0; |
1376 | |
1377 | /* audit_filter_mutex synchronizes the writers */ |
1378 | mutex_lock(&audit_filter_mutex); |
1379 | |
1380 | for (i = 0; i < AUDIT_NR_FILTERS; i++) { |
1381 | list_for_each_entry_safe(r, n, &audit_rules_list[i], list) { |
1382 | int res = update_lsm_rule(r); |
1383 | if (!err) |
1384 | err = res; |
1385 | } |
1386 | } |
1387 | mutex_unlock(&audit_filter_mutex); |
1388 | |
1389 | return err; |
1390 | } |
1391 |
Branches:
ben-wpan
ben-wpan-stefan
javiroman/ks7010
jz-2.6.34
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master
Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9