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fe7752ba DW |
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/netlink.h> | |
3dc7e315 | 26 | #include <linux/selinux.h> |
fe7752ba DW |
27 | #include "audit.h" |
28 | ||
29 | /* There are three lists of rules -- one to search at task creation | |
30 | * time, one to search at syscall entry time, and another to search at | |
31 | * syscall exit time. */ | |
32 | struct list_head audit_filter_list[AUDIT_NR_FILTERS] = { | |
33 | LIST_HEAD_INIT(audit_filter_list[0]), | |
34 | LIST_HEAD_INIT(audit_filter_list[1]), | |
35 | LIST_HEAD_INIT(audit_filter_list[2]), | |
36 | LIST_HEAD_INIT(audit_filter_list[3]), | |
37 | LIST_HEAD_INIT(audit_filter_list[4]), | |
38 | LIST_HEAD_INIT(audit_filter_list[5]), | |
39 | #if AUDIT_NR_FILTERS != 6 | |
40 | #error Fix audit_filter_list initialiser | |
41 | #endif | |
42 | }; | |
43 | ||
93315ed6 | 44 | static inline void audit_free_rule(struct audit_entry *e) |
fe7752ba | 45 | { |
3dc7e315 DG |
46 | int i; |
47 | if (e->rule.fields) | |
48 | for (i = 0; i < e->rule.field_count; i++) { | |
49 | struct audit_field *f = &e->rule.fields[i]; | |
50 | kfree(f->se_str); | |
51 | selinux_audit_rule_free(f->se_rule); | |
52 | } | |
93315ed6 AG |
53 | kfree(e->rule.fields); |
54 | kfree(e); | |
55 | } | |
56 | ||
57 | static inline void audit_free_rule_rcu(struct rcu_head *head) | |
58 | { | |
59 | struct audit_entry *e = container_of(head, struct audit_entry, rcu); | |
60 | audit_free_rule(e); | |
61 | } | |
62 | ||
3dc7e315 DG |
63 | /* Initialize an audit filterlist entry. */ |
64 | static inline struct audit_entry *audit_init_entry(u32 field_count) | |
65 | { | |
66 | struct audit_entry *entry; | |
67 | struct audit_field *fields; | |
68 | ||
69 | entry = kzalloc(sizeof(*entry), GFP_KERNEL); | |
70 | if (unlikely(!entry)) | |
71 | return NULL; | |
72 | ||
73 | fields = kzalloc(sizeof(*fields) * field_count, GFP_KERNEL); | |
74 | if (unlikely(!fields)) { | |
75 | kfree(entry); | |
76 | return NULL; | |
77 | } | |
78 | entry->rule.fields = fields; | |
79 | ||
80 | return entry; | |
81 | } | |
82 | ||
93315ed6 AG |
83 | /* Unpack a filter field's string representation from user-space |
84 | * buffer. */ | |
3dc7e315 | 85 | static char *audit_unpack_string(void **bufp, size_t *remain, size_t len) |
93315ed6 AG |
86 | { |
87 | char *str; | |
88 | ||
89 | if (!*bufp || (len == 0) || (len > *remain)) | |
90 | return ERR_PTR(-EINVAL); | |
91 | ||
92 | /* Of the currently implemented string fields, PATH_MAX | |
93 | * defines the longest valid length. | |
94 | */ | |
95 | if (len > PATH_MAX) | |
96 | return ERR_PTR(-ENAMETOOLONG); | |
97 | ||
98 | str = kmalloc(len + 1, GFP_KERNEL); | |
99 | if (unlikely(!str)) | |
100 | return ERR_PTR(-ENOMEM); | |
101 | ||
102 | memcpy(str, *bufp, len); | |
103 | str[len] = 0; | |
104 | *bufp += len; | |
105 | *remain -= len; | |
106 | ||
107 | return str; | |
108 | } | |
109 | ||
110 | /* Common user-space to kernel rule translation. */ | |
111 | static inline struct audit_entry *audit_to_entry_common(struct audit_rule *rule) | |
112 | { | |
113 | unsigned listnr; | |
114 | struct audit_entry *entry; | |
93315ed6 AG |
115 | int i, err; |
116 | ||
117 | err = -EINVAL; | |
118 | listnr = rule->flags & ~AUDIT_FILTER_PREPEND; | |
119 | switch(listnr) { | |
120 | default: | |
121 | goto exit_err; | |
122 | case AUDIT_FILTER_USER: | |
123 | case AUDIT_FILTER_TYPE: | |
124 | #ifdef CONFIG_AUDITSYSCALL | |
125 | case AUDIT_FILTER_ENTRY: | |
126 | case AUDIT_FILTER_EXIT: | |
127 | case AUDIT_FILTER_TASK: | |
128 | #endif | |
129 | ; | |
130 | } | |
131 | if (rule->action != AUDIT_NEVER && rule->action != AUDIT_POSSIBLE && | |
132 | rule->action != AUDIT_ALWAYS) | |
133 | goto exit_err; | |
134 | if (rule->field_count > AUDIT_MAX_FIELDS) | |
135 | goto exit_err; | |
136 | ||
137 | err = -ENOMEM; | |
3dc7e315 DG |
138 | entry = audit_init_entry(rule->field_count); |
139 | if (!entry) | |
93315ed6 | 140 | goto exit_err; |
93315ed6 AG |
141 | |
142 | entry->rule.flags = rule->flags & AUDIT_FILTER_PREPEND; | |
143 | entry->rule.listnr = listnr; | |
144 | entry->rule.action = rule->action; | |
145 | entry->rule.field_count = rule->field_count; | |
93315ed6 AG |
146 | |
147 | for (i = 0; i < AUDIT_BITMASK_SIZE; i++) | |
148 | entry->rule.mask[i] = rule->mask[i]; | |
149 | ||
150 | return entry; | |
151 | ||
152 | exit_err: | |
153 | return ERR_PTR(err); | |
154 | } | |
155 | ||
156 | /* Translate struct audit_rule to kernel's rule respresentation. | |
157 | * Exists for backward compatibility with userspace. */ | |
158 | static struct audit_entry *audit_rule_to_entry(struct audit_rule *rule) | |
159 | { | |
160 | struct audit_entry *entry; | |
161 | int err = 0; | |
fe7752ba DW |
162 | int i; |
163 | ||
93315ed6 AG |
164 | entry = audit_to_entry_common(rule); |
165 | if (IS_ERR(entry)) | |
166 | goto exit_nofree; | |
167 | ||
168 | for (i = 0; i < rule->field_count; i++) { | |
169 | struct audit_field *f = &entry->rule.fields[i]; | |
170 | ||
93315ed6 AG |
171 | f->op = rule->fields[i] & (AUDIT_NEGATE|AUDIT_OPERATORS); |
172 | f->type = rule->fields[i] & ~(AUDIT_NEGATE|AUDIT_OPERATORS); | |
173 | f->val = rule->values[i]; | |
174 | ||
3dc7e315 DG |
175 | if (f->type & AUDIT_UNUSED_BITS || |
176 | f->type == AUDIT_SE_USER || | |
177 | f->type == AUDIT_SE_ROLE || | |
178 | f->type == AUDIT_SE_TYPE || | |
179 | f->type == AUDIT_SE_SEN || | |
180 | f->type == AUDIT_SE_CLR) { | |
181 | err = -EINVAL; | |
182 | goto exit_free; | |
183 | } | |
184 | ||
93315ed6 | 185 | entry->rule.vers_ops = (f->op & AUDIT_OPERATORS) ? 2 : 1; |
d9d9ec6e DK |
186 | |
187 | /* Support for legacy operators where | |
188 | * AUDIT_NEGATE bit signifies != and otherwise assumes == */ | |
93315ed6 | 189 | if (f->op & AUDIT_NEGATE) |
d9d9ec6e DK |
190 | f->op = AUDIT_NOT_EQUAL; |
191 | else if (!f->op) | |
192 | f->op = AUDIT_EQUAL; | |
193 | else if (f->op == AUDIT_OPERATORS) { | |
194 | err = -EINVAL; | |
195 | goto exit_free; | |
196 | } | |
fe7752ba | 197 | } |
93315ed6 AG |
198 | |
199 | exit_nofree: | |
200 | return entry; | |
201 | ||
202 | exit_free: | |
203 | audit_free_rule(entry); | |
204 | return ERR_PTR(err); | |
fe7752ba DW |
205 | } |
206 | ||
93315ed6 AG |
207 | /* Translate struct audit_rule_data to kernel's rule respresentation. */ |
208 | static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data, | |
209 | size_t datasz) | |
fe7752ba | 210 | { |
93315ed6 AG |
211 | int err = 0; |
212 | struct audit_entry *entry; | |
213 | void *bufp; | |
3dc7e315 | 214 | size_t remain = datasz - sizeof(struct audit_rule_data); |
fe7752ba | 215 | int i; |
3dc7e315 | 216 | char *str; |
fe7752ba | 217 | |
93315ed6 AG |
218 | entry = audit_to_entry_common((struct audit_rule *)data); |
219 | if (IS_ERR(entry)) | |
220 | goto exit_nofree; | |
fe7752ba | 221 | |
93315ed6 AG |
222 | bufp = data->buf; |
223 | entry->rule.vers_ops = 2; | |
224 | for (i = 0; i < data->field_count; i++) { | |
225 | struct audit_field *f = &entry->rule.fields[i]; | |
226 | ||
227 | err = -EINVAL; | |
228 | if (!(data->fieldflags[i] & AUDIT_OPERATORS) || | |
229 | data->fieldflags[i] & ~AUDIT_OPERATORS) | |
230 | goto exit_free; | |
231 | ||
232 | f->op = data->fieldflags[i] & AUDIT_OPERATORS; | |
233 | f->type = data->fields[i]; | |
3dc7e315 DG |
234 | f->val = data->values[i]; |
235 | f->se_str = NULL; | |
236 | f->se_rule = NULL; | |
93315ed6 | 237 | switch(f->type) { |
3dc7e315 DG |
238 | case AUDIT_SE_USER: |
239 | case AUDIT_SE_ROLE: | |
240 | case AUDIT_SE_TYPE: | |
241 | case AUDIT_SE_SEN: | |
242 | case AUDIT_SE_CLR: | |
243 | str = audit_unpack_string(&bufp, &remain, f->val); | |
244 | if (IS_ERR(str)) | |
245 | goto exit_free; | |
246 | entry->rule.buflen += f->val; | |
247 | ||
248 | err = selinux_audit_rule_init(f->type, f->op, str, | |
249 | &f->se_rule); | |
250 | /* Keep currently invalid fields around in case they | |
251 | * become valid after a policy reload. */ | |
252 | if (err == -EINVAL) { | |
253 | printk(KERN_WARNING "audit rule for selinux " | |
254 | "\'%s\' is invalid\n", str); | |
255 | err = 0; | |
256 | } | |
257 | if (err) { | |
258 | kfree(str); | |
259 | goto exit_free; | |
260 | } else | |
261 | f->se_str = str; | |
262 | break; | |
93315ed6 AG |
263 | } |
264 | } | |
265 | ||
266 | exit_nofree: | |
267 | return entry; | |
268 | ||
269 | exit_free: | |
270 | audit_free_rule(entry); | |
271 | return ERR_PTR(err); | |
272 | } | |
273 | ||
274 | /* Pack a filter field's string representation into data block. */ | |
275 | static inline size_t audit_pack_string(void **bufp, char *str) | |
276 | { | |
277 | size_t len = strlen(str); | |
278 | ||
279 | memcpy(*bufp, str, len); | |
280 | *bufp += len; | |
281 | ||
282 | return len; | |
283 | } | |
284 | ||
285 | /* Translate kernel rule respresentation to struct audit_rule. | |
286 | * Exists for backward compatibility with userspace. */ | |
287 | static struct audit_rule *audit_krule_to_rule(struct audit_krule *krule) | |
288 | { | |
289 | struct audit_rule *rule; | |
290 | int i; | |
291 | ||
292 | rule = kmalloc(sizeof(*rule), GFP_KERNEL); | |
293 | if (unlikely(!rule)) | |
294 | return ERR_PTR(-ENOMEM); | |
295 | memset(rule, 0, sizeof(*rule)); | |
296 | ||
297 | rule->flags = krule->flags | krule->listnr; | |
298 | rule->action = krule->action; | |
299 | rule->field_count = krule->field_count; | |
300 | for (i = 0; i < rule->field_count; i++) { | |
301 | rule->values[i] = krule->fields[i].val; | |
302 | rule->fields[i] = krule->fields[i].type; | |
303 | ||
304 | if (krule->vers_ops == 1) { | |
305 | if (krule->fields[i].op & AUDIT_NOT_EQUAL) | |
306 | rule->fields[i] |= AUDIT_NEGATE; | |
307 | } else { | |
308 | rule->fields[i] |= krule->fields[i].op; | |
309 | } | |
310 | } | |
311 | for (i = 0; i < AUDIT_BITMASK_SIZE; i++) rule->mask[i] = krule->mask[i]; | |
312 | ||
313 | return rule; | |
314 | } | |
fe7752ba | 315 | |
93315ed6 AG |
316 | /* Translate kernel rule respresentation to struct audit_rule_data. */ |
317 | static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule) | |
318 | { | |
319 | struct audit_rule_data *data; | |
320 | void *bufp; | |
321 | int i; | |
322 | ||
323 | data = kmalloc(sizeof(*data) + krule->buflen, GFP_KERNEL); | |
324 | if (unlikely(!data)) | |
325 | return ERR_PTR(-ENOMEM); | |
326 | memset(data, 0, sizeof(*data)); | |
327 | ||
328 | data->flags = krule->flags | krule->listnr; | |
329 | data->action = krule->action; | |
330 | data->field_count = krule->field_count; | |
331 | bufp = data->buf; | |
332 | for (i = 0; i < data->field_count; i++) { | |
333 | struct audit_field *f = &krule->fields[i]; | |
334 | ||
335 | data->fields[i] = f->type; | |
336 | data->fieldflags[i] = f->op; | |
337 | switch(f->type) { | |
3dc7e315 DG |
338 | case AUDIT_SE_USER: |
339 | case AUDIT_SE_ROLE: | |
340 | case AUDIT_SE_TYPE: | |
341 | case AUDIT_SE_SEN: | |
342 | case AUDIT_SE_CLR: | |
343 | data->buflen += data->values[i] = | |
344 | audit_pack_string(&bufp, f->se_str); | |
345 | break; | |
93315ed6 AG |
346 | default: |
347 | data->values[i] = f->val; | |
348 | } | |
349 | } | |
350 | for (i = 0; i < AUDIT_BITMASK_SIZE; i++) data->mask[i] = krule->mask[i]; | |
351 | ||
352 | return data; | |
353 | } | |
354 | ||
355 | /* Compare two rules in kernel format. Considered success if rules | |
356 | * don't match. */ | |
357 | static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b) | |
358 | { | |
359 | int i; | |
360 | ||
361 | if (a->flags != b->flags || | |
362 | a->listnr != b->listnr || | |
363 | a->action != b->action || | |
364 | a->field_count != b->field_count) | |
fe7752ba DW |
365 | return 1; |
366 | ||
367 | for (i = 0; i < a->field_count; i++) { | |
93315ed6 AG |
368 | if (a->fields[i].type != b->fields[i].type || |
369 | a->fields[i].op != b->fields[i].op) | |
fe7752ba | 370 | return 1; |
93315ed6 AG |
371 | |
372 | switch(a->fields[i].type) { | |
3dc7e315 DG |
373 | case AUDIT_SE_USER: |
374 | case AUDIT_SE_ROLE: | |
375 | case AUDIT_SE_TYPE: | |
376 | case AUDIT_SE_SEN: | |
377 | case AUDIT_SE_CLR: | |
378 | if (strcmp(a->fields[i].se_str, b->fields[i].se_str)) | |
379 | return 1; | |
380 | break; | |
93315ed6 AG |
381 | default: |
382 | if (a->fields[i].val != b->fields[i].val) | |
383 | return 1; | |
384 | } | |
fe7752ba DW |
385 | } |
386 | ||
387 | for (i = 0; i < AUDIT_BITMASK_SIZE; i++) | |
388 | if (a->mask[i] != b->mask[i]) | |
389 | return 1; | |
390 | ||
391 | return 0; | |
392 | } | |
393 | ||
3dc7e315 DG |
394 | /* Duplicate selinux field information. The se_rule is opaque, so must be |
395 | * re-initialized. */ | |
396 | static inline int audit_dupe_selinux_field(struct audit_field *df, | |
397 | struct audit_field *sf) | |
398 | { | |
399 | int ret = 0; | |
400 | char *se_str; | |
401 | ||
402 | /* our own copy of se_str */ | |
403 | se_str = kstrdup(sf->se_str, GFP_KERNEL); | |
404 | if (unlikely(IS_ERR(se_str))) | |
405 | return -ENOMEM; | |
406 | df->se_str = se_str; | |
407 | ||
408 | /* our own (refreshed) copy of se_rule */ | |
409 | ret = selinux_audit_rule_init(df->type, df->op, df->se_str, | |
410 | &df->se_rule); | |
411 | /* Keep currently invalid fields around in case they | |
412 | * become valid after a policy reload. */ | |
413 | if (ret == -EINVAL) { | |
414 | printk(KERN_WARNING "audit rule for selinux \'%s\' is " | |
415 | "invalid\n", df->se_str); | |
416 | ret = 0; | |
417 | } | |
418 | ||
419 | return ret; | |
420 | } | |
421 | ||
422 | /* Duplicate an audit rule. This will be a deep copy with the exception | |
423 | * of the watch - that pointer is carried over. The selinux specific fields | |
424 | * will be updated in the copy. The point is to be able to replace the old | |
425 | * rule with the new rule in the filterlist, then free the old rule. */ | |
426 | static struct audit_entry *audit_dupe_rule(struct audit_krule *old) | |
427 | { | |
428 | u32 fcount = old->field_count; | |
429 | struct audit_entry *entry; | |
430 | struct audit_krule *new; | |
431 | int i, err = 0; | |
432 | ||
433 | entry = audit_init_entry(fcount); | |
434 | if (unlikely(!entry)) | |
435 | return ERR_PTR(-ENOMEM); | |
436 | ||
437 | new = &entry->rule; | |
438 | new->vers_ops = old->vers_ops; | |
439 | new->flags = old->flags; | |
440 | new->listnr = old->listnr; | |
441 | new->action = old->action; | |
442 | for (i = 0; i < AUDIT_BITMASK_SIZE; i++) | |
443 | new->mask[i] = old->mask[i]; | |
444 | new->buflen = old->buflen; | |
445 | new->field_count = old->field_count; | |
446 | memcpy(new->fields, old->fields, sizeof(struct audit_field) * fcount); | |
447 | ||
448 | /* deep copy this information, updating the se_rule fields, because | |
449 | * the originals will all be freed when the old rule is freed. */ | |
450 | for (i = 0; i < fcount; i++) { | |
451 | switch (new->fields[i].type) { | |
452 | case AUDIT_SE_USER: | |
453 | case AUDIT_SE_ROLE: | |
454 | case AUDIT_SE_TYPE: | |
455 | case AUDIT_SE_SEN: | |
456 | case AUDIT_SE_CLR: | |
457 | err = audit_dupe_selinux_field(&new->fields[i], | |
458 | &old->fields[i]); | |
459 | } | |
460 | if (err) { | |
461 | audit_free_rule(entry); | |
462 | return ERR_PTR(err); | |
463 | } | |
464 | } | |
465 | ||
466 | return entry; | |
467 | } | |
468 | ||
93315ed6 | 469 | /* Add rule to given filterlist if not a duplicate. Protected by |
5a0bbce5 | 470 | * audit_netlink_mutex. */ |
93315ed6 | 471 | static inline int audit_add_rule(struct audit_entry *entry, |
fe7752ba DW |
472 | struct list_head *list) |
473 | { | |
93315ed6 | 474 | struct audit_entry *e; |
fe7752ba DW |
475 | |
476 | /* Do not use the _rcu iterator here, since this is the only | |
477 | * addition routine. */ | |
93315ed6 AG |
478 | list_for_each_entry(e, list, list) { |
479 | if (!audit_compare_rule(&entry->rule, &e->rule)) | |
fe7752ba | 480 | return -EEXIST; |
fe7752ba DW |
481 | } |
482 | ||
fe7752ba | 483 | if (entry->rule.flags & AUDIT_FILTER_PREPEND) { |
fe7752ba DW |
484 | list_add_rcu(&entry->list, list); |
485 | } else { | |
486 | list_add_tail_rcu(&entry->list, list); | |
487 | } | |
488 | ||
489 | return 0; | |
490 | } | |
491 | ||
93315ed6 | 492 | /* Remove an existing rule from filterlist. Protected by |
5a0bbce5 | 493 | * audit_netlink_mutex. */ |
93315ed6 | 494 | static inline int audit_del_rule(struct audit_entry *entry, |
fe7752ba DW |
495 | struct list_head *list) |
496 | { | |
497 | struct audit_entry *e; | |
498 | ||
499 | /* Do not use the _rcu iterator here, since this is the only | |
500 | * deletion routine. */ | |
501 | list_for_each_entry(e, list, list) { | |
93315ed6 | 502 | if (!audit_compare_rule(&entry->rule, &e->rule)) { |
fe7752ba | 503 | list_del_rcu(&e->list); |
93315ed6 | 504 | call_rcu(&e->rcu, audit_free_rule_rcu); |
fe7752ba DW |
505 | return 0; |
506 | } | |
507 | } | |
508 | return -ENOENT; /* No matching rule */ | |
509 | } | |
510 | ||
93315ed6 AG |
511 | /* List rules using struct audit_rule. Exists for backward |
512 | * compatibility with userspace. */ | |
9044e6bc | 513 | static void audit_list(int pid, int seq, struct sk_buff_head *q) |
fe7752ba | 514 | { |
9044e6bc | 515 | struct sk_buff *skb; |
fe7752ba DW |
516 | struct audit_entry *entry; |
517 | int i; | |
518 | ||
fe7752ba | 519 | /* The *_rcu iterators not needed here because we are |
5a0bbce5 | 520 | always called with audit_netlink_mutex held. */ |
fe7752ba | 521 | for (i=0; i<AUDIT_NR_FILTERS; i++) { |
93315ed6 AG |
522 | list_for_each_entry(entry, &audit_filter_list[i], list) { |
523 | struct audit_rule *rule; | |
524 | ||
525 | rule = audit_krule_to_rule(&entry->rule); | |
526 | if (unlikely(!rule)) | |
527 | break; | |
9044e6bc | 528 | skb = audit_make_reply(pid, seq, AUDIT_LIST, 0, 1, |
93315ed6 | 529 | rule, sizeof(*rule)); |
9044e6bc AV |
530 | if (skb) |
531 | skb_queue_tail(q, skb); | |
93315ed6 AG |
532 | kfree(rule); |
533 | } | |
fe7752ba | 534 | } |
9044e6bc AV |
535 | skb = audit_make_reply(pid, seq, AUDIT_LIST, 1, 1, NULL, 0); |
536 | if (skb) | |
537 | skb_queue_tail(q, skb); | |
fe7752ba DW |
538 | } |
539 | ||
93315ed6 | 540 | /* List rules using struct audit_rule_data. */ |
9044e6bc | 541 | static void audit_list_rules(int pid, int seq, struct sk_buff_head *q) |
93315ed6 | 542 | { |
9044e6bc | 543 | struct sk_buff *skb; |
93315ed6 AG |
544 | struct audit_entry *e; |
545 | int i; | |
546 | ||
93315ed6 | 547 | /* The *_rcu iterators not needed here because we are |
5a0bbce5 | 548 | always called with audit_netlink_mutex held. */ |
93315ed6 AG |
549 | for (i=0; i<AUDIT_NR_FILTERS; i++) { |
550 | list_for_each_entry(e, &audit_filter_list[i], list) { | |
551 | struct audit_rule_data *data; | |
552 | ||
553 | data = audit_krule_to_data(&e->rule); | |
554 | if (unlikely(!data)) | |
555 | break; | |
9044e6bc | 556 | skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 0, 1, |
93315ed6 | 557 | data, sizeof(*data)); |
9044e6bc AV |
558 | if (skb) |
559 | skb_queue_tail(q, skb); | |
93315ed6 AG |
560 | kfree(data); |
561 | } | |
562 | } | |
9044e6bc AV |
563 | skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 1, 1, NULL, 0); |
564 | if (skb) | |
565 | skb_queue_tail(q, skb); | |
93315ed6 AG |
566 | } |
567 | ||
fe7752ba DW |
568 | /** |
569 | * audit_receive_filter - apply all rules to the specified message type | |
570 | * @type: audit message type | |
571 | * @pid: target pid for netlink audit messages | |
572 | * @uid: target uid for netlink audit messages | |
573 | * @seq: netlink audit message sequence (serial) number | |
574 | * @data: payload data | |
93315ed6 | 575 | * @datasz: size of payload data |
fe7752ba | 576 | * @loginuid: loginuid of sender |
ce29b682 | 577 | * @sid: SE Linux Security ID of sender |
fe7752ba DW |
578 | */ |
579 | int audit_receive_filter(int type, int pid, int uid, int seq, void *data, | |
ce29b682 | 580 | size_t datasz, uid_t loginuid, u32 sid) |
fe7752ba DW |
581 | { |
582 | struct task_struct *tsk; | |
9044e6bc | 583 | struct audit_netlink_list *dest; |
93315ed6 AG |
584 | int err = 0; |
585 | struct audit_entry *entry; | |
fe7752ba DW |
586 | |
587 | switch (type) { | |
588 | case AUDIT_LIST: | |
93315ed6 | 589 | case AUDIT_LIST_RULES: |
fe7752ba DW |
590 | /* We can't just spew out the rules here because we might fill |
591 | * the available socket buffer space and deadlock waiting for | |
592 | * auditctl to read from it... which isn't ever going to | |
593 | * happen if we're actually running in the context of auditctl | |
594 | * trying to _send_ the stuff */ | |
595 | ||
9044e6bc | 596 | dest = kmalloc(sizeof(struct audit_netlink_list), GFP_KERNEL); |
fe7752ba DW |
597 | if (!dest) |
598 | return -ENOMEM; | |
9044e6bc AV |
599 | dest->pid = pid; |
600 | skb_queue_head_init(&dest->q); | |
fe7752ba | 601 | |
93315ed6 | 602 | if (type == AUDIT_LIST) |
9044e6bc | 603 | audit_list(pid, seq, &dest->q); |
93315ed6 | 604 | else |
9044e6bc AV |
605 | audit_list_rules(pid, seq, &dest->q); |
606 | ||
607 | tsk = kthread_run(audit_send_list, dest, "audit_send_list"); | |
fe7752ba | 608 | if (IS_ERR(tsk)) { |
9044e6bc | 609 | skb_queue_purge(&dest->q); |
fe7752ba DW |
610 | kfree(dest); |
611 | err = PTR_ERR(tsk); | |
612 | } | |
613 | break; | |
614 | case AUDIT_ADD: | |
93315ed6 AG |
615 | case AUDIT_ADD_RULE: |
616 | if (type == AUDIT_ADD) | |
617 | entry = audit_rule_to_entry(data); | |
618 | else | |
619 | entry = audit_data_to_entry(data, datasz); | |
620 | if (IS_ERR(entry)) | |
621 | return PTR_ERR(entry); | |
622 | ||
623 | err = audit_add_rule(entry, | |
624 | &audit_filter_list[entry->rule.listnr]); | |
ce29b682 SG |
625 | if (sid) { |
626 | char *ctx = NULL; | |
627 | u32 len; | |
628 | if (selinux_ctxid_to_string(sid, &ctx, &len)) { | |
629 | /* Maybe call audit_panic? */ | |
630 | audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE, | |
631 | "auid=%u ssid=%u add rule to list=%d res=%d", | |
632 | loginuid, sid, entry->rule.listnr, !err); | |
633 | } else | |
634 | audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE, | |
635 | "auid=%u subj=%s add rule to list=%d res=%d", | |
636 | loginuid, ctx, entry->rule.listnr, !err); | |
637 | kfree(ctx); | |
638 | } else | |
639 | audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE, | |
640 | "auid=%u add rule to list=%d res=%d", | |
641 | loginuid, entry->rule.listnr, !err); | |
5d330108 SG |
642 | |
643 | if (err) | |
93315ed6 | 644 | audit_free_rule(entry); |
fe7752ba DW |
645 | break; |
646 | case AUDIT_DEL: | |
93315ed6 AG |
647 | case AUDIT_DEL_RULE: |
648 | if (type == AUDIT_DEL) | |
649 | entry = audit_rule_to_entry(data); | |
650 | else | |
651 | entry = audit_data_to_entry(data, datasz); | |
652 | if (IS_ERR(entry)) | |
653 | return PTR_ERR(entry); | |
654 | ||
655 | err = audit_del_rule(entry, | |
656 | &audit_filter_list[entry->rule.listnr]); | |
ce29b682 SG |
657 | |
658 | if (sid) { | |
659 | char *ctx = NULL; | |
660 | u32 len; | |
661 | if (selinux_ctxid_to_string(sid, &ctx, &len)) { | |
662 | /* Maybe call audit_panic? */ | |
663 | audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE, | |
664 | "auid=%u ssid=%u remove rule from list=%d res=%d", | |
665 | loginuid, sid, entry->rule.listnr, !err); | |
666 | } else | |
667 | audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE, | |
668 | "auid=%u subj=%s remove rule from list=%d res=%d", | |
669 | loginuid, ctx, entry->rule.listnr, !err); | |
670 | kfree(ctx); | |
671 | } else | |
672 | audit_log(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE, | |
673 | "auid=%u remove rule from list=%d res=%d", | |
674 | loginuid, entry->rule.listnr, !err); | |
5d330108 | 675 | |
93315ed6 | 676 | audit_free_rule(entry); |
fe7752ba DW |
677 | break; |
678 | default: | |
679 | return -EINVAL; | |
680 | } | |
681 | ||
682 | return err; | |
683 | } | |
684 | ||
685 | int audit_comparator(const u32 left, const u32 op, const u32 right) | |
686 | { | |
687 | switch (op) { | |
688 | case AUDIT_EQUAL: | |
689 | return (left == right); | |
690 | case AUDIT_NOT_EQUAL: | |
691 | return (left != right); | |
692 | case AUDIT_LESS_THAN: | |
693 | return (left < right); | |
694 | case AUDIT_LESS_THAN_OR_EQUAL: | |
695 | return (left <= right); | |
696 | case AUDIT_GREATER_THAN: | |
697 | return (left > right); | |
698 | case AUDIT_GREATER_THAN_OR_EQUAL: | |
699 | return (left >= right); | |
fe7752ba | 700 | } |
d9d9ec6e DK |
701 | BUG(); |
702 | return 0; | |
fe7752ba DW |
703 | } |
704 | ||
705 | ||
706 | ||
707 | static int audit_filter_user_rules(struct netlink_skb_parms *cb, | |
93315ed6 | 708 | struct audit_krule *rule, |
fe7752ba DW |
709 | enum audit_state *state) |
710 | { | |
711 | int i; | |
712 | ||
713 | for (i = 0; i < rule->field_count; i++) { | |
93315ed6 | 714 | struct audit_field *f = &rule->fields[i]; |
fe7752ba DW |
715 | int result = 0; |
716 | ||
93315ed6 | 717 | switch (f->type) { |
fe7752ba | 718 | case AUDIT_PID: |
93315ed6 | 719 | result = audit_comparator(cb->creds.pid, f->op, f->val); |
fe7752ba DW |
720 | break; |
721 | case AUDIT_UID: | |
93315ed6 | 722 | result = audit_comparator(cb->creds.uid, f->op, f->val); |
fe7752ba DW |
723 | break; |
724 | case AUDIT_GID: | |
93315ed6 | 725 | result = audit_comparator(cb->creds.gid, f->op, f->val); |
fe7752ba DW |
726 | break; |
727 | case AUDIT_LOGINUID: | |
93315ed6 | 728 | result = audit_comparator(cb->loginuid, f->op, f->val); |
fe7752ba DW |
729 | break; |
730 | } | |
731 | ||
732 | if (!result) | |
733 | return 0; | |
734 | } | |
735 | switch (rule->action) { | |
736 | case AUDIT_NEVER: *state = AUDIT_DISABLED; break; | |
737 | case AUDIT_POSSIBLE: *state = AUDIT_BUILD_CONTEXT; break; | |
738 | case AUDIT_ALWAYS: *state = AUDIT_RECORD_CONTEXT; break; | |
739 | } | |
740 | return 1; | |
741 | } | |
742 | ||
743 | int audit_filter_user(struct netlink_skb_parms *cb, int type) | |
744 | { | |
745 | struct audit_entry *e; | |
746 | enum audit_state state; | |
747 | int ret = 1; | |
748 | ||
749 | rcu_read_lock(); | |
750 | list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_USER], list) { | |
751 | if (audit_filter_user_rules(cb, &e->rule, &state)) { | |
752 | if (state == AUDIT_DISABLED) | |
753 | ret = 0; | |
754 | break; | |
755 | } | |
756 | } | |
757 | rcu_read_unlock(); | |
758 | ||
759 | return ret; /* Audit by default */ | |
760 | } | |
761 | ||
762 | int audit_filter_type(int type) | |
763 | { | |
764 | struct audit_entry *e; | |
765 | int result = 0; | |
766 | ||
767 | rcu_read_lock(); | |
768 | if (list_empty(&audit_filter_list[AUDIT_FILTER_TYPE])) | |
769 | goto unlock_and_return; | |
770 | ||
771 | list_for_each_entry_rcu(e, &audit_filter_list[AUDIT_FILTER_TYPE], | |
772 | list) { | |
fe7752ba | 773 | int i; |
93315ed6 AG |
774 | for (i = 0; i < e->rule.field_count; i++) { |
775 | struct audit_field *f = &e->rule.fields[i]; | |
776 | if (f->type == AUDIT_MSGTYPE) { | |
777 | result = audit_comparator(type, f->op, f->val); | |
fe7752ba DW |
778 | if (!result) |
779 | break; | |
780 | } | |
781 | } | |
782 | if (result) | |
783 | goto unlock_and_return; | |
784 | } | |
785 | unlock_and_return: | |
786 | rcu_read_unlock(); | |
787 | return result; | |
788 | } | |
3dc7e315 DG |
789 | |
790 | /* Check to see if the rule contains any selinux fields. Returns 1 if there | |
791 | are selinux fields specified in the rule, 0 otherwise. */ | |
792 | static inline int audit_rule_has_selinux(struct audit_krule *rule) | |
793 | { | |
794 | int i; | |
795 | ||
796 | for (i = 0; i < rule->field_count; i++) { | |
797 | struct audit_field *f = &rule->fields[i]; | |
798 | switch (f->type) { | |
799 | case AUDIT_SE_USER: | |
800 | case AUDIT_SE_ROLE: | |
801 | case AUDIT_SE_TYPE: | |
802 | case AUDIT_SE_SEN: | |
803 | case AUDIT_SE_CLR: | |
804 | return 1; | |
805 | } | |
806 | } | |
807 | ||
808 | return 0; | |
809 | } | |
810 | ||
811 | /* This function will re-initialize the se_rule field of all applicable rules. | |
812 | * It will traverse the filter lists serarching for rules that contain selinux | |
813 | * specific filter fields. When such a rule is found, it is copied, the | |
814 | * selinux field is re-initialized, and the old rule is replaced with the | |
815 | * updated rule. */ | |
816 | int selinux_audit_rule_update(void) | |
817 | { | |
818 | struct audit_entry *entry, *n, *nentry; | |
819 | int i, err = 0; | |
820 | ||
821 | /* audit_netlink_mutex synchronizes the writers */ | |
822 | mutex_lock(&audit_netlink_mutex); | |
823 | ||
824 | for (i = 0; i < AUDIT_NR_FILTERS; i++) { | |
825 | list_for_each_entry_safe(entry, n, &audit_filter_list[i], list) { | |
826 | if (!audit_rule_has_selinux(&entry->rule)) | |
827 | continue; | |
828 | ||
829 | nentry = audit_dupe_rule(&entry->rule); | |
830 | if (unlikely(IS_ERR(nentry))) { | |
831 | /* save the first error encountered for the | |
832 | * return value */ | |
833 | if (!err) | |
834 | err = PTR_ERR(nentry); | |
835 | audit_panic("error updating selinux filters"); | |
836 | list_del_rcu(&entry->list); | |
837 | } else { | |
838 | list_replace_rcu(&entry->list, &nentry->list); | |
839 | } | |
840 | call_rcu(&entry->rcu, audit_free_rule_rcu); | |
841 | } | |
842 | } | |
843 | ||
844 | mutex_unlock(&audit_netlink_mutex); | |
845 | ||
846 | return err; | |
847 | } |