Commit | Line | Data |
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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> | |
f368c07d AG |
25 | #include <linux/mutex.h> |
26 | #include <linux/fs.h> | |
27 | #include <linux/namei.h> | |
fe7752ba | 28 | #include <linux/netlink.h> |
f368c07d | 29 | #include <linux/sched.h> |
5a0e3ad6 | 30 | #include <linux/slab.h> |
2a862b32 | 31 | #include <linux/security.h> |
fe7752ba DW |
32 | #include "audit.h" |
33 | ||
f368c07d AG |
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 | |
d7a96f3a | 41 | * LSM rules during filtering. If modified, these structures |
f368c07d AG |
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 | ||
f368c07d | 47 | /* Audit filter lists, defined in <linux/audit.h> */ |
fe7752ba DW |
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 | }; | |
e45aa212 AV |
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 | }; | |
fe7752ba | 67 | |
74c3cbe3 | 68 | DEFINE_MUTEX(audit_filter_mutex); |
f368c07d | 69 | |
93315ed6 | 70 | static inline void audit_free_rule(struct audit_entry *e) |
fe7752ba | 71 | { |
3dc7e315 | 72 | int i; |
c28bb7da | 73 | struct audit_krule *erule = &e->rule; |
f368c07d | 74 | /* some rules don't have associated watches */ |
c28bb7da ZX |
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]; | |
04305e4a AD |
80 | kfree(f->lsm_str); |
81 | security_audit_rule_free(f->lsm_rule); | |
3dc7e315 | 82 | } |
c28bb7da ZX |
83 | kfree(erule->fields); |
84 | kfree(erule->filterkey); | |
93315ed6 AG |
85 | kfree(e); |
86 | } | |
87 | ||
74c3cbe3 | 88 | void audit_free_rule_rcu(struct rcu_head *head) |
93315ed6 AG |
89 | { |
90 | struct audit_entry *e = container_of(head, struct audit_entry, rcu); | |
91 | audit_free_rule(e); | |
92 | } | |
93 | ||
3dc7e315 DG |
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 | ||
93315ed6 AG |
114 | /* Unpack a filter field's string representation from user-space |
115 | * buffer. */ | |
74c3cbe3 | 116 | char *audit_unpack_string(void **bufp, size_t *remain, size_t len) |
93315ed6 AG |
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 | ||
f368c07d AG |
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 || | |
5af75d8d AV |
146 | krule->watch || krule->inode_f || krule->tree || |
147 | (f->op != Audit_equal && f->op != Audit_not_equal)) | |
f368c07d AG |
148 | return -EINVAL; |
149 | ||
150 | krule->inode_f = f; | |
151 | return 0; | |
152 | } | |
153 | ||
b915543b AV |
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 | ||
55669bfa AV |
177 | int audit_match_class(int class, unsigned syscall) |
178 | { | |
c926e4f4 | 179 | if (unlikely(syscall >= AUDIT_BITMASK_SIZE * 32)) |
55669bfa AV |
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 | ||
327b9eeb | 186 | #ifdef CONFIG_AUDITSYSCALL |
e54dc243 AG |
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 | } | |
327b9eeb | 223 | #endif |
e54dc243 | 224 | |
93315ed6 AG |
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; | |
93315ed6 AG |
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 | } | |
014149cc AV |
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) | |
93315ed6 AG |
251 | goto exit_err; |
252 | if (rule->field_count > AUDIT_MAX_FIELDS) | |
253 | goto exit_err; | |
254 | ||
255 | err = -ENOMEM; | |
3dc7e315 DG |
256 | entry = audit_init_entry(rule->field_count); |
257 | if (!entry) | |
93315ed6 | 258 | goto exit_err; |
93315ed6 AG |
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; | |
93315ed6 AG |
264 | |
265 | for (i = 0; i < AUDIT_BITMASK_SIZE; i++) | |
266 | entry->rule.mask[i] = rule->mask[i]; | |
267 | ||
b915543b AV |
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 | ||
93315ed6 AG |
284 | return entry; |
285 | ||
286 | exit_err: | |
287 | return ERR_PTR(err); | |
288 | } | |
289 | ||
5af75d8d AV |
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 | ||
93315ed6 AG |
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; | |
fe7752ba DW |
317 | int i; |
318 | ||
93315ed6 AG |
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]; | |
5af75d8d AV |
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; | |
93315ed6 | 339 | |
93315ed6 AG |
340 | f->type = rule->fields[i] & ~(AUDIT_NEGATE|AUDIT_OPERATORS); |
341 | f->val = rule->values[i]; | |
342 | ||
f368c07d | 343 | err = -EINVAL; |
5af75d8d AV |
344 | if (f->op == Audit_bad) |
345 | goto exit_free; | |
346 | ||
f368c07d | 347 | switch(f->type) { |
0a73dccc | 348 | default: |
3dc7e315 | 349 | goto exit_free; |
0a73dccc AV |
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: | |
0a73dccc | 361 | case AUDIT_MSGTYPE: |
3b33ac31 | 362 | case AUDIT_PPID: |
0a73dccc AV |
363 | case AUDIT_DEVMAJOR: |
364 | case AUDIT_DEVMINOR: | |
365 | case AUDIT_EXIT: | |
366 | case AUDIT_SUCCESS: | |
74f2345b | 367 | /* bit ops are only useful on syscall args */ |
5af75d8d | 368 | if (f->op == Audit_bitmask || f->op == Audit_bittest) |
74f2345b | 369 | goto exit_free; |
74f2345b | 370 | break; |
0a73dccc AV |
371 | case AUDIT_ARG0: |
372 | case AUDIT_ARG1: | |
373 | case AUDIT_ARG2: | |
374 | case AUDIT_ARG3: | |
375 | break; | |
4b8a311b EP |
376 | /* arch is only allowed to be = or != */ |
377 | case AUDIT_ARCH: | |
5af75d8d | 378 | if (f->op != Audit_not_equal && f->op != Audit_equal) |
4b8a311b | 379 | goto exit_free; |
e54dc243 | 380 | entry->rule.arch_f = f; |
4b8a311b | 381 | break; |
55669bfa AV |
382 | case AUDIT_PERM: |
383 | if (f->val & ~15) | |
384 | goto exit_free; | |
385 | break; | |
8b67dca9 AV |
386 | case AUDIT_FILETYPE: |
387 | if ((f->val & ~S_IFMT) > S_IFMT) | |
388 | goto exit_free; | |
389 | break; | |
f368c07d AG |
390 | case AUDIT_INODE: |
391 | err = audit_to_inode(&entry->rule, f); | |
392 | if (err) | |
393 | goto exit_free; | |
394 | break; | |
3dc7e315 | 395 | } |
fe7752ba | 396 | } |
93315ed6 | 397 | |
5af75d8d AV |
398 | if (entry->rule.inode_f && entry->rule.inode_f->op == Audit_not_equal) |
399 | entry->rule.inode_f = NULL; | |
f368c07d | 400 | |
93315ed6 AG |
401 | exit_nofree: |
402 | return entry; | |
403 | ||
404 | exit_free: | |
405 | audit_free_rule(entry); | |
406 | return ERR_PTR(err); | |
fe7752ba DW |
407 | } |
408 | ||
93315ed6 AG |
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) | |
fe7752ba | 412 | { |
93315ed6 AG |
413 | int err = 0; |
414 | struct audit_entry *entry; | |
415 | void *bufp; | |
3dc7e315 | 416 | size_t remain = datasz - sizeof(struct audit_rule_data); |
fe7752ba | 417 | int i; |
3dc7e315 | 418 | char *str; |
fe7752ba | 419 | |
93315ed6 AG |
420 | entry = audit_to_entry_common((struct audit_rule *)data); |
421 | if (IS_ERR(entry)) | |
422 | goto exit_nofree; | |
fe7752ba | 423 | |
93315ed6 AG |
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; | |
5af75d8d AV |
430 | |
431 | f->op = audit_to_op(data->fieldflags[i]); | |
432 | if (f->op == Audit_bad) | |
93315ed6 AG |
433 | goto exit_free; |
434 | ||
93315ed6 | 435 | f->type = data->fields[i]; |
3dc7e315 | 436 | f->val = data->values[i]; |
04305e4a AD |
437 | f->lsm_str = NULL; |
438 | f->lsm_rule = NULL; | |
93315ed6 | 439 | switch(f->type) { |
0a73dccc AV |
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: | |
0a73dccc AV |
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; | |
e54dc243 AG |
462 | case AUDIT_ARCH: |
463 | entry->rule.arch_f = f; | |
464 | break; | |
3a6b9f85 DG |
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: | |
6e5a2d1d DG |
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: | |
3dc7e315 DG |
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 | ||
d7a96f3a | 480 | err = security_audit_rule_init(f->type, f->op, str, |
04305e4a | 481 | (void **)&f->lsm_rule); |
3dc7e315 DG |
482 | /* Keep currently invalid fields around in case they |
483 | * become valid after a policy reload. */ | |
484 | if (err == -EINVAL) { | |
d7a96f3a | 485 | printk(KERN_WARNING "audit rule for LSM " |
3dc7e315 DG |
486 | "\'%s\' is invalid\n", str); |
487 | err = 0; | |
488 | } | |
489 | if (err) { | |
490 | kfree(str); | |
491 | goto exit_free; | |
492 | } else | |
04305e4a | 493 | f->lsm_str = str; |
3dc7e315 | 494 | break; |
f368c07d AG |
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; | |
74c3cbe3 AV |
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; | |
f368c07d AG |
518 | case AUDIT_INODE: |
519 | err = audit_to_inode(&entry->rule, f); | |
520 | if (err) | |
521 | goto exit_free; | |
522 | break; | |
5adc8a6a AG |
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; | |
55669bfa AV |
533 | case AUDIT_PERM: |
534 | if (f->val & ~15) | |
535 | goto exit_free; | |
536 | break; | |
8b67dca9 AV |
537 | case AUDIT_FILETYPE: |
538 | if ((f->val & ~S_IFMT) > S_IFMT) | |
539 | goto exit_free; | |
540 | break; | |
0a73dccc AV |
541 | default: |
542 | goto exit_free; | |
f368c07d AG |
543 | } |
544 | } | |
545 | ||
5af75d8d AV |
546 | if (entry->rule.inode_f && entry->rule.inode_f->op == Audit_not_equal) |
547 | entry->rule.inode_f = NULL; | |
93315ed6 AG |
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. */ | |
74c3cbe3 | 558 | static inline size_t audit_pack_string(void **bufp, const char *str) |
93315ed6 AG |
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 | ||
4668edc3 | 575 | rule = kzalloc(sizeof(*rule), GFP_KERNEL); |
93315ed6 | 576 | if (unlikely(!rule)) |
0a3b483e | 577 | return NULL; |
93315ed6 AG |
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) { | |
5af75d8d | 587 | if (krule->fields[i].op == Audit_not_equal) |
93315ed6 AG |
588 | rule->fields[i] |= AUDIT_NEGATE; |
589 | } else { | |
5af75d8d | 590 | rule->fields[i] |= audit_ops[krule->fields[i].op]; |
93315ed6 AG |
591 | } |
592 | } | |
593 | for (i = 0; i < AUDIT_BITMASK_SIZE; i++) rule->mask[i] = krule->mask[i]; | |
594 | ||
595 | return rule; | |
596 | } | |
fe7752ba | 597 | |
93315ed6 AG |
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)) | |
0a3b483e | 607 | return NULL; |
93315ed6 AG |
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; | |
5af75d8d | 618 | data->fieldflags[i] = audit_ops[f->op]; |
93315ed6 | 619 | switch(f->type) { |
3a6b9f85 DG |
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: | |
6e5a2d1d DG |
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: | |
3dc7e315 | 630 | data->buflen += data->values[i] = |
04305e4a | 631 | audit_pack_string(&bufp, f->lsm_str); |
3dc7e315 | 632 | break; |
f368c07d AG |
633 | case AUDIT_WATCH: |
634 | data->buflen += data->values[i] = | |
cfcad62c EP |
635 | audit_pack_string(&bufp, |
636 | audit_watch_path(krule->watch)); | |
f368c07d | 637 | break; |
74c3cbe3 AV |
638 | case AUDIT_DIR: |
639 | data->buflen += data->values[i] = | |
640 | audit_pack_string(&bufp, | |
641 | audit_tree_path(krule->tree)); | |
642 | break; | |
5adc8a6a AG |
643 | case AUDIT_FILTERKEY: |
644 | data->buflen += data->values[i] = | |
645 | audit_pack_string(&bufp, krule->filterkey); | |
646 | break; | |
93315ed6 AG |
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) | |
fe7752ba DW |
666 | return 1; |
667 | ||
668 | for (i = 0; i < a->field_count; i++) { | |
93315ed6 AG |
669 | if (a->fields[i].type != b->fields[i].type || |
670 | a->fields[i].op != b->fields[i].op) | |
fe7752ba | 671 | return 1; |
93315ed6 AG |
672 | |
673 | switch(a->fields[i].type) { | |
3a6b9f85 DG |
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: | |
6e5a2d1d DG |
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: | |
04305e4a | 684 | if (strcmp(a->fields[i].lsm_str, b->fields[i].lsm_str)) |
3dc7e315 DG |
685 | return 1; |
686 | break; | |
f368c07d | 687 | case AUDIT_WATCH: |
cfcad62c EP |
688 | if (strcmp(audit_watch_path(a->watch), |
689 | audit_watch_path(b->watch))) | |
f368c07d AG |
690 | return 1; |
691 | break; | |
74c3cbe3 AV |
692 | case AUDIT_DIR: |
693 | if (strcmp(audit_tree_path(a->tree), | |
694 | audit_tree_path(b->tree))) | |
695 | return 1; | |
696 | break; | |
5adc8a6a AG |
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; | |
93315ed6 AG |
702 | default: |
703 | if (a->fields[i].val != b->fields[i].val) | |
704 | return 1; | |
705 | } | |
fe7752ba DW |
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 | ||
04305e4a | 715 | /* Duplicate LSM field information. The lsm_rule is opaque, so must be |
3dc7e315 | 716 | * re-initialized. */ |
d7a96f3a | 717 | static inline int audit_dupe_lsm_field(struct audit_field *df, |
3dc7e315 DG |
718 | struct audit_field *sf) |
719 | { | |
720 | int ret = 0; | |
04305e4a | 721 | char *lsm_str; |
3dc7e315 | 722 | |
04305e4a AD |
723 | /* our own copy of lsm_str */ |
724 | lsm_str = kstrdup(sf->lsm_str, GFP_KERNEL); | |
725 | if (unlikely(!lsm_str)) | |
3e1fbd12 | 726 | return -ENOMEM; |
04305e4a | 727 | df->lsm_str = lsm_str; |
3dc7e315 | 728 | |
04305e4a AD |
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); | |
3dc7e315 DG |
732 | /* Keep currently invalid fields around in case they |
733 | * become valid after a policy reload. */ | |
734 | if (ret == -EINVAL) { | |
d7a96f3a | 735 | printk(KERN_WARNING "audit rule for LSM \'%s\' is " |
04305e4a | 736 | "invalid\n", df->lsm_str); |
3dc7e315 DG |
737 | ret = 0; |
738 | } | |
739 | ||
740 | return ret; | |
741 | } | |
742 | ||
743 | /* Duplicate an audit rule. This will be a deep copy with the exception | |
d7a96f3a | 744 | * of the watch - that pointer is carried over. The LSM specific fields |
3dc7e315 | 745 | * will be updated in the copy. The point is to be able to replace the old |
f368c07d AG |
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. */ | |
cfcad62c EP |
749 | struct audit_entry *audit_dupe_rule(struct audit_krule *old, |
750 | struct audit_watch *watch) | |
3dc7e315 DG |
751 | { |
752 | u32 fcount = old->field_count; | |
753 | struct audit_entry *entry; | |
754 | struct audit_krule *new; | |
5adc8a6a | 755 | char *fk; |
3dc7e315 DG |
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]; | |
0590b933 | 769 | new->prio = old->prio; |
3dc7e315 | 770 | new->buflen = old->buflen; |
f368c07d AG |
771 | new->inode_f = old->inode_f; |
772 | new->watch = NULL; | |
3dc7e315 | 773 | new->field_count = old->field_count; |
74c3cbe3 AV |
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; | |
3dc7e315 DG |
782 | memcpy(new->fields, old->fields, sizeof(struct audit_field) * fcount); |
783 | ||
04305e4a | 784 | /* deep copy this information, updating the lsm_rule fields, because |
3dc7e315 DG |
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) { | |
3a6b9f85 DG |
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: | |
6e5a2d1d DG |
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: | |
d7a96f3a | 798 | err = audit_dupe_lsm_field(&new->fields[i], |
3dc7e315 | 799 | &old->fields[i]); |
5adc8a6a AG |
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; | |
3dc7e315 DG |
807 | } |
808 | if (err) { | |
809 | audit_free_rule(entry); | |
810 | return ERR_PTR(err); | |
811 | } | |
812 | } | |
813 | ||
f368c07d AG |
814 | if (watch) { |
815 | audit_get_watch(watch); | |
816 | new->watch = watch; | |
817 | } | |
818 | ||
3dc7e315 DG |
819 | return entry; |
820 | } | |
821 | ||
f368c07d AG |
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, | |
36c4f1b1 | 825 | struct list_head **p) |
f368c07d AG |
826 | { |
827 | struct audit_entry *e, *found = NULL; | |
36c4f1b1 | 828 | struct list_head *list; |
f368c07d AG |
829 | int h; |
830 | ||
36c4f1b1 AV |
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) { | |
f368c07d AG |
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; | |
36c4f1b1 AV |
845 | } else { |
846 | *p = list = &audit_filter_list[entry->rule.listnr]; | |
f368c07d AG |
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 | ||
0590b933 AV |
859 | static u64 prio_low = ~0ULL/2; |
860 | static u64 prio_high = ~0ULL/2 - 1; | |
861 | ||
f368c07d | 862 | /* Add rule to given filterlist if not a duplicate. */ |
36c4f1b1 | 863 | static inline int audit_add_rule(struct audit_entry *entry) |
fe7752ba | 864 | { |
93315ed6 | 865 | struct audit_entry *e; |
f368c07d | 866 | struct audit_watch *watch = entry->rule.watch; |
74c3cbe3 | 867 | struct audit_tree *tree = entry->rule.tree; |
36c4f1b1 | 868 | struct list_head *list; |
6f686d3d | 869 | int h, err; |
471a5c7c AV |
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 | |
f368c07d | 878 | |
f368c07d | 879 | mutex_lock(&audit_filter_mutex); |
36c4f1b1 | 880 | e = audit_find_rule(entry, &list); |
f368c07d | 881 | if (e) { |
35fe4d0b | 882 | mutex_unlock(&audit_filter_mutex); |
f368c07d | 883 | err = -EEXIST; |
74c3cbe3 AV |
884 | /* normally audit_add_tree_rule() will free it on failure */ |
885 | if (tree) | |
886 | audit_put_tree(tree); | |
f368c07d AG |
887 | goto error; |
888 | } | |
fe7752ba | 889 | |
f368c07d AG |
890 | if (watch) { |
891 | /* audit_filter_mutex is dropped and re-taken during this call */ | |
35fe4d0b | 892 | err = audit_add_watch(&entry->rule); |
f368c07d AG |
893 | if (err) { |
894 | mutex_unlock(&audit_filter_mutex); | |
895 | goto error; | |
896 | } | |
35aa901c EP |
897 | /* entry->rule.watch may have changed during audit_add_watch() */ |
898 | watch = entry->rule.watch; | |
cfcad62c | 899 | h = audit_hash_ino((u32)audit_watch_inode(watch)); |
f368c07d | 900 | list = &audit_inode_hash[h]; |
fe7752ba | 901 | } |
74c3cbe3 AV |
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 | } | |
fe7752ba | 909 | |
0590b933 AV |
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 | ||
fe7752ba | 918 | if (entry->rule.flags & AUDIT_FILTER_PREPEND) { |
e45aa212 AV |
919 | list_add(&entry->rule.list, |
920 | &audit_rules_list[entry->rule.listnr]); | |
fe7752ba | 921 | list_add_rcu(&entry->list, list); |
6a2bceec | 922 | entry->rule.flags &= ~AUDIT_FILTER_PREPEND; |
fe7752ba | 923 | } else { |
e45aa212 AV |
924 | list_add_tail(&entry->rule.list, |
925 | &audit_rules_list[entry->rule.listnr]); | |
fe7752ba DW |
926 | list_add_tail_rcu(&entry->list, list); |
927 | } | |
471a5c7c AV |
928 | #ifdef CONFIG_AUDITSYSCALL |
929 | if (!dont_count) | |
930 | audit_n_rules++; | |
e54dc243 AG |
931 | |
932 | if (!audit_match_signal(entry)) | |
933 | audit_signals++; | |
471a5c7c | 934 | #endif |
f368c07d | 935 | mutex_unlock(&audit_filter_mutex); |
fe7752ba | 936 | |
f368c07d AG |
937 | return 0; |
938 | ||
939 | error: | |
f368c07d AG |
940 | if (watch) |
941 | audit_put_watch(watch); /* tmp watch, matches initial get */ | |
942 | return err; | |
fe7752ba DW |
943 | } |
944 | ||
f368c07d | 945 | /* Remove an existing rule from filterlist. */ |
36c4f1b1 | 946 | static inline int audit_del_rule(struct audit_entry *entry) |
fe7752ba DW |
947 | { |
948 | struct audit_entry *e; | |
cfcad62c | 949 | struct audit_watch *watch = entry->rule.watch; |
74c3cbe3 | 950 | struct audit_tree *tree = entry->rule.tree; |
36c4f1b1 | 951 | struct list_head *list; |
f368c07d | 952 | LIST_HEAD(inotify_list); |
36c4f1b1 | 953 | int ret = 0; |
471a5c7c AV |
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 | |
f368c07d | 962 | |
f368c07d | 963 | mutex_lock(&audit_filter_mutex); |
36c4f1b1 | 964 | e = audit_find_rule(entry, &list); |
f368c07d AG |
965 | if (!e) { |
966 | mutex_unlock(&audit_filter_mutex); | |
967 | ret = -ENOENT; | |
968 | goto out; | |
969 | } | |
970 | ||
cfcad62c EP |
971 | if (e->rule.watch) |
972 | audit_remove_watch_rule(&e->rule, &inotify_list); | |
f368c07d | 973 | |
74c3cbe3 AV |
974 | if (e->rule.tree) |
975 | audit_remove_tree_rule(&e->rule); | |
976 | ||
f368c07d | 977 | list_del_rcu(&e->list); |
e45aa212 | 978 | list_del(&e->rule.list); |
f368c07d AG |
979 | call_rcu(&e->rcu, audit_free_rule_rcu); |
980 | ||
471a5c7c AV |
981 | #ifdef CONFIG_AUDITSYSCALL |
982 | if (!dont_count) | |
983 | audit_n_rules--; | |
e54dc243 AG |
984 | |
985 | if (!audit_match_signal(entry)) | |
986 | audit_signals--; | |
471a5c7c | 987 | #endif |
f368c07d AG |
988 | mutex_unlock(&audit_filter_mutex); |
989 | ||
990 | if (!list_empty(&inotify_list)) | |
991 | audit_inotify_unregister(&inotify_list); | |
992 | ||
993 | out: | |
cfcad62c EP |
994 | if (watch) |
995 | audit_put_watch(watch); /* match initial get */ | |
74c3cbe3 AV |
996 | if (tree) |
997 | audit_put_tree(tree); /* that's the temporary one */ | |
f368c07d AG |
998 | |
999 | return ret; | |
fe7752ba DW |
1000 | } |
1001 | ||
93315ed6 AG |
1002 | /* List rules using struct audit_rule. Exists for backward |
1003 | * compatibility with userspace. */ | |
9044e6bc | 1004 | static void audit_list(int pid, int seq, struct sk_buff_head *q) |
fe7752ba | 1005 | { |
9044e6bc | 1006 | struct sk_buff *skb; |
e45aa212 | 1007 | struct audit_krule *r; |
fe7752ba DW |
1008 | int i; |
1009 | ||
f368c07d AG |
1010 | /* This is a blocking read, so use audit_filter_mutex instead of rcu |
1011 | * iterator to sync with list writers. */ | |
fe7752ba | 1012 | for (i=0; i<AUDIT_NR_FILTERS; i++) { |
e45aa212 | 1013 | list_for_each_entry(r, &audit_rules_list[i], list) { |
f368c07d AG |
1014 | struct audit_rule *rule; |
1015 | ||
e45aa212 | 1016 | rule = audit_krule_to_rule(r); |
f368c07d AG |
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 | } | |
9044e6bc AV |
1026 | skb = audit_make_reply(pid, seq, AUDIT_LIST, 1, 1, NULL, 0); |
1027 | if (skb) | |
1028 | skb_queue_tail(q, skb); | |
fe7752ba DW |
1029 | } |
1030 | ||
93315ed6 | 1031 | /* List rules using struct audit_rule_data. */ |
9044e6bc | 1032 | static void audit_list_rules(int pid, int seq, struct sk_buff_head *q) |
93315ed6 | 1033 | { |
9044e6bc | 1034 | struct sk_buff *skb; |
e45aa212 | 1035 | struct audit_krule *r; |
93315ed6 AG |
1036 | int i; |
1037 | ||
f368c07d AG |
1038 | /* This is a blocking read, so use audit_filter_mutex instead of rcu |
1039 | * iterator to sync with list writers. */ | |
93315ed6 | 1040 | for (i=0; i<AUDIT_NR_FILTERS; i++) { |
e45aa212 | 1041 | list_for_each_entry(r, &audit_rules_list[i], list) { |
f368c07d AG |
1042 | struct audit_rule_data *data; |
1043 | ||
e45aa212 | 1044 | data = audit_krule_to_data(r); |
f368c07d AG |
1045 | if (unlikely(!data)) |
1046 | break; | |
1047 | skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 0, 1, | |
1048 | data, sizeof(*data) + data->buflen); | |
9044e6bc AV |
1049 | if (skb) |
1050 | skb_queue_tail(q, skb); | |
93315ed6 AG |
1051 | kfree(data); |
1052 | } | |
1053 | } | |
9044e6bc AV |
1054 | skb = audit_make_reply(pid, seq, AUDIT_LIST_RULES, 1, 1, NULL, 0); |
1055 | if (skb) | |
1056 | skb_queue_tail(q, skb); | |
93315ed6 AG |
1057 | } |
1058 | ||
5adc8a6a | 1059 | /* Log rule additions and removals */ |
2532386f EP |
1060 | static void audit_log_rule_change(uid_t loginuid, u32 sessionid, u32 sid, |
1061 | char *action, struct audit_krule *rule, | |
1062 | int res) | |
5adc8a6a AG |
1063 | { |
1064 | struct audit_buffer *ab; | |
1065 | ||
1a6b9f23 EP |
1066 | if (!audit_enabled) |
1067 | return; | |
1068 | ||
5adc8a6a AG |
1069 | ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE); |
1070 | if (!ab) | |
1071 | return; | |
2532386f | 1072 | audit_log_format(ab, "auid=%u ses=%u", loginuid, sessionid); |
5adc8a6a AG |
1073 | if (sid) { |
1074 | char *ctx = NULL; | |
1075 | u32 len; | |
2a862b32 | 1076 | if (security_secid_to_secctx(sid, &ctx, &len)) |
5adc8a6a | 1077 | audit_log_format(ab, " ssid=%u", sid); |
2a862b32 | 1078 | else { |
5adc8a6a | 1079 | audit_log_format(ab, " subj=%s", ctx); |
2a862b32 AD |
1080 | security_release_secctx(ctx, len); |
1081 | } | |
5adc8a6a | 1082 | } |
9d960985 EP |
1083 | audit_log_format(ab, " op="); |
1084 | audit_log_string(ab, action); | |
1085 | audit_log_key(ab, rule->filterkey); | |
5adc8a6a AG |
1086 | audit_log_format(ab, " list=%d res=%d", rule->listnr, res); |
1087 | audit_log_end(ab); | |
1088 | } | |
1089 | ||
fe7752ba DW |
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 | |
93315ed6 | 1097 | * @datasz: size of payload data |
fe7752ba | 1098 | * @loginuid: loginuid of sender |
9f0aecdd | 1099 | * @sessionid: sessionid for netlink audit message |
ce29b682 | 1100 | * @sid: SE Linux Security ID of sender |
fe7752ba DW |
1101 | */ |
1102 | int audit_receive_filter(int type, int pid, int uid, int seq, void *data, | |
2532386f | 1103 | size_t datasz, uid_t loginuid, u32 sessionid, u32 sid) |
fe7752ba DW |
1104 | { |
1105 | struct task_struct *tsk; | |
9044e6bc | 1106 | struct audit_netlink_list *dest; |
93315ed6 AG |
1107 | int err = 0; |
1108 | struct audit_entry *entry; | |
fe7752ba DW |
1109 | |
1110 | switch (type) { | |
1111 | case AUDIT_LIST: | |
93315ed6 | 1112 | case AUDIT_LIST_RULES: |
fe7752ba DW |
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 */ | |
9ce34218 | 1118 | |
9044e6bc | 1119 | dest = kmalloc(sizeof(struct audit_netlink_list), GFP_KERNEL); |
fe7752ba DW |
1120 | if (!dest) |
1121 | return -ENOMEM; | |
9044e6bc AV |
1122 | dest->pid = pid; |
1123 | skb_queue_head_init(&dest->q); | |
fe7752ba | 1124 | |
f368c07d | 1125 | mutex_lock(&audit_filter_mutex); |
93315ed6 | 1126 | if (type == AUDIT_LIST) |
9044e6bc | 1127 | audit_list(pid, seq, &dest->q); |
93315ed6 | 1128 | else |
9044e6bc | 1129 | audit_list_rules(pid, seq, &dest->q); |
f368c07d | 1130 | mutex_unlock(&audit_filter_mutex); |
9044e6bc AV |
1131 | |
1132 | tsk = kthread_run(audit_send_list, dest, "audit_send_list"); | |
fe7752ba | 1133 | if (IS_ERR(tsk)) { |
9044e6bc | 1134 | skb_queue_purge(&dest->q); |
fe7752ba DW |
1135 | kfree(dest); |
1136 | err = PTR_ERR(tsk); | |
1137 | } | |
1138 | break; | |
1139 | case AUDIT_ADD: | |
93315ed6 AG |
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 | ||
36c4f1b1 | 1148 | err = audit_add_rule(entry); |
9d960985 | 1149 | audit_log_rule_change(loginuid, sessionid, sid, "add rule", |
2532386f | 1150 | &entry->rule, !err); |
5d330108 AV |
1151 | |
1152 | if (err) | |
93315ed6 | 1153 | audit_free_rule(entry); |
fe7752ba DW |
1154 | break; |
1155 | case AUDIT_DEL: | |
93315ed6 AG |
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 | ||
36c4f1b1 | 1164 | err = audit_del_rule(entry); |
9d960985 | 1165 | audit_log_rule_change(loginuid, sessionid, sid, "remove rule", |
2532386f | 1166 | &entry->rule, !err); |
5d330108 | 1167 | |
93315ed6 | 1168 | audit_free_rule(entry); |
fe7752ba DW |
1169 | break; |
1170 | default: | |
1171 | return -EINVAL; | |
1172 | } | |
1173 | ||
1174 | return err; | |
1175 | } | |
1176 | ||
5af75d8d | 1177 | int audit_comparator(u32 left, u32 op, u32 right) |
fe7752ba DW |
1178 | { |
1179 | switch (op) { | |
5af75d8d | 1180 | case Audit_equal: |
fe7752ba | 1181 | return (left == right); |
5af75d8d | 1182 | case Audit_not_equal: |
fe7752ba | 1183 | return (left != right); |
5af75d8d | 1184 | case Audit_lt: |
fe7752ba | 1185 | return (left < right); |
5af75d8d | 1186 | case Audit_le: |
fe7752ba | 1187 | return (left <= right); |
5af75d8d | 1188 | case Audit_gt: |
fe7752ba | 1189 | return (left > right); |
5af75d8d | 1190 | case Audit_ge: |
fe7752ba | 1191 | return (left >= right); |
5af75d8d | 1192 | case Audit_bitmask: |
74f2345b | 1193 | return (left & right); |
5af75d8d | 1194 | case Audit_bittest: |
74f2345b | 1195 | return ((left & right) == right); |
5af75d8d AV |
1196 | default: |
1197 | BUG(); | |
1198 | return 0; | |
fe7752ba DW |
1199 | } |
1200 | } | |
1201 | ||
f368c07d AG |
1202 | /* Compare given dentry name with last component in given path, |
1203 | * return of 0 indicates a match. */ | |
9c937dcc AG |
1204 | int audit_compare_dname_path(const char *dname, const char *path, |
1205 | int *dirlen) | |
f368c07d AG |
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 | } | |
fe7752ba | 1233 | |
9c937dcc AG |
1234 | /* return length of path's directory component */ |
1235 | if (dirlen) | |
1236 | *dirlen = p - path; | |
f368c07d AG |
1237 | return strncmp(p, dname, dlen); |
1238 | } | |
fe7752ba DW |
1239 | |
1240 | static int audit_filter_user_rules(struct netlink_skb_parms *cb, | |
93315ed6 | 1241 | struct audit_krule *rule, |
fe7752ba DW |
1242 | enum audit_state *state) |
1243 | { | |
1244 | int i; | |
1245 | ||
1246 | for (i = 0; i < rule->field_count; i++) { | |
93315ed6 | 1247 | struct audit_field *f = &rule->fields[i]; |
fe7752ba DW |
1248 | int result = 0; |
1249 | ||
93315ed6 | 1250 | switch (f->type) { |
fe7752ba | 1251 | case AUDIT_PID: |
93315ed6 | 1252 | result = audit_comparator(cb->creds.pid, f->op, f->val); |
fe7752ba DW |
1253 | break; |
1254 | case AUDIT_UID: | |
93315ed6 | 1255 | result = audit_comparator(cb->creds.uid, f->op, f->val); |
fe7752ba DW |
1256 | break; |
1257 | case AUDIT_GID: | |
93315ed6 | 1258 | result = audit_comparator(cb->creds.gid, f->op, f->val); |
fe7752ba DW |
1259 | break; |
1260 | case AUDIT_LOGINUID: | |
93315ed6 | 1261 | result = audit_comparator(cb->loginuid, f->op, f->val); |
fe7752ba DW |
1262 | break; |
1263 | } | |
1264 | ||
1265 | if (!result) | |
1266 | return 0; | |
1267 | } | |
1268 | switch (rule->action) { | |
1269 | case AUDIT_NEVER: *state = AUDIT_DISABLED; break; | |
fe7752ba DW |
1270 | case AUDIT_ALWAYS: *state = AUDIT_RECORD_CONTEXT; break; |
1271 | } | |
1272 | return 1; | |
1273 | } | |
1274 | ||
d8de7247 | 1275 | int audit_filter_user(struct netlink_skb_parms *cb) |
fe7752ba | 1276 | { |
11f57ced | 1277 | enum audit_state state = AUDIT_DISABLED; |
fe7752ba | 1278 | struct audit_entry *e; |
fe7752ba DW |
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; | |
9ce34218 | 1298 | |
fe7752ba DW |
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) { | |
fe7752ba | 1305 | int i; |
93315ed6 AG |
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); | |
fe7752ba DW |
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 | } | |
3dc7e315 | 1321 | |
e45aa212 | 1322 | static int update_lsm_rule(struct audit_krule *r) |
1a9d0797 | 1323 | { |
e45aa212 | 1324 | struct audit_entry *entry = container_of(r, struct audit_entry, rule); |
1a9d0797 AV |
1325 | struct audit_entry *nentry; |
1326 | struct audit_watch *watch; | |
1327 | struct audit_tree *tree; | |
1328 | int err = 0; | |
1329 | ||
e45aa212 | 1330 | if (!security_audit_rule_known(r)) |
1a9d0797 AV |
1331 | return 0; |
1332 | ||
e45aa212 AV |
1333 | watch = r->watch; |
1334 | tree = r->tree; | |
1335 | nentry = audit_dupe_rule(r, watch); | |
1a9d0797 AV |
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) | |
e45aa212 | 1342 | list_del(&r->rlist); |
1a9d0797 | 1343 | list_del_rcu(&entry->list); |
e45aa212 | 1344 | list_del(&r->list); |
1a9d0797 AV |
1345 | } else { |
1346 | if (watch) { | |
cfcad62c | 1347 | list_add(&nentry->rule.rlist, audit_watch_rules(watch)); |
e45aa212 | 1348 | list_del(&r->rlist); |
1a9d0797 | 1349 | } else if (tree) |
e45aa212 | 1350 | list_replace_init(&r->rlist, &nentry->rule.rlist); |
1a9d0797 | 1351 | list_replace_rcu(&entry->list, &nentry->list); |
e45aa212 | 1352 | list_replace(&r->list, &nentry->rule.list); |
1a9d0797 AV |
1353 | } |
1354 | call_rcu(&entry->rcu, audit_free_rule_rcu); | |
1355 | ||
1356 | return err; | |
1357 | } | |
1358 | ||
04305e4a | 1359 | /* This function will re-initialize the lsm_rule field of all applicable rules. |
d7a96f3a | 1360 | * It will traverse the filter lists serarching for rules that contain LSM |
3dc7e315 | 1361 | * specific filter fields. When such a rule is found, it is copied, the |
d7a96f3a | 1362 | * LSM field is re-initialized, and the old rule is replaced with the |
3dc7e315 | 1363 | * updated rule. */ |
d7a96f3a | 1364 | int audit_update_lsm_rules(void) |
3dc7e315 | 1365 | { |
e45aa212 | 1366 | struct audit_krule *r, *n; |
3dc7e315 DG |
1367 | int i, err = 0; |
1368 | ||
f368c07d AG |
1369 | /* audit_filter_mutex synchronizes the writers */ |
1370 | mutex_lock(&audit_filter_mutex); | |
3dc7e315 DG |
1371 | |
1372 | for (i = 0; i < AUDIT_NR_FILTERS; i++) { | |
e45aa212 AV |
1373 | list_for_each_entry_safe(r, n, &audit_rules_list[i], list) { |
1374 | int res = update_lsm_rule(r); | |
1a9d0797 AV |
1375 | if (!err) |
1376 | err = res; | |
3dc7e315 DG |
1377 | } |
1378 | } | |
f368c07d | 1379 | mutex_unlock(&audit_filter_mutex); |
3dc7e315 DG |
1380 | |
1381 | return err; | |
1382 | } |