1 | // SPDX-License-Identifier: GPL-2.0-or-later |
2 | /* auditfilter.c -- filtering of audit events |
3 | * |
4 | * Copyright 2003-2004 Red Hat, Inc. |
5 | * Copyright 2005 Hewlett-Packard Development Company, L.P. |
6 | * Copyright 2005 IBM Corporation |
7 | */ |
8 | |
9 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
10 | |
11 | #include <linux/kernel.h> |
12 | #include <linux/audit.h> |
13 | #include <linux/kthread.h> |
14 | #include <linux/mutex.h> |
15 | #include <linux/fs.h> |
16 | #include <linux/namei.h> |
17 | #include <linux/netlink.h> |
18 | #include <linux/sched.h> |
19 | #include <linux/slab.h> |
20 | #include <linux/security.h> |
21 | #include <net/net_namespace.h> |
22 | #include <net/sock.h> |
23 | #include "audit.h" |
24 | |
25 | /* |
26 | * Locking model: |
27 | * |
28 | * audit_filter_mutex: |
29 | * Synchronizes writes and blocking reads of audit's filterlist |
30 | * data. Rcu is used to traverse the filterlist and access |
31 | * contents of structs audit_entry, audit_watch and opaque |
32 | * LSM rules during filtering. If modified, these structures |
33 | * must be copied and replace their counterparts in the filterlist. |
34 | * An audit_parent struct is not accessed during filtering, so may |
35 | * be written directly provided audit_filter_mutex is held. |
36 | */ |
37 | |
38 | /* Audit filter lists, defined in <linux/audit.h> */ |
39 | struct list_head audit_filter_list[AUDIT_NR_FILTERS] = { |
40 | LIST_HEAD_INIT(audit_filter_list[0]), |
41 | LIST_HEAD_INIT(audit_filter_list[1]), |
42 | LIST_HEAD_INIT(audit_filter_list[2]), |
43 | LIST_HEAD_INIT(audit_filter_list[3]), |
44 | LIST_HEAD_INIT(audit_filter_list[4]), |
45 | LIST_HEAD_INIT(audit_filter_list[5]), |
46 | LIST_HEAD_INIT(audit_filter_list[6]), |
47 | LIST_HEAD_INIT(audit_filter_list[7]), |
48 | #if AUDIT_NR_FILTERS != 8 |
49 | #error Fix audit_filter_list initialiser |
50 | #endif |
51 | }; |
52 | static struct list_head audit_rules_list[AUDIT_NR_FILTERS] = { |
53 | LIST_HEAD_INIT(audit_rules_list[0]), |
54 | LIST_HEAD_INIT(audit_rules_list[1]), |
55 | LIST_HEAD_INIT(audit_rules_list[2]), |
56 | LIST_HEAD_INIT(audit_rules_list[3]), |
57 | LIST_HEAD_INIT(audit_rules_list[4]), |
58 | LIST_HEAD_INIT(audit_rules_list[5]), |
59 | LIST_HEAD_INIT(audit_rules_list[6]), |
60 | LIST_HEAD_INIT(audit_rules_list[7]), |
61 | }; |
62 | |
63 | DEFINE_MUTEX(audit_filter_mutex); |
64 | |
65 | static void audit_free_lsm_field(struct audit_field *f) |
66 | { |
67 | switch (f->type) { |
68 | case AUDIT_SUBJ_USER: |
69 | case AUDIT_SUBJ_ROLE: |
70 | case AUDIT_SUBJ_TYPE: |
71 | case AUDIT_SUBJ_SEN: |
72 | case AUDIT_SUBJ_CLR: |
73 | case AUDIT_OBJ_USER: |
74 | case AUDIT_OBJ_ROLE: |
75 | case AUDIT_OBJ_TYPE: |
76 | case AUDIT_OBJ_LEV_LOW: |
77 | case AUDIT_OBJ_LEV_HIGH: |
78 | kfree(objp: f->lsm_str); |
79 | security_audit_rule_free(lsmrule: f->lsm_rule); |
80 | } |
81 | } |
82 | |
83 | static inline void audit_free_rule(struct audit_entry *e) |
84 | { |
85 | int i; |
86 | struct audit_krule *erule = &e->rule; |
87 | |
88 | /* some rules don't have associated watches */ |
89 | if (erule->watch) |
90 | audit_put_watch(watch: erule->watch); |
91 | if (erule->fields) |
92 | for (i = 0; i < erule->field_count; i++) |
93 | audit_free_lsm_field(f: &erule->fields[i]); |
94 | kfree(objp: erule->fields); |
95 | kfree(objp: erule->filterkey); |
96 | kfree(objp: e); |
97 | } |
98 | |
99 | void audit_free_rule_rcu(struct rcu_head *head) |
100 | { |
101 | struct audit_entry *e = container_of(head, struct audit_entry, rcu); |
102 | audit_free_rule(e); |
103 | } |
104 | |
105 | /* Initialize an audit filterlist entry. */ |
106 | static inline struct audit_entry *audit_init_entry(u32 field_count) |
107 | { |
108 | struct audit_entry *entry; |
109 | struct audit_field *fields; |
110 | |
111 | entry = kzalloc(size: sizeof(*entry), GFP_KERNEL); |
112 | if (unlikely(!entry)) |
113 | return NULL; |
114 | |
115 | fields = kcalloc(n: field_count, size: sizeof(*fields), GFP_KERNEL); |
116 | if (unlikely(!fields)) { |
117 | kfree(objp: entry); |
118 | return NULL; |
119 | } |
120 | entry->rule.fields = fields; |
121 | |
122 | return entry; |
123 | } |
124 | |
125 | /* Unpack a filter field's string representation from user-space |
126 | * buffer. */ |
127 | char *audit_unpack_string(void **bufp, size_t *remain, size_t len) |
128 | { |
129 | char *str; |
130 | |
131 | if (!*bufp || (len == 0) || (len > *remain)) |
132 | return ERR_PTR(error: -EINVAL); |
133 | |
134 | /* Of the currently implemented string fields, PATH_MAX |
135 | * defines the longest valid length. |
136 | */ |
137 | if (len > PATH_MAX) |
138 | return ERR_PTR(error: -ENAMETOOLONG); |
139 | |
140 | str = kmalloc(size: len + 1, GFP_KERNEL); |
141 | if (unlikely(!str)) |
142 | return ERR_PTR(error: -ENOMEM); |
143 | |
144 | memcpy(str, *bufp, len); |
145 | str[len] = 0; |
146 | *bufp += len; |
147 | *remain -= len; |
148 | |
149 | return str; |
150 | } |
151 | |
152 | /* Translate an inode field to kernel representation. */ |
153 | static inline int audit_to_inode(struct audit_krule *krule, |
154 | struct audit_field *f) |
155 | { |
156 | if ((krule->listnr != AUDIT_FILTER_EXIT && |
157 | krule->listnr != AUDIT_FILTER_URING_EXIT) || |
158 | krule->inode_f || krule->watch || krule->tree || |
159 | (f->op != Audit_equal && f->op != Audit_not_equal)) |
160 | return -EINVAL; |
161 | |
162 | krule->inode_f = f; |
163 | return 0; |
164 | } |
165 | |
166 | static __u32 *classes[AUDIT_SYSCALL_CLASSES]; |
167 | |
168 | int __init audit_register_class(int class, unsigned *list) |
169 | { |
170 | __u32 *p = kcalloc(AUDIT_BITMASK_SIZE, size: sizeof(__u32), GFP_KERNEL); |
171 | if (!p) |
172 | return -ENOMEM; |
173 | while (*list != ~0U) { |
174 | unsigned n = *list++; |
175 | if (n >= AUDIT_BITMASK_SIZE * 32 - AUDIT_SYSCALL_CLASSES) { |
176 | kfree(objp: p); |
177 | return -EINVAL; |
178 | } |
179 | p[AUDIT_WORD(n)] |= AUDIT_BIT(n); |
180 | } |
181 | if (class >= AUDIT_SYSCALL_CLASSES || classes[class]) { |
182 | kfree(objp: p); |
183 | return -EINVAL; |
184 | } |
185 | classes[class] = p; |
186 | return 0; |
187 | } |
188 | |
189 | int audit_match_class(int class, unsigned syscall) |
190 | { |
191 | if (unlikely(syscall >= AUDIT_BITMASK_SIZE * 32)) |
192 | return 0; |
193 | if (unlikely(class >= AUDIT_SYSCALL_CLASSES || !classes[class])) |
194 | return 0; |
195 | return classes[class][AUDIT_WORD(syscall)] & AUDIT_BIT(syscall); |
196 | } |
197 | |
198 | #ifdef CONFIG_AUDITSYSCALL |
199 | static inline int audit_match_class_bits(int class, u32 *mask) |
200 | { |
201 | int i; |
202 | |
203 | if (classes[class]) { |
204 | for (i = 0; i < AUDIT_BITMASK_SIZE; i++) |
205 | if (mask[i] & classes[class][i]) |
206 | return 0; |
207 | } |
208 | return 1; |
209 | } |
210 | |
211 | static int audit_match_signal(struct audit_entry *entry) |
212 | { |
213 | struct audit_field *arch = entry->rule.arch_f; |
214 | |
215 | if (!arch) { |
216 | /* When arch is unspecified, we must check both masks on biarch |
217 | * as syscall number alone is ambiguous. */ |
218 | return (audit_match_class_bits(AUDIT_CLASS_SIGNAL, |
219 | mask: entry->rule.mask) && |
220 | audit_match_class_bits(AUDIT_CLASS_SIGNAL_32, |
221 | mask: entry->rule.mask)); |
222 | } |
223 | |
224 | switch (audit_classify_arch(arch: arch->val)) { |
225 | case 0: /* native */ |
226 | return (audit_match_class_bits(AUDIT_CLASS_SIGNAL, |
227 | mask: entry->rule.mask)); |
228 | case 1: /* 32bit on biarch */ |
229 | return (audit_match_class_bits(AUDIT_CLASS_SIGNAL_32, |
230 | mask: entry->rule.mask)); |
231 | default: |
232 | return 1; |
233 | } |
234 | } |
235 | #endif |
236 | |
237 | /* Common user-space to kernel rule translation. */ |
238 | static inline struct audit_entry *audit_to_entry_common(struct audit_rule_data *rule) |
239 | { |
240 | unsigned listnr; |
241 | struct audit_entry *entry; |
242 | int i, err; |
243 | |
244 | err = -EINVAL; |
245 | listnr = rule->flags & ~AUDIT_FILTER_PREPEND; |
246 | switch (listnr) { |
247 | default: |
248 | goto exit_err; |
249 | #ifdef CONFIG_AUDITSYSCALL |
250 | case AUDIT_FILTER_ENTRY: |
251 | pr_err("AUDIT_FILTER_ENTRY is deprecated\n" ); |
252 | goto exit_err; |
253 | case AUDIT_FILTER_EXIT: |
254 | case AUDIT_FILTER_URING_EXIT: |
255 | case AUDIT_FILTER_TASK: |
256 | #endif |
257 | case AUDIT_FILTER_USER: |
258 | case AUDIT_FILTER_EXCLUDE: |
259 | case AUDIT_FILTER_FS: |
260 | ; |
261 | } |
262 | if (unlikely(rule->action == AUDIT_POSSIBLE)) { |
263 | pr_err("AUDIT_POSSIBLE is deprecated\n" ); |
264 | goto exit_err; |
265 | } |
266 | if (rule->action != AUDIT_NEVER && rule->action != AUDIT_ALWAYS) |
267 | goto exit_err; |
268 | if (rule->field_count > AUDIT_MAX_FIELDS) |
269 | goto exit_err; |
270 | |
271 | err = -ENOMEM; |
272 | entry = audit_init_entry(field_count: rule->field_count); |
273 | if (!entry) |
274 | goto exit_err; |
275 | |
276 | entry->rule.flags = rule->flags & AUDIT_FILTER_PREPEND; |
277 | entry->rule.listnr = listnr; |
278 | entry->rule.action = rule->action; |
279 | entry->rule.field_count = rule->field_count; |
280 | |
281 | for (i = 0; i < AUDIT_BITMASK_SIZE; i++) |
282 | entry->rule.mask[i] = rule->mask[i]; |
283 | |
284 | for (i = 0; i < AUDIT_SYSCALL_CLASSES; i++) { |
285 | int bit = AUDIT_BITMASK_SIZE * 32 - i - 1; |
286 | __u32 *p = &entry->rule.mask[AUDIT_WORD(bit)]; |
287 | __u32 *class; |
288 | |
289 | if (!(*p & AUDIT_BIT(bit))) |
290 | continue; |
291 | *p &= ~AUDIT_BIT(bit); |
292 | class = classes[i]; |
293 | if (class) { |
294 | int j; |
295 | for (j = 0; j < AUDIT_BITMASK_SIZE; j++) |
296 | entry->rule.mask[j] |= class[j]; |
297 | } |
298 | } |
299 | |
300 | return entry; |
301 | |
302 | exit_err: |
303 | return ERR_PTR(error: err); |
304 | } |
305 | |
306 | static u32 audit_ops[] = |
307 | { |
308 | [Audit_equal] = AUDIT_EQUAL, |
309 | [Audit_not_equal] = AUDIT_NOT_EQUAL, |
310 | [Audit_bitmask] = AUDIT_BIT_MASK, |
311 | [Audit_bittest] = AUDIT_BIT_TEST, |
312 | [Audit_lt] = AUDIT_LESS_THAN, |
313 | [Audit_gt] = AUDIT_GREATER_THAN, |
314 | [Audit_le] = AUDIT_LESS_THAN_OR_EQUAL, |
315 | [Audit_ge] = AUDIT_GREATER_THAN_OR_EQUAL, |
316 | }; |
317 | |
318 | static u32 audit_to_op(u32 op) |
319 | { |
320 | u32 n; |
321 | for (n = Audit_equal; n < Audit_bad && audit_ops[n] != op; n++) |
322 | ; |
323 | return n; |
324 | } |
325 | |
326 | /* check if an audit field is valid */ |
327 | static int audit_field_valid(struct audit_entry *entry, struct audit_field *f) |
328 | { |
329 | switch (f->type) { |
330 | case AUDIT_MSGTYPE: |
331 | if (entry->rule.listnr != AUDIT_FILTER_EXCLUDE && |
332 | entry->rule.listnr != AUDIT_FILTER_USER) |
333 | return -EINVAL; |
334 | break; |
335 | case AUDIT_FSTYPE: |
336 | if (entry->rule.listnr != AUDIT_FILTER_FS) |
337 | return -EINVAL; |
338 | break; |
339 | case AUDIT_PERM: |
340 | if (entry->rule.listnr == AUDIT_FILTER_URING_EXIT) |
341 | return -EINVAL; |
342 | break; |
343 | } |
344 | |
345 | switch (entry->rule.listnr) { |
346 | case AUDIT_FILTER_FS: |
347 | switch (f->type) { |
348 | case AUDIT_FSTYPE: |
349 | case AUDIT_FILTERKEY: |
350 | break; |
351 | default: |
352 | return -EINVAL; |
353 | } |
354 | } |
355 | |
356 | /* Check for valid field type and op */ |
357 | switch (f->type) { |
358 | case AUDIT_ARG0: |
359 | case AUDIT_ARG1: |
360 | case AUDIT_ARG2: |
361 | case AUDIT_ARG3: |
362 | case AUDIT_PERS: /* <uapi/linux/personality.h> */ |
363 | case AUDIT_DEVMINOR: |
364 | /* all ops are valid */ |
365 | break; |
366 | case AUDIT_UID: |
367 | case AUDIT_EUID: |
368 | case AUDIT_SUID: |
369 | case AUDIT_FSUID: |
370 | case AUDIT_LOGINUID: |
371 | case AUDIT_OBJ_UID: |
372 | case AUDIT_GID: |
373 | case AUDIT_EGID: |
374 | case AUDIT_SGID: |
375 | case AUDIT_FSGID: |
376 | case AUDIT_OBJ_GID: |
377 | case AUDIT_PID: |
378 | case AUDIT_MSGTYPE: |
379 | case AUDIT_PPID: |
380 | case AUDIT_DEVMAJOR: |
381 | case AUDIT_EXIT: |
382 | case AUDIT_SUCCESS: |
383 | case AUDIT_INODE: |
384 | case AUDIT_SESSIONID: |
385 | case AUDIT_SUBJ_SEN: |
386 | case AUDIT_SUBJ_CLR: |
387 | case AUDIT_OBJ_LEV_LOW: |
388 | case AUDIT_OBJ_LEV_HIGH: |
389 | case AUDIT_SADDR_FAM: |
390 | /* bit ops are only useful on syscall args */ |
391 | if (f->op == Audit_bitmask || f->op == Audit_bittest) |
392 | return -EINVAL; |
393 | break; |
394 | case AUDIT_SUBJ_USER: |
395 | case AUDIT_SUBJ_ROLE: |
396 | case AUDIT_SUBJ_TYPE: |
397 | case AUDIT_OBJ_USER: |
398 | case AUDIT_OBJ_ROLE: |
399 | case AUDIT_OBJ_TYPE: |
400 | case AUDIT_WATCH: |
401 | case AUDIT_DIR: |
402 | case AUDIT_FILTERKEY: |
403 | case AUDIT_LOGINUID_SET: |
404 | case AUDIT_ARCH: |
405 | case AUDIT_FSTYPE: |
406 | case AUDIT_PERM: |
407 | case AUDIT_FILETYPE: |
408 | case AUDIT_FIELD_COMPARE: |
409 | case AUDIT_EXE: |
410 | /* only equal and not equal valid ops */ |
411 | if (f->op != Audit_not_equal && f->op != Audit_equal) |
412 | return -EINVAL; |
413 | break; |
414 | default: |
415 | /* field not recognized */ |
416 | return -EINVAL; |
417 | } |
418 | |
419 | /* Check for select valid field values */ |
420 | switch (f->type) { |
421 | case AUDIT_LOGINUID_SET: |
422 | if ((f->val != 0) && (f->val != 1)) |
423 | return -EINVAL; |
424 | break; |
425 | case AUDIT_PERM: |
426 | if (f->val & ~15) |
427 | return -EINVAL; |
428 | break; |
429 | case AUDIT_FILETYPE: |
430 | if (f->val & ~S_IFMT) |
431 | return -EINVAL; |
432 | break; |
433 | case AUDIT_FIELD_COMPARE: |
434 | if (f->val > AUDIT_MAX_FIELD_COMPARE) |
435 | return -EINVAL; |
436 | break; |
437 | case AUDIT_SADDR_FAM: |
438 | if (f->val >= AF_MAX) |
439 | return -EINVAL; |
440 | break; |
441 | default: |
442 | break; |
443 | } |
444 | |
445 | return 0; |
446 | } |
447 | |
448 | /* Translate struct audit_rule_data to kernel's rule representation. */ |
449 | static struct audit_entry *audit_data_to_entry(struct audit_rule_data *data, |
450 | size_t datasz) |
451 | { |
452 | int err = 0; |
453 | struct audit_entry *entry; |
454 | void *bufp; |
455 | size_t remain = datasz - sizeof(struct audit_rule_data); |
456 | int i; |
457 | char *str; |
458 | struct audit_fsnotify_mark *audit_mark; |
459 | |
460 | entry = audit_to_entry_common(rule: data); |
461 | if (IS_ERR(ptr: entry)) |
462 | goto exit_nofree; |
463 | |
464 | bufp = data->buf; |
465 | for (i = 0; i < data->field_count; i++) { |
466 | struct audit_field *f = &entry->rule.fields[i]; |
467 | u32 f_val; |
468 | |
469 | err = -EINVAL; |
470 | |
471 | f->op = audit_to_op(op: data->fieldflags[i]); |
472 | if (f->op == Audit_bad) |
473 | goto exit_free; |
474 | |
475 | f->type = data->fields[i]; |
476 | f_val = data->values[i]; |
477 | |
478 | /* Support legacy tests for a valid loginuid */ |
479 | if ((f->type == AUDIT_LOGINUID) && (f_val == AUDIT_UID_UNSET)) { |
480 | f->type = AUDIT_LOGINUID_SET; |
481 | f_val = 0; |
482 | entry->rule.pflags |= AUDIT_LOGINUID_LEGACY; |
483 | } |
484 | |
485 | err = audit_field_valid(entry, f); |
486 | if (err) |
487 | goto exit_free; |
488 | |
489 | err = -EINVAL; |
490 | switch (f->type) { |
491 | case AUDIT_LOGINUID: |
492 | case AUDIT_UID: |
493 | case AUDIT_EUID: |
494 | case AUDIT_SUID: |
495 | case AUDIT_FSUID: |
496 | case AUDIT_OBJ_UID: |
497 | f->uid = make_kuid(current_user_ns(), uid: f_val); |
498 | if (!uid_valid(uid: f->uid)) |
499 | goto exit_free; |
500 | break; |
501 | case AUDIT_GID: |
502 | case AUDIT_EGID: |
503 | case AUDIT_SGID: |
504 | case AUDIT_FSGID: |
505 | case AUDIT_OBJ_GID: |
506 | f->gid = make_kgid(current_user_ns(), gid: f_val); |
507 | if (!gid_valid(gid: f->gid)) |
508 | goto exit_free; |
509 | break; |
510 | case AUDIT_ARCH: |
511 | f->val = f_val; |
512 | entry->rule.arch_f = f; |
513 | break; |
514 | case AUDIT_SUBJ_USER: |
515 | case AUDIT_SUBJ_ROLE: |
516 | case AUDIT_SUBJ_TYPE: |
517 | case AUDIT_SUBJ_SEN: |
518 | case AUDIT_SUBJ_CLR: |
519 | case AUDIT_OBJ_USER: |
520 | case AUDIT_OBJ_ROLE: |
521 | case AUDIT_OBJ_TYPE: |
522 | case AUDIT_OBJ_LEV_LOW: |
523 | case AUDIT_OBJ_LEV_HIGH: |
524 | str = audit_unpack_string(bufp: &bufp, remain: &remain, len: f_val); |
525 | if (IS_ERR(ptr: str)) { |
526 | err = PTR_ERR(ptr: str); |
527 | goto exit_free; |
528 | } |
529 | entry->rule.buflen += f_val; |
530 | f->lsm_str = str; |
531 | err = security_audit_rule_init(field: f->type, op: f->op, rulestr: str, |
532 | lsmrule: (void **)&f->lsm_rule); |
533 | /* Keep currently invalid fields around in case they |
534 | * become valid after a policy reload. */ |
535 | if (err == -EINVAL) { |
536 | pr_warn("audit rule for LSM \'%s\' is invalid\n" , |
537 | str); |
538 | err = 0; |
539 | } else if (err) |
540 | goto exit_free; |
541 | break; |
542 | case AUDIT_WATCH: |
543 | str = audit_unpack_string(bufp: &bufp, remain: &remain, len: f_val); |
544 | if (IS_ERR(ptr: str)) { |
545 | err = PTR_ERR(ptr: str); |
546 | goto exit_free; |
547 | } |
548 | err = audit_to_watch(krule: &entry->rule, path: str, len: f_val, op: f->op); |
549 | if (err) { |
550 | kfree(objp: str); |
551 | goto exit_free; |
552 | } |
553 | entry->rule.buflen += f_val; |
554 | break; |
555 | case AUDIT_DIR: |
556 | str = audit_unpack_string(bufp: &bufp, remain: &remain, len: f_val); |
557 | if (IS_ERR(ptr: str)) { |
558 | err = PTR_ERR(ptr: str); |
559 | goto exit_free; |
560 | } |
561 | err = audit_make_tree(rule: &entry->rule, pathname: str, op: f->op); |
562 | kfree(objp: str); |
563 | if (err) |
564 | goto exit_free; |
565 | entry->rule.buflen += f_val; |
566 | break; |
567 | case AUDIT_INODE: |
568 | f->val = f_val; |
569 | err = audit_to_inode(krule: &entry->rule, f); |
570 | if (err) |
571 | goto exit_free; |
572 | break; |
573 | case AUDIT_FILTERKEY: |
574 | if (entry->rule.filterkey || f_val > AUDIT_MAX_KEY_LEN) |
575 | goto exit_free; |
576 | str = audit_unpack_string(bufp: &bufp, remain: &remain, len: f_val); |
577 | if (IS_ERR(ptr: str)) { |
578 | err = PTR_ERR(ptr: str); |
579 | goto exit_free; |
580 | } |
581 | entry->rule.buflen += f_val; |
582 | entry->rule.filterkey = str; |
583 | break; |
584 | case AUDIT_EXE: |
585 | if (entry->rule.exe || f_val > PATH_MAX) |
586 | goto exit_free; |
587 | str = audit_unpack_string(bufp: &bufp, remain: &remain, len: f_val); |
588 | if (IS_ERR(ptr: str)) { |
589 | err = PTR_ERR(ptr: str); |
590 | goto exit_free; |
591 | } |
592 | audit_mark = audit_alloc_mark(krule: &entry->rule, pathname: str, len: f_val); |
593 | if (IS_ERR(ptr: audit_mark)) { |
594 | kfree(objp: str); |
595 | err = PTR_ERR(ptr: audit_mark); |
596 | goto exit_free; |
597 | } |
598 | entry->rule.buflen += f_val; |
599 | entry->rule.exe = audit_mark; |
600 | break; |
601 | default: |
602 | f->val = f_val; |
603 | break; |
604 | } |
605 | } |
606 | |
607 | if (entry->rule.inode_f && entry->rule.inode_f->op == Audit_not_equal) |
608 | entry->rule.inode_f = NULL; |
609 | |
610 | exit_nofree: |
611 | return entry; |
612 | |
613 | exit_free: |
614 | if (entry->rule.tree) |
615 | audit_put_tree(tree: entry->rule.tree); /* that's the temporary one */ |
616 | if (entry->rule.exe) |
617 | audit_remove_mark(audit_mark: entry->rule.exe); /* that's the template one */ |
618 | audit_free_rule(e: entry); |
619 | return ERR_PTR(error: err); |
620 | } |
621 | |
622 | /* Pack a filter field's string representation into data block. */ |
623 | static inline size_t audit_pack_string(void **bufp, const char *str) |
624 | { |
625 | size_t len = strlen(str); |
626 | |
627 | memcpy(*bufp, str, len); |
628 | *bufp += len; |
629 | |
630 | return len; |
631 | } |
632 | |
633 | /* Translate kernel rule representation to struct audit_rule_data. */ |
634 | static struct audit_rule_data *audit_krule_to_data(struct audit_krule *krule) |
635 | { |
636 | struct audit_rule_data *data; |
637 | void *bufp; |
638 | int i; |
639 | |
640 | data = kmalloc(struct_size(data, buf, krule->buflen), GFP_KERNEL); |
641 | if (unlikely(!data)) |
642 | return NULL; |
643 | memset(data, 0, sizeof(*data)); |
644 | |
645 | data->flags = krule->flags | krule->listnr; |
646 | data->action = krule->action; |
647 | data->field_count = krule->field_count; |
648 | bufp = data->buf; |
649 | for (i = 0; i < data->field_count; i++) { |
650 | struct audit_field *f = &krule->fields[i]; |
651 | |
652 | data->fields[i] = f->type; |
653 | data->fieldflags[i] = audit_ops[f->op]; |
654 | switch (f->type) { |
655 | case AUDIT_SUBJ_USER: |
656 | case AUDIT_SUBJ_ROLE: |
657 | case AUDIT_SUBJ_TYPE: |
658 | case AUDIT_SUBJ_SEN: |
659 | case AUDIT_SUBJ_CLR: |
660 | case AUDIT_OBJ_USER: |
661 | case AUDIT_OBJ_ROLE: |
662 | case AUDIT_OBJ_TYPE: |
663 | case AUDIT_OBJ_LEV_LOW: |
664 | case AUDIT_OBJ_LEV_HIGH: |
665 | data->buflen += data->values[i] = |
666 | audit_pack_string(bufp: &bufp, str: f->lsm_str); |
667 | break; |
668 | case AUDIT_WATCH: |
669 | data->buflen += data->values[i] = |
670 | audit_pack_string(bufp: &bufp, |
671 | str: audit_watch_path(watch: krule->watch)); |
672 | break; |
673 | case AUDIT_DIR: |
674 | data->buflen += data->values[i] = |
675 | audit_pack_string(bufp: &bufp, |
676 | str: audit_tree_path(tree: krule->tree)); |
677 | break; |
678 | case AUDIT_FILTERKEY: |
679 | data->buflen += data->values[i] = |
680 | audit_pack_string(bufp: &bufp, str: krule->filterkey); |
681 | break; |
682 | case AUDIT_EXE: |
683 | data->buflen += data->values[i] = |
684 | audit_pack_string(bufp: &bufp, str: audit_mark_path(mark: krule->exe)); |
685 | break; |
686 | case AUDIT_LOGINUID_SET: |
687 | if (krule->pflags & AUDIT_LOGINUID_LEGACY && !f->val) { |
688 | data->fields[i] = AUDIT_LOGINUID; |
689 | data->values[i] = AUDIT_UID_UNSET; |
690 | break; |
691 | } |
692 | fallthrough; /* if set */ |
693 | default: |
694 | data->values[i] = f->val; |
695 | } |
696 | } |
697 | for (i = 0; i < AUDIT_BITMASK_SIZE; i++) |
698 | data->mask[i] = krule->mask[i]; |
699 | |
700 | return data; |
701 | } |
702 | |
703 | /* Compare two rules in kernel format. Considered success if rules |
704 | * don't match. */ |
705 | static int audit_compare_rule(struct audit_krule *a, struct audit_krule *b) |
706 | { |
707 | int i; |
708 | |
709 | if (a->flags != b->flags || |
710 | a->pflags != b->pflags || |
711 | a->listnr != b->listnr || |
712 | a->action != b->action || |
713 | a->field_count != b->field_count) |
714 | return 1; |
715 | |
716 | for (i = 0; i < a->field_count; i++) { |
717 | if (a->fields[i].type != b->fields[i].type || |
718 | a->fields[i].op != b->fields[i].op) |
719 | return 1; |
720 | |
721 | switch (a->fields[i].type) { |
722 | case AUDIT_SUBJ_USER: |
723 | case AUDIT_SUBJ_ROLE: |
724 | case AUDIT_SUBJ_TYPE: |
725 | case AUDIT_SUBJ_SEN: |
726 | case AUDIT_SUBJ_CLR: |
727 | case AUDIT_OBJ_USER: |
728 | case AUDIT_OBJ_ROLE: |
729 | case AUDIT_OBJ_TYPE: |
730 | case AUDIT_OBJ_LEV_LOW: |
731 | case AUDIT_OBJ_LEV_HIGH: |
732 | if (strcmp(a->fields[i].lsm_str, b->fields[i].lsm_str)) |
733 | return 1; |
734 | break; |
735 | case AUDIT_WATCH: |
736 | if (strcmp(audit_watch_path(watch: a->watch), |
737 | audit_watch_path(watch: b->watch))) |
738 | return 1; |
739 | break; |
740 | case AUDIT_DIR: |
741 | if (strcmp(audit_tree_path(tree: a->tree), |
742 | audit_tree_path(tree: b->tree))) |
743 | return 1; |
744 | break; |
745 | case AUDIT_FILTERKEY: |
746 | /* both filterkeys exist based on above type compare */ |
747 | if (strcmp(a->filterkey, b->filterkey)) |
748 | return 1; |
749 | break; |
750 | case AUDIT_EXE: |
751 | /* both paths exist based on above type compare */ |
752 | if (strcmp(audit_mark_path(mark: a->exe), |
753 | audit_mark_path(mark: b->exe))) |
754 | return 1; |
755 | break; |
756 | case AUDIT_UID: |
757 | case AUDIT_EUID: |
758 | case AUDIT_SUID: |
759 | case AUDIT_FSUID: |
760 | case AUDIT_LOGINUID: |
761 | case AUDIT_OBJ_UID: |
762 | if (!uid_eq(left: a->fields[i].uid, right: b->fields[i].uid)) |
763 | return 1; |
764 | break; |
765 | case AUDIT_GID: |
766 | case AUDIT_EGID: |
767 | case AUDIT_SGID: |
768 | case AUDIT_FSGID: |
769 | case AUDIT_OBJ_GID: |
770 | if (!gid_eq(left: a->fields[i].gid, right: b->fields[i].gid)) |
771 | return 1; |
772 | break; |
773 | default: |
774 | if (a->fields[i].val != b->fields[i].val) |
775 | return 1; |
776 | } |
777 | } |
778 | |
779 | for (i = 0; i < AUDIT_BITMASK_SIZE; i++) |
780 | if (a->mask[i] != b->mask[i]) |
781 | return 1; |
782 | |
783 | return 0; |
784 | } |
785 | |
786 | /* Duplicate LSM field information. The lsm_rule is opaque, so must be |
787 | * re-initialized. */ |
788 | static inline int audit_dupe_lsm_field(struct audit_field *df, |
789 | struct audit_field *sf) |
790 | { |
791 | int ret = 0; |
792 | char *lsm_str; |
793 | |
794 | /* our own copy of lsm_str */ |
795 | lsm_str = kstrdup(s: sf->lsm_str, GFP_KERNEL); |
796 | if (unlikely(!lsm_str)) |
797 | return -ENOMEM; |
798 | df->lsm_str = lsm_str; |
799 | |
800 | /* our own (refreshed) copy of lsm_rule */ |
801 | ret = security_audit_rule_init(field: df->type, op: df->op, rulestr: df->lsm_str, |
802 | lsmrule: (void **)&df->lsm_rule); |
803 | /* Keep currently invalid fields around in case they |
804 | * become valid after a policy reload. */ |
805 | if (ret == -EINVAL) { |
806 | pr_warn("audit rule for LSM \'%s\' is invalid\n" , |
807 | df->lsm_str); |
808 | ret = 0; |
809 | } |
810 | |
811 | return ret; |
812 | } |
813 | |
814 | /* Duplicate an audit rule. This will be a deep copy with the exception |
815 | * of the watch - that pointer is carried over. The LSM specific fields |
816 | * will be updated in the copy. The point is to be able to replace the old |
817 | * rule with the new rule in the filterlist, then free the old rule. |
818 | * The rlist element is undefined; list manipulations are handled apart from |
819 | * the initial copy. */ |
820 | struct audit_entry *audit_dupe_rule(struct audit_krule *old) |
821 | { |
822 | u32 fcount = old->field_count; |
823 | struct audit_entry *entry; |
824 | struct audit_krule *new; |
825 | char *fk; |
826 | int i, err = 0; |
827 | |
828 | entry = audit_init_entry(field_count: fcount); |
829 | if (unlikely(!entry)) |
830 | return ERR_PTR(error: -ENOMEM); |
831 | |
832 | new = &entry->rule; |
833 | new->flags = old->flags; |
834 | new->pflags = old->pflags; |
835 | new->listnr = old->listnr; |
836 | new->action = old->action; |
837 | for (i = 0; i < AUDIT_BITMASK_SIZE; i++) |
838 | new->mask[i] = old->mask[i]; |
839 | new->prio = old->prio; |
840 | new->buflen = old->buflen; |
841 | new->inode_f = old->inode_f; |
842 | new->field_count = old->field_count; |
843 | |
844 | /* |
845 | * note that we are OK with not refcounting here; audit_match_tree() |
846 | * never dereferences tree and we can't get false positives there |
847 | * since we'd have to have rule gone from the list *and* removed |
848 | * before the chunks found by lookup had been allocated, i.e. before |
849 | * the beginning of list scan. |
850 | */ |
851 | new->tree = old->tree; |
852 | memcpy(new->fields, old->fields, sizeof(struct audit_field) * fcount); |
853 | |
854 | /* deep copy this information, updating the lsm_rule fields, because |
855 | * the originals will all be freed when the old rule is freed. */ |
856 | for (i = 0; i < fcount; i++) { |
857 | switch (new->fields[i].type) { |
858 | case AUDIT_SUBJ_USER: |
859 | case AUDIT_SUBJ_ROLE: |
860 | case AUDIT_SUBJ_TYPE: |
861 | case AUDIT_SUBJ_SEN: |
862 | case AUDIT_SUBJ_CLR: |
863 | case AUDIT_OBJ_USER: |
864 | case AUDIT_OBJ_ROLE: |
865 | case AUDIT_OBJ_TYPE: |
866 | case AUDIT_OBJ_LEV_LOW: |
867 | case AUDIT_OBJ_LEV_HIGH: |
868 | err = audit_dupe_lsm_field(df: &new->fields[i], |
869 | sf: &old->fields[i]); |
870 | break; |
871 | case AUDIT_FILTERKEY: |
872 | fk = kstrdup(s: old->filterkey, GFP_KERNEL); |
873 | if (unlikely(!fk)) |
874 | err = -ENOMEM; |
875 | else |
876 | new->filterkey = fk; |
877 | break; |
878 | case AUDIT_EXE: |
879 | err = audit_dupe_exe(new, old); |
880 | break; |
881 | } |
882 | if (err) { |
883 | if (new->exe) |
884 | audit_remove_mark(audit_mark: new->exe); |
885 | audit_free_rule(e: entry); |
886 | return ERR_PTR(error: err); |
887 | } |
888 | } |
889 | |
890 | if (old->watch) { |
891 | audit_get_watch(watch: old->watch); |
892 | new->watch = old->watch; |
893 | } |
894 | |
895 | return entry; |
896 | } |
897 | |
898 | /* Find an existing audit rule. |
899 | * Caller must hold audit_filter_mutex to prevent stale rule data. */ |
900 | static struct audit_entry *audit_find_rule(struct audit_entry *entry, |
901 | struct list_head **p) |
902 | { |
903 | struct audit_entry *e, *found = NULL; |
904 | struct list_head *list; |
905 | int h; |
906 | |
907 | if (entry->rule.inode_f) { |
908 | h = audit_hash_ino(ino: entry->rule.inode_f->val); |
909 | *p = list = &audit_inode_hash[h]; |
910 | } else if (entry->rule.watch) { |
911 | /* we don't know the inode number, so must walk entire hash */ |
912 | for (h = 0; h < AUDIT_INODE_BUCKETS; h++) { |
913 | list = &audit_inode_hash[h]; |
914 | list_for_each_entry(e, list, list) |
915 | if (!audit_compare_rule(a: &entry->rule, b: &e->rule)) { |
916 | found = e; |
917 | goto out; |
918 | } |
919 | } |
920 | goto out; |
921 | } else { |
922 | *p = list = &audit_filter_list[entry->rule.listnr]; |
923 | } |
924 | |
925 | list_for_each_entry(e, list, list) |
926 | if (!audit_compare_rule(a: &entry->rule, b: &e->rule)) { |
927 | found = e; |
928 | goto out; |
929 | } |
930 | |
931 | out: |
932 | return found; |
933 | } |
934 | |
935 | static u64 prio_low = ~0ULL/2; |
936 | static u64 prio_high = ~0ULL/2 - 1; |
937 | |
938 | /* Add rule to given filterlist if not a duplicate. */ |
939 | static inline int audit_add_rule(struct audit_entry *entry) |
940 | { |
941 | struct audit_entry *e; |
942 | struct audit_watch *watch = entry->rule.watch; |
943 | struct audit_tree *tree = entry->rule.tree; |
944 | struct list_head *list; |
945 | int err = 0; |
946 | #ifdef CONFIG_AUDITSYSCALL |
947 | int dont_count = 0; |
948 | |
949 | /* If any of these, don't count towards total */ |
950 | switch (entry->rule.listnr) { |
951 | case AUDIT_FILTER_USER: |
952 | case AUDIT_FILTER_EXCLUDE: |
953 | case AUDIT_FILTER_FS: |
954 | dont_count = 1; |
955 | } |
956 | #endif |
957 | |
958 | mutex_lock(&audit_filter_mutex); |
959 | e = audit_find_rule(entry, p: &list); |
960 | if (e) { |
961 | mutex_unlock(lock: &audit_filter_mutex); |
962 | err = -EEXIST; |
963 | /* normally audit_add_tree_rule() will free it on failure */ |
964 | if (tree) |
965 | audit_put_tree(tree); |
966 | return err; |
967 | } |
968 | |
969 | if (watch) { |
970 | /* audit_filter_mutex is dropped and re-taken during this call */ |
971 | err = audit_add_watch(krule: &entry->rule, list: &list); |
972 | if (err) { |
973 | mutex_unlock(lock: &audit_filter_mutex); |
974 | /* |
975 | * normally audit_add_tree_rule() will free it |
976 | * on failure |
977 | */ |
978 | if (tree) |
979 | audit_put_tree(tree); |
980 | return err; |
981 | } |
982 | } |
983 | if (tree) { |
984 | err = audit_add_tree_rule(rule: &entry->rule); |
985 | if (err) { |
986 | mutex_unlock(lock: &audit_filter_mutex); |
987 | return err; |
988 | } |
989 | } |
990 | |
991 | entry->rule.prio = ~0ULL; |
992 | if (entry->rule.listnr == AUDIT_FILTER_EXIT || |
993 | entry->rule.listnr == AUDIT_FILTER_URING_EXIT) { |
994 | if (entry->rule.flags & AUDIT_FILTER_PREPEND) |
995 | entry->rule.prio = ++prio_high; |
996 | else |
997 | entry->rule.prio = --prio_low; |
998 | } |
999 | |
1000 | if (entry->rule.flags & AUDIT_FILTER_PREPEND) { |
1001 | list_add(new: &entry->rule.list, |
1002 | head: &audit_rules_list[entry->rule.listnr]); |
1003 | list_add_rcu(new: &entry->list, head: list); |
1004 | entry->rule.flags &= ~AUDIT_FILTER_PREPEND; |
1005 | } else { |
1006 | list_add_tail(new: &entry->rule.list, |
1007 | head: &audit_rules_list[entry->rule.listnr]); |
1008 | list_add_tail_rcu(new: &entry->list, head: list); |
1009 | } |
1010 | #ifdef CONFIG_AUDITSYSCALL |
1011 | if (!dont_count) |
1012 | audit_n_rules++; |
1013 | |
1014 | if (!audit_match_signal(entry)) |
1015 | audit_signals++; |
1016 | #endif |
1017 | mutex_unlock(lock: &audit_filter_mutex); |
1018 | |
1019 | return err; |
1020 | } |
1021 | |
1022 | /* Remove an existing rule from filterlist. */ |
1023 | int audit_del_rule(struct audit_entry *entry) |
1024 | { |
1025 | struct audit_entry *e; |
1026 | struct audit_tree *tree = entry->rule.tree; |
1027 | struct list_head *list; |
1028 | int ret = 0; |
1029 | #ifdef CONFIG_AUDITSYSCALL |
1030 | int dont_count = 0; |
1031 | |
1032 | /* If any of these, don't count towards total */ |
1033 | switch (entry->rule.listnr) { |
1034 | case AUDIT_FILTER_USER: |
1035 | case AUDIT_FILTER_EXCLUDE: |
1036 | case AUDIT_FILTER_FS: |
1037 | dont_count = 1; |
1038 | } |
1039 | #endif |
1040 | |
1041 | mutex_lock(&audit_filter_mutex); |
1042 | e = audit_find_rule(entry, p: &list); |
1043 | if (!e) { |
1044 | ret = -ENOENT; |
1045 | goto out; |
1046 | } |
1047 | |
1048 | if (e->rule.watch) |
1049 | audit_remove_watch_rule(krule: &e->rule); |
1050 | |
1051 | if (e->rule.tree) |
1052 | audit_remove_tree_rule(rule: &e->rule); |
1053 | |
1054 | if (e->rule.exe) |
1055 | audit_remove_mark_rule(krule: &e->rule); |
1056 | |
1057 | #ifdef CONFIG_AUDITSYSCALL |
1058 | if (!dont_count) |
1059 | audit_n_rules--; |
1060 | |
1061 | if (!audit_match_signal(entry)) |
1062 | audit_signals--; |
1063 | #endif |
1064 | |
1065 | list_del_rcu(entry: &e->list); |
1066 | list_del(entry: &e->rule.list); |
1067 | call_rcu(head: &e->rcu, func: audit_free_rule_rcu); |
1068 | |
1069 | out: |
1070 | mutex_unlock(lock: &audit_filter_mutex); |
1071 | |
1072 | if (tree) |
1073 | audit_put_tree(tree); /* that's the temporary one */ |
1074 | |
1075 | return ret; |
1076 | } |
1077 | |
1078 | /* List rules using struct audit_rule_data. */ |
1079 | static void audit_list_rules(int seq, struct sk_buff_head *q) |
1080 | { |
1081 | struct sk_buff *skb; |
1082 | struct audit_krule *r; |
1083 | int i; |
1084 | |
1085 | /* This is a blocking read, so use audit_filter_mutex instead of rcu |
1086 | * iterator to sync with list writers. */ |
1087 | for (i = 0; i < AUDIT_NR_FILTERS; i++) { |
1088 | list_for_each_entry(r, &audit_rules_list[i], list) { |
1089 | struct audit_rule_data *data; |
1090 | |
1091 | data = audit_krule_to_data(krule: r); |
1092 | if (unlikely(!data)) |
1093 | break; |
1094 | skb = audit_make_reply(seq, AUDIT_LIST_RULES, done: 0, multi: 1, |
1095 | payload: data, |
1096 | struct_size(data, buf, data->buflen)); |
1097 | if (skb) |
1098 | skb_queue_tail(list: q, newsk: skb); |
1099 | kfree(objp: data); |
1100 | } |
1101 | } |
1102 | skb = audit_make_reply(seq, AUDIT_LIST_RULES, done: 1, multi: 1, NULL, size: 0); |
1103 | if (skb) |
1104 | skb_queue_tail(list: q, newsk: skb); |
1105 | } |
1106 | |
1107 | /* Log rule additions and removals */ |
1108 | static void audit_log_rule_change(char *action, struct audit_krule *rule, int res) |
1109 | { |
1110 | struct audit_buffer *ab; |
1111 | |
1112 | if (!audit_enabled) |
1113 | return; |
1114 | |
1115 | ab = audit_log_start(ctx: audit_context(), GFP_KERNEL, AUDIT_CONFIG_CHANGE); |
1116 | if (!ab) |
1117 | return; |
1118 | audit_log_session_info(ab); |
1119 | audit_log_task_context(ab); |
1120 | audit_log_format(ab, fmt: " op=%s" , action); |
1121 | audit_log_key(ab, key: rule->filterkey); |
1122 | audit_log_format(ab, fmt: " list=%d res=%d" , rule->listnr, res); |
1123 | audit_log_end(ab); |
1124 | } |
1125 | |
1126 | /** |
1127 | * audit_rule_change - apply all rules to the specified message type |
1128 | * @type: audit message type |
1129 | * @seq: netlink audit message sequence (serial) number |
1130 | * @data: payload data |
1131 | * @datasz: size of payload data |
1132 | */ |
1133 | int audit_rule_change(int type, int seq, void *data, size_t datasz) |
1134 | { |
1135 | int err = 0; |
1136 | struct audit_entry *entry; |
1137 | |
1138 | switch (type) { |
1139 | case AUDIT_ADD_RULE: |
1140 | entry = audit_data_to_entry(data, datasz); |
1141 | if (IS_ERR(ptr: entry)) |
1142 | return PTR_ERR(ptr: entry); |
1143 | err = audit_add_rule(entry); |
1144 | audit_log_rule_change(action: "add_rule" , rule: &entry->rule, res: !err); |
1145 | break; |
1146 | case AUDIT_DEL_RULE: |
1147 | entry = audit_data_to_entry(data, datasz); |
1148 | if (IS_ERR(ptr: entry)) |
1149 | return PTR_ERR(ptr: entry); |
1150 | err = audit_del_rule(entry); |
1151 | audit_log_rule_change(action: "remove_rule" , rule: &entry->rule, res: !err); |
1152 | break; |
1153 | default: |
1154 | WARN_ON(1); |
1155 | return -EINVAL; |
1156 | } |
1157 | |
1158 | if (err || type == AUDIT_DEL_RULE) { |
1159 | if (entry->rule.exe) |
1160 | audit_remove_mark(audit_mark: entry->rule.exe); |
1161 | audit_free_rule(e: entry); |
1162 | } |
1163 | |
1164 | return err; |
1165 | } |
1166 | |
1167 | /** |
1168 | * audit_list_rules_send - list the audit rules |
1169 | * @request_skb: skb of request we are replying to (used to target the reply) |
1170 | * @seq: netlink audit message sequence (serial) number |
1171 | */ |
1172 | int audit_list_rules_send(struct sk_buff *request_skb, int seq) |
1173 | { |
1174 | struct task_struct *tsk; |
1175 | struct audit_netlink_list *dest; |
1176 | |
1177 | /* We can't just spew out the rules here because we might fill |
1178 | * the available socket buffer space and deadlock waiting for |
1179 | * auditctl to read from it... which isn't ever going to |
1180 | * happen if we're actually running in the context of auditctl |
1181 | * trying to _send_ the stuff */ |
1182 | |
1183 | dest = kmalloc(size: sizeof(*dest), GFP_KERNEL); |
1184 | if (!dest) |
1185 | return -ENOMEM; |
1186 | dest->net = get_net(net: sock_net(NETLINK_CB(request_skb).sk)); |
1187 | dest->portid = NETLINK_CB(request_skb).portid; |
1188 | skb_queue_head_init(list: &dest->q); |
1189 | |
1190 | mutex_lock(&audit_filter_mutex); |
1191 | audit_list_rules(seq, q: &dest->q); |
1192 | mutex_unlock(lock: &audit_filter_mutex); |
1193 | |
1194 | tsk = kthread_run(audit_send_list_thread, dest, "audit_send_list" ); |
1195 | if (IS_ERR(ptr: tsk)) { |
1196 | skb_queue_purge(list: &dest->q); |
1197 | put_net(net: dest->net); |
1198 | kfree(objp: dest); |
1199 | return PTR_ERR(ptr: tsk); |
1200 | } |
1201 | |
1202 | return 0; |
1203 | } |
1204 | |
1205 | int audit_comparator(u32 left, u32 op, u32 right) |
1206 | { |
1207 | switch (op) { |
1208 | case Audit_equal: |
1209 | return (left == right); |
1210 | case Audit_not_equal: |
1211 | return (left != right); |
1212 | case Audit_lt: |
1213 | return (left < right); |
1214 | case Audit_le: |
1215 | return (left <= right); |
1216 | case Audit_gt: |
1217 | return (left > right); |
1218 | case Audit_ge: |
1219 | return (left >= right); |
1220 | case Audit_bitmask: |
1221 | return (left & right); |
1222 | case Audit_bittest: |
1223 | return ((left & right) == right); |
1224 | default: |
1225 | return 0; |
1226 | } |
1227 | } |
1228 | |
1229 | int audit_uid_comparator(kuid_t left, u32 op, kuid_t right) |
1230 | { |
1231 | switch (op) { |
1232 | case Audit_equal: |
1233 | return uid_eq(left, right); |
1234 | case Audit_not_equal: |
1235 | return !uid_eq(left, right); |
1236 | case Audit_lt: |
1237 | return uid_lt(left, right); |
1238 | case Audit_le: |
1239 | return uid_lte(left, right); |
1240 | case Audit_gt: |
1241 | return uid_gt(left, right); |
1242 | case Audit_ge: |
1243 | return uid_gte(left, right); |
1244 | case Audit_bitmask: |
1245 | case Audit_bittest: |
1246 | default: |
1247 | return 0; |
1248 | } |
1249 | } |
1250 | |
1251 | int audit_gid_comparator(kgid_t left, u32 op, kgid_t right) |
1252 | { |
1253 | switch (op) { |
1254 | case Audit_equal: |
1255 | return gid_eq(left, right); |
1256 | case Audit_not_equal: |
1257 | return !gid_eq(left, right); |
1258 | case Audit_lt: |
1259 | return gid_lt(left, right); |
1260 | case Audit_le: |
1261 | return gid_lte(left, right); |
1262 | case Audit_gt: |
1263 | return gid_gt(left, right); |
1264 | case Audit_ge: |
1265 | return gid_gte(left, right); |
1266 | case Audit_bitmask: |
1267 | case Audit_bittest: |
1268 | default: |
1269 | return 0; |
1270 | } |
1271 | } |
1272 | |
1273 | /** |
1274 | * parent_len - find the length of the parent portion of a pathname |
1275 | * @path: pathname of which to determine length |
1276 | */ |
1277 | int parent_len(const char *path) |
1278 | { |
1279 | int plen; |
1280 | const char *p; |
1281 | |
1282 | plen = strlen(path); |
1283 | |
1284 | if (plen == 0) |
1285 | return plen; |
1286 | |
1287 | /* disregard trailing slashes */ |
1288 | p = path + plen - 1; |
1289 | while ((*p == '/') && (p > path)) |
1290 | p--; |
1291 | |
1292 | /* walk backward until we find the next slash or hit beginning */ |
1293 | while ((*p != '/') && (p > path)) |
1294 | p--; |
1295 | |
1296 | /* did we find a slash? Then increment to include it in path */ |
1297 | if (*p == '/') |
1298 | p++; |
1299 | |
1300 | return p - path; |
1301 | } |
1302 | |
1303 | /** |
1304 | * audit_compare_dname_path - compare given dentry name with last component in |
1305 | * given path. Return of 0 indicates a match. |
1306 | * @dname: dentry name that we're comparing |
1307 | * @path: full pathname that we're comparing |
1308 | * @parentlen: length of the parent if known. Passing in AUDIT_NAME_FULL |
1309 | * here indicates that we must compute this value. |
1310 | */ |
1311 | int audit_compare_dname_path(const struct qstr *dname, const char *path, int parentlen) |
1312 | { |
1313 | int dlen, pathlen; |
1314 | const char *p; |
1315 | |
1316 | dlen = dname->len; |
1317 | pathlen = strlen(path); |
1318 | if (pathlen < dlen) |
1319 | return 1; |
1320 | |
1321 | parentlen = parentlen == AUDIT_NAME_FULL ? parent_len(path) : parentlen; |
1322 | if (pathlen - parentlen != dlen) |
1323 | return 1; |
1324 | |
1325 | p = path + parentlen; |
1326 | |
1327 | return strncmp(p, dname->name, dlen); |
1328 | } |
1329 | |
1330 | int audit_filter(int msgtype, unsigned int listtype) |
1331 | { |
1332 | struct audit_entry *e; |
1333 | int ret = 1; /* Audit by default */ |
1334 | |
1335 | rcu_read_lock(); |
1336 | list_for_each_entry_rcu(e, &audit_filter_list[listtype], list) { |
1337 | int i, result = 0; |
1338 | |
1339 | for (i = 0; i < e->rule.field_count; i++) { |
1340 | struct audit_field *f = &e->rule.fields[i]; |
1341 | pid_t pid; |
1342 | u32 sid; |
1343 | |
1344 | switch (f->type) { |
1345 | case AUDIT_PID: |
1346 | pid = task_pid_nr(current); |
1347 | result = audit_comparator(left: pid, op: f->op, right: f->val); |
1348 | break; |
1349 | case AUDIT_UID: |
1350 | result = audit_uid_comparator(current_uid(), op: f->op, right: f->uid); |
1351 | break; |
1352 | case AUDIT_GID: |
1353 | result = audit_gid_comparator(current_gid(), op: f->op, right: f->gid); |
1354 | break; |
1355 | case AUDIT_LOGINUID: |
1356 | result = audit_uid_comparator(left: audit_get_loginuid(current), |
1357 | op: f->op, right: f->uid); |
1358 | break; |
1359 | case AUDIT_LOGINUID_SET: |
1360 | result = audit_comparator(left: audit_loginuid_set(current), |
1361 | op: f->op, right: f->val); |
1362 | break; |
1363 | case AUDIT_MSGTYPE: |
1364 | result = audit_comparator(left: msgtype, op: f->op, right: f->val); |
1365 | break; |
1366 | case AUDIT_SUBJ_USER: |
1367 | case AUDIT_SUBJ_ROLE: |
1368 | case AUDIT_SUBJ_TYPE: |
1369 | case AUDIT_SUBJ_SEN: |
1370 | case AUDIT_SUBJ_CLR: |
1371 | if (f->lsm_rule) { |
1372 | security_current_getsecid_subj(secid: &sid); |
1373 | result = security_audit_rule_match(secid: sid, |
1374 | field: f->type, op: f->op, lsmrule: f->lsm_rule); |
1375 | } |
1376 | break; |
1377 | case AUDIT_EXE: |
1378 | result = audit_exe_compare(current, mark: e->rule.exe); |
1379 | if (f->op == Audit_not_equal) |
1380 | result = !result; |
1381 | break; |
1382 | default: |
1383 | goto unlock_and_return; |
1384 | } |
1385 | if (result < 0) /* error */ |
1386 | goto unlock_and_return; |
1387 | if (!result) |
1388 | break; |
1389 | } |
1390 | if (result > 0) { |
1391 | if (e->rule.action == AUDIT_NEVER || listtype == AUDIT_FILTER_EXCLUDE) |
1392 | ret = 0; |
1393 | break; |
1394 | } |
1395 | } |
1396 | unlock_and_return: |
1397 | rcu_read_unlock(); |
1398 | return ret; |
1399 | } |
1400 | |
1401 | static int update_lsm_rule(struct audit_krule *r) |
1402 | { |
1403 | struct audit_entry *entry = container_of(r, struct audit_entry, rule); |
1404 | struct audit_entry *nentry; |
1405 | int err = 0; |
1406 | |
1407 | if (!security_audit_rule_known(krule: r)) |
1408 | return 0; |
1409 | |
1410 | nentry = audit_dupe_rule(old: r); |
1411 | if (entry->rule.exe) |
1412 | audit_remove_mark(audit_mark: entry->rule.exe); |
1413 | if (IS_ERR(ptr: nentry)) { |
1414 | /* save the first error encountered for the |
1415 | * return value */ |
1416 | err = PTR_ERR(ptr: nentry); |
1417 | audit_panic(message: "error updating LSM filters" ); |
1418 | if (r->watch) |
1419 | list_del(entry: &r->rlist); |
1420 | list_del_rcu(entry: &entry->list); |
1421 | list_del(entry: &r->list); |
1422 | } else { |
1423 | if (r->watch || r->tree) |
1424 | list_replace_init(old: &r->rlist, new: &nentry->rule.rlist); |
1425 | list_replace_rcu(old: &entry->list, new: &nentry->list); |
1426 | list_replace(old: &r->list, new: &nentry->rule.list); |
1427 | } |
1428 | call_rcu(head: &entry->rcu, func: audit_free_rule_rcu); |
1429 | |
1430 | return err; |
1431 | } |
1432 | |
1433 | /* This function will re-initialize the lsm_rule field of all applicable rules. |
1434 | * It will traverse the filter lists serarching for rules that contain LSM |
1435 | * specific filter fields. When such a rule is found, it is copied, the |
1436 | * LSM field is re-initialized, and the old rule is replaced with the |
1437 | * updated rule. */ |
1438 | int audit_update_lsm_rules(void) |
1439 | { |
1440 | struct audit_krule *r, *n; |
1441 | int i, err = 0; |
1442 | |
1443 | /* audit_filter_mutex synchronizes the writers */ |
1444 | mutex_lock(&audit_filter_mutex); |
1445 | |
1446 | for (i = 0; i < AUDIT_NR_FILTERS; i++) { |
1447 | list_for_each_entry_safe(r, n, &audit_rules_list[i], list) { |
1448 | int res = update_lsm_rule(r); |
1449 | if (!err) |
1450 | err = res; |
1451 | } |
1452 | } |
1453 | mutex_unlock(lock: &audit_filter_mutex); |
1454 | |
1455 | return err; |
1456 | } |
1457 | |