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> */
39struct 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};
52static 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
63DEFINE_MUTEX(audit_filter_mutex);
64
65static 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(f->lsm_str);
79		security_audit_rule_free(f->lsm_rule);
80	}
81}
82
83static 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(erule->watch);
91	if (erule->fields)
92		for (i = 0; i < erule->field_count; i++)
93			audit_free_lsm_field(&erule->fields[i]);
94	kfree(erule->fields);
95	kfree(erule->filterkey);
96	kfree(e);
97}
98
99void 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. */
106static 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(sizeof(*entry), GFP_KERNEL);
112	if (unlikely(!entry))
113		return NULL;
114
115	fields = kcalloc(field_count, sizeof(*fields), GFP_KERNEL);
116	if (unlikely(!fields)) {
117		kfree(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. */
127char *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(-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(-ENAMETOOLONG);
139
140	str = kmalloc(len + 1, GFP_KERNEL);
141	if (unlikely(!str))
142		return ERR_PTR(-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. */
153static 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
166static __u32 *classes[AUDIT_SYSCALL_CLASSES];
167
168int __init audit_register_class(int class, unsigned *list)
169{
170	__u32 *p = kcalloc(AUDIT_BITMASK_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(p);
177			return -EINVAL;
178		}
179		p[AUDIT_WORD(n)] |= AUDIT_BIT(n);
180	}
181	if (class >= AUDIT_SYSCALL_CLASSES || classes[class]) {
182		kfree(p);
183		return -EINVAL;
184	}
185	classes[class] = p;
186	return 0;
187}
188
189int 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
199static 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
211static 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					       entry->rule.mask) &&
220			audit_match_class_bits(AUDIT_CLASS_SIGNAL_32,
221					       entry->rule.mask));
222	}
223
224	switch (audit_classify_arch(arch->val)) {
225	case 0: /* native */
226		return (audit_match_class_bits(AUDIT_CLASS_SIGNAL,
227					       entry->rule.mask));
228	case 1: /* 32bit on biarch */
229		return (audit_match_class_bits(AUDIT_CLASS_SIGNAL_32,
230					       entry->rule.mask));
231	default:
232		return 1;
233	}
234}
235#endif
236
237/* Common user-space to kernel rule translation. */
238static 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(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
302exit_err:
303	return ERR_PTR(err);
304}
305
306static 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
318static 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 */
327static 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. */
449static 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(data);
461	if (IS_ERR(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(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(), f_val);
498			if (!uid_valid(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(), f_val);
507			if (!gid_valid(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, &remain, f_val);
525			if (IS_ERR(str)) {
526				err = PTR_ERR(str);
527				goto exit_free;
528			}
529			entry->rule.buflen += f_val;
530			f->lsm_str = str;
531			err = security_audit_rule_init(f->type, f->op, str,
532						       (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, &remain, f_val);
544			if (IS_ERR(str)) {
545				err = PTR_ERR(str);
546				goto exit_free;
547			}
548			err = audit_to_watch(&entry->rule, str, f_val, f->op);
549			if (err) {
550				kfree(str);
551				goto exit_free;
552			}
553			entry->rule.buflen += f_val;
554			break;
555		case AUDIT_DIR:
556			str = audit_unpack_string(&bufp, &remain, f_val);
557			if (IS_ERR(str)) {
558				err = PTR_ERR(str);
559				goto exit_free;
560			}
561			err = audit_make_tree(&entry->rule, str, f->op);
562			kfree(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(&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, &remain, f_val);
577			if (IS_ERR(str)) {
578				err = PTR_ERR(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, &remain, f_val);
588			if (IS_ERR(str)) {
589				err = PTR_ERR(str);
590				goto exit_free;
591			}
592			audit_mark = audit_alloc_mark(&entry->rule, str, f_val);
593			if (IS_ERR(audit_mark)) {
594				kfree(str);
595				err = PTR_ERR(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
610exit_nofree:
611	return entry;
612
613exit_free:
614	if (entry->rule.tree)
615		audit_put_tree(entry->rule.tree); /* that's the temporary one */
616	if (entry->rule.exe)
617		audit_remove_mark(entry->rule.exe); /* that's the template one */
618	audit_free_rule(entry);
619	return ERR_PTR(err);
620}
621
622/* Pack a filter field's string representation into data block. */
623static 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. */
634static 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, f->lsm_str);
667			break;
668		case AUDIT_WATCH:
669			data->buflen += data->values[i] =
670				audit_pack_string(&bufp,
671						  audit_watch_path(krule->watch));
672			break;
673		case AUDIT_DIR:
674			data->buflen += data->values[i] =
675				audit_pack_string(&bufp,
676						  audit_tree_path(krule->tree));
677			break;
678		case AUDIT_FILTERKEY:
679			data->buflen += data->values[i] =
680				audit_pack_string(&bufp, krule->filterkey);
681			break;
682		case AUDIT_EXE:
683			data->buflen += data->values[i] =
684				audit_pack_string(&bufp, audit_mark_path(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. */
705static 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(a->watch),
737				   audit_watch_path(b->watch)))
738				return 1;
739			break;
740		case AUDIT_DIR:
741			if (strcmp(audit_tree_path(a->tree),
742				   audit_tree_path(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(a->exe),
753				   audit_mark_path(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(a->fields[i].uid, 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(a->fields[i].gid, 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. */
788static inline int audit_dupe_lsm_field(struct audit_field *df,
789					   struct audit_field *sf)
790{
791	int ret;
792	char *lsm_str;
793
794	/* our own copy of lsm_str */
795	lsm_str = kstrdup(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(df->type, df->op, df->lsm_str,
802				       (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. */
820struct 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(fcount);
829	if (unlikely(!entry))
830		return ERR_PTR(-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(&new->fields[i],
869						       &old->fields[i]);
870			break;
871		case AUDIT_FILTERKEY:
872			fk = kstrdup(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(new->exe);
885			audit_free_rule(entry);
886			return ERR_PTR(err);
887		}
888	}
889
890	if (old->watch) {
891		audit_get_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. */
900static 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(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(&entry->rule, &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(&entry->rule, &e->rule)) {
927			found = e;
928			goto out;
929		}
930
931out:
932	return found;
933}
934
935static u64 prio_low = ~0ULL/2;
936static u64 prio_high = ~0ULL/2 - 1;
937
938/* Add rule to given filterlist if not a duplicate. */
939static 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, &list);
960	if (e) {
961		mutex_unlock(&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(&entry->rule, &list);
972		if (err) {
973			mutex_unlock(&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(&entry->rule);
985		if (err) {
986			mutex_unlock(&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(&entry->rule.list,
1002			 &audit_rules_list[entry->rule.listnr]);
1003		list_add_rcu(&entry->list, list);
1004		entry->rule.flags &= ~AUDIT_FILTER_PREPEND;
1005	} else {
1006		list_add_tail(&entry->rule.list,
1007			      &audit_rules_list[entry->rule.listnr]);
1008		list_add_tail_rcu(&entry->list, 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(&audit_filter_mutex);
1018
1019	return err;
1020}
1021
1022/* Remove an existing rule from filterlist. */
1023int 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, &list);
1043	if (!e) {
1044		ret = -ENOENT;
1045		goto out;
1046	}
1047
1048	if (e->rule.watch)
1049		audit_remove_watch_rule(&e->rule);
1050
1051	if (e->rule.tree)
1052		audit_remove_tree_rule(&e->rule);
1053
1054	if (e->rule.exe)
1055		audit_remove_mark_rule(&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(&e->list);
1066	list_del(&e->rule.list);
1067	call_rcu(&e->rcu, audit_free_rule_rcu);
1068
1069out:
1070	mutex_unlock(&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. */
1079static 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(r);
1092			if (unlikely(!data))
1093				break;
1094			skb = audit_make_reply(seq, AUDIT_LIST_RULES, 0, 1,
1095					       data,
1096					       struct_size(data, buf, data->buflen));
1097			if (skb)
1098				skb_queue_tail(q, skb);
1099			kfree(data);
1100		}
1101	}
1102	skb = audit_make_reply(seq, AUDIT_LIST_RULES, 1, 1, NULL, 0);
1103	if (skb)
1104		skb_queue_tail(q, skb);
1105}
1106
1107/* Log rule additions and removals */
1108static 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(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, " op=%s", action);
1121	audit_log_key(ab, rule->filterkey);
1122	audit_log_format(ab, " 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 */
1133int 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(entry))
1142			return PTR_ERR(entry);
1143		err = audit_add_rule(entry);
1144		audit_log_rule_change("add_rule", &entry->rule, !err);
1145		break;
1146	case AUDIT_DEL_RULE:
1147		entry = audit_data_to_entry(data, datasz);
1148		if (IS_ERR(entry))
1149			return PTR_ERR(entry);
1150		err = audit_del_rule(entry);
1151		audit_log_rule_change("remove_rule", &entry->rule, !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(entry->rule.exe);
1161		audit_free_rule(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 */
1172int 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(sizeof(*dest), GFP_KERNEL);
1184	if (!dest)
1185		return -ENOMEM;
1186	dest->net = get_net(sock_net(NETLINK_CB(request_skb).sk));
1187	dest->portid = NETLINK_CB(request_skb).portid;
1188	skb_queue_head_init(&dest->q);
1189
1190	mutex_lock(&audit_filter_mutex);
1191	audit_list_rules(seq, &dest->q);
1192	mutex_unlock(&audit_filter_mutex);
1193
1194	tsk = kthread_run(audit_send_list_thread, dest, "audit_send_list");
1195	if (IS_ERR(tsk)) {
1196		skb_queue_purge(&dest->q);
1197		put_net(dest->net);
1198		kfree(dest);
1199		return PTR_ERR(tsk);
1200	}
1201
1202	return 0;
1203}
1204
1205int 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
1229int 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
1251int 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 */
1277int 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 */
1311int 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
1330int 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(pid, f->op, f->val);
1348				break;
1349			case AUDIT_UID:
1350				result = audit_uid_comparator(current_uid(), f->op, f->uid);
1351				break;
1352			case AUDIT_GID:
1353				result = audit_gid_comparator(current_gid(), f->op, f->gid);
1354				break;
1355			case AUDIT_LOGINUID:
1356				result = audit_uid_comparator(audit_get_loginuid(current),
1357							      f->op, f->uid);
1358				break;
1359			case AUDIT_LOGINUID_SET:
1360				result = audit_comparator(audit_loginuid_set(current),
1361							  f->op, f->val);
1362				break;
1363			case AUDIT_MSGTYPE:
1364				result = audit_comparator(msgtype, f->op, 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(&sid);
1373					result = security_audit_rule_match(sid,
1374						   f->type, f->op, f->lsm_rule);
1375				}
1376				break;
1377			case AUDIT_EXE:
1378				result = audit_exe_compare(current, 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	}
1396unlock_and_return:
1397	rcu_read_unlock();
1398	return ret;
1399}
1400
1401static 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(r))
1408		return 0;
1409
1410	nentry = audit_dupe_rule(r);
1411	if (entry->rule.exe)
1412		audit_remove_mark(entry->rule.exe);
1413	if (IS_ERR(nentry)) {
1414		/* save the first error encountered for the
1415		 * return value */
1416		err = PTR_ERR(nentry);
1417		audit_panic("error updating LSM filters");
1418		if (r->watch)
1419			list_del(&r->rlist);
1420		list_del_rcu(&entry->list);
1421		list_del(&r->list);
1422	} else {
1423		if (r->watch || r->tree)
1424			list_replace_init(&r->rlist, &nentry->rule.rlist);
1425		list_replace_rcu(&entry->list, &nentry->list);
1426		list_replace(&r->list, &nentry->rule.list);
1427	}
1428	call_rcu(&entry->rcu, 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. */
1438int 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(&audit_filter_mutex);
1454
1455	return err;
1456}
1457