1 /* auditfilter.c -- filtering of audit events
3 * Copyright 2003-2004 Red Hat, Inc.
4 * Copyright 2005 Hewlett-Packard Development Company, L.P.
5 * Copyright 2005 IBM Corporation
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.
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.
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
22 #include <linux/kernel.h>
23 #include <linux/audit.h>
24 #include <linux/kthread.h>
25 #include <linux/mutex.h>
27 #include <linux/namei.h>
28 #include <linux/netlink.h>
29 #include <linux/sched.h>
30 #include <linux/inotify.h>
31 #include <linux/selinux.h>
38 * Synchronizes writes and blocking reads of audit's filterlist
39 * data. Rcu is used to traverse the filterlist and access
40 * contents of structs audit_entry, audit_watch and opaque
41 * selinux rules during filtering. If modified, these structures
42 * must be copied and replace their counterparts in the filterlist.
43 * An audit_parent struct is not accessed during filtering, so may
44 * be written directly provided audit_filter_mutex is held.
50 * audit_parent: lifetime is from audit_init_parent() to receipt of an IN_IGNORED
51 * event. Each audit_watch holds a reference to its associated parent.
53 * audit_watch: if added to lists, lifetime is from audit_init_watch() to
54 * audit_remove_watch(). Additionally, an audit_watch may exist
55 * temporarily to assist in searching existing filter data. Each
56 * audit_krule holds a reference to its associated watch.
60 struct list_head ilist
; /* entry in inotify registration list */
61 struct list_head watches
; /* associated watches */
62 struct inotify_watch wdata
; /* inotify watch data */
63 unsigned flags
; /* status flags */
67 * audit_parent status flags:
69 * AUDIT_PARENT_INVALID - set anytime rules/watches are auto-removed due to
70 * a filesystem event to ensure we're adding audit watches to a valid parent.
71 * Technically not needed for IN_DELETE_SELF or IN_UNMOUNT events, as we cannot
72 * receive them while we have nameidata, but must be used for IN_MOVE_SELF which
73 * we can receive while holding nameidata.
75 #define AUDIT_PARENT_INVALID 0x001
77 /* Audit filter lists, defined in <linux/audit.h> */
78 struct list_head audit_filter_list
[AUDIT_NR_FILTERS
] = {
79 LIST_HEAD_INIT(audit_filter_list
[0]),
80 LIST_HEAD_INIT(audit_filter_list
[1]),
81 LIST_HEAD_INIT(audit_filter_list
[2]),
82 LIST_HEAD_INIT(audit_filter_list
[3]),
83 LIST_HEAD_INIT(audit_filter_list
[4]),
84 LIST_HEAD_INIT(audit_filter_list
[5]),
85 #if AUDIT_NR_FILTERS != 6
86 #error Fix audit_filter_list initialiser
90 static DEFINE_MUTEX(audit_filter_mutex
);
93 extern struct inotify_handle
*audit_ih
;
95 /* Inotify events we care about. */
96 #define AUDIT_IN_WATCH IN_MOVE|IN_CREATE|IN_DELETE|IN_DELETE_SELF|IN_MOVE_SELF
98 void audit_free_parent(struct inotify_watch
*i_watch
)
100 struct audit_parent
*parent
;
102 parent
= container_of(i_watch
, struct audit_parent
, wdata
);
103 WARN_ON(!list_empty(&parent
->watches
));
107 static inline void audit_get_watch(struct audit_watch
*watch
)
109 atomic_inc(&watch
->count
);
112 static void audit_put_watch(struct audit_watch
*watch
)
114 if (atomic_dec_and_test(&watch
->count
)) {
115 WARN_ON(watch
->parent
);
116 WARN_ON(!list_empty(&watch
->rules
));
122 static void audit_remove_watch(struct audit_watch
*watch
)
124 list_del(&watch
->wlist
);
125 put_inotify_watch(&watch
->parent
->wdata
);
126 watch
->parent
= NULL
;
127 audit_put_watch(watch
); /* match initial get */
130 static inline void audit_free_rule(struct audit_entry
*e
)
134 /* some rules don't have associated watches */
136 audit_put_watch(e
->rule
.watch
);
138 for (i
= 0; i
< e
->rule
.field_count
; i
++) {
139 struct audit_field
*f
= &e
->rule
.fields
[i
];
141 selinux_audit_rule_free(f
->se_rule
);
143 kfree(e
->rule
.fields
);
144 kfree(e
->rule
.filterkey
);
148 static inline void audit_free_rule_rcu(struct rcu_head
*head
)
150 struct audit_entry
*e
= container_of(head
, struct audit_entry
, rcu
);
154 /* Initialize a parent watch entry. */
155 static struct audit_parent
*audit_init_parent(struct nameidata
*ndp
)
157 struct audit_parent
*parent
;
160 parent
= kzalloc(sizeof(*parent
), GFP_KERNEL
);
161 if (unlikely(!parent
))
162 return ERR_PTR(-ENOMEM
);
164 INIT_LIST_HEAD(&parent
->watches
);
167 inotify_init_watch(&parent
->wdata
);
168 /* grab a ref so inotify watch hangs around until we take audit_filter_mutex */
169 get_inotify_watch(&parent
->wdata
);
170 wd
= inotify_add_watch(audit_ih
, &parent
->wdata
, ndp
->dentry
->d_inode
,
173 audit_free_parent(&parent
->wdata
);
180 /* Initialize a watch entry. */
181 static struct audit_watch
*audit_init_watch(char *path
)
183 struct audit_watch
*watch
;
185 watch
= kzalloc(sizeof(*watch
), GFP_KERNEL
);
186 if (unlikely(!watch
))
187 return ERR_PTR(-ENOMEM
);
189 INIT_LIST_HEAD(&watch
->rules
);
190 atomic_set(&watch
->count
, 1);
192 watch
->dev
= (dev_t
)-1;
193 watch
->ino
= (unsigned long)-1;
198 /* Initialize an audit filterlist entry. */
199 static inline struct audit_entry
*audit_init_entry(u32 field_count
)
201 struct audit_entry
*entry
;
202 struct audit_field
*fields
;
204 entry
= kzalloc(sizeof(*entry
), GFP_KERNEL
);
205 if (unlikely(!entry
))
208 fields
= kzalloc(sizeof(*fields
) * field_count
, GFP_KERNEL
);
209 if (unlikely(!fields
)) {
213 entry
->rule
.fields
= fields
;
218 /* Unpack a filter field's string representation from user-space
220 static char *audit_unpack_string(void **bufp
, size_t *remain
, size_t len
)
224 if (!*bufp
|| (len
== 0) || (len
> *remain
))
225 return ERR_PTR(-EINVAL
);
227 /* Of the currently implemented string fields, PATH_MAX
228 * defines the longest valid length.
231 return ERR_PTR(-ENAMETOOLONG
);
233 str
= kmalloc(len
+ 1, GFP_KERNEL
);
235 return ERR_PTR(-ENOMEM
);
237 memcpy(str
, *bufp
, len
);
245 /* Translate an inode field to kernel respresentation. */
246 static inline int audit_to_inode(struct audit_krule
*krule
,
247 struct audit_field
*f
)
249 if (krule
->listnr
!= AUDIT_FILTER_EXIT
||
250 krule
->watch
|| krule
->inode_f
)
257 /* Translate a watch string to kernel respresentation. */
258 static int audit_to_watch(struct audit_krule
*krule
, char *path
, int len
,
261 struct audit_watch
*watch
;
266 if (path
[0] != '/' || path
[len
-1] == '/' ||
267 krule
->listnr
!= AUDIT_FILTER_EXIT
||
269 krule
->inode_f
|| krule
->watch
) /* 1 inode # per rule, for hash */
272 watch
= audit_init_watch(path
);
273 if (unlikely(IS_ERR(watch
)))
274 return PTR_ERR(watch
);
276 audit_get_watch(watch
);
277 krule
->watch
= watch
;
282 /* Common user-space to kernel rule translation. */
283 static inline struct audit_entry
*audit_to_entry_common(struct audit_rule
*rule
)
286 struct audit_entry
*entry
;
290 listnr
= rule
->flags
& ~AUDIT_FILTER_PREPEND
;
294 case AUDIT_FILTER_USER
:
295 case AUDIT_FILTER_TYPE
:
296 #ifdef CONFIG_AUDITSYSCALL
297 case AUDIT_FILTER_ENTRY
:
298 case AUDIT_FILTER_EXIT
:
299 case AUDIT_FILTER_TASK
:
303 if (unlikely(rule
->action
== AUDIT_POSSIBLE
)) {
304 printk(KERN_ERR
"AUDIT_POSSIBLE is deprecated\n");
307 if (rule
->action
!= AUDIT_NEVER
&& rule
->action
!= AUDIT_ALWAYS
)
309 if (rule
->field_count
> AUDIT_MAX_FIELDS
)
313 entry
= audit_init_entry(rule
->field_count
);
317 entry
->rule
.flags
= rule
->flags
& AUDIT_FILTER_PREPEND
;
318 entry
->rule
.listnr
= listnr
;
319 entry
->rule
.action
= rule
->action
;
320 entry
->rule
.field_count
= rule
->field_count
;
322 for (i
= 0; i
< AUDIT_BITMASK_SIZE
; i
++)
323 entry
->rule
.mask
[i
] = rule
->mask
[i
];
331 /* Translate struct audit_rule to kernel's rule respresentation.
332 * Exists for backward compatibility with userspace. */
333 static struct audit_entry
*audit_rule_to_entry(struct audit_rule
*rule
)
335 struct audit_entry
*entry
;
336 struct audit_field
*f
;
340 entry
= audit_to_entry_common(rule
);
344 for (i
= 0; i
< rule
->field_count
; i
++) {
345 struct audit_field
*f
= &entry
->rule
.fields
[i
];
347 f
->op
= rule
->fields
[i
] & (AUDIT_NEGATE
|AUDIT_OPERATORS
);
348 f
->type
= rule
->fields
[i
] & ~(AUDIT_NEGATE
|AUDIT_OPERATORS
);
349 f
->val
= rule
->values
[i
];
378 err
= audit_to_inode(&entry
->rule
, f
);
384 entry
->rule
.vers_ops
= (f
->op
& AUDIT_OPERATORS
) ? 2 : 1;
386 /* Support for legacy operators where
387 * AUDIT_NEGATE bit signifies != and otherwise assumes == */
388 if (f
->op
& AUDIT_NEGATE
)
389 f
->op
= AUDIT_NOT_EQUAL
;
392 else if (f
->op
== AUDIT_OPERATORS
) {
398 f
= entry
->rule
.inode_f
;
401 case AUDIT_NOT_EQUAL
:
402 entry
->rule
.inode_f
= NULL
;
414 audit_free_rule(entry
);
418 /* Translate struct audit_rule_data to kernel's rule respresentation. */
419 static struct audit_entry
*audit_data_to_entry(struct audit_rule_data
*data
,
423 struct audit_entry
*entry
;
424 struct audit_field
*f
;
426 size_t remain
= datasz
- sizeof(struct audit_rule_data
);
430 entry
= audit_to_entry_common((struct audit_rule
*)data
);
435 entry
->rule
.vers_ops
= 2;
436 for (i
= 0; i
< data
->field_count
; i
++) {
437 struct audit_field
*f
= &entry
->rule
.fields
[i
];
440 if (!(data
->fieldflags
[i
] & AUDIT_OPERATORS
) ||
441 data
->fieldflags
[i
] & ~AUDIT_OPERATORS
)
444 f
->op
= data
->fieldflags
[i
] & AUDIT_OPERATORS
;
445 f
->type
= data
->fields
[i
];
446 f
->val
= data
->values
[i
];
473 case AUDIT_SUBJ_USER
:
474 case AUDIT_SUBJ_ROLE
:
475 case AUDIT_SUBJ_TYPE
:
481 case AUDIT_OBJ_LEV_LOW
:
482 case AUDIT_OBJ_LEV_HIGH
:
483 str
= audit_unpack_string(&bufp
, &remain
, f
->val
);
486 entry
->rule
.buflen
+= f
->val
;
488 err
= selinux_audit_rule_init(f
->type
, f
->op
, str
,
490 /* Keep currently invalid fields around in case they
491 * become valid after a policy reload. */
492 if (err
== -EINVAL
) {
493 printk(KERN_WARNING
"audit rule for selinux "
494 "\'%s\' is invalid\n", str
);
504 str
= audit_unpack_string(&bufp
, &remain
, f
->val
);
507 entry
->rule
.buflen
+= f
->val
;
509 err
= audit_to_watch(&entry
->rule
, str
, f
->val
, f
->op
);
516 err
= audit_to_inode(&entry
->rule
, f
);
520 case AUDIT_FILTERKEY
:
522 if (entry
->rule
.filterkey
|| f
->val
> AUDIT_MAX_KEY_LEN
)
524 str
= audit_unpack_string(&bufp
, &remain
, f
->val
);
527 entry
->rule
.buflen
+= f
->val
;
528 entry
->rule
.filterkey
= str
;
535 f
= entry
->rule
.inode_f
;
538 case AUDIT_NOT_EQUAL
:
539 entry
->rule
.inode_f
= NULL
;
551 audit_free_rule(entry
);
555 /* Pack a filter field's string representation into data block. */
556 static inline size_t audit_pack_string(void **bufp
, char *str
)
558 size_t len
= strlen(str
);
560 memcpy(*bufp
, str
, len
);
566 /* Translate kernel rule respresentation to struct audit_rule.
567 * Exists for backward compatibility with userspace. */
568 static struct audit_rule
*audit_krule_to_rule(struct audit_krule
*krule
)
570 struct audit_rule
*rule
;
573 rule
= kmalloc(sizeof(*rule
), GFP_KERNEL
);
576 memset(rule
, 0, sizeof(*rule
));
578 rule
->flags
= krule
->flags
| krule
->listnr
;
579 rule
->action
= krule
->action
;
580 rule
->field_count
= krule
->field_count
;
581 for (i
= 0; i
< rule
->field_count
; i
++) {
582 rule
->values
[i
] = krule
->fields
[i
].val
;
583 rule
->fields
[i
] = krule
->fields
[i
].type
;
585 if (krule
->vers_ops
== 1) {
586 if (krule
->fields
[i
].op
& AUDIT_NOT_EQUAL
)
587 rule
->fields
[i
] |= AUDIT_NEGATE
;
589 rule
->fields
[i
] |= krule
->fields
[i
].op
;
592 for (i
= 0; i
< AUDIT_BITMASK_SIZE
; i
++) rule
->mask
[i
] = krule
->mask
[i
];
597 /* Translate kernel rule respresentation to struct audit_rule_data. */
598 static struct audit_rule_data
*audit_krule_to_data(struct audit_krule
*krule
)
600 struct audit_rule_data
*data
;
604 data
= kmalloc(sizeof(*data
) + krule
->buflen
, GFP_KERNEL
);
607 memset(data
, 0, sizeof(*data
));
609 data
->flags
= krule
->flags
| krule
->listnr
;
610 data
->action
= krule
->action
;
611 data
->field_count
= krule
->field_count
;
613 for (i
= 0; i
< data
->field_count
; i
++) {
614 struct audit_field
*f
= &krule
->fields
[i
];
616 data
->fields
[i
] = f
->type
;
617 data
->fieldflags
[i
] = f
->op
;
619 case AUDIT_SUBJ_USER
:
620 case AUDIT_SUBJ_ROLE
:
621 case AUDIT_SUBJ_TYPE
:
627 case AUDIT_OBJ_LEV_LOW
:
628 case AUDIT_OBJ_LEV_HIGH
:
629 data
->buflen
+= data
->values
[i
] =
630 audit_pack_string(&bufp
, f
->se_str
);
633 data
->buflen
+= data
->values
[i
] =
634 audit_pack_string(&bufp
, krule
->watch
->path
);
636 case AUDIT_FILTERKEY
:
637 data
->buflen
+= data
->values
[i
] =
638 audit_pack_string(&bufp
, krule
->filterkey
);
641 data
->values
[i
] = f
->val
;
644 for (i
= 0; i
< AUDIT_BITMASK_SIZE
; i
++) data
->mask
[i
] = krule
->mask
[i
];
649 /* Compare two rules in kernel format. Considered success if rules
651 static int audit_compare_rule(struct audit_krule
*a
, struct audit_krule
*b
)
655 if (a
->flags
!= b
->flags
||
656 a
->listnr
!= b
->listnr
||
657 a
->action
!= b
->action
||
658 a
->field_count
!= b
->field_count
)
661 for (i
= 0; i
< a
->field_count
; i
++) {
662 if (a
->fields
[i
].type
!= b
->fields
[i
].type
||
663 a
->fields
[i
].op
!= b
->fields
[i
].op
)
666 switch(a
->fields
[i
].type
) {
667 case AUDIT_SUBJ_USER
:
668 case AUDIT_SUBJ_ROLE
:
669 case AUDIT_SUBJ_TYPE
:
675 case AUDIT_OBJ_LEV_LOW
:
676 case AUDIT_OBJ_LEV_HIGH
:
677 if (strcmp(a
->fields
[i
].se_str
, b
->fields
[i
].se_str
))
681 if (strcmp(a
->watch
->path
, b
->watch
->path
))
684 case AUDIT_FILTERKEY
:
685 /* both filterkeys exist based on above type compare */
686 if (strcmp(a
->filterkey
, b
->filterkey
))
690 if (a
->fields
[i
].val
!= b
->fields
[i
].val
)
695 for (i
= 0; i
< AUDIT_BITMASK_SIZE
; i
++)
696 if (a
->mask
[i
] != b
->mask
[i
])
702 /* Duplicate the given audit watch. The new watch's rules list is initialized
703 * to an empty list and wlist is undefined. */
704 static struct audit_watch
*audit_dupe_watch(struct audit_watch
*old
)
707 struct audit_watch
*new;
709 path
= kstrdup(old
->path
, GFP_KERNEL
);
711 return ERR_PTR(-ENOMEM
);
713 new = audit_init_watch(path
);
714 if (unlikely(IS_ERR(new))) {
721 get_inotify_watch(&old
->parent
->wdata
);
722 new->parent
= old
->parent
;
728 /* Duplicate selinux field information. The se_rule is opaque, so must be
730 static inline int audit_dupe_selinux_field(struct audit_field
*df
,
731 struct audit_field
*sf
)
736 /* our own copy of se_str */
737 se_str
= kstrdup(sf
->se_str
, GFP_KERNEL
);
738 if (unlikely(IS_ERR(se_str
)))
742 /* our own (refreshed) copy of se_rule */
743 ret
= selinux_audit_rule_init(df
->type
, df
->op
, df
->se_str
,
745 /* Keep currently invalid fields around in case they
746 * become valid after a policy reload. */
747 if (ret
== -EINVAL
) {
748 printk(KERN_WARNING
"audit rule for selinux \'%s\' is "
749 "invalid\n", df
->se_str
);
756 /* Duplicate an audit rule. This will be a deep copy with the exception
757 * of the watch - that pointer is carried over. The selinux specific fields
758 * will be updated in the copy. The point is to be able to replace the old
759 * rule with the new rule in the filterlist, then free the old rule.
760 * The rlist element is undefined; list manipulations are handled apart from
761 * the initial copy. */
762 static struct audit_entry
*audit_dupe_rule(struct audit_krule
*old
,
763 struct audit_watch
*watch
)
765 u32 fcount
= old
->field_count
;
766 struct audit_entry
*entry
;
767 struct audit_krule
*new;
771 entry
= audit_init_entry(fcount
);
772 if (unlikely(!entry
))
773 return ERR_PTR(-ENOMEM
);
776 new->vers_ops
= old
->vers_ops
;
777 new->flags
= old
->flags
;
778 new->listnr
= old
->listnr
;
779 new->action
= old
->action
;
780 for (i
= 0; i
< AUDIT_BITMASK_SIZE
; i
++)
781 new->mask
[i
] = old
->mask
[i
];
782 new->buflen
= old
->buflen
;
783 new->inode_f
= old
->inode_f
;
785 new->field_count
= old
->field_count
;
786 memcpy(new->fields
, old
->fields
, sizeof(struct audit_field
) * fcount
);
788 /* deep copy this information, updating the se_rule fields, because
789 * the originals will all be freed when the old rule is freed. */
790 for (i
= 0; i
< fcount
; i
++) {
791 switch (new->fields
[i
].type
) {
792 case AUDIT_SUBJ_USER
:
793 case AUDIT_SUBJ_ROLE
:
794 case AUDIT_SUBJ_TYPE
:
800 case AUDIT_OBJ_LEV_LOW
:
801 case AUDIT_OBJ_LEV_HIGH
:
802 err
= audit_dupe_selinux_field(&new->fields
[i
],
805 case AUDIT_FILTERKEY
:
806 fk
= kstrdup(old
->filterkey
, GFP_KERNEL
);
813 audit_free_rule(entry
);
819 audit_get_watch(watch
);
826 /* Update inode info in audit rules based on filesystem event. */
827 static void audit_update_watch(struct audit_parent
*parent
,
828 const char *dname
, dev_t dev
,
829 unsigned long ino
, unsigned invalidating
)
831 struct audit_watch
*owatch
, *nwatch
, *nextw
;
832 struct audit_krule
*r
, *nextr
;
833 struct audit_entry
*oentry
, *nentry
;
834 struct audit_buffer
*ab
;
836 mutex_lock(&audit_filter_mutex
);
837 list_for_each_entry_safe(owatch
, nextw
, &parent
->watches
, wlist
) {
838 if (audit_compare_dname_path(dname
, owatch
->path
, NULL
))
841 /* If the update involves invalidating rules, do the inode-based
842 * filtering now, so we don't omit records. */
844 audit_filter_inodes(current
, current
->audit_context
) == AUDIT_RECORD_CONTEXT
)
845 audit_set_auditable(current
->audit_context
);
847 nwatch
= audit_dupe_watch(owatch
);
848 if (unlikely(IS_ERR(nwatch
))) {
849 mutex_unlock(&audit_filter_mutex
);
850 audit_panic("error updating watch, skipping");
856 list_for_each_entry_safe(r
, nextr
, &owatch
->rules
, rlist
) {
858 oentry
= container_of(r
, struct audit_entry
, rule
);
859 list_del(&oentry
->rule
.rlist
);
860 list_del_rcu(&oentry
->list
);
862 nentry
= audit_dupe_rule(&oentry
->rule
, nwatch
);
863 if (unlikely(IS_ERR(nentry
)))
864 audit_panic("error updating watch, removing");
866 int h
= audit_hash_ino((u32
)ino
);
867 list_add(&nentry
->rule
.rlist
, &nwatch
->rules
);
868 list_add_rcu(&nentry
->list
, &audit_inode_hash
[h
]);
871 call_rcu(&oentry
->rcu
, audit_free_rule_rcu
);
874 ab
= audit_log_start(NULL
, GFP_KERNEL
, AUDIT_CONFIG_CHANGE
);
875 audit_log_format(ab
, "audit updated rules specifying watch=");
876 audit_log_untrustedstring(ab
, owatch
->path
);
877 audit_log_format(ab
, " with dev=%u ino=%lu\n", dev
, ino
);
880 audit_remove_watch(owatch
);
881 goto add_watch_to_parent
; /* event applies to a single watch */
883 mutex_unlock(&audit_filter_mutex
);
887 list_add(&nwatch
->wlist
, &parent
->watches
);
888 mutex_unlock(&audit_filter_mutex
);
892 /* Remove all watches & rules associated with a parent that is going away. */
893 static void audit_remove_parent_watches(struct audit_parent
*parent
)
895 struct audit_watch
*w
, *nextw
;
896 struct audit_krule
*r
, *nextr
;
897 struct audit_entry
*e
;
899 mutex_lock(&audit_filter_mutex
);
900 parent
->flags
|= AUDIT_PARENT_INVALID
;
901 list_for_each_entry_safe(w
, nextw
, &parent
->watches
, wlist
) {
902 list_for_each_entry_safe(r
, nextr
, &w
->rules
, rlist
) {
903 e
= container_of(r
, struct audit_entry
, rule
);
905 list_del_rcu(&e
->list
);
906 call_rcu(&e
->rcu
, audit_free_rule_rcu
);
908 audit_log(NULL
, GFP_KERNEL
, AUDIT_CONFIG_CHANGE
,
909 "audit implicitly removed rule from list=%d\n",
912 audit_remove_watch(w
);
914 mutex_unlock(&audit_filter_mutex
);
917 /* Unregister inotify watches for parents on in_list.
918 * Generates an IN_IGNORED event. */
919 static void audit_inotify_unregister(struct list_head
*in_list
)
921 struct audit_parent
*p
, *n
;
923 list_for_each_entry_safe(p
, n
, in_list
, ilist
) {
925 inotify_rm_watch(audit_ih
, &p
->wdata
);
926 /* the put matching the get in audit_do_del_rule() */
927 put_inotify_watch(&p
->wdata
);
931 /* Find an existing audit rule.
932 * Caller must hold audit_filter_mutex to prevent stale rule data. */
933 static struct audit_entry
*audit_find_rule(struct audit_entry
*entry
,
934 struct list_head
*list
)
936 struct audit_entry
*e
, *found
= NULL
;
939 if (entry
->rule
.watch
) {
940 /* we don't know the inode number, so must walk entire hash */
941 for (h
= 0; h
< AUDIT_INODE_BUCKETS
; h
++) {
942 list
= &audit_inode_hash
[h
];
943 list_for_each_entry(e
, list
, list
)
944 if (!audit_compare_rule(&entry
->rule
, &e
->rule
)) {
952 list_for_each_entry(e
, list
, list
)
953 if (!audit_compare_rule(&entry
->rule
, &e
->rule
)) {
962 /* Get path information necessary for adding watches. */
963 static int audit_get_nd(char *path
, struct nameidata
**ndp
,
964 struct nameidata
**ndw
)
966 struct nameidata
*ndparent
, *ndwatch
;
969 ndparent
= kmalloc(sizeof(*ndparent
), GFP_KERNEL
);
970 if (unlikely(!ndparent
))
973 ndwatch
= kmalloc(sizeof(*ndwatch
), GFP_KERNEL
);
974 if (unlikely(!ndwatch
)) {
979 err
= path_lookup(path
, LOOKUP_PARENT
, ndparent
);
986 err
= path_lookup(path
, 0, ndwatch
);
998 /* Release resources used for watch path information. */
999 static void audit_put_nd(struct nameidata
*ndp
, struct nameidata
*ndw
)
1011 /* Associate the given rule with an existing parent inotify_watch.
1012 * Caller must hold audit_filter_mutex. */
1013 static void audit_add_to_parent(struct audit_krule
*krule
,
1014 struct audit_parent
*parent
)
1016 struct audit_watch
*w
, *watch
= krule
->watch
;
1017 int watch_found
= 0;
1019 list_for_each_entry(w
, &parent
->watches
, wlist
) {
1020 if (strcmp(watch
->path
, w
->path
))
1025 /* put krule's and initial refs to temporary watch */
1026 audit_put_watch(watch
);
1027 audit_put_watch(watch
);
1030 krule
->watch
= watch
= w
;
1035 get_inotify_watch(&parent
->wdata
);
1036 watch
->parent
= parent
;
1038 list_add(&watch
->wlist
, &parent
->watches
);
1040 list_add(&krule
->rlist
, &watch
->rules
);
1043 /* Find a matching watch entry, or add this one.
1044 * Caller must hold audit_filter_mutex. */
1045 static int audit_add_watch(struct audit_krule
*krule
, struct nameidata
*ndp
,
1046 struct nameidata
*ndw
)
1048 struct audit_watch
*watch
= krule
->watch
;
1049 struct inotify_watch
*i_watch
;
1050 struct audit_parent
*parent
;
1053 /* update watch filter fields */
1055 watch
->dev
= ndw
->dentry
->d_inode
->i_sb
->s_dev
;
1056 watch
->ino
= ndw
->dentry
->d_inode
->i_ino
;
1059 /* The audit_filter_mutex must not be held during inotify calls because
1060 * we hold it during inotify event callback processing. If an existing
1061 * inotify watch is found, inotify_find_watch() grabs a reference before
1064 mutex_unlock(&audit_filter_mutex
);
1066 if (inotify_find_watch(audit_ih
, ndp
->dentry
->d_inode
, &i_watch
) < 0) {
1067 parent
= audit_init_parent(ndp
);
1068 if (IS_ERR(parent
)) {
1069 /* caller expects mutex locked */
1070 mutex_lock(&audit_filter_mutex
);
1071 return PTR_ERR(parent
);
1074 parent
= container_of(i_watch
, struct audit_parent
, wdata
);
1076 mutex_lock(&audit_filter_mutex
);
1078 /* parent was moved before we took audit_filter_mutex */
1079 if (parent
->flags
& AUDIT_PARENT_INVALID
)
1082 audit_add_to_parent(krule
, parent
);
1084 /* match get in audit_init_parent or inotify_find_watch */
1085 put_inotify_watch(&parent
->wdata
);
1089 /* Add rule to given filterlist if not a duplicate. */
1090 static inline int audit_add_rule(struct audit_entry
*entry
,
1091 struct list_head
*list
)
1093 struct audit_entry
*e
;
1094 struct audit_field
*inode_f
= entry
->rule
.inode_f
;
1095 struct audit_watch
*watch
= entry
->rule
.watch
;
1096 struct nameidata
*ndp
, *ndw
;
1097 int h
, err
, putnd_needed
= 0;
1100 h
= audit_hash_ino(inode_f
->val
);
1101 list
= &audit_inode_hash
[h
];
1104 mutex_lock(&audit_filter_mutex
);
1105 e
= audit_find_rule(entry
, list
);
1106 mutex_unlock(&audit_filter_mutex
);
1112 /* Avoid calling path_lookup under audit_filter_mutex. */
1114 err
= audit_get_nd(watch
->path
, &ndp
, &ndw
);
1120 mutex_lock(&audit_filter_mutex
);
1122 /* audit_filter_mutex is dropped and re-taken during this call */
1123 err
= audit_add_watch(&entry
->rule
, ndp
, ndw
);
1125 mutex_unlock(&audit_filter_mutex
);
1128 h
= audit_hash_ino((u32
)watch
->ino
);
1129 list
= &audit_inode_hash
[h
];
1132 if (entry
->rule
.flags
& AUDIT_FILTER_PREPEND
) {
1133 list_add_rcu(&entry
->list
, list
);
1134 entry
->rule
.flags
&= ~AUDIT_FILTER_PREPEND
;
1136 list_add_tail_rcu(&entry
->list
, list
);
1138 mutex_unlock(&audit_filter_mutex
);
1141 audit_put_nd(ndp
, ndw
);
1147 audit_put_nd(ndp
, ndw
);
1149 audit_put_watch(watch
); /* tmp watch, matches initial get */
1153 /* Remove an existing rule from filterlist. */
1154 static inline int audit_del_rule(struct audit_entry
*entry
,
1155 struct list_head
*list
)
1157 struct audit_entry
*e
;
1158 struct audit_field
*inode_f
= entry
->rule
.inode_f
;
1159 struct audit_watch
*watch
, *tmp_watch
= entry
->rule
.watch
;
1160 LIST_HEAD(inotify_list
);
1164 h
= audit_hash_ino(inode_f
->val
);
1165 list
= &audit_inode_hash
[h
];
1168 mutex_lock(&audit_filter_mutex
);
1169 e
= audit_find_rule(entry
, list
);
1171 mutex_unlock(&audit_filter_mutex
);
1176 watch
= e
->rule
.watch
;
1178 struct audit_parent
*parent
= watch
->parent
;
1180 list_del(&e
->rule
.rlist
);
1182 if (list_empty(&watch
->rules
)) {
1183 audit_remove_watch(watch
);
1185 if (list_empty(&parent
->watches
)) {
1186 /* Put parent on the inotify un-registration
1187 * list. Grab a reference before releasing
1188 * audit_filter_mutex, to be released in
1189 * audit_inotify_unregister(). */
1190 list_add(&parent
->ilist
, &inotify_list
);
1191 get_inotify_watch(&parent
->wdata
);
1196 list_del_rcu(&e
->list
);
1197 call_rcu(&e
->rcu
, audit_free_rule_rcu
);
1199 mutex_unlock(&audit_filter_mutex
);
1201 if (!list_empty(&inotify_list
))
1202 audit_inotify_unregister(&inotify_list
);
1206 audit_put_watch(tmp_watch
); /* match initial get */
1211 /* List rules using struct audit_rule. Exists for backward
1212 * compatibility with userspace. */
1213 static void audit_list(int pid
, int seq
, struct sk_buff_head
*q
)
1215 struct sk_buff
*skb
;
1216 struct audit_entry
*entry
;
1219 /* This is a blocking read, so use audit_filter_mutex instead of rcu
1220 * iterator to sync with list writers. */
1221 for (i
=0; i
<AUDIT_NR_FILTERS
; i
++) {
1222 list_for_each_entry(entry
, &audit_filter_list
[i
], list
) {
1223 struct audit_rule
*rule
;
1225 rule
= audit_krule_to_rule(&entry
->rule
);
1226 if (unlikely(!rule
))
1228 skb
= audit_make_reply(pid
, seq
, AUDIT_LIST
, 0, 1,
1229 rule
, sizeof(*rule
));
1231 skb_queue_tail(q
, skb
);
1235 for (i
= 0; i
< AUDIT_INODE_BUCKETS
; i
++) {
1236 list_for_each_entry(entry
, &audit_inode_hash
[i
], list
) {
1237 struct audit_rule
*rule
;
1239 rule
= audit_krule_to_rule(&entry
->rule
);
1240 if (unlikely(!rule
))
1242 skb
= audit_make_reply(pid
, seq
, AUDIT_LIST
, 0, 1,
1243 rule
, sizeof(*rule
));
1245 skb_queue_tail(q
, skb
);
1249 skb
= audit_make_reply(pid
, seq
, AUDIT_LIST
, 1, 1, NULL
, 0);
1251 skb_queue_tail(q
, skb
);
1254 /* List rules using struct audit_rule_data. */
1255 static void audit_list_rules(int pid
, int seq
, struct sk_buff_head
*q
)
1257 struct sk_buff
*skb
;
1258 struct audit_entry
*e
;
1261 /* This is a blocking read, so use audit_filter_mutex instead of rcu
1262 * iterator to sync with list writers. */
1263 for (i
=0; i
<AUDIT_NR_FILTERS
; i
++) {
1264 list_for_each_entry(e
, &audit_filter_list
[i
], list
) {
1265 struct audit_rule_data
*data
;
1267 data
= audit_krule_to_data(&e
->rule
);
1268 if (unlikely(!data
))
1270 skb
= audit_make_reply(pid
, seq
, AUDIT_LIST_RULES
, 0, 1,
1271 data
, sizeof(*data
) + data
->buflen
);
1273 skb_queue_tail(q
, skb
);
1277 for (i
=0; i
< AUDIT_INODE_BUCKETS
; i
++) {
1278 list_for_each_entry(e
, &audit_inode_hash
[i
], list
) {
1279 struct audit_rule_data
*data
;
1281 data
= audit_krule_to_data(&e
->rule
);
1282 if (unlikely(!data
))
1284 skb
= audit_make_reply(pid
, seq
, AUDIT_LIST_RULES
, 0, 1,
1285 data
, sizeof(*data
) + data
->buflen
);
1287 skb_queue_tail(q
, skb
);
1291 skb
= audit_make_reply(pid
, seq
, AUDIT_LIST_RULES
, 1, 1, NULL
, 0);
1293 skb_queue_tail(q
, skb
);
1296 /* Log rule additions and removals */
1297 static void audit_log_rule_change(uid_t loginuid
, u32 sid
, char *action
,
1298 struct audit_krule
*rule
, int res
)
1300 struct audit_buffer
*ab
;
1302 ab
= audit_log_start(NULL
, GFP_KERNEL
, AUDIT_CONFIG_CHANGE
);
1305 audit_log_format(ab
, "auid=%u", loginuid
);
1309 if (selinux_ctxid_to_string(sid
, &ctx
, &len
))
1310 audit_log_format(ab
, " ssid=%u", sid
);
1312 audit_log_format(ab
, " subj=%s", ctx
);
1315 audit_log_format(ab
, " %s rule key=", action
);
1316 if (rule
->filterkey
)
1317 audit_log_untrustedstring(ab
, rule
->filterkey
);
1319 audit_log_format(ab
, "(null)");
1320 audit_log_format(ab
, " list=%d res=%d", rule
->listnr
, res
);
1325 * audit_receive_filter - apply all rules to the specified message type
1326 * @type: audit message type
1327 * @pid: target pid for netlink audit messages
1328 * @uid: target uid for netlink audit messages
1329 * @seq: netlink audit message sequence (serial) number
1330 * @data: payload data
1331 * @datasz: size of payload data
1332 * @loginuid: loginuid of sender
1333 * @sid: SE Linux Security ID of sender
1335 int audit_receive_filter(int type
, int pid
, int uid
, int seq
, void *data
,
1336 size_t datasz
, uid_t loginuid
, u32 sid
)
1338 struct task_struct
*tsk
;
1339 struct audit_netlink_list
*dest
;
1341 struct audit_entry
*entry
;
1345 case AUDIT_LIST_RULES
:
1346 /* We can't just spew out the rules here because we might fill
1347 * the available socket buffer space and deadlock waiting for
1348 * auditctl to read from it... which isn't ever going to
1349 * happen if we're actually running in the context of auditctl
1350 * trying to _send_ the stuff */
1352 dest
= kmalloc(sizeof(struct audit_netlink_list
), GFP_KERNEL
);
1356 skb_queue_head_init(&dest
->q
);
1358 mutex_lock(&audit_filter_mutex
);
1359 if (type
== AUDIT_LIST
)
1360 audit_list(pid
, seq
, &dest
->q
);
1362 audit_list_rules(pid
, seq
, &dest
->q
);
1363 mutex_unlock(&audit_filter_mutex
);
1365 tsk
= kthread_run(audit_send_list
, dest
, "audit_send_list");
1367 skb_queue_purge(&dest
->q
);
1373 case AUDIT_ADD_RULE
:
1374 if (type
== AUDIT_ADD
)
1375 entry
= audit_rule_to_entry(data
);
1377 entry
= audit_data_to_entry(data
, datasz
);
1379 return PTR_ERR(entry
);
1381 err
= audit_add_rule(entry
,
1382 &audit_filter_list
[entry
->rule
.listnr
]);
1383 audit_log_rule_change(loginuid
, sid
, "add", &entry
->rule
, !err
);
1386 audit_free_rule(entry
);
1389 case AUDIT_DEL_RULE
:
1390 if (type
== AUDIT_DEL
)
1391 entry
= audit_rule_to_entry(data
);
1393 entry
= audit_data_to_entry(data
, datasz
);
1395 return PTR_ERR(entry
);
1397 err
= audit_del_rule(entry
,
1398 &audit_filter_list
[entry
->rule
.listnr
]);
1399 audit_log_rule_change(loginuid
, sid
, "remove", &entry
->rule
,
1402 audit_free_rule(entry
);
1411 int audit_comparator(const u32 left
, const u32 op
, const u32 right
)
1415 return (left
== right
);
1416 case AUDIT_NOT_EQUAL
:
1417 return (left
!= right
);
1418 case AUDIT_LESS_THAN
:
1419 return (left
< right
);
1420 case AUDIT_LESS_THAN_OR_EQUAL
:
1421 return (left
<= right
);
1422 case AUDIT_GREATER_THAN
:
1423 return (left
> right
);
1424 case AUDIT_GREATER_THAN_OR_EQUAL
:
1425 return (left
>= right
);
1431 /* Compare given dentry name with last component in given path,
1432 * return of 0 indicates a match. */
1433 int audit_compare_dname_path(const char *dname
, const char *path
,
1439 if (!dname
|| !path
)
1442 dlen
= strlen(dname
);
1443 plen
= strlen(path
);
1447 /* disregard trailing slashes */
1448 p
= path
+ plen
- 1;
1449 while ((*p
== '/') && (p
> path
))
1452 /* find last path component */
1456 else if (p
> path
) {
1463 /* return length of path's directory component */
1466 return strncmp(p
, dname
, dlen
);
1469 static int audit_filter_user_rules(struct netlink_skb_parms
*cb
,
1470 struct audit_krule
*rule
,
1471 enum audit_state
*state
)
1475 for (i
= 0; i
< rule
->field_count
; i
++) {
1476 struct audit_field
*f
= &rule
->fields
[i
];
1481 result
= audit_comparator(cb
->creds
.pid
, f
->op
, f
->val
);
1484 result
= audit_comparator(cb
->creds
.uid
, f
->op
, f
->val
);
1487 result
= audit_comparator(cb
->creds
.gid
, f
->op
, f
->val
);
1489 case AUDIT_LOGINUID
:
1490 result
= audit_comparator(cb
->loginuid
, f
->op
, f
->val
);
1497 switch (rule
->action
) {
1498 case AUDIT_NEVER
: *state
= AUDIT_DISABLED
; break;
1499 case AUDIT_ALWAYS
: *state
= AUDIT_RECORD_CONTEXT
; break;
1504 int audit_filter_user(struct netlink_skb_parms
*cb
, int type
)
1506 struct audit_entry
*e
;
1507 enum audit_state state
;
1511 list_for_each_entry_rcu(e
, &audit_filter_list
[AUDIT_FILTER_USER
], list
) {
1512 if (audit_filter_user_rules(cb
, &e
->rule
, &state
)) {
1513 if (state
== AUDIT_DISABLED
)
1520 return ret
; /* Audit by default */
1523 int audit_filter_type(int type
)
1525 struct audit_entry
*e
;
1529 if (list_empty(&audit_filter_list
[AUDIT_FILTER_TYPE
]))
1530 goto unlock_and_return
;
1532 list_for_each_entry_rcu(e
, &audit_filter_list
[AUDIT_FILTER_TYPE
],
1535 for (i
= 0; i
< e
->rule
.field_count
; i
++) {
1536 struct audit_field
*f
= &e
->rule
.fields
[i
];
1537 if (f
->type
== AUDIT_MSGTYPE
) {
1538 result
= audit_comparator(type
, f
->op
, f
->val
);
1544 goto unlock_and_return
;
1551 /* Check to see if the rule contains any selinux fields. Returns 1 if there
1552 are selinux fields specified in the rule, 0 otherwise. */
1553 static inline int audit_rule_has_selinux(struct audit_krule
*rule
)
1557 for (i
= 0; i
< rule
->field_count
; i
++) {
1558 struct audit_field
*f
= &rule
->fields
[i
];
1560 case AUDIT_SUBJ_USER
:
1561 case AUDIT_SUBJ_ROLE
:
1562 case AUDIT_SUBJ_TYPE
:
1563 case AUDIT_SUBJ_SEN
:
1564 case AUDIT_SUBJ_CLR
:
1565 case AUDIT_OBJ_USER
:
1566 case AUDIT_OBJ_ROLE
:
1567 case AUDIT_OBJ_TYPE
:
1568 case AUDIT_OBJ_LEV_LOW
:
1569 case AUDIT_OBJ_LEV_HIGH
:
1577 /* This function will re-initialize the se_rule field of all applicable rules.
1578 * It will traverse the filter lists serarching for rules that contain selinux
1579 * specific filter fields. When such a rule is found, it is copied, the
1580 * selinux field is re-initialized, and the old rule is replaced with the
1582 int selinux_audit_rule_update(void)
1584 struct audit_entry
*entry
, *n
, *nentry
;
1585 struct audit_watch
*watch
;
1588 /* audit_filter_mutex synchronizes the writers */
1589 mutex_lock(&audit_filter_mutex
);
1591 for (i
= 0; i
< AUDIT_NR_FILTERS
; i
++) {
1592 list_for_each_entry_safe(entry
, n
, &audit_filter_list
[i
], list
) {
1593 if (!audit_rule_has_selinux(&entry
->rule
))
1596 watch
= entry
->rule
.watch
;
1597 nentry
= audit_dupe_rule(&entry
->rule
, watch
);
1598 if (unlikely(IS_ERR(nentry
))) {
1599 /* save the first error encountered for the
1602 err
= PTR_ERR(nentry
);
1603 audit_panic("error updating selinux filters");
1605 list_del(&entry
->rule
.rlist
);
1606 list_del_rcu(&entry
->list
);
1609 list_add(&nentry
->rule
.rlist
,
1611 list_del(&entry
->rule
.rlist
);
1613 list_replace_rcu(&entry
->list
, &nentry
->list
);
1615 call_rcu(&entry
->rcu
, audit_free_rule_rcu
);
1619 mutex_unlock(&audit_filter_mutex
);
1624 /* Update watch data in audit rules based on inotify events. */
1625 void audit_handle_ievent(struct inotify_watch
*i_watch
, u32 wd
, u32 mask
,
1626 u32 cookie
, const char *dname
, struct inode
*inode
)
1628 struct audit_parent
*parent
;
1630 parent
= container_of(i_watch
, struct audit_parent
, wdata
);
1632 if (mask
& (IN_CREATE
|IN_MOVED_TO
) && inode
)
1633 audit_update_watch(parent
, dname
, inode
->i_sb
->s_dev
,
1635 else if (mask
& (IN_DELETE
|IN_MOVED_FROM
))
1636 audit_update_watch(parent
, dname
, (dev_t
)-1, (unsigned long)-1, 1);
1637 /* inotify automatically removes the watch and sends IN_IGNORED */
1638 else if (mask
& (IN_DELETE_SELF
|IN_UNMOUNT
))
1639 audit_remove_parent_watches(parent
);
1640 /* inotify does not remove the watch, so remove it manually */
1641 else if(mask
& IN_MOVE_SELF
) {
1642 audit_remove_parent_watches(parent
);
1643 inotify_remove_watch_locked(audit_ih
, i_watch
);
1644 } else if (mask
& IN_IGNORED
)
1645 put_inotify_watch(i_watch
);