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
);
147 static inline void audit_free_rule_rcu(struct rcu_head
*head
)
149 struct audit_entry
*e
= container_of(head
, struct audit_entry
, rcu
);
153 /* Initialize a parent watch entry. */
154 static struct audit_parent
*audit_init_parent(struct nameidata
*ndp
)
156 struct audit_parent
*parent
;
159 parent
= kzalloc(sizeof(*parent
), GFP_KERNEL
);
160 if (unlikely(!parent
))
161 return ERR_PTR(-ENOMEM
);
163 INIT_LIST_HEAD(&parent
->watches
);
166 inotify_init_watch(&parent
->wdata
);
167 /* grab a ref so inotify watch hangs around until we take audit_filter_mutex */
168 get_inotify_watch(&parent
->wdata
);
169 wd
= inotify_add_watch(audit_ih
, &parent
->wdata
, ndp
->dentry
->d_inode
,
172 audit_free_parent(&parent
->wdata
);
179 /* Initialize a watch entry. */
180 static struct audit_watch
*audit_init_watch(char *path
)
182 struct audit_watch
*watch
;
184 watch
= kzalloc(sizeof(*watch
), GFP_KERNEL
);
185 if (unlikely(!watch
))
186 return ERR_PTR(-ENOMEM
);
188 INIT_LIST_HEAD(&watch
->rules
);
189 atomic_set(&watch
->count
, 1);
191 watch
->dev
= (dev_t
)-1;
192 watch
->ino
= (unsigned long)-1;
197 /* Initialize an audit filterlist entry. */
198 static inline struct audit_entry
*audit_init_entry(u32 field_count
)
200 struct audit_entry
*entry
;
201 struct audit_field
*fields
;
203 entry
= kzalloc(sizeof(*entry
), GFP_KERNEL
);
204 if (unlikely(!entry
))
207 fields
= kzalloc(sizeof(*fields
) * field_count
, GFP_KERNEL
);
208 if (unlikely(!fields
)) {
212 entry
->rule
.fields
= fields
;
217 /* Unpack a filter field's string representation from user-space
219 static char *audit_unpack_string(void **bufp
, size_t *remain
, size_t len
)
223 if (!*bufp
|| (len
== 0) || (len
> *remain
))
224 return ERR_PTR(-EINVAL
);
226 /* Of the currently implemented string fields, PATH_MAX
227 * defines the longest valid length.
230 return ERR_PTR(-ENAMETOOLONG
);
232 str
= kmalloc(len
+ 1, GFP_KERNEL
);
234 return ERR_PTR(-ENOMEM
);
236 memcpy(str
, *bufp
, len
);
244 /* Translate an inode field to kernel respresentation. */
245 static inline int audit_to_inode(struct audit_krule
*krule
,
246 struct audit_field
*f
)
248 if (krule
->listnr
!= AUDIT_FILTER_EXIT
||
249 krule
->watch
|| krule
->inode_f
)
256 /* Translate a watch string to kernel respresentation. */
257 static int audit_to_watch(struct audit_krule
*krule
, char *path
, int len
,
260 struct audit_watch
*watch
;
265 if (path
[0] != '/' || path
[len
-1] == '/' ||
266 krule
->listnr
!= AUDIT_FILTER_EXIT
||
268 krule
->inode_f
|| krule
->watch
) /* 1 inode # per rule, for hash */
271 watch
= audit_init_watch(path
);
272 if (unlikely(IS_ERR(watch
)))
273 return PTR_ERR(watch
);
275 audit_get_watch(watch
);
276 krule
->watch
= watch
;
281 /* Common user-space to kernel rule translation. */
282 static inline struct audit_entry
*audit_to_entry_common(struct audit_rule
*rule
)
285 struct audit_entry
*entry
;
289 listnr
= rule
->flags
& ~AUDIT_FILTER_PREPEND
;
293 case AUDIT_FILTER_USER
:
294 case AUDIT_FILTER_TYPE
:
295 #ifdef CONFIG_AUDITSYSCALL
296 case AUDIT_FILTER_ENTRY
:
297 case AUDIT_FILTER_EXIT
:
298 case AUDIT_FILTER_TASK
:
302 if (unlikely(rule
->action
== AUDIT_POSSIBLE
)) {
303 printk(KERN_ERR
"AUDIT_POSSIBLE is deprecated\n");
306 if (rule
->action
!= AUDIT_NEVER
&& rule
->action
!= AUDIT_ALWAYS
)
308 if (rule
->field_count
> AUDIT_MAX_FIELDS
)
312 entry
= audit_init_entry(rule
->field_count
);
316 entry
->rule
.flags
= rule
->flags
& AUDIT_FILTER_PREPEND
;
317 entry
->rule
.listnr
= listnr
;
318 entry
->rule
.action
= rule
->action
;
319 entry
->rule
.field_count
= rule
->field_count
;
321 for (i
= 0; i
< AUDIT_BITMASK_SIZE
; i
++)
322 entry
->rule
.mask
[i
] = rule
->mask
[i
];
330 /* Translate struct audit_rule to kernel's rule respresentation.
331 * Exists for backward compatibility with userspace. */
332 static struct audit_entry
*audit_rule_to_entry(struct audit_rule
*rule
)
334 struct audit_entry
*entry
;
335 struct audit_field
*f
;
339 entry
= audit_to_entry_common(rule
);
343 for (i
= 0; i
< rule
->field_count
; i
++) {
344 struct audit_field
*f
= &entry
->rule
.fields
[i
];
346 f
->op
= rule
->fields
[i
] & (AUDIT_NEGATE
|AUDIT_OPERATORS
);
347 f
->type
= rule
->fields
[i
] & ~(AUDIT_NEGATE
|AUDIT_OPERATORS
);
348 f
->val
= rule
->values
[i
];
377 err
= audit_to_inode(&entry
->rule
, f
);
383 entry
->rule
.vers_ops
= (f
->op
& AUDIT_OPERATORS
) ? 2 : 1;
385 /* Support for legacy operators where
386 * AUDIT_NEGATE bit signifies != and otherwise assumes == */
387 if (f
->op
& AUDIT_NEGATE
)
388 f
->op
= AUDIT_NOT_EQUAL
;
391 else if (f
->op
== AUDIT_OPERATORS
) {
397 f
= entry
->rule
.inode_f
;
400 case AUDIT_NOT_EQUAL
:
401 entry
->rule
.inode_f
= NULL
;
413 audit_free_rule(entry
);
417 /* Translate struct audit_rule_data to kernel's rule respresentation. */
418 static struct audit_entry
*audit_data_to_entry(struct audit_rule_data
*data
,
422 struct audit_entry
*entry
;
423 struct audit_field
*f
;
425 size_t remain
= datasz
- sizeof(struct audit_rule_data
);
429 entry
= audit_to_entry_common((struct audit_rule
*)data
);
434 entry
->rule
.vers_ops
= 2;
435 for (i
= 0; i
< data
->field_count
; i
++) {
436 struct audit_field
*f
= &entry
->rule
.fields
[i
];
439 if (!(data
->fieldflags
[i
] & AUDIT_OPERATORS
) ||
440 data
->fieldflags
[i
] & ~AUDIT_OPERATORS
)
443 f
->op
= data
->fieldflags
[i
] & AUDIT_OPERATORS
;
444 f
->type
= data
->fields
[i
];
445 f
->val
= data
->values
[i
];
477 str
= audit_unpack_string(&bufp
, &remain
, f
->val
);
480 entry
->rule
.buflen
+= f
->val
;
482 err
= selinux_audit_rule_init(f
->type
, f
->op
, str
,
484 /* Keep currently invalid fields around in case they
485 * become valid after a policy reload. */
486 if (err
== -EINVAL
) {
487 printk(KERN_WARNING
"audit rule for selinux "
488 "\'%s\' is invalid\n", str
);
498 str
= audit_unpack_string(&bufp
, &remain
, f
->val
);
501 entry
->rule
.buflen
+= f
->val
;
503 err
= audit_to_watch(&entry
->rule
, str
, f
->val
, f
->op
);
510 err
= audit_to_inode(&entry
->rule
, f
);
519 f
= entry
->rule
.inode_f
;
522 case AUDIT_NOT_EQUAL
:
523 entry
->rule
.inode_f
= NULL
;
535 audit_free_rule(entry
);
539 /* Pack a filter field's string representation into data block. */
540 static inline size_t audit_pack_string(void **bufp
, char *str
)
542 size_t len
= strlen(str
);
544 memcpy(*bufp
, str
, len
);
550 /* Translate kernel rule respresentation to struct audit_rule.
551 * Exists for backward compatibility with userspace. */
552 static struct audit_rule
*audit_krule_to_rule(struct audit_krule
*krule
)
554 struct audit_rule
*rule
;
557 rule
= kmalloc(sizeof(*rule
), GFP_KERNEL
);
560 memset(rule
, 0, sizeof(*rule
));
562 rule
->flags
= krule
->flags
| krule
->listnr
;
563 rule
->action
= krule
->action
;
564 rule
->field_count
= krule
->field_count
;
565 for (i
= 0; i
< rule
->field_count
; i
++) {
566 rule
->values
[i
] = krule
->fields
[i
].val
;
567 rule
->fields
[i
] = krule
->fields
[i
].type
;
569 if (krule
->vers_ops
== 1) {
570 if (krule
->fields
[i
].op
& AUDIT_NOT_EQUAL
)
571 rule
->fields
[i
] |= AUDIT_NEGATE
;
573 rule
->fields
[i
] |= krule
->fields
[i
].op
;
576 for (i
= 0; i
< AUDIT_BITMASK_SIZE
; i
++) rule
->mask
[i
] = krule
->mask
[i
];
581 /* Translate kernel rule respresentation to struct audit_rule_data. */
582 static struct audit_rule_data
*audit_krule_to_data(struct audit_krule
*krule
)
584 struct audit_rule_data
*data
;
588 data
= kmalloc(sizeof(*data
) + krule
->buflen
, GFP_KERNEL
);
591 memset(data
, 0, sizeof(*data
));
593 data
->flags
= krule
->flags
| krule
->listnr
;
594 data
->action
= krule
->action
;
595 data
->field_count
= krule
->field_count
;
597 for (i
= 0; i
< data
->field_count
; i
++) {
598 struct audit_field
*f
= &krule
->fields
[i
];
600 data
->fields
[i
] = f
->type
;
601 data
->fieldflags
[i
] = f
->op
;
608 data
->buflen
+= data
->values
[i
] =
609 audit_pack_string(&bufp
, f
->se_str
);
612 data
->buflen
+= data
->values
[i
] =
613 audit_pack_string(&bufp
, krule
->watch
->path
);
616 data
->values
[i
] = f
->val
;
619 for (i
= 0; i
< AUDIT_BITMASK_SIZE
; i
++) data
->mask
[i
] = krule
->mask
[i
];
624 /* Compare two rules in kernel format. Considered success if rules
626 static int audit_compare_rule(struct audit_krule
*a
, struct audit_krule
*b
)
630 if (a
->flags
!= b
->flags
||
631 a
->listnr
!= b
->listnr
||
632 a
->action
!= b
->action
||
633 a
->field_count
!= b
->field_count
)
636 for (i
= 0; i
< a
->field_count
; i
++) {
637 if (a
->fields
[i
].type
!= b
->fields
[i
].type
||
638 a
->fields
[i
].op
!= b
->fields
[i
].op
)
641 switch(a
->fields
[i
].type
) {
647 if (strcmp(a
->fields
[i
].se_str
, b
->fields
[i
].se_str
))
651 if (strcmp(a
->watch
->path
, b
->watch
->path
))
655 if (a
->fields
[i
].val
!= b
->fields
[i
].val
)
660 for (i
= 0; i
< AUDIT_BITMASK_SIZE
; i
++)
661 if (a
->mask
[i
] != b
->mask
[i
])
667 /* Duplicate the given audit watch. The new watch's rules list is initialized
668 * to an empty list and wlist is undefined. */
669 static struct audit_watch
*audit_dupe_watch(struct audit_watch
*old
)
672 struct audit_watch
*new;
674 path
= kstrdup(old
->path
, GFP_KERNEL
);
676 return ERR_PTR(-ENOMEM
);
678 new = audit_init_watch(path
);
679 if (unlikely(IS_ERR(new))) {
686 get_inotify_watch(&old
->parent
->wdata
);
687 new->parent
= old
->parent
;
693 /* Duplicate selinux field information. The se_rule is opaque, so must be
695 static inline int audit_dupe_selinux_field(struct audit_field
*df
,
696 struct audit_field
*sf
)
701 /* our own copy of se_str */
702 se_str
= kstrdup(sf
->se_str
, GFP_KERNEL
);
703 if (unlikely(IS_ERR(se_str
)))
707 /* our own (refreshed) copy of se_rule */
708 ret
= selinux_audit_rule_init(df
->type
, df
->op
, df
->se_str
,
710 /* Keep currently invalid fields around in case they
711 * become valid after a policy reload. */
712 if (ret
== -EINVAL
) {
713 printk(KERN_WARNING
"audit rule for selinux \'%s\' is "
714 "invalid\n", df
->se_str
);
721 /* Duplicate an audit rule. This will be a deep copy with the exception
722 * of the watch - that pointer is carried over. The selinux specific fields
723 * will be updated in the copy. The point is to be able to replace the old
724 * rule with the new rule in the filterlist, then free the old rule.
725 * The rlist element is undefined; list manipulations are handled apart from
726 * the initial copy. */
727 static struct audit_entry
*audit_dupe_rule(struct audit_krule
*old
,
728 struct audit_watch
*watch
)
730 u32 fcount
= old
->field_count
;
731 struct audit_entry
*entry
;
732 struct audit_krule
*new;
735 entry
= audit_init_entry(fcount
);
736 if (unlikely(!entry
))
737 return ERR_PTR(-ENOMEM
);
740 new->vers_ops
= old
->vers_ops
;
741 new->flags
= old
->flags
;
742 new->listnr
= old
->listnr
;
743 new->action
= old
->action
;
744 for (i
= 0; i
< AUDIT_BITMASK_SIZE
; i
++)
745 new->mask
[i
] = old
->mask
[i
];
746 new->buflen
= old
->buflen
;
747 new->inode_f
= old
->inode_f
;
749 new->field_count
= old
->field_count
;
750 memcpy(new->fields
, old
->fields
, sizeof(struct audit_field
) * fcount
);
752 /* deep copy this information, updating the se_rule fields, because
753 * the originals will all be freed when the old rule is freed. */
754 for (i
= 0; i
< fcount
; i
++) {
755 switch (new->fields
[i
].type
) {
761 err
= audit_dupe_selinux_field(&new->fields
[i
],
765 audit_free_rule(entry
);
771 audit_get_watch(watch
);
778 /* Update inode info in audit rules based on filesystem event. */
779 static void audit_update_watch(struct audit_parent
*parent
,
780 const char *dname
, dev_t dev
,
781 unsigned long ino
, unsigned invalidating
)
783 struct audit_watch
*owatch
, *nwatch
, *nextw
;
784 struct audit_krule
*r
, *nextr
;
785 struct audit_entry
*oentry
, *nentry
;
786 struct audit_buffer
*ab
;
788 mutex_lock(&audit_filter_mutex
);
789 list_for_each_entry_safe(owatch
, nextw
, &parent
->watches
, wlist
) {
790 if (audit_compare_dname_path(dname
, owatch
->path
, NULL
))
793 /* If the update involves invalidating rules, do the inode-based
794 * filtering now, so we don't omit records. */
796 audit_filter_inodes(current
, current
->audit_context
) == AUDIT_RECORD_CONTEXT
)
797 audit_set_auditable(current
->audit_context
);
799 nwatch
= audit_dupe_watch(owatch
);
800 if (unlikely(IS_ERR(nwatch
))) {
801 mutex_unlock(&audit_filter_mutex
);
802 audit_panic("error updating watch, skipping");
808 list_for_each_entry_safe(r
, nextr
, &owatch
->rules
, rlist
) {
810 oentry
= container_of(r
, struct audit_entry
, rule
);
811 list_del(&oentry
->rule
.rlist
);
812 list_del_rcu(&oentry
->list
);
814 nentry
= audit_dupe_rule(&oentry
->rule
, nwatch
);
815 if (unlikely(IS_ERR(nentry
)))
816 audit_panic("error updating watch, removing");
818 int h
= audit_hash_ino((u32
)ino
);
819 list_add(&nentry
->rule
.rlist
, &nwatch
->rules
);
820 list_add_rcu(&nentry
->list
, &audit_inode_hash
[h
]);
823 call_rcu(&oentry
->rcu
, audit_free_rule_rcu
);
826 ab
= audit_log_start(NULL
, GFP_KERNEL
, AUDIT_CONFIG_CHANGE
);
827 audit_log_format(ab
, "audit updated rules specifying watch=");
828 audit_log_untrustedstring(ab
, owatch
->path
);
829 audit_log_format(ab
, " with dev=%u ino=%lu\n", dev
, ino
);
832 audit_remove_watch(owatch
);
833 goto add_watch_to_parent
; /* event applies to a single watch */
835 mutex_unlock(&audit_filter_mutex
);
839 list_add(&nwatch
->wlist
, &parent
->watches
);
840 mutex_unlock(&audit_filter_mutex
);
844 /* Remove all watches & rules associated with a parent that is going away. */
845 static void audit_remove_parent_watches(struct audit_parent
*parent
)
847 struct audit_watch
*w
, *nextw
;
848 struct audit_krule
*r
, *nextr
;
849 struct audit_entry
*e
;
851 mutex_lock(&audit_filter_mutex
);
852 parent
->flags
|= AUDIT_PARENT_INVALID
;
853 list_for_each_entry_safe(w
, nextw
, &parent
->watches
, wlist
) {
854 list_for_each_entry_safe(r
, nextr
, &w
->rules
, rlist
) {
855 e
= container_of(r
, struct audit_entry
, rule
);
857 list_del_rcu(&e
->list
);
858 call_rcu(&e
->rcu
, audit_free_rule_rcu
);
860 audit_log(NULL
, GFP_KERNEL
, AUDIT_CONFIG_CHANGE
,
861 "audit implicitly removed rule from list=%d\n",
864 audit_remove_watch(w
);
866 mutex_unlock(&audit_filter_mutex
);
869 /* Unregister inotify watches for parents on in_list.
870 * Generates an IN_IGNORED event. */
871 static void audit_inotify_unregister(struct list_head
*in_list
)
873 struct audit_parent
*p
, *n
;
875 list_for_each_entry_safe(p
, n
, in_list
, ilist
) {
877 inotify_rm_watch(audit_ih
, &p
->wdata
);
878 /* the put matching the get in audit_do_del_rule() */
879 put_inotify_watch(&p
->wdata
);
883 /* Find an existing audit rule.
884 * Caller must hold audit_filter_mutex to prevent stale rule data. */
885 static struct audit_entry
*audit_find_rule(struct audit_entry
*entry
,
886 struct list_head
*list
)
888 struct audit_entry
*e
, *found
= NULL
;
891 if (entry
->rule
.watch
) {
892 /* we don't know the inode number, so must walk entire hash */
893 for (h
= 0; h
< AUDIT_INODE_BUCKETS
; h
++) {
894 list
= &audit_inode_hash
[h
];
895 list_for_each_entry(e
, list
, list
)
896 if (!audit_compare_rule(&entry
->rule
, &e
->rule
)) {
904 list_for_each_entry(e
, list
, list
)
905 if (!audit_compare_rule(&entry
->rule
, &e
->rule
)) {
914 /* Get path information necessary for adding watches. */
915 static int audit_get_nd(char *path
, struct nameidata
**ndp
,
916 struct nameidata
**ndw
)
918 struct nameidata
*ndparent
, *ndwatch
;
921 ndparent
= kmalloc(sizeof(*ndparent
), GFP_KERNEL
);
922 if (unlikely(!ndparent
))
925 ndwatch
= kmalloc(sizeof(*ndwatch
), GFP_KERNEL
);
926 if (unlikely(!ndwatch
)) {
931 err
= path_lookup(path
, LOOKUP_PARENT
, ndparent
);
938 err
= path_lookup(path
, 0, ndwatch
);
950 /* Release resources used for watch path information. */
951 static void audit_put_nd(struct nameidata
*ndp
, struct nameidata
*ndw
)
963 /* Associate the given rule with an existing parent inotify_watch.
964 * Caller must hold audit_filter_mutex. */
965 static void audit_add_to_parent(struct audit_krule
*krule
,
966 struct audit_parent
*parent
)
968 struct audit_watch
*w
, *watch
= krule
->watch
;
971 list_for_each_entry(w
, &parent
->watches
, wlist
) {
972 if (strcmp(watch
->path
, w
->path
))
977 /* put krule's and initial refs to temporary watch */
978 audit_put_watch(watch
);
979 audit_put_watch(watch
);
982 krule
->watch
= watch
= w
;
987 get_inotify_watch(&parent
->wdata
);
988 watch
->parent
= parent
;
990 list_add(&watch
->wlist
, &parent
->watches
);
992 list_add(&krule
->rlist
, &watch
->rules
);
995 /* Find a matching watch entry, or add this one.
996 * Caller must hold audit_filter_mutex. */
997 static int audit_add_watch(struct audit_krule
*krule
, struct nameidata
*ndp
,
998 struct nameidata
*ndw
)
1000 struct audit_watch
*watch
= krule
->watch
;
1001 struct inotify_watch
*i_watch
;
1002 struct audit_parent
*parent
;
1005 /* update watch filter fields */
1007 watch
->dev
= ndw
->dentry
->d_inode
->i_sb
->s_dev
;
1008 watch
->ino
= ndw
->dentry
->d_inode
->i_ino
;
1011 /* The audit_filter_mutex must not be held during inotify calls because
1012 * we hold it during inotify event callback processing. If an existing
1013 * inotify watch is found, inotify_find_watch() grabs a reference before
1016 mutex_unlock(&audit_filter_mutex
);
1018 if (inotify_find_watch(audit_ih
, ndp
->dentry
->d_inode
, &i_watch
) < 0) {
1019 parent
= audit_init_parent(ndp
);
1020 if (IS_ERR(parent
)) {
1021 /* caller expects mutex locked */
1022 mutex_lock(&audit_filter_mutex
);
1023 return PTR_ERR(parent
);
1026 parent
= container_of(i_watch
, struct audit_parent
, wdata
);
1028 mutex_lock(&audit_filter_mutex
);
1030 /* parent was moved before we took audit_filter_mutex */
1031 if (parent
->flags
& AUDIT_PARENT_INVALID
)
1034 audit_add_to_parent(krule
, parent
);
1036 /* match get in audit_init_parent or inotify_find_watch */
1037 put_inotify_watch(&parent
->wdata
);
1041 /* Add rule to given filterlist if not a duplicate. */
1042 static inline int audit_add_rule(struct audit_entry
*entry
,
1043 struct list_head
*list
)
1045 struct audit_entry
*e
;
1046 struct audit_field
*inode_f
= entry
->rule
.inode_f
;
1047 struct audit_watch
*watch
= entry
->rule
.watch
;
1048 struct nameidata
*ndp
, *ndw
;
1049 int h
, err
, putnd_needed
= 0;
1052 h
= audit_hash_ino(inode_f
->val
);
1053 list
= &audit_inode_hash
[h
];
1056 mutex_lock(&audit_filter_mutex
);
1057 e
= audit_find_rule(entry
, list
);
1058 mutex_unlock(&audit_filter_mutex
);
1064 /* Avoid calling path_lookup under audit_filter_mutex. */
1066 err
= audit_get_nd(watch
->path
, &ndp
, &ndw
);
1072 mutex_lock(&audit_filter_mutex
);
1074 /* audit_filter_mutex is dropped and re-taken during this call */
1075 err
= audit_add_watch(&entry
->rule
, ndp
, ndw
);
1077 mutex_unlock(&audit_filter_mutex
);
1080 h
= audit_hash_ino((u32
)watch
->ino
);
1081 list
= &audit_inode_hash
[h
];
1084 if (entry
->rule
.flags
& AUDIT_FILTER_PREPEND
) {
1085 list_add_rcu(&entry
->list
, list
);
1086 entry
->rule
.flags
&= ~AUDIT_FILTER_PREPEND
;
1088 list_add_tail_rcu(&entry
->list
, list
);
1090 mutex_unlock(&audit_filter_mutex
);
1093 audit_put_nd(ndp
, ndw
);
1099 audit_put_nd(ndp
, ndw
);
1101 audit_put_watch(watch
); /* tmp watch, matches initial get */
1105 /* Remove an existing rule from filterlist. */
1106 static inline int audit_del_rule(struct audit_entry
*entry
,
1107 struct list_head
*list
)
1109 struct audit_entry
*e
;
1110 struct audit_field
*inode_f
= entry
->rule
.inode_f
;
1111 struct audit_watch
*watch
, *tmp_watch
= entry
->rule
.watch
;
1112 LIST_HEAD(inotify_list
);
1116 h
= audit_hash_ino(inode_f
->val
);
1117 list
= &audit_inode_hash
[h
];
1120 mutex_lock(&audit_filter_mutex
);
1121 e
= audit_find_rule(entry
, list
);
1123 mutex_unlock(&audit_filter_mutex
);
1128 watch
= e
->rule
.watch
;
1130 struct audit_parent
*parent
= watch
->parent
;
1132 list_del(&e
->rule
.rlist
);
1134 if (list_empty(&watch
->rules
)) {
1135 audit_remove_watch(watch
);
1137 if (list_empty(&parent
->watches
)) {
1138 /* Put parent on the inotify un-registration
1139 * list. Grab a reference before releasing
1140 * audit_filter_mutex, to be released in
1141 * audit_inotify_unregister(). */
1142 list_add(&parent
->ilist
, &inotify_list
);
1143 get_inotify_watch(&parent
->wdata
);
1148 list_del_rcu(&e
->list
);
1149 call_rcu(&e
->rcu
, audit_free_rule_rcu
);
1151 mutex_unlock(&audit_filter_mutex
);
1153 if (!list_empty(&inotify_list
))
1154 audit_inotify_unregister(&inotify_list
);
1158 audit_put_watch(tmp_watch
); /* match initial get */
1163 /* List rules using struct audit_rule. Exists for backward
1164 * compatibility with userspace. */
1165 static void audit_list(int pid
, int seq
, struct sk_buff_head
*q
)
1167 struct sk_buff
*skb
;
1168 struct audit_entry
*entry
;
1171 /* This is a blocking read, so use audit_filter_mutex instead of rcu
1172 * iterator to sync with list writers. */
1173 for (i
=0; i
<AUDIT_NR_FILTERS
; i
++) {
1174 list_for_each_entry(entry
, &audit_filter_list
[i
], list
) {
1175 struct audit_rule
*rule
;
1177 rule
= audit_krule_to_rule(&entry
->rule
);
1178 if (unlikely(!rule
))
1180 skb
= audit_make_reply(pid
, seq
, AUDIT_LIST
, 0, 1,
1181 rule
, sizeof(*rule
));
1183 skb_queue_tail(q
, skb
);
1187 for (i
= 0; i
< AUDIT_INODE_BUCKETS
; i
++) {
1188 list_for_each_entry(entry
, &audit_inode_hash
[i
], list
) {
1189 struct audit_rule
*rule
;
1191 rule
= audit_krule_to_rule(&entry
->rule
);
1192 if (unlikely(!rule
))
1194 skb
= audit_make_reply(pid
, seq
, AUDIT_LIST
, 0, 1,
1195 rule
, sizeof(*rule
));
1197 skb_queue_tail(q
, skb
);
1201 skb
= audit_make_reply(pid
, seq
, AUDIT_LIST
, 1, 1, NULL
, 0);
1203 skb_queue_tail(q
, skb
);
1206 /* List rules using struct audit_rule_data. */
1207 static void audit_list_rules(int pid
, int seq
, struct sk_buff_head
*q
)
1209 struct sk_buff
*skb
;
1210 struct audit_entry
*e
;
1213 /* This is a blocking read, so use audit_filter_mutex instead of rcu
1214 * iterator to sync with list writers. */
1215 for (i
=0; i
<AUDIT_NR_FILTERS
; i
++) {
1216 list_for_each_entry(e
, &audit_filter_list
[i
], list
) {
1217 struct audit_rule_data
*data
;
1219 data
= audit_krule_to_data(&e
->rule
);
1220 if (unlikely(!data
))
1222 skb
= audit_make_reply(pid
, seq
, AUDIT_LIST_RULES
, 0, 1,
1223 data
, sizeof(*data
) + data
->buflen
);
1225 skb_queue_tail(q
, skb
);
1229 for (i
=0; i
< AUDIT_INODE_BUCKETS
; i
++) {
1230 list_for_each_entry(e
, &audit_inode_hash
[i
], list
) {
1231 struct audit_rule_data
*data
;
1233 data
= audit_krule_to_data(&e
->rule
);
1234 if (unlikely(!data
))
1236 skb
= audit_make_reply(pid
, seq
, AUDIT_LIST_RULES
, 0, 1,
1237 data
, sizeof(*data
) + data
->buflen
);
1239 skb_queue_tail(q
, skb
);
1243 skb
= audit_make_reply(pid
, seq
, AUDIT_LIST_RULES
, 1, 1, NULL
, 0);
1245 skb_queue_tail(q
, skb
);
1249 * audit_receive_filter - apply all rules to the specified message type
1250 * @type: audit message type
1251 * @pid: target pid for netlink audit messages
1252 * @uid: target uid for netlink audit messages
1253 * @seq: netlink audit message sequence (serial) number
1254 * @data: payload data
1255 * @datasz: size of payload data
1256 * @loginuid: loginuid of sender
1257 * @sid: SE Linux Security ID of sender
1259 int audit_receive_filter(int type
, int pid
, int uid
, int seq
, void *data
,
1260 size_t datasz
, uid_t loginuid
, u32 sid
)
1262 struct task_struct
*tsk
;
1263 struct audit_netlink_list
*dest
;
1265 struct audit_entry
*entry
;
1269 case AUDIT_LIST_RULES
:
1270 /* We can't just spew out the rules here because we might fill
1271 * the available socket buffer space and deadlock waiting for
1272 * auditctl to read from it... which isn't ever going to
1273 * happen if we're actually running in the context of auditctl
1274 * trying to _send_ the stuff */
1276 dest
= kmalloc(sizeof(struct audit_netlink_list
), GFP_KERNEL
);
1280 skb_queue_head_init(&dest
->q
);
1282 mutex_lock(&audit_filter_mutex
);
1283 if (type
== AUDIT_LIST
)
1284 audit_list(pid
, seq
, &dest
->q
);
1286 audit_list_rules(pid
, seq
, &dest
->q
);
1287 mutex_unlock(&audit_filter_mutex
);
1289 tsk
= kthread_run(audit_send_list
, dest
, "audit_send_list");
1291 skb_queue_purge(&dest
->q
);
1297 case AUDIT_ADD_RULE
:
1298 if (type
== AUDIT_ADD
)
1299 entry
= audit_rule_to_entry(data
);
1301 entry
= audit_data_to_entry(data
, datasz
);
1303 return PTR_ERR(entry
);
1305 err
= audit_add_rule(entry
,
1306 &audit_filter_list
[entry
->rule
.listnr
]);
1311 if (selinux_ctxid_to_string(sid
, &ctx
, &len
)) {
1312 /* Maybe call audit_panic? */
1313 audit_log(NULL
, GFP_KERNEL
, AUDIT_CONFIG_CHANGE
,
1314 "auid=%u ssid=%u add rule to list=%d res=%d",
1315 loginuid
, sid
, entry
->rule
.listnr
, !err
);
1317 audit_log(NULL
, GFP_KERNEL
, AUDIT_CONFIG_CHANGE
,
1318 "auid=%u subj=%s add rule to list=%d res=%d",
1319 loginuid
, ctx
, entry
->rule
.listnr
, !err
);
1322 audit_log(NULL
, GFP_KERNEL
, AUDIT_CONFIG_CHANGE
,
1323 "auid=%u add rule to list=%d res=%d",
1324 loginuid
, entry
->rule
.listnr
, !err
);
1327 audit_free_rule(entry
);
1330 case AUDIT_DEL_RULE
:
1331 if (type
== AUDIT_DEL
)
1332 entry
= audit_rule_to_entry(data
);
1334 entry
= audit_data_to_entry(data
, datasz
);
1336 return PTR_ERR(entry
);
1338 err
= audit_del_rule(entry
,
1339 &audit_filter_list
[entry
->rule
.listnr
]);
1344 if (selinux_ctxid_to_string(sid
, &ctx
, &len
)) {
1345 /* Maybe call audit_panic? */
1346 audit_log(NULL
, GFP_KERNEL
, AUDIT_CONFIG_CHANGE
,
1347 "auid=%u ssid=%u remove rule from list=%d res=%d",
1348 loginuid
, sid
, entry
->rule
.listnr
, !err
);
1350 audit_log(NULL
, GFP_KERNEL
, AUDIT_CONFIG_CHANGE
,
1351 "auid=%u subj=%s remove rule from list=%d res=%d",
1352 loginuid
, ctx
, entry
->rule
.listnr
, !err
);
1355 audit_log(NULL
, GFP_KERNEL
, AUDIT_CONFIG_CHANGE
,
1356 "auid=%u remove rule from list=%d res=%d",
1357 loginuid
, entry
->rule
.listnr
, !err
);
1359 audit_free_rule(entry
);
1368 int audit_comparator(const u32 left
, const u32 op
, const u32 right
)
1372 return (left
== right
);
1373 case AUDIT_NOT_EQUAL
:
1374 return (left
!= right
);
1375 case AUDIT_LESS_THAN
:
1376 return (left
< right
);
1377 case AUDIT_LESS_THAN_OR_EQUAL
:
1378 return (left
<= right
);
1379 case AUDIT_GREATER_THAN
:
1380 return (left
> right
);
1381 case AUDIT_GREATER_THAN_OR_EQUAL
:
1382 return (left
>= right
);
1388 /* Compare given dentry name with last component in given path,
1389 * return of 0 indicates a match. */
1390 int audit_compare_dname_path(const char *dname
, const char *path
,
1396 if (!dname
|| !path
)
1399 dlen
= strlen(dname
);
1400 plen
= strlen(path
);
1404 /* disregard trailing slashes */
1405 p
= path
+ plen
- 1;
1406 while ((*p
== '/') && (p
> path
))
1409 /* find last path component */
1413 else if (p
> path
) {
1420 /* return length of path's directory component */
1423 return strncmp(p
, dname
, dlen
);
1426 static int audit_filter_user_rules(struct netlink_skb_parms
*cb
,
1427 struct audit_krule
*rule
,
1428 enum audit_state
*state
)
1432 for (i
= 0; i
< rule
->field_count
; i
++) {
1433 struct audit_field
*f
= &rule
->fields
[i
];
1438 result
= audit_comparator(cb
->creds
.pid
, f
->op
, f
->val
);
1441 result
= audit_comparator(cb
->creds
.uid
, f
->op
, f
->val
);
1444 result
= audit_comparator(cb
->creds
.gid
, f
->op
, f
->val
);
1446 case AUDIT_LOGINUID
:
1447 result
= audit_comparator(cb
->loginuid
, f
->op
, f
->val
);
1454 switch (rule
->action
) {
1455 case AUDIT_NEVER
: *state
= AUDIT_DISABLED
; break;
1456 case AUDIT_ALWAYS
: *state
= AUDIT_RECORD_CONTEXT
; break;
1461 int audit_filter_user(struct netlink_skb_parms
*cb
, int type
)
1463 struct audit_entry
*e
;
1464 enum audit_state state
;
1468 list_for_each_entry_rcu(e
, &audit_filter_list
[AUDIT_FILTER_USER
], list
) {
1469 if (audit_filter_user_rules(cb
, &e
->rule
, &state
)) {
1470 if (state
== AUDIT_DISABLED
)
1477 return ret
; /* Audit by default */
1480 int audit_filter_type(int type
)
1482 struct audit_entry
*e
;
1486 if (list_empty(&audit_filter_list
[AUDIT_FILTER_TYPE
]))
1487 goto unlock_and_return
;
1489 list_for_each_entry_rcu(e
, &audit_filter_list
[AUDIT_FILTER_TYPE
],
1492 for (i
= 0; i
< e
->rule
.field_count
; i
++) {
1493 struct audit_field
*f
= &e
->rule
.fields
[i
];
1494 if (f
->type
== AUDIT_MSGTYPE
) {
1495 result
= audit_comparator(type
, f
->op
, f
->val
);
1501 goto unlock_and_return
;
1508 /* Check to see if the rule contains any selinux fields. Returns 1 if there
1509 are selinux fields specified in the rule, 0 otherwise. */
1510 static inline int audit_rule_has_selinux(struct audit_krule
*rule
)
1514 for (i
= 0; i
< rule
->field_count
; i
++) {
1515 struct audit_field
*f
= &rule
->fields
[i
];
1529 /* This function will re-initialize the se_rule field of all applicable rules.
1530 * It will traverse the filter lists serarching for rules that contain selinux
1531 * specific filter fields. When such a rule is found, it is copied, the
1532 * selinux field is re-initialized, and the old rule is replaced with the
1534 int selinux_audit_rule_update(void)
1536 struct audit_entry
*entry
, *n
, *nentry
;
1537 struct audit_watch
*watch
;
1540 /* audit_filter_mutex synchronizes the writers */
1541 mutex_lock(&audit_filter_mutex
);
1543 for (i
= 0; i
< AUDIT_NR_FILTERS
; i
++) {
1544 list_for_each_entry_safe(entry
, n
, &audit_filter_list
[i
], list
) {
1545 if (!audit_rule_has_selinux(&entry
->rule
))
1548 watch
= entry
->rule
.watch
;
1549 nentry
= audit_dupe_rule(&entry
->rule
, watch
);
1550 if (unlikely(IS_ERR(nentry
))) {
1551 /* save the first error encountered for the
1554 err
= PTR_ERR(nentry
);
1555 audit_panic("error updating selinux filters");
1557 list_del(&entry
->rule
.rlist
);
1558 list_del_rcu(&entry
->list
);
1561 list_add(&nentry
->rule
.rlist
,
1563 list_del(&entry
->rule
.rlist
);
1565 list_replace_rcu(&entry
->list
, &nentry
->list
);
1567 call_rcu(&entry
->rcu
, audit_free_rule_rcu
);
1571 mutex_unlock(&audit_filter_mutex
);
1576 /* Update watch data in audit rules based on inotify events. */
1577 void audit_handle_ievent(struct inotify_watch
*i_watch
, u32 wd
, u32 mask
,
1578 u32 cookie
, const char *dname
, struct inode
*inode
)
1580 struct audit_parent
*parent
;
1582 parent
= container_of(i_watch
, struct audit_parent
, wdata
);
1584 if (mask
& (IN_CREATE
|IN_MOVED_TO
) && inode
)
1585 audit_update_watch(parent
, dname
, inode
->i_sb
->s_dev
,
1587 else if (mask
& (IN_DELETE
|IN_MOVED_FROM
))
1588 audit_update_watch(parent
, dname
, (dev_t
)-1, (unsigned long)-1, 1);
1589 /* inotify automatically removes the watch and sends IN_IGNORED */
1590 else if (mask
& (IN_DELETE_SELF
|IN_UNMOUNT
))
1591 audit_remove_parent_watches(parent
);
1592 /* inotify does not remove the watch, so remove it manually */
1593 else if(mask
& IN_MOVE_SELF
) {
1594 audit_remove_parent_watches(parent
);
1595 inotify_remove_watch_locked(audit_ih
, i_watch
);
1596 } else if (mask
& IN_IGNORED
)
1597 put_inotify_watch(i_watch
);