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
:
478 str
= audit_unpack_string(&bufp
, &remain
, f
->val
);
481 entry
->rule
.buflen
+= f
->val
;
483 err
= selinux_audit_rule_init(f
->type
, f
->op
, str
,
485 /* Keep currently invalid fields around in case they
486 * become valid after a policy reload. */
487 if (err
== -EINVAL
) {
488 printk(KERN_WARNING
"audit rule for selinux "
489 "\'%s\' is invalid\n", str
);
499 str
= audit_unpack_string(&bufp
, &remain
, f
->val
);
502 entry
->rule
.buflen
+= f
->val
;
504 err
= audit_to_watch(&entry
->rule
, str
, f
->val
, f
->op
);
511 err
= audit_to_inode(&entry
->rule
, f
);
515 case AUDIT_FILTERKEY
:
517 if (entry
->rule
.filterkey
|| f
->val
> AUDIT_MAX_KEY_LEN
)
519 str
= audit_unpack_string(&bufp
, &remain
, f
->val
);
522 entry
->rule
.buflen
+= f
->val
;
523 entry
->rule
.filterkey
= str
;
530 f
= entry
->rule
.inode_f
;
533 case AUDIT_NOT_EQUAL
:
534 entry
->rule
.inode_f
= NULL
;
546 audit_free_rule(entry
);
550 /* Pack a filter field's string representation into data block. */
551 static inline size_t audit_pack_string(void **bufp
, char *str
)
553 size_t len
= strlen(str
);
555 memcpy(*bufp
, str
, len
);
561 /* Translate kernel rule respresentation to struct audit_rule.
562 * Exists for backward compatibility with userspace. */
563 static struct audit_rule
*audit_krule_to_rule(struct audit_krule
*krule
)
565 struct audit_rule
*rule
;
568 rule
= kmalloc(sizeof(*rule
), GFP_KERNEL
);
571 memset(rule
, 0, sizeof(*rule
));
573 rule
->flags
= krule
->flags
| krule
->listnr
;
574 rule
->action
= krule
->action
;
575 rule
->field_count
= krule
->field_count
;
576 for (i
= 0; i
< rule
->field_count
; i
++) {
577 rule
->values
[i
] = krule
->fields
[i
].val
;
578 rule
->fields
[i
] = krule
->fields
[i
].type
;
580 if (krule
->vers_ops
== 1) {
581 if (krule
->fields
[i
].op
& AUDIT_NOT_EQUAL
)
582 rule
->fields
[i
] |= AUDIT_NEGATE
;
584 rule
->fields
[i
] |= krule
->fields
[i
].op
;
587 for (i
= 0; i
< AUDIT_BITMASK_SIZE
; i
++) rule
->mask
[i
] = krule
->mask
[i
];
592 /* Translate kernel rule respresentation to struct audit_rule_data. */
593 static struct audit_rule_data
*audit_krule_to_data(struct audit_krule
*krule
)
595 struct audit_rule_data
*data
;
599 data
= kmalloc(sizeof(*data
) + krule
->buflen
, GFP_KERNEL
);
602 memset(data
, 0, sizeof(*data
));
604 data
->flags
= krule
->flags
| krule
->listnr
;
605 data
->action
= krule
->action
;
606 data
->field_count
= krule
->field_count
;
608 for (i
= 0; i
< data
->field_count
; i
++) {
609 struct audit_field
*f
= &krule
->fields
[i
];
611 data
->fields
[i
] = f
->type
;
612 data
->fieldflags
[i
] = f
->op
;
614 case AUDIT_SUBJ_USER
:
615 case AUDIT_SUBJ_ROLE
:
616 case AUDIT_SUBJ_TYPE
:
619 data
->buflen
+= data
->values
[i
] =
620 audit_pack_string(&bufp
, f
->se_str
);
623 data
->buflen
+= data
->values
[i
] =
624 audit_pack_string(&bufp
, krule
->watch
->path
);
626 case AUDIT_FILTERKEY
:
627 data
->buflen
+= data
->values
[i
] =
628 audit_pack_string(&bufp
, krule
->filterkey
);
631 data
->values
[i
] = f
->val
;
634 for (i
= 0; i
< AUDIT_BITMASK_SIZE
; i
++) data
->mask
[i
] = krule
->mask
[i
];
639 /* Compare two rules in kernel format. Considered success if rules
641 static int audit_compare_rule(struct audit_krule
*a
, struct audit_krule
*b
)
645 if (a
->flags
!= b
->flags
||
646 a
->listnr
!= b
->listnr
||
647 a
->action
!= b
->action
||
648 a
->field_count
!= b
->field_count
)
651 for (i
= 0; i
< a
->field_count
; i
++) {
652 if (a
->fields
[i
].type
!= b
->fields
[i
].type
||
653 a
->fields
[i
].op
!= b
->fields
[i
].op
)
656 switch(a
->fields
[i
].type
) {
657 case AUDIT_SUBJ_USER
:
658 case AUDIT_SUBJ_ROLE
:
659 case AUDIT_SUBJ_TYPE
:
662 if (strcmp(a
->fields
[i
].se_str
, b
->fields
[i
].se_str
))
666 if (strcmp(a
->watch
->path
, b
->watch
->path
))
669 case AUDIT_FILTERKEY
:
670 /* both filterkeys exist based on above type compare */
671 if (strcmp(a
->filterkey
, b
->filterkey
))
675 if (a
->fields
[i
].val
!= b
->fields
[i
].val
)
680 for (i
= 0; i
< AUDIT_BITMASK_SIZE
; i
++)
681 if (a
->mask
[i
] != b
->mask
[i
])
687 /* Duplicate the given audit watch. The new watch's rules list is initialized
688 * to an empty list and wlist is undefined. */
689 static struct audit_watch
*audit_dupe_watch(struct audit_watch
*old
)
692 struct audit_watch
*new;
694 path
= kstrdup(old
->path
, GFP_KERNEL
);
696 return ERR_PTR(-ENOMEM
);
698 new = audit_init_watch(path
);
699 if (unlikely(IS_ERR(new))) {
706 get_inotify_watch(&old
->parent
->wdata
);
707 new->parent
= old
->parent
;
713 /* Duplicate selinux field information. The se_rule is opaque, so must be
715 static inline int audit_dupe_selinux_field(struct audit_field
*df
,
716 struct audit_field
*sf
)
721 /* our own copy of se_str */
722 se_str
= kstrdup(sf
->se_str
, GFP_KERNEL
);
723 if (unlikely(IS_ERR(se_str
)))
727 /* our own (refreshed) copy of se_rule */
728 ret
= selinux_audit_rule_init(df
->type
, df
->op
, df
->se_str
,
730 /* Keep currently invalid fields around in case they
731 * become valid after a policy reload. */
732 if (ret
== -EINVAL
) {
733 printk(KERN_WARNING
"audit rule for selinux \'%s\' is "
734 "invalid\n", df
->se_str
);
741 /* Duplicate an audit rule. This will be a deep copy with the exception
742 * of the watch - that pointer is carried over. The selinux specific fields
743 * will be updated in the copy. The point is to be able to replace the old
744 * rule with the new rule in the filterlist, then free the old rule.
745 * The rlist element is undefined; list manipulations are handled apart from
746 * the initial copy. */
747 static struct audit_entry
*audit_dupe_rule(struct audit_krule
*old
,
748 struct audit_watch
*watch
)
750 u32 fcount
= old
->field_count
;
751 struct audit_entry
*entry
;
752 struct audit_krule
*new;
756 entry
= audit_init_entry(fcount
);
757 if (unlikely(!entry
))
758 return ERR_PTR(-ENOMEM
);
761 new->vers_ops
= old
->vers_ops
;
762 new->flags
= old
->flags
;
763 new->listnr
= old
->listnr
;
764 new->action
= old
->action
;
765 for (i
= 0; i
< AUDIT_BITMASK_SIZE
; i
++)
766 new->mask
[i
] = old
->mask
[i
];
767 new->buflen
= old
->buflen
;
768 new->inode_f
= old
->inode_f
;
770 new->field_count
= old
->field_count
;
771 memcpy(new->fields
, old
->fields
, sizeof(struct audit_field
) * fcount
);
773 /* deep copy this information, updating the se_rule fields, because
774 * the originals will all be freed when the old rule is freed. */
775 for (i
= 0; i
< fcount
; i
++) {
776 switch (new->fields
[i
].type
) {
777 case AUDIT_SUBJ_USER
:
778 case AUDIT_SUBJ_ROLE
:
779 case AUDIT_SUBJ_TYPE
:
782 err
= audit_dupe_selinux_field(&new->fields
[i
],
785 case AUDIT_FILTERKEY
:
786 fk
= kstrdup(old
->filterkey
, GFP_KERNEL
);
793 audit_free_rule(entry
);
799 audit_get_watch(watch
);
806 /* Update inode info in audit rules based on filesystem event. */
807 static void audit_update_watch(struct audit_parent
*parent
,
808 const char *dname
, dev_t dev
,
809 unsigned long ino
, unsigned invalidating
)
811 struct audit_watch
*owatch
, *nwatch
, *nextw
;
812 struct audit_krule
*r
, *nextr
;
813 struct audit_entry
*oentry
, *nentry
;
814 struct audit_buffer
*ab
;
816 mutex_lock(&audit_filter_mutex
);
817 list_for_each_entry_safe(owatch
, nextw
, &parent
->watches
, wlist
) {
818 if (audit_compare_dname_path(dname
, owatch
->path
, NULL
))
821 /* If the update involves invalidating rules, do the inode-based
822 * filtering now, so we don't omit records. */
824 audit_filter_inodes(current
, current
->audit_context
) == AUDIT_RECORD_CONTEXT
)
825 audit_set_auditable(current
->audit_context
);
827 nwatch
= audit_dupe_watch(owatch
);
828 if (unlikely(IS_ERR(nwatch
))) {
829 mutex_unlock(&audit_filter_mutex
);
830 audit_panic("error updating watch, skipping");
836 list_for_each_entry_safe(r
, nextr
, &owatch
->rules
, rlist
) {
838 oentry
= container_of(r
, struct audit_entry
, rule
);
839 list_del(&oentry
->rule
.rlist
);
840 list_del_rcu(&oentry
->list
);
842 nentry
= audit_dupe_rule(&oentry
->rule
, nwatch
);
843 if (unlikely(IS_ERR(nentry
)))
844 audit_panic("error updating watch, removing");
846 int h
= audit_hash_ino((u32
)ino
);
847 list_add(&nentry
->rule
.rlist
, &nwatch
->rules
);
848 list_add_rcu(&nentry
->list
, &audit_inode_hash
[h
]);
851 call_rcu(&oentry
->rcu
, audit_free_rule_rcu
);
854 ab
= audit_log_start(NULL
, GFP_KERNEL
, AUDIT_CONFIG_CHANGE
);
855 audit_log_format(ab
, "audit updated rules specifying watch=");
856 audit_log_untrustedstring(ab
, owatch
->path
);
857 audit_log_format(ab
, " with dev=%u ino=%lu\n", dev
, ino
);
860 audit_remove_watch(owatch
);
861 goto add_watch_to_parent
; /* event applies to a single watch */
863 mutex_unlock(&audit_filter_mutex
);
867 list_add(&nwatch
->wlist
, &parent
->watches
);
868 mutex_unlock(&audit_filter_mutex
);
872 /* Remove all watches & rules associated with a parent that is going away. */
873 static void audit_remove_parent_watches(struct audit_parent
*parent
)
875 struct audit_watch
*w
, *nextw
;
876 struct audit_krule
*r
, *nextr
;
877 struct audit_entry
*e
;
879 mutex_lock(&audit_filter_mutex
);
880 parent
->flags
|= AUDIT_PARENT_INVALID
;
881 list_for_each_entry_safe(w
, nextw
, &parent
->watches
, wlist
) {
882 list_for_each_entry_safe(r
, nextr
, &w
->rules
, rlist
) {
883 e
= container_of(r
, struct audit_entry
, rule
);
885 list_del_rcu(&e
->list
);
886 call_rcu(&e
->rcu
, audit_free_rule_rcu
);
888 audit_log(NULL
, GFP_KERNEL
, AUDIT_CONFIG_CHANGE
,
889 "audit implicitly removed rule from list=%d\n",
892 audit_remove_watch(w
);
894 mutex_unlock(&audit_filter_mutex
);
897 /* Unregister inotify watches for parents on in_list.
898 * Generates an IN_IGNORED event. */
899 static void audit_inotify_unregister(struct list_head
*in_list
)
901 struct audit_parent
*p
, *n
;
903 list_for_each_entry_safe(p
, n
, in_list
, ilist
) {
905 inotify_rm_watch(audit_ih
, &p
->wdata
);
906 /* the put matching the get in audit_do_del_rule() */
907 put_inotify_watch(&p
->wdata
);
911 /* Find an existing audit rule.
912 * Caller must hold audit_filter_mutex to prevent stale rule data. */
913 static struct audit_entry
*audit_find_rule(struct audit_entry
*entry
,
914 struct list_head
*list
)
916 struct audit_entry
*e
, *found
= NULL
;
919 if (entry
->rule
.watch
) {
920 /* we don't know the inode number, so must walk entire hash */
921 for (h
= 0; h
< AUDIT_INODE_BUCKETS
; h
++) {
922 list
= &audit_inode_hash
[h
];
923 list_for_each_entry(e
, list
, list
)
924 if (!audit_compare_rule(&entry
->rule
, &e
->rule
)) {
932 list_for_each_entry(e
, list
, list
)
933 if (!audit_compare_rule(&entry
->rule
, &e
->rule
)) {
942 /* Get path information necessary for adding watches. */
943 static int audit_get_nd(char *path
, struct nameidata
**ndp
,
944 struct nameidata
**ndw
)
946 struct nameidata
*ndparent
, *ndwatch
;
949 ndparent
= kmalloc(sizeof(*ndparent
), GFP_KERNEL
);
950 if (unlikely(!ndparent
))
953 ndwatch
= kmalloc(sizeof(*ndwatch
), GFP_KERNEL
);
954 if (unlikely(!ndwatch
)) {
959 err
= path_lookup(path
, LOOKUP_PARENT
, ndparent
);
966 err
= path_lookup(path
, 0, ndwatch
);
978 /* Release resources used for watch path information. */
979 static void audit_put_nd(struct nameidata
*ndp
, struct nameidata
*ndw
)
991 /* Associate the given rule with an existing parent inotify_watch.
992 * Caller must hold audit_filter_mutex. */
993 static void audit_add_to_parent(struct audit_krule
*krule
,
994 struct audit_parent
*parent
)
996 struct audit_watch
*w
, *watch
= krule
->watch
;
999 list_for_each_entry(w
, &parent
->watches
, wlist
) {
1000 if (strcmp(watch
->path
, w
->path
))
1005 /* put krule's and initial refs to temporary watch */
1006 audit_put_watch(watch
);
1007 audit_put_watch(watch
);
1010 krule
->watch
= watch
= w
;
1015 get_inotify_watch(&parent
->wdata
);
1016 watch
->parent
= parent
;
1018 list_add(&watch
->wlist
, &parent
->watches
);
1020 list_add(&krule
->rlist
, &watch
->rules
);
1023 /* Find a matching watch entry, or add this one.
1024 * Caller must hold audit_filter_mutex. */
1025 static int audit_add_watch(struct audit_krule
*krule
, struct nameidata
*ndp
,
1026 struct nameidata
*ndw
)
1028 struct audit_watch
*watch
= krule
->watch
;
1029 struct inotify_watch
*i_watch
;
1030 struct audit_parent
*parent
;
1033 /* update watch filter fields */
1035 watch
->dev
= ndw
->dentry
->d_inode
->i_sb
->s_dev
;
1036 watch
->ino
= ndw
->dentry
->d_inode
->i_ino
;
1039 /* The audit_filter_mutex must not be held during inotify calls because
1040 * we hold it during inotify event callback processing. If an existing
1041 * inotify watch is found, inotify_find_watch() grabs a reference before
1044 mutex_unlock(&audit_filter_mutex
);
1046 if (inotify_find_watch(audit_ih
, ndp
->dentry
->d_inode
, &i_watch
) < 0) {
1047 parent
= audit_init_parent(ndp
);
1048 if (IS_ERR(parent
)) {
1049 /* caller expects mutex locked */
1050 mutex_lock(&audit_filter_mutex
);
1051 return PTR_ERR(parent
);
1054 parent
= container_of(i_watch
, struct audit_parent
, wdata
);
1056 mutex_lock(&audit_filter_mutex
);
1058 /* parent was moved before we took audit_filter_mutex */
1059 if (parent
->flags
& AUDIT_PARENT_INVALID
)
1062 audit_add_to_parent(krule
, parent
);
1064 /* match get in audit_init_parent or inotify_find_watch */
1065 put_inotify_watch(&parent
->wdata
);
1069 /* Add rule to given filterlist if not a duplicate. */
1070 static inline int audit_add_rule(struct audit_entry
*entry
,
1071 struct list_head
*list
)
1073 struct audit_entry
*e
;
1074 struct audit_field
*inode_f
= entry
->rule
.inode_f
;
1075 struct audit_watch
*watch
= entry
->rule
.watch
;
1076 struct nameidata
*ndp
, *ndw
;
1077 int h
, err
, putnd_needed
= 0;
1080 h
= audit_hash_ino(inode_f
->val
);
1081 list
= &audit_inode_hash
[h
];
1084 mutex_lock(&audit_filter_mutex
);
1085 e
= audit_find_rule(entry
, list
);
1086 mutex_unlock(&audit_filter_mutex
);
1092 /* Avoid calling path_lookup under audit_filter_mutex. */
1094 err
= audit_get_nd(watch
->path
, &ndp
, &ndw
);
1100 mutex_lock(&audit_filter_mutex
);
1102 /* audit_filter_mutex is dropped and re-taken during this call */
1103 err
= audit_add_watch(&entry
->rule
, ndp
, ndw
);
1105 mutex_unlock(&audit_filter_mutex
);
1108 h
= audit_hash_ino((u32
)watch
->ino
);
1109 list
= &audit_inode_hash
[h
];
1112 if (entry
->rule
.flags
& AUDIT_FILTER_PREPEND
) {
1113 list_add_rcu(&entry
->list
, list
);
1114 entry
->rule
.flags
&= ~AUDIT_FILTER_PREPEND
;
1116 list_add_tail_rcu(&entry
->list
, list
);
1118 mutex_unlock(&audit_filter_mutex
);
1121 audit_put_nd(ndp
, ndw
);
1127 audit_put_nd(ndp
, ndw
);
1129 audit_put_watch(watch
); /* tmp watch, matches initial get */
1133 /* Remove an existing rule from filterlist. */
1134 static inline int audit_del_rule(struct audit_entry
*entry
,
1135 struct list_head
*list
)
1137 struct audit_entry
*e
;
1138 struct audit_field
*inode_f
= entry
->rule
.inode_f
;
1139 struct audit_watch
*watch
, *tmp_watch
= entry
->rule
.watch
;
1140 LIST_HEAD(inotify_list
);
1144 h
= audit_hash_ino(inode_f
->val
);
1145 list
= &audit_inode_hash
[h
];
1148 mutex_lock(&audit_filter_mutex
);
1149 e
= audit_find_rule(entry
, list
);
1151 mutex_unlock(&audit_filter_mutex
);
1156 watch
= e
->rule
.watch
;
1158 struct audit_parent
*parent
= watch
->parent
;
1160 list_del(&e
->rule
.rlist
);
1162 if (list_empty(&watch
->rules
)) {
1163 audit_remove_watch(watch
);
1165 if (list_empty(&parent
->watches
)) {
1166 /* Put parent on the inotify un-registration
1167 * list. Grab a reference before releasing
1168 * audit_filter_mutex, to be released in
1169 * audit_inotify_unregister(). */
1170 list_add(&parent
->ilist
, &inotify_list
);
1171 get_inotify_watch(&parent
->wdata
);
1176 list_del_rcu(&e
->list
);
1177 call_rcu(&e
->rcu
, audit_free_rule_rcu
);
1179 mutex_unlock(&audit_filter_mutex
);
1181 if (!list_empty(&inotify_list
))
1182 audit_inotify_unregister(&inotify_list
);
1186 audit_put_watch(tmp_watch
); /* match initial get */
1191 /* List rules using struct audit_rule. Exists for backward
1192 * compatibility with userspace. */
1193 static void audit_list(int pid
, int seq
, struct sk_buff_head
*q
)
1195 struct sk_buff
*skb
;
1196 struct audit_entry
*entry
;
1199 /* This is a blocking read, so use audit_filter_mutex instead of rcu
1200 * iterator to sync with list writers. */
1201 for (i
=0; i
<AUDIT_NR_FILTERS
; i
++) {
1202 list_for_each_entry(entry
, &audit_filter_list
[i
], list
) {
1203 struct audit_rule
*rule
;
1205 rule
= audit_krule_to_rule(&entry
->rule
);
1206 if (unlikely(!rule
))
1208 skb
= audit_make_reply(pid
, seq
, AUDIT_LIST
, 0, 1,
1209 rule
, sizeof(*rule
));
1211 skb_queue_tail(q
, skb
);
1215 for (i
= 0; i
< AUDIT_INODE_BUCKETS
; i
++) {
1216 list_for_each_entry(entry
, &audit_inode_hash
[i
], list
) {
1217 struct audit_rule
*rule
;
1219 rule
= audit_krule_to_rule(&entry
->rule
);
1220 if (unlikely(!rule
))
1222 skb
= audit_make_reply(pid
, seq
, AUDIT_LIST
, 0, 1,
1223 rule
, sizeof(*rule
));
1225 skb_queue_tail(q
, skb
);
1229 skb
= audit_make_reply(pid
, seq
, AUDIT_LIST
, 1, 1, NULL
, 0);
1231 skb_queue_tail(q
, skb
);
1234 /* List rules using struct audit_rule_data. */
1235 static void audit_list_rules(int pid
, int seq
, struct sk_buff_head
*q
)
1237 struct sk_buff
*skb
;
1238 struct audit_entry
*e
;
1241 /* This is a blocking read, so use audit_filter_mutex instead of rcu
1242 * iterator to sync with list writers. */
1243 for (i
=0; i
<AUDIT_NR_FILTERS
; i
++) {
1244 list_for_each_entry(e
, &audit_filter_list
[i
], list
) {
1245 struct audit_rule_data
*data
;
1247 data
= audit_krule_to_data(&e
->rule
);
1248 if (unlikely(!data
))
1250 skb
= audit_make_reply(pid
, seq
, AUDIT_LIST_RULES
, 0, 1,
1251 data
, sizeof(*data
) + data
->buflen
);
1253 skb_queue_tail(q
, skb
);
1257 for (i
=0; i
< AUDIT_INODE_BUCKETS
; i
++) {
1258 list_for_each_entry(e
, &audit_inode_hash
[i
], list
) {
1259 struct audit_rule_data
*data
;
1261 data
= audit_krule_to_data(&e
->rule
);
1262 if (unlikely(!data
))
1264 skb
= audit_make_reply(pid
, seq
, AUDIT_LIST_RULES
, 0, 1,
1265 data
, sizeof(*data
) + data
->buflen
);
1267 skb_queue_tail(q
, skb
);
1271 skb
= audit_make_reply(pid
, seq
, AUDIT_LIST_RULES
, 1, 1, NULL
, 0);
1273 skb_queue_tail(q
, skb
);
1276 /* Log rule additions and removals */
1277 static void audit_log_rule_change(uid_t loginuid
, u32 sid
, char *action
,
1278 struct audit_krule
*rule
, int res
)
1280 struct audit_buffer
*ab
;
1282 ab
= audit_log_start(NULL
, GFP_KERNEL
, AUDIT_CONFIG_CHANGE
);
1285 audit_log_format(ab
, "auid=%u", loginuid
);
1289 if (selinux_ctxid_to_string(sid
, &ctx
, &len
))
1290 audit_log_format(ab
, " ssid=%u", sid
);
1292 audit_log_format(ab
, " subj=%s", ctx
);
1295 audit_log_format(ab
, " %s rule key=", action
);
1296 if (rule
->filterkey
)
1297 audit_log_untrustedstring(ab
, rule
->filterkey
);
1299 audit_log_format(ab
, "(null)");
1300 audit_log_format(ab
, " list=%d res=%d", rule
->listnr
, res
);
1305 * audit_receive_filter - apply all rules to the specified message type
1306 * @type: audit message type
1307 * @pid: target pid for netlink audit messages
1308 * @uid: target uid for netlink audit messages
1309 * @seq: netlink audit message sequence (serial) number
1310 * @data: payload data
1311 * @datasz: size of payload data
1312 * @loginuid: loginuid of sender
1313 * @sid: SE Linux Security ID of sender
1315 int audit_receive_filter(int type
, int pid
, int uid
, int seq
, void *data
,
1316 size_t datasz
, uid_t loginuid
, u32 sid
)
1318 struct task_struct
*tsk
;
1319 struct audit_netlink_list
*dest
;
1321 struct audit_entry
*entry
;
1325 case AUDIT_LIST_RULES
:
1326 /* We can't just spew out the rules here because we might fill
1327 * the available socket buffer space and deadlock waiting for
1328 * auditctl to read from it... which isn't ever going to
1329 * happen if we're actually running in the context of auditctl
1330 * trying to _send_ the stuff */
1332 dest
= kmalloc(sizeof(struct audit_netlink_list
), GFP_KERNEL
);
1336 skb_queue_head_init(&dest
->q
);
1338 mutex_lock(&audit_filter_mutex
);
1339 if (type
== AUDIT_LIST
)
1340 audit_list(pid
, seq
, &dest
->q
);
1342 audit_list_rules(pid
, seq
, &dest
->q
);
1343 mutex_unlock(&audit_filter_mutex
);
1345 tsk
= kthread_run(audit_send_list
, dest
, "audit_send_list");
1347 skb_queue_purge(&dest
->q
);
1353 case AUDIT_ADD_RULE
:
1354 if (type
== AUDIT_ADD
)
1355 entry
= audit_rule_to_entry(data
);
1357 entry
= audit_data_to_entry(data
, datasz
);
1359 return PTR_ERR(entry
);
1361 err
= audit_add_rule(entry
,
1362 &audit_filter_list
[entry
->rule
.listnr
]);
1363 audit_log_rule_change(loginuid
, sid
, "add", &entry
->rule
, !err
);
1366 audit_free_rule(entry
);
1369 case AUDIT_DEL_RULE
:
1370 if (type
== AUDIT_DEL
)
1371 entry
= audit_rule_to_entry(data
);
1373 entry
= audit_data_to_entry(data
, datasz
);
1375 return PTR_ERR(entry
);
1377 err
= audit_del_rule(entry
,
1378 &audit_filter_list
[entry
->rule
.listnr
]);
1379 audit_log_rule_change(loginuid
, sid
, "remove", &entry
->rule
,
1382 audit_free_rule(entry
);
1391 int audit_comparator(const u32 left
, const u32 op
, const u32 right
)
1395 return (left
== right
);
1396 case AUDIT_NOT_EQUAL
:
1397 return (left
!= right
);
1398 case AUDIT_LESS_THAN
:
1399 return (left
< right
);
1400 case AUDIT_LESS_THAN_OR_EQUAL
:
1401 return (left
<= right
);
1402 case AUDIT_GREATER_THAN
:
1403 return (left
> right
);
1404 case AUDIT_GREATER_THAN_OR_EQUAL
:
1405 return (left
>= right
);
1411 /* Compare given dentry name with last component in given path,
1412 * return of 0 indicates a match. */
1413 int audit_compare_dname_path(const char *dname
, const char *path
,
1419 if (!dname
|| !path
)
1422 dlen
= strlen(dname
);
1423 plen
= strlen(path
);
1427 /* disregard trailing slashes */
1428 p
= path
+ plen
- 1;
1429 while ((*p
== '/') && (p
> path
))
1432 /* find last path component */
1436 else if (p
> path
) {
1443 /* return length of path's directory component */
1446 return strncmp(p
, dname
, dlen
);
1449 static int audit_filter_user_rules(struct netlink_skb_parms
*cb
,
1450 struct audit_krule
*rule
,
1451 enum audit_state
*state
)
1455 for (i
= 0; i
< rule
->field_count
; i
++) {
1456 struct audit_field
*f
= &rule
->fields
[i
];
1461 result
= audit_comparator(cb
->creds
.pid
, f
->op
, f
->val
);
1464 result
= audit_comparator(cb
->creds
.uid
, f
->op
, f
->val
);
1467 result
= audit_comparator(cb
->creds
.gid
, f
->op
, f
->val
);
1469 case AUDIT_LOGINUID
:
1470 result
= audit_comparator(cb
->loginuid
, f
->op
, f
->val
);
1477 switch (rule
->action
) {
1478 case AUDIT_NEVER
: *state
= AUDIT_DISABLED
; break;
1479 case AUDIT_ALWAYS
: *state
= AUDIT_RECORD_CONTEXT
; break;
1484 int audit_filter_user(struct netlink_skb_parms
*cb
, int type
)
1486 struct audit_entry
*e
;
1487 enum audit_state state
;
1491 list_for_each_entry_rcu(e
, &audit_filter_list
[AUDIT_FILTER_USER
], list
) {
1492 if (audit_filter_user_rules(cb
, &e
->rule
, &state
)) {
1493 if (state
== AUDIT_DISABLED
)
1500 return ret
; /* Audit by default */
1503 int audit_filter_type(int type
)
1505 struct audit_entry
*e
;
1509 if (list_empty(&audit_filter_list
[AUDIT_FILTER_TYPE
]))
1510 goto unlock_and_return
;
1512 list_for_each_entry_rcu(e
, &audit_filter_list
[AUDIT_FILTER_TYPE
],
1515 for (i
= 0; i
< e
->rule
.field_count
; i
++) {
1516 struct audit_field
*f
= &e
->rule
.fields
[i
];
1517 if (f
->type
== AUDIT_MSGTYPE
) {
1518 result
= audit_comparator(type
, f
->op
, f
->val
);
1524 goto unlock_and_return
;
1531 /* Check to see if the rule contains any selinux fields. Returns 1 if there
1532 are selinux fields specified in the rule, 0 otherwise. */
1533 static inline int audit_rule_has_selinux(struct audit_krule
*rule
)
1537 for (i
= 0; i
< rule
->field_count
; i
++) {
1538 struct audit_field
*f
= &rule
->fields
[i
];
1540 case AUDIT_SUBJ_USER
:
1541 case AUDIT_SUBJ_ROLE
:
1542 case AUDIT_SUBJ_TYPE
:
1543 case AUDIT_SUBJ_SEN
:
1544 case AUDIT_SUBJ_CLR
:
1552 /* This function will re-initialize the se_rule field of all applicable rules.
1553 * It will traverse the filter lists serarching for rules that contain selinux
1554 * specific filter fields. When such a rule is found, it is copied, the
1555 * selinux field is re-initialized, and the old rule is replaced with the
1557 int selinux_audit_rule_update(void)
1559 struct audit_entry
*entry
, *n
, *nentry
;
1560 struct audit_watch
*watch
;
1563 /* audit_filter_mutex synchronizes the writers */
1564 mutex_lock(&audit_filter_mutex
);
1566 for (i
= 0; i
< AUDIT_NR_FILTERS
; i
++) {
1567 list_for_each_entry_safe(entry
, n
, &audit_filter_list
[i
], list
) {
1568 if (!audit_rule_has_selinux(&entry
->rule
))
1571 watch
= entry
->rule
.watch
;
1572 nentry
= audit_dupe_rule(&entry
->rule
, watch
);
1573 if (unlikely(IS_ERR(nentry
))) {
1574 /* save the first error encountered for the
1577 err
= PTR_ERR(nentry
);
1578 audit_panic("error updating selinux filters");
1580 list_del(&entry
->rule
.rlist
);
1581 list_del_rcu(&entry
->list
);
1584 list_add(&nentry
->rule
.rlist
,
1586 list_del(&entry
->rule
.rlist
);
1588 list_replace_rcu(&entry
->list
, &nentry
->list
);
1590 call_rcu(&entry
->rcu
, audit_free_rule_rcu
);
1594 mutex_unlock(&audit_filter_mutex
);
1599 /* Update watch data in audit rules based on inotify events. */
1600 void audit_handle_ievent(struct inotify_watch
*i_watch
, u32 wd
, u32 mask
,
1601 u32 cookie
, const char *dname
, struct inode
*inode
)
1603 struct audit_parent
*parent
;
1605 parent
= container_of(i_watch
, struct audit_parent
, wdata
);
1607 if (mask
& (IN_CREATE
|IN_MOVED_TO
) && inode
)
1608 audit_update_watch(parent
, dname
, inode
->i_sb
->s_dev
,
1610 else if (mask
& (IN_DELETE
|IN_MOVED_FROM
))
1611 audit_update_watch(parent
, dname
, (dev_t
)-1, (unsigned long)-1, 1);
1612 /* inotify automatically removes the watch and sends IN_IGNORED */
1613 else if (mask
& (IN_DELETE_SELF
|IN_UNMOUNT
))
1614 audit_remove_parent_watches(parent
);
1615 /* inotify does not remove the watch, so remove it manually */
1616 else if(mask
& IN_MOVE_SELF
) {
1617 audit_remove_parent_watches(parent
);
1618 inotify_remove_watch_locked(audit_ih
, i_watch
);
1619 } else if (mask
& IN_IGNORED
)
1620 put_inotify_watch(i_watch
);