1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /* auditfilter.c -- filtering of audit events
4 * Copyright 2003-2004 Red Hat, Inc.
5 * Copyright 2005 Hewlett-Packard Development Company, L.P.
6 * Copyright 2005 IBM Corporation
9 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
11 #include <linux/kernel.h>
12 #include <linux/audit.h>
13 #include <linux/kthread.h>
14 #include <linux/mutex.h>
16 #include <linux/namei.h>
17 #include <linux/netlink.h>
18 #include <linux/sched.h>
19 #include <linux/slab.h>
20 #include <linux/security.h>
21 #include <net/net_namespace.h>
29 * Synchronizes writes and blocking reads of audit's filterlist
30 * data. Rcu is used to traverse the filterlist and access
31 * contents of structs audit_entry, audit_watch and opaque
32 * LSM rules during filtering. If modified, these structures
33 * must be copied and replace their counterparts in the filterlist.
34 * An audit_parent struct is not accessed during filtering, so may
35 * be written directly provided audit_filter_mutex is held.
38 /* Audit filter lists, defined in <linux/audit.h> */
39 struct list_head audit_filter_list
[AUDIT_NR_FILTERS
] = {
40 LIST_HEAD_INIT(audit_filter_list
[0]),
41 LIST_HEAD_INIT(audit_filter_list
[1]),
42 LIST_HEAD_INIT(audit_filter_list
[2]),
43 LIST_HEAD_INIT(audit_filter_list
[3]),
44 LIST_HEAD_INIT(audit_filter_list
[4]),
45 LIST_HEAD_INIT(audit_filter_list
[5]),
46 LIST_HEAD_INIT(audit_filter_list
[6]),
47 #if AUDIT_NR_FILTERS != 7
48 #error Fix audit_filter_list initialiser
51 static struct list_head audit_rules_list
[AUDIT_NR_FILTERS
] = {
52 LIST_HEAD_INIT(audit_rules_list
[0]),
53 LIST_HEAD_INIT(audit_rules_list
[1]),
54 LIST_HEAD_INIT(audit_rules_list
[2]),
55 LIST_HEAD_INIT(audit_rules_list
[3]),
56 LIST_HEAD_INIT(audit_rules_list
[4]),
57 LIST_HEAD_INIT(audit_rules_list
[5]),
58 LIST_HEAD_INIT(audit_rules_list
[6]),
61 DEFINE_MUTEX(audit_filter_mutex
);
63 static void audit_free_lsm_field(struct audit_field
*f
)
74 case AUDIT_OBJ_LEV_LOW
:
75 case AUDIT_OBJ_LEV_HIGH
:
77 security_audit_rule_free(f
->lsm_rule
);
81 static inline void audit_free_rule(struct audit_entry
*e
)
84 struct audit_krule
*erule
= &e
->rule
;
86 /* some rules don't have associated watches */
88 audit_put_watch(erule
->watch
);
90 for (i
= 0; i
< erule
->field_count
; i
++)
91 audit_free_lsm_field(&erule
->fields
[i
]);
93 kfree(erule
->filterkey
);
97 void audit_free_rule_rcu(struct rcu_head
*head
)
99 struct audit_entry
*e
= container_of(head
, struct audit_entry
, rcu
);
103 /* Initialize an audit filterlist entry. */
104 static inline struct audit_entry
*audit_init_entry(u32 field_count
)
106 struct audit_entry
*entry
;
107 struct audit_field
*fields
;
109 entry
= kzalloc(sizeof(*entry
), GFP_KERNEL
);
110 if (unlikely(!entry
))
113 fields
= kcalloc(field_count
, sizeof(*fields
), GFP_KERNEL
);
114 if (unlikely(!fields
)) {
118 entry
->rule
.fields
= fields
;
123 /* Unpack a filter field's string representation from user-space
125 char *audit_unpack_string(void **bufp
, size_t *remain
, size_t len
)
129 if (!*bufp
|| (len
== 0) || (len
> *remain
))
130 return ERR_PTR(-EINVAL
);
132 /* Of the currently implemented string fields, PATH_MAX
133 * defines the longest valid length.
136 return ERR_PTR(-ENAMETOOLONG
);
138 str
= kmalloc(len
+ 1, GFP_KERNEL
);
140 return ERR_PTR(-ENOMEM
);
142 memcpy(str
, *bufp
, len
);
150 /* Translate an inode field to kernel representation. */
151 static inline int audit_to_inode(struct audit_krule
*krule
,
152 struct audit_field
*f
)
154 if (krule
->listnr
!= AUDIT_FILTER_EXIT
||
155 krule
->inode_f
|| krule
->watch
|| krule
->tree
||
156 (f
->op
!= Audit_equal
&& f
->op
!= Audit_not_equal
))
163 static __u32
*classes
[AUDIT_SYSCALL_CLASSES
];
165 int __init
audit_register_class(int class, unsigned *list
)
167 __u32
*p
= kcalloc(AUDIT_BITMASK_SIZE
, sizeof(__u32
), GFP_KERNEL
);
170 while (*list
!= ~0U) {
171 unsigned n
= *list
++;
172 if (n
>= AUDIT_BITMASK_SIZE
* 32 - AUDIT_SYSCALL_CLASSES
) {
176 p
[AUDIT_WORD(n
)] |= AUDIT_BIT(n
);
178 if (class >= AUDIT_SYSCALL_CLASSES
|| classes
[class]) {
186 int audit_match_class(int class, unsigned syscall
)
188 if (unlikely(syscall
>= AUDIT_BITMASK_SIZE
* 32))
190 if (unlikely(class >= AUDIT_SYSCALL_CLASSES
|| !classes
[class]))
192 return classes
[class][AUDIT_WORD(syscall
)] & AUDIT_BIT(syscall
);
195 #ifdef CONFIG_AUDITSYSCALL
196 static inline int audit_match_class_bits(int class, u32
*mask
)
200 if (classes
[class]) {
201 for (i
= 0; i
< AUDIT_BITMASK_SIZE
; i
++)
202 if (mask
[i
] & classes
[class][i
])
208 static int audit_match_signal(struct audit_entry
*entry
)
210 struct audit_field
*arch
= entry
->rule
.arch_f
;
213 /* When arch is unspecified, we must check both masks on biarch
214 * as syscall number alone is ambiguous. */
215 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL
,
217 audit_match_class_bits(AUDIT_CLASS_SIGNAL_32
,
221 switch(audit_classify_arch(arch
->val
)) {
223 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL
,
225 case 1: /* 32bit on biarch */
226 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL_32
,
234 /* Common user-space to kernel rule translation. */
235 static inline struct audit_entry
*audit_to_entry_common(struct audit_rule_data
*rule
)
238 struct audit_entry
*entry
;
242 listnr
= rule
->flags
& ~AUDIT_FILTER_PREPEND
;
246 #ifdef CONFIG_AUDITSYSCALL
247 case AUDIT_FILTER_ENTRY
:
248 pr_err("AUDIT_FILTER_ENTRY is deprecated\n");
250 case AUDIT_FILTER_EXIT
:
251 case AUDIT_FILTER_TASK
:
253 case AUDIT_FILTER_USER
:
254 case AUDIT_FILTER_EXCLUDE
:
255 case AUDIT_FILTER_FS
:
258 if (unlikely(rule
->action
== AUDIT_POSSIBLE
)) {
259 pr_err("AUDIT_POSSIBLE is deprecated\n");
262 if (rule
->action
!= AUDIT_NEVER
&& rule
->action
!= AUDIT_ALWAYS
)
264 if (rule
->field_count
> AUDIT_MAX_FIELDS
)
268 entry
= audit_init_entry(rule
->field_count
);
272 entry
->rule
.flags
= rule
->flags
& AUDIT_FILTER_PREPEND
;
273 entry
->rule
.listnr
= listnr
;
274 entry
->rule
.action
= rule
->action
;
275 entry
->rule
.field_count
= rule
->field_count
;
277 for (i
= 0; i
< AUDIT_BITMASK_SIZE
; i
++)
278 entry
->rule
.mask
[i
] = rule
->mask
[i
];
280 for (i
= 0; i
< AUDIT_SYSCALL_CLASSES
; i
++) {
281 int bit
= AUDIT_BITMASK_SIZE
* 32 - i
- 1;
282 __u32
*p
= &entry
->rule
.mask
[AUDIT_WORD(bit
)];
285 if (!(*p
& AUDIT_BIT(bit
)))
287 *p
&= ~AUDIT_BIT(bit
);
291 for (j
= 0; j
< AUDIT_BITMASK_SIZE
; j
++)
292 entry
->rule
.mask
[j
] |= class[j
];
302 static u32 audit_ops
[] =
304 [Audit_equal
] = AUDIT_EQUAL
,
305 [Audit_not_equal
] = AUDIT_NOT_EQUAL
,
306 [Audit_bitmask
] = AUDIT_BIT_MASK
,
307 [Audit_bittest
] = AUDIT_BIT_TEST
,
308 [Audit_lt
] = AUDIT_LESS_THAN
,
309 [Audit_gt
] = AUDIT_GREATER_THAN
,
310 [Audit_le
] = AUDIT_LESS_THAN_OR_EQUAL
,
311 [Audit_ge
] = AUDIT_GREATER_THAN_OR_EQUAL
,
314 static u32
audit_to_op(u32 op
)
317 for (n
= Audit_equal
; n
< Audit_bad
&& audit_ops
[n
] != op
; n
++)
322 /* check if an audit field is valid */
323 static int audit_field_valid(struct audit_entry
*entry
, struct audit_field
*f
)
327 if (entry
->rule
.listnr
!= AUDIT_FILTER_EXCLUDE
&&
328 entry
->rule
.listnr
!= AUDIT_FILTER_USER
)
332 if (entry
->rule
.listnr
!= AUDIT_FILTER_FS
)
337 switch (entry
->rule
.listnr
) {
338 case AUDIT_FILTER_FS
:
341 case AUDIT_FILTERKEY
:
348 /* Check for valid field type and op */
354 case AUDIT_PERS
: /* <uapi/linux/personality.h> */
356 /* all ops are valid */
376 case AUDIT_SESSIONID
:
379 case AUDIT_OBJ_LEV_LOW
:
380 case AUDIT_OBJ_LEV_HIGH
:
381 case AUDIT_SADDR_FAM
:
382 /* bit ops are only useful on syscall args */
383 if (f
->op
== Audit_bitmask
|| f
->op
== Audit_bittest
)
386 case AUDIT_SUBJ_USER
:
387 case AUDIT_SUBJ_ROLE
:
388 case AUDIT_SUBJ_TYPE
:
394 case AUDIT_FILTERKEY
:
395 case AUDIT_LOGINUID_SET
:
400 case AUDIT_FIELD_COMPARE
:
402 /* only equal and not equal valid ops */
403 if (f
->op
!= Audit_not_equal
&& f
->op
!= Audit_equal
)
407 /* field not recognized */
411 /* Check for select valid field values */
413 case AUDIT_LOGINUID_SET
:
414 if ((f
->val
!= 0) && (f
->val
!= 1))
422 if (f
->val
& ~S_IFMT
)
425 case AUDIT_FIELD_COMPARE
:
426 if (f
->val
> AUDIT_MAX_FIELD_COMPARE
)
429 case AUDIT_SADDR_FAM
:
430 if (f
->val
>= AF_MAX
)
440 /* Translate struct audit_rule_data to kernel's rule representation. */
441 static struct audit_entry
*audit_data_to_entry(struct audit_rule_data
*data
,
445 struct audit_entry
*entry
;
447 size_t remain
= datasz
- sizeof(struct audit_rule_data
);
450 struct audit_fsnotify_mark
*audit_mark
;
452 entry
= audit_to_entry_common(data
);
457 for (i
= 0; i
< data
->field_count
; i
++) {
458 struct audit_field
*f
= &entry
->rule
.fields
[i
];
463 f
->op
= audit_to_op(data
->fieldflags
[i
]);
464 if (f
->op
== Audit_bad
)
467 f
->type
= data
->fields
[i
];
468 f_val
= data
->values
[i
];
470 /* Support legacy tests for a valid loginuid */
471 if ((f
->type
== AUDIT_LOGINUID
) && (f_val
== AUDIT_UID_UNSET
)) {
472 f
->type
= AUDIT_LOGINUID_SET
;
474 entry
->rule
.pflags
|= AUDIT_LOGINUID_LEGACY
;
477 err
= audit_field_valid(entry
, f
);
489 f
->uid
= make_kuid(current_user_ns(), f_val
);
490 if (!uid_valid(f
->uid
))
498 f
->gid
= make_kgid(current_user_ns(), f_val
);
499 if (!gid_valid(f
->gid
))
504 entry
->rule
.arch_f
= f
;
506 case AUDIT_SUBJ_USER
:
507 case AUDIT_SUBJ_ROLE
:
508 case AUDIT_SUBJ_TYPE
:
514 case AUDIT_OBJ_LEV_LOW
:
515 case AUDIT_OBJ_LEV_HIGH
:
516 str
= audit_unpack_string(&bufp
, &remain
, f_val
);
521 entry
->rule
.buflen
+= f_val
;
523 err
= security_audit_rule_init(f
->type
, f
->op
, str
,
524 (void **)&f
->lsm_rule
);
525 /* Keep currently invalid fields around in case they
526 * become valid after a policy reload. */
527 if (err
== -EINVAL
) {
528 pr_warn("audit rule for LSM \'%s\' is invalid\n",
535 str
= audit_unpack_string(&bufp
, &remain
, f_val
);
540 err
= audit_to_watch(&entry
->rule
, str
, f_val
, f
->op
);
545 entry
->rule
.buflen
+= f_val
;
548 str
= audit_unpack_string(&bufp
, &remain
, f_val
);
553 err
= audit_make_tree(&entry
->rule
, str
, f
->op
);
557 entry
->rule
.buflen
+= f_val
;
561 err
= audit_to_inode(&entry
->rule
, f
);
565 case AUDIT_FILTERKEY
:
566 if (entry
->rule
.filterkey
|| f_val
> AUDIT_MAX_KEY_LEN
)
568 str
= audit_unpack_string(&bufp
, &remain
, f_val
);
573 entry
->rule
.buflen
+= f_val
;
574 entry
->rule
.filterkey
= str
;
577 if (entry
->rule
.exe
|| f_val
> PATH_MAX
)
579 str
= audit_unpack_string(&bufp
, &remain
, f_val
);
584 audit_mark
= audit_alloc_mark(&entry
->rule
, str
, f_val
);
585 if (IS_ERR(audit_mark
)) {
587 err
= PTR_ERR(audit_mark
);
590 entry
->rule
.buflen
+= f_val
;
591 entry
->rule
.exe
= audit_mark
;
599 if (entry
->rule
.inode_f
&& entry
->rule
.inode_f
->op
== Audit_not_equal
)
600 entry
->rule
.inode_f
= NULL
;
606 if (entry
->rule
.tree
)
607 audit_put_tree(entry
->rule
.tree
); /* that's the temporary one */
609 audit_remove_mark(entry
->rule
.exe
); /* that's the template one */
610 audit_free_rule(entry
);
614 /* Pack a filter field's string representation into data block. */
615 static inline size_t audit_pack_string(void **bufp
, const char *str
)
617 size_t len
= strlen(str
);
619 memcpy(*bufp
, str
, len
);
625 /* Translate kernel rule representation to struct audit_rule_data. */
626 static struct audit_rule_data
*audit_krule_to_data(struct audit_krule
*krule
)
628 struct audit_rule_data
*data
;
632 data
= kmalloc(sizeof(*data
) + krule
->buflen
, GFP_KERNEL
);
635 memset(data
, 0, sizeof(*data
));
637 data
->flags
= krule
->flags
| krule
->listnr
;
638 data
->action
= krule
->action
;
639 data
->field_count
= krule
->field_count
;
641 for (i
= 0; i
< data
->field_count
; i
++) {
642 struct audit_field
*f
= &krule
->fields
[i
];
644 data
->fields
[i
] = f
->type
;
645 data
->fieldflags
[i
] = audit_ops
[f
->op
];
647 case AUDIT_SUBJ_USER
:
648 case AUDIT_SUBJ_ROLE
:
649 case AUDIT_SUBJ_TYPE
:
655 case AUDIT_OBJ_LEV_LOW
:
656 case AUDIT_OBJ_LEV_HIGH
:
657 data
->buflen
+= data
->values
[i
] =
658 audit_pack_string(&bufp
, f
->lsm_str
);
661 data
->buflen
+= data
->values
[i
] =
662 audit_pack_string(&bufp
,
663 audit_watch_path(krule
->watch
));
666 data
->buflen
+= data
->values
[i
] =
667 audit_pack_string(&bufp
,
668 audit_tree_path(krule
->tree
));
670 case AUDIT_FILTERKEY
:
671 data
->buflen
+= data
->values
[i
] =
672 audit_pack_string(&bufp
, krule
->filterkey
);
675 data
->buflen
+= data
->values
[i
] =
676 audit_pack_string(&bufp
, audit_mark_path(krule
->exe
));
678 case AUDIT_LOGINUID_SET
:
679 if (krule
->pflags
& AUDIT_LOGINUID_LEGACY
&& !f
->val
) {
680 data
->fields
[i
] = AUDIT_LOGINUID
;
681 data
->values
[i
] = AUDIT_UID_UNSET
;
684 /* fall through - if set */
686 data
->values
[i
] = f
->val
;
689 for (i
= 0; i
< AUDIT_BITMASK_SIZE
; i
++) data
->mask
[i
] = krule
->mask
[i
];
694 /* Compare two rules in kernel format. Considered success if rules
696 static int audit_compare_rule(struct audit_krule
*a
, struct audit_krule
*b
)
700 if (a
->flags
!= b
->flags
||
701 a
->pflags
!= b
->pflags
||
702 a
->listnr
!= b
->listnr
||
703 a
->action
!= b
->action
||
704 a
->field_count
!= b
->field_count
)
707 for (i
= 0; i
< a
->field_count
; i
++) {
708 if (a
->fields
[i
].type
!= b
->fields
[i
].type
||
709 a
->fields
[i
].op
!= b
->fields
[i
].op
)
712 switch(a
->fields
[i
].type
) {
713 case AUDIT_SUBJ_USER
:
714 case AUDIT_SUBJ_ROLE
:
715 case AUDIT_SUBJ_TYPE
:
721 case AUDIT_OBJ_LEV_LOW
:
722 case AUDIT_OBJ_LEV_HIGH
:
723 if (strcmp(a
->fields
[i
].lsm_str
, b
->fields
[i
].lsm_str
))
727 if (strcmp(audit_watch_path(a
->watch
),
728 audit_watch_path(b
->watch
)))
732 if (strcmp(audit_tree_path(a
->tree
),
733 audit_tree_path(b
->tree
)))
736 case AUDIT_FILTERKEY
:
737 /* both filterkeys exist based on above type compare */
738 if (strcmp(a
->filterkey
, b
->filterkey
))
742 /* both paths exist based on above type compare */
743 if (strcmp(audit_mark_path(a
->exe
),
744 audit_mark_path(b
->exe
)))
753 if (!uid_eq(a
->fields
[i
].uid
, b
->fields
[i
].uid
))
761 if (!gid_eq(a
->fields
[i
].gid
, b
->fields
[i
].gid
))
765 if (a
->fields
[i
].val
!= b
->fields
[i
].val
)
770 for (i
= 0; i
< AUDIT_BITMASK_SIZE
; i
++)
771 if (a
->mask
[i
] != b
->mask
[i
])
777 /* Duplicate LSM field information. The lsm_rule is opaque, so must be
779 static inline int audit_dupe_lsm_field(struct audit_field
*df
,
780 struct audit_field
*sf
)
785 /* our own copy of lsm_str */
786 lsm_str
= kstrdup(sf
->lsm_str
, GFP_KERNEL
);
787 if (unlikely(!lsm_str
))
789 df
->lsm_str
= lsm_str
;
791 /* our own (refreshed) copy of lsm_rule */
792 ret
= security_audit_rule_init(df
->type
, df
->op
, df
->lsm_str
,
793 (void **)&df
->lsm_rule
);
794 /* Keep currently invalid fields around in case they
795 * become valid after a policy reload. */
796 if (ret
== -EINVAL
) {
797 pr_warn("audit rule for LSM \'%s\' is invalid\n",
805 /* Duplicate an audit rule. This will be a deep copy with the exception
806 * of the watch - that pointer is carried over. The LSM specific fields
807 * will be updated in the copy. The point is to be able to replace the old
808 * rule with the new rule in the filterlist, then free the old rule.
809 * The rlist element is undefined; list manipulations are handled apart from
810 * the initial copy. */
811 struct audit_entry
*audit_dupe_rule(struct audit_krule
*old
)
813 u32 fcount
= old
->field_count
;
814 struct audit_entry
*entry
;
815 struct audit_krule
*new;
819 entry
= audit_init_entry(fcount
);
820 if (unlikely(!entry
))
821 return ERR_PTR(-ENOMEM
);
824 new->flags
= old
->flags
;
825 new->pflags
= old
->pflags
;
826 new->listnr
= old
->listnr
;
827 new->action
= old
->action
;
828 for (i
= 0; i
< AUDIT_BITMASK_SIZE
; i
++)
829 new->mask
[i
] = old
->mask
[i
];
830 new->prio
= old
->prio
;
831 new->buflen
= old
->buflen
;
832 new->inode_f
= old
->inode_f
;
833 new->field_count
= old
->field_count
;
836 * note that we are OK with not refcounting here; audit_match_tree()
837 * never dereferences tree and we can't get false positives there
838 * since we'd have to have rule gone from the list *and* removed
839 * before the chunks found by lookup had been allocated, i.e. before
840 * the beginning of list scan.
842 new->tree
= old
->tree
;
843 memcpy(new->fields
, old
->fields
, sizeof(struct audit_field
) * fcount
);
845 /* deep copy this information, updating the lsm_rule fields, because
846 * the originals will all be freed when the old rule is freed. */
847 for (i
= 0; i
< fcount
; i
++) {
848 switch (new->fields
[i
].type
) {
849 case AUDIT_SUBJ_USER
:
850 case AUDIT_SUBJ_ROLE
:
851 case AUDIT_SUBJ_TYPE
:
857 case AUDIT_OBJ_LEV_LOW
:
858 case AUDIT_OBJ_LEV_HIGH
:
859 err
= audit_dupe_lsm_field(&new->fields
[i
],
862 case AUDIT_FILTERKEY
:
863 fk
= kstrdup(old
->filterkey
, GFP_KERNEL
);
870 err
= audit_dupe_exe(new, old
);
875 audit_remove_mark(new->exe
);
876 audit_free_rule(entry
);
882 audit_get_watch(old
->watch
);
883 new->watch
= old
->watch
;
889 /* Find an existing audit rule.
890 * Caller must hold audit_filter_mutex to prevent stale rule data. */
891 static struct audit_entry
*audit_find_rule(struct audit_entry
*entry
,
892 struct list_head
**p
)
894 struct audit_entry
*e
, *found
= NULL
;
895 struct list_head
*list
;
898 if (entry
->rule
.inode_f
) {
899 h
= audit_hash_ino(entry
->rule
.inode_f
->val
);
900 *p
= list
= &audit_inode_hash
[h
];
901 } else if (entry
->rule
.watch
) {
902 /* we don't know the inode number, so must walk entire hash */
903 for (h
= 0; h
< AUDIT_INODE_BUCKETS
; h
++) {
904 list
= &audit_inode_hash
[h
];
905 list_for_each_entry(e
, list
, list
)
906 if (!audit_compare_rule(&entry
->rule
, &e
->rule
)) {
913 *p
= list
= &audit_filter_list
[entry
->rule
.listnr
];
916 list_for_each_entry(e
, list
, list
)
917 if (!audit_compare_rule(&entry
->rule
, &e
->rule
)) {
926 static u64 prio_low
= ~0ULL/2;
927 static u64 prio_high
= ~0ULL/2 - 1;
929 /* Add rule to given filterlist if not a duplicate. */
930 static inline int audit_add_rule(struct audit_entry
*entry
)
932 struct audit_entry
*e
;
933 struct audit_watch
*watch
= entry
->rule
.watch
;
934 struct audit_tree
*tree
= entry
->rule
.tree
;
935 struct list_head
*list
;
937 #ifdef CONFIG_AUDITSYSCALL
940 /* If any of these, don't count towards total */
941 switch(entry
->rule
.listnr
) {
942 case AUDIT_FILTER_USER
:
943 case AUDIT_FILTER_EXCLUDE
:
944 case AUDIT_FILTER_FS
:
949 mutex_lock(&audit_filter_mutex
);
950 e
= audit_find_rule(entry
, &list
);
952 mutex_unlock(&audit_filter_mutex
);
954 /* normally audit_add_tree_rule() will free it on failure */
956 audit_put_tree(tree
);
961 /* audit_filter_mutex is dropped and re-taken during this call */
962 err
= audit_add_watch(&entry
->rule
, &list
);
964 mutex_unlock(&audit_filter_mutex
);
966 * normally audit_add_tree_rule() will free it
970 audit_put_tree(tree
);
975 err
= audit_add_tree_rule(&entry
->rule
);
977 mutex_unlock(&audit_filter_mutex
);
982 entry
->rule
.prio
= ~0ULL;
983 if (entry
->rule
.listnr
== AUDIT_FILTER_EXIT
) {
984 if (entry
->rule
.flags
& AUDIT_FILTER_PREPEND
)
985 entry
->rule
.prio
= ++prio_high
;
987 entry
->rule
.prio
= --prio_low
;
990 if (entry
->rule
.flags
& AUDIT_FILTER_PREPEND
) {
991 list_add(&entry
->rule
.list
,
992 &audit_rules_list
[entry
->rule
.listnr
]);
993 list_add_rcu(&entry
->list
, list
);
994 entry
->rule
.flags
&= ~AUDIT_FILTER_PREPEND
;
996 list_add_tail(&entry
->rule
.list
,
997 &audit_rules_list
[entry
->rule
.listnr
]);
998 list_add_tail_rcu(&entry
->list
, list
);
1000 #ifdef CONFIG_AUDITSYSCALL
1004 if (!audit_match_signal(entry
))
1007 mutex_unlock(&audit_filter_mutex
);
1012 /* Remove an existing rule from filterlist. */
1013 int audit_del_rule(struct audit_entry
*entry
)
1015 struct audit_entry
*e
;
1016 struct audit_tree
*tree
= entry
->rule
.tree
;
1017 struct list_head
*list
;
1019 #ifdef CONFIG_AUDITSYSCALL
1022 /* If any of these, don't count towards total */
1023 switch(entry
->rule
.listnr
) {
1024 case AUDIT_FILTER_USER
:
1025 case AUDIT_FILTER_EXCLUDE
:
1026 case AUDIT_FILTER_FS
:
1031 mutex_lock(&audit_filter_mutex
);
1032 e
= audit_find_rule(entry
, &list
);
1039 audit_remove_watch_rule(&e
->rule
);
1042 audit_remove_tree_rule(&e
->rule
);
1045 audit_remove_mark_rule(&e
->rule
);
1047 #ifdef CONFIG_AUDITSYSCALL
1051 if (!audit_match_signal(entry
))
1055 list_del_rcu(&e
->list
);
1056 list_del(&e
->rule
.list
);
1057 call_rcu(&e
->rcu
, audit_free_rule_rcu
);
1060 mutex_unlock(&audit_filter_mutex
);
1063 audit_put_tree(tree
); /* that's the temporary one */
1068 /* List rules using struct audit_rule_data. */
1069 static void audit_list_rules(int seq
, struct sk_buff_head
*q
)
1071 struct sk_buff
*skb
;
1072 struct audit_krule
*r
;
1075 /* This is a blocking read, so use audit_filter_mutex instead of rcu
1076 * iterator to sync with list writers. */
1077 for (i
=0; i
<AUDIT_NR_FILTERS
; i
++) {
1078 list_for_each_entry(r
, &audit_rules_list
[i
], list
) {
1079 struct audit_rule_data
*data
;
1081 data
= audit_krule_to_data(r
);
1082 if (unlikely(!data
))
1084 skb
= audit_make_reply(seq
, AUDIT_LIST_RULES
, 0, 1,
1086 sizeof(*data
) + data
->buflen
);
1088 skb_queue_tail(q
, skb
);
1092 skb
= audit_make_reply(seq
, AUDIT_LIST_RULES
, 1, 1, NULL
, 0);
1094 skb_queue_tail(q
, skb
);
1097 /* Log rule additions and removals */
1098 static void audit_log_rule_change(char *action
, struct audit_krule
*rule
, int res
)
1100 struct audit_buffer
*ab
;
1105 ab
= audit_log_start(audit_context(), GFP_KERNEL
, AUDIT_CONFIG_CHANGE
);
1108 audit_log_session_info(ab
);
1109 audit_log_task_context(ab
);
1110 audit_log_format(ab
, " op=%s", action
);
1111 audit_log_key(ab
, rule
->filterkey
);
1112 audit_log_format(ab
, " list=%d res=%d", rule
->listnr
, res
);
1117 * audit_rule_change - apply all rules to the specified message type
1118 * @type: audit message type
1119 * @seq: netlink audit message sequence (serial) number
1120 * @data: payload data
1121 * @datasz: size of payload data
1123 int audit_rule_change(int type
, int seq
, void *data
, size_t datasz
)
1126 struct audit_entry
*entry
;
1129 case AUDIT_ADD_RULE
:
1130 entry
= audit_data_to_entry(data
, datasz
);
1132 return PTR_ERR(entry
);
1133 err
= audit_add_rule(entry
);
1134 audit_log_rule_change("add_rule", &entry
->rule
, !err
);
1136 case AUDIT_DEL_RULE
:
1137 entry
= audit_data_to_entry(data
, datasz
);
1139 return PTR_ERR(entry
);
1140 err
= audit_del_rule(entry
);
1141 audit_log_rule_change("remove_rule", &entry
->rule
, !err
);
1148 if (err
|| type
== AUDIT_DEL_RULE
) {
1149 if (entry
->rule
.exe
)
1150 audit_remove_mark(entry
->rule
.exe
);
1151 audit_free_rule(entry
);
1158 * audit_list_rules_send - list the audit rules
1159 * @request_skb: skb of request we are replying to (used to target the reply)
1160 * @seq: netlink audit message sequence (serial) number
1162 int audit_list_rules_send(struct sk_buff
*request_skb
, int seq
)
1164 struct task_struct
*tsk
;
1165 struct audit_netlink_list
*dest
;
1167 /* We can't just spew out the rules here because we might fill
1168 * the available socket buffer space and deadlock waiting for
1169 * auditctl to read from it... which isn't ever going to
1170 * happen if we're actually running in the context of auditctl
1171 * trying to _send_ the stuff */
1173 dest
= kmalloc(sizeof(*dest
), GFP_KERNEL
);
1176 dest
->net
= get_net(sock_net(NETLINK_CB(request_skb
).sk
));
1177 dest
->portid
= NETLINK_CB(request_skb
).portid
;
1178 skb_queue_head_init(&dest
->q
);
1180 mutex_lock(&audit_filter_mutex
);
1181 audit_list_rules(seq
, &dest
->q
);
1182 mutex_unlock(&audit_filter_mutex
);
1184 tsk
= kthread_run(audit_send_list_thread
, dest
, "audit_send_list");
1186 skb_queue_purge(&dest
->q
);
1189 return PTR_ERR(tsk
);
1195 int audit_comparator(u32 left
, u32 op
, u32 right
)
1199 return (left
== right
);
1200 case Audit_not_equal
:
1201 return (left
!= right
);
1203 return (left
< right
);
1205 return (left
<= right
);
1207 return (left
> right
);
1209 return (left
>= right
);
1211 return (left
& right
);
1213 return ((left
& right
) == right
);
1219 int audit_uid_comparator(kuid_t left
, u32 op
, kuid_t right
)
1223 return uid_eq(left
, right
);
1224 case Audit_not_equal
:
1225 return !uid_eq(left
, right
);
1227 return uid_lt(left
, right
);
1229 return uid_lte(left
, right
);
1231 return uid_gt(left
, right
);
1233 return uid_gte(left
, right
);
1241 int audit_gid_comparator(kgid_t left
, u32 op
, kgid_t right
)
1245 return gid_eq(left
, right
);
1246 case Audit_not_equal
:
1247 return !gid_eq(left
, right
);
1249 return gid_lt(left
, right
);
1251 return gid_lte(left
, right
);
1253 return gid_gt(left
, right
);
1255 return gid_gte(left
, right
);
1264 * parent_len - find the length of the parent portion of a pathname
1265 * @path: pathname of which to determine length
1267 int parent_len(const char *path
)
1272 plen
= strlen(path
);
1277 /* disregard trailing slashes */
1278 p
= path
+ plen
- 1;
1279 while ((*p
== '/') && (p
> path
))
1282 /* walk backward until we find the next slash or hit beginning */
1283 while ((*p
!= '/') && (p
> path
))
1286 /* did we find a slash? Then increment to include it in path */
1294 * audit_compare_dname_path - compare given dentry name with last component in
1295 * given path. Return of 0 indicates a match.
1296 * @dname: dentry name that we're comparing
1297 * @path: full pathname that we're comparing
1298 * @parentlen: length of the parent if known. Passing in AUDIT_NAME_FULL
1299 * here indicates that we must compute this value.
1301 int audit_compare_dname_path(const struct qstr
*dname
, const char *path
, int parentlen
)
1307 pathlen
= strlen(path
);
1311 parentlen
= parentlen
== AUDIT_NAME_FULL
? parent_len(path
) : parentlen
;
1312 if (pathlen
- parentlen
!= dlen
)
1315 p
= path
+ parentlen
;
1317 return strncmp(p
, dname
->name
, dlen
);
1320 int audit_filter(int msgtype
, unsigned int listtype
)
1322 struct audit_entry
*e
;
1323 int ret
= 1; /* Audit by default */
1326 list_for_each_entry_rcu(e
, &audit_filter_list
[listtype
], list
) {
1329 for (i
= 0; i
< e
->rule
.field_count
; i
++) {
1330 struct audit_field
*f
= &e
->rule
.fields
[i
];
1336 pid
= task_pid_nr(current
);
1337 result
= audit_comparator(pid
, f
->op
, f
->val
);
1340 result
= audit_uid_comparator(current_uid(), f
->op
, f
->uid
);
1343 result
= audit_gid_comparator(current_gid(), f
->op
, f
->gid
);
1345 case AUDIT_LOGINUID
:
1346 result
= audit_uid_comparator(audit_get_loginuid(current
),
1349 case AUDIT_LOGINUID_SET
:
1350 result
= audit_comparator(audit_loginuid_set(current
),
1354 result
= audit_comparator(msgtype
, f
->op
, f
->val
);
1356 case AUDIT_SUBJ_USER
:
1357 case AUDIT_SUBJ_ROLE
:
1358 case AUDIT_SUBJ_TYPE
:
1359 case AUDIT_SUBJ_SEN
:
1360 case AUDIT_SUBJ_CLR
:
1362 security_task_getsecid(current
, &sid
);
1363 result
= security_audit_rule_match(sid
,
1364 f
->type
, f
->op
, f
->lsm_rule
);
1368 result
= audit_exe_compare(current
, e
->rule
.exe
);
1369 if (f
->op
== Audit_not_equal
)
1373 goto unlock_and_return
;
1375 if (result
< 0) /* error */
1376 goto unlock_and_return
;
1381 if (e
->rule
.action
== AUDIT_NEVER
|| listtype
== AUDIT_FILTER_EXCLUDE
)
1391 static int update_lsm_rule(struct audit_krule
*r
)
1393 struct audit_entry
*entry
= container_of(r
, struct audit_entry
, rule
);
1394 struct audit_entry
*nentry
;
1397 if (!security_audit_rule_known(r
))
1400 nentry
= audit_dupe_rule(r
);
1401 if (entry
->rule
.exe
)
1402 audit_remove_mark(entry
->rule
.exe
);
1403 if (IS_ERR(nentry
)) {
1404 /* save the first error encountered for the
1406 err
= PTR_ERR(nentry
);
1407 audit_panic("error updating LSM filters");
1409 list_del(&r
->rlist
);
1410 list_del_rcu(&entry
->list
);
1413 if (r
->watch
|| r
->tree
)
1414 list_replace_init(&r
->rlist
, &nentry
->rule
.rlist
);
1415 list_replace_rcu(&entry
->list
, &nentry
->list
);
1416 list_replace(&r
->list
, &nentry
->rule
.list
);
1418 call_rcu(&entry
->rcu
, audit_free_rule_rcu
);
1423 /* This function will re-initialize the lsm_rule field of all applicable rules.
1424 * It will traverse the filter lists serarching for rules that contain LSM
1425 * specific filter fields. When such a rule is found, it is copied, the
1426 * LSM field is re-initialized, and the old rule is replaced with the
1428 int audit_update_lsm_rules(void)
1430 struct audit_krule
*r
, *n
;
1433 /* audit_filter_mutex synchronizes the writers */
1434 mutex_lock(&audit_filter_mutex
);
1436 for (i
= 0; i
< AUDIT_NR_FILTERS
; i
++) {
1437 list_for_each_entry_safe(r
, n
, &audit_rules_list
[i
], list
) {
1438 int res
= update_lsm_rule(r
);
1443 mutex_unlock(&audit_filter_mutex
);