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 LIST_HEAD_INIT(audit_filter_list
[7]),
48 #if AUDIT_NR_FILTERS != 8
49 #error Fix audit_filter_list initialiser
52 static struct list_head audit_rules_list
[AUDIT_NR_FILTERS
] = {
53 LIST_HEAD_INIT(audit_rules_list
[0]),
54 LIST_HEAD_INIT(audit_rules_list
[1]),
55 LIST_HEAD_INIT(audit_rules_list
[2]),
56 LIST_HEAD_INIT(audit_rules_list
[3]),
57 LIST_HEAD_INIT(audit_rules_list
[4]),
58 LIST_HEAD_INIT(audit_rules_list
[5]),
59 LIST_HEAD_INIT(audit_rules_list
[6]),
60 LIST_HEAD_INIT(audit_rules_list
[7]),
63 DEFINE_MUTEX(audit_filter_mutex
);
65 static void audit_free_lsm_field(struct audit_field
*f
)
76 case AUDIT_OBJ_LEV_LOW
:
77 case AUDIT_OBJ_LEV_HIGH
:
79 security_audit_rule_free(f
->lsm_rule
);
83 static inline void audit_free_rule(struct audit_entry
*e
)
86 struct audit_krule
*erule
= &e
->rule
;
88 /* some rules don't have associated watches */
90 audit_put_watch(erule
->watch
);
92 for (i
= 0; i
< erule
->field_count
; i
++)
93 audit_free_lsm_field(&erule
->fields
[i
]);
95 kfree(erule
->filterkey
);
99 void audit_free_rule_rcu(struct rcu_head
*head
)
101 struct audit_entry
*e
= container_of(head
, struct audit_entry
, rcu
);
105 /* Initialize an audit filterlist entry. */
106 static inline struct audit_entry
*audit_init_entry(u32 field_count
)
108 struct audit_entry
*entry
;
109 struct audit_field
*fields
;
111 entry
= kzalloc(sizeof(*entry
), GFP_KERNEL
);
112 if (unlikely(!entry
))
115 fields
= kcalloc(field_count
, sizeof(*fields
), GFP_KERNEL
);
116 if (unlikely(!fields
)) {
120 entry
->rule
.fields
= fields
;
125 /* Unpack a filter field's string representation from user-space
127 char *audit_unpack_string(void **bufp
, size_t *remain
, size_t len
)
131 if (!*bufp
|| (len
== 0) || (len
> *remain
))
132 return ERR_PTR(-EINVAL
);
134 /* Of the currently implemented string fields, PATH_MAX
135 * defines the longest valid length.
138 return ERR_PTR(-ENAMETOOLONG
);
140 str
= kmalloc(len
+ 1, GFP_KERNEL
);
142 return ERR_PTR(-ENOMEM
);
144 memcpy(str
, *bufp
, len
);
152 /* Translate an inode field to kernel representation. */
153 static inline int audit_to_inode(struct audit_krule
*krule
,
154 struct audit_field
*f
)
156 if ((krule
->listnr
!= AUDIT_FILTER_EXIT
&&
157 krule
->listnr
!= AUDIT_FILTER_URING_EXIT
) ||
158 krule
->inode_f
|| krule
->watch
|| krule
->tree
||
159 (f
->op
!= Audit_equal
&& f
->op
!= Audit_not_equal
))
166 static __u32
*classes
[AUDIT_SYSCALL_CLASSES
];
168 int __init
audit_register_class(int class, unsigned *list
)
170 __u32
*p
= kcalloc(AUDIT_BITMASK_SIZE
, sizeof(__u32
), GFP_KERNEL
);
173 while (*list
!= ~0U) {
174 unsigned n
= *list
++;
175 if (n
>= AUDIT_BITMASK_SIZE
* 32 - AUDIT_SYSCALL_CLASSES
) {
179 p
[AUDIT_WORD(n
)] |= AUDIT_BIT(n
);
181 if (class >= AUDIT_SYSCALL_CLASSES
|| classes
[class]) {
189 int audit_match_class(int class, unsigned syscall
)
191 if (unlikely(syscall
>= AUDIT_BITMASK_SIZE
* 32))
193 if (unlikely(class >= AUDIT_SYSCALL_CLASSES
|| !classes
[class]))
195 return classes
[class][AUDIT_WORD(syscall
)] & AUDIT_BIT(syscall
);
198 #ifdef CONFIG_AUDITSYSCALL
199 static inline int audit_match_class_bits(int class, u32
*mask
)
203 if (classes
[class]) {
204 for (i
= 0; i
< AUDIT_BITMASK_SIZE
; i
++)
205 if (mask
[i
] & classes
[class][i
])
211 static int audit_match_signal(struct audit_entry
*entry
)
213 struct audit_field
*arch
= entry
->rule
.arch_f
;
216 /* When arch is unspecified, we must check both masks on biarch
217 * as syscall number alone is ambiguous. */
218 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL
,
220 audit_match_class_bits(AUDIT_CLASS_SIGNAL_32
,
224 switch (audit_classify_arch(arch
->val
)) {
226 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL
,
228 case 1: /* 32bit on biarch */
229 return (audit_match_class_bits(AUDIT_CLASS_SIGNAL_32
,
237 /* Common user-space to kernel rule translation. */
238 static inline struct audit_entry
*audit_to_entry_common(struct audit_rule_data
*rule
)
241 struct audit_entry
*entry
;
245 listnr
= rule
->flags
& ~AUDIT_FILTER_PREPEND
;
249 #ifdef CONFIG_AUDITSYSCALL
250 case AUDIT_FILTER_ENTRY
:
251 pr_err("AUDIT_FILTER_ENTRY is deprecated\n");
253 case AUDIT_FILTER_EXIT
:
254 case AUDIT_FILTER_URING_EXIT
:
255 case AUDIT_FILTER_TASK
:
257 case AUDIT_FILTER_USER
:
258 case AUDIT_FILTER_EXCLUDE
:
259 case AUDIT_FILTER_FS
:
262 if (unlikely(rule
->action
== AUDIT_POSSIBLE
)) {
263 pr_err("AUDIT_POSSIBLE is deprecated\n");
266 if (rule
->action
!= AUDIT_NEVER
&& rule
->action
!= AUDIT_ALWAYS
)
268 if (rule
->field_count
> AUDIT_MAX_FIELDS
)
272 entry
= audit_init_entry(rule
->field_count
);
276 entry
->rule
.flags
= rule
->flags
& AUDIT_FILTER_PREPEND
;
277 entry
->rule
.listnr
= listnr
;
278 entry
->rule
.action
= rule
->action
;
279 entry
->rule
.field_count
= rule
->field_count
;
281 for (i
= 0; i
< AUDIT_BITMASK_SIZE
; i
++)
282 entry
->rule
.mask
[i
] = rule
->mask
[i
];
284 for (i
= 0; i
< AUDIT_SYSCALL_CLASSES
; i
++) {
285 int bit
= AUDIT_BITMASK_SIZE
* 32 - i
- 1;
286 __u32
*p
= &entry
->rule
.mask
[AUDIT_WORD(bit
)];
289 if (!(*p
& AUDIT_BIT(bit
)))
291 *p
&= ~AUDIT_BIT(bit
);
295 for (j
= 0; j
< AUDIT_BITMASK_SIZE
; j
++)
296 entry
->rule
.mask
[j
] |= class[j
];
306 static u32 audit_ops
[] =
308 [Audit_equal
] = AUDIT_EQUAL
,
309 [Audit_not_equal
] = AUDIT_NOT_EQUAL
,
310 [Audit_bitmask
] = AUDIT_BIT_MASK
,
311 [Audit_bittest
] = AUDIT_BIT_TEST
,
312 [Audit_lt
] = AUDIT_LESS_THAN
,
313 [Audit_gt
] = AUDIT_GREATER_THAN
,
314 [Audit_le
] = AUDIT_LESS_THAN_OR_EQUAL
,
315 [Audit_ge
] = AUDIT_GREATER_THAN_OR_EQUAL
,
318 static u32
audit_to_op(u32 op
)
321 for (n
= Audit_equal
; n
< Audit_bad
&& audit_ops
[n
] != op
; n
++)
326 /* check if an audit field is valid */
327 static int audit_field_valid(struct audit_entry
*entry
, struct audit_field
*f
)
331 if (entry
->rule
.listnr
!= AUDIT_FILTER_EXCLUDE
&&
332 entry
->rule
.listnr
!= AUDIT_FILTER_USER
)
336 if (entry
->rule
.listnr
!= AUDIT_FILTER_FS
)
340 if (entry
->rule
.listnr
== AUDIT_FILTER_URING_EXIT
)
345 switch (entry
->rule
.listnr
) {
346 case AUDIT_FILTER_FS
:
349 case AUDIT_FILTERKEY
:
356 /* Check for valid field type and op */
362 case AUDIT_PERS
: /* <uapi/linux/personality.h> */
364 /* all ops are valid */
384 case AUDIT_SESSIONID
:
387 case AUDIT_OBJ_LEV_LOW
:
388 case AUDIT_OBJ_LEV_HIGH
:
389 case AUDIT_SADDR_FAM
:
390 /* bit ops are only useful on syscall args */
391 if (f
->op
== Audit_bitmask
|| f
->op
== Audit_bittest
)
394 case AUDIT_SUBJ_USER
:
395 case AUDIT_SUBJ_ROLE
:
396 case AUDIT_SUBJ_TYPE
:
402 case AUDIT_FILTERKEY
:
403 case AUDIT_LOGINUID_SET
:
408 case AUDIT_FIELD_COMPARE
:
410 /* only equal and not equal valid ops */
411 if (f
->op
!= Audit_not_equal
&& f
->op
!= Audit_equal
)
415 /* field not recognized */
419 /* Check for select valid field values */
421 case AUDIT_LOGINUID_SET
:
422 if ((f
->val
!= 0) && (f
->val
!= 1))
430 if (f
->val
& ~S_IFMT
)
433 case AUDIT_FIELD_COMPARE
:
434 if (f
->val
> AUDIT_MAX_FIELD_COMPARE
)
437 case AUDIT_SADDR_FAM
:
438 if (f
->val
>= AF_MAX
)
448 /* Translate struct audit_rule_data to kernel's rule representation. */
449 static struct audit_entry
*audit_data_to_entry(struct audit_rule_data
*data
,
453 struct audit_entry
*entry
;
455 size_t remain
= datasz
- sizeof(struct audit_rule_data
);
458 struct audit_fsnotify_mark
*audit_mark
;
460 entry
= audit_to_entry_common(data
);
465 for (i
= 0; i
< data
->field_count
; i
++) {
466 struct audit_field
*f
= &entry
->rule
.fields
[i
];
471 f
->op
= audit_to_op(data
->fieldflags
[i
]);
472 if (f
->op
== Audit_bad
)
475 f
->type
= data
->fields
[i
];
476 f_val
= data
->values
[i
];
478 /* Support legacy tests for a valid loginuid */
479 if ((f
->type
== AUDIT_LOGINUID
) && (f_val
== AUDIT_UID_UNSET
)) {
480 f
->type
= AUDIT_LOGINUID_SET
;
482 entry
->rule
.pflags
|= AUDIT_LOGINUID_LEGACY
;
485 err
= audit_field_valid(entry
, f
);
497 f
->uid
= make_kuid(current_user_ns(), f_val
);
498 if (!uid_valid(f
->uid
))
506 f
->gid
= make_kgid(current_user_ns(), f_val
);
507 if (!gid_valid(f
->gid
))
512 entry
->rule
.arch_f
= f
;
514 case AUDIT_SUBJ_USER
:
515 case AUDIT_SUBJ_ROLE
:
516 case AUDIT_SUBJ_TYPE
:
522 case AUDIT_OBJ_LEV_LOW
:
523 case AUDIT_OBJ_LEV_HIGH
:
524 str
= audit_unpack_string(&bufp
, &remain
, f_val
);
529 entry
->rule
.buflen
+= f_val
;
531 err
= security_audit_rule_init(f
->type
, f
->op
, str
,
532 (void **)&f
->lsm_rule
,
534 /* Keep currently invalid fields around in case they
535 * become valid after a policy reload. */
536 if (err
== -EINVAL
) {
537 pr_warn("audit rule for LSM \'%s\' is invalid\n",
544 str
= audit_unpack_string(&bufp
, &remain
, f_val
);
549 err
= audit_to_watch(&entry
->rule
, str
, f_val
, f
->op
);
554 entry
->rule
.buflen
+= f_val
;
557 str
= audit_unpack_string(&bufp
, &remain
, f_val
);
562 err
= audit_make_tree(&entry
->rule
, str
, f
->op
);
566 entry
->rule
.buflen
+= f_val
;
570 err
= audit_to_inode(&entry
->rule
, f
);
574 case AUDIT_FILTERKEY
:
575 if (entry
->rule
.filterkey
|| f_val
> AUDIT_MAX_KEY_LEN
)
577 str
= audit_unpack_string(&bufp
, &remain
, f_val
);
582 entry
->rule
.buflen
+= f_val
;
583 entry
->rule
.filterkey
= str
;
586 if (entry
->rule
.exe
|| f_val
> PATH_MAX
)
588 str
= audit_unpack_string(&bufp
, &remain
, f_val
);
593 audit_mark
= audit_alloc_mark(&entry
->rule
, str
, f_val
);
594 if (IS_ERR(audit_mark
)) {
596 err
= PTR_ERR(audit_mark
);
599 entry
->rule
.buflen
+= f_val
;
600 entry
->rule
.exe
= audit_mark
;
608 if (entry
->rule
.inode_f
&& entry
->rule
.inode_f
->op
== Audit_not_equal
)
609 entry
->rule
.inode_f
= NULL
;
615 if (entry
->rule
.tree
)
616 audit_put_tree(entry
->rule
.tree
); /* that's the temporary one */
618 audit_remove_mark(entry
->rule
.exe
); /* that's the template one */
619 audit_free_rule(entry
);
623 /* Pack a filter field's string representation into data block. */
624 static inline size_t audit_pack_string(void **bufp
, const char *str
)
626 size_t len
= strlen(str
);
628 memcpy(*bufp
, str
, len
);
634 /* Translate kernel rule representation to struct audit_rule_data. */
635 static struct audit_rule_data
*audit_krule_to_data(struct audit_krule
*krule
)
637 struct audit_rule_data
*data
;
641 data
= kmalloc(struct_size(data
, buf
, krule
->buflen
), GFP_KERNEL
);
644 memset(data
, 0, sizeof(*data
));
646 data
->flags
= krule
->flags
| krule
->listnr
;
647 data
->action
= krule
->action
;
648 data
->field_count
= krule
->field_count
;
650 for (i
= 0; i
< data
->field_count
; i
++) {
651 struct audit_field
*f
= &krule
->fields
[i
];
653 data
->fields
[i
] = f
->type
;
654 data
->fieldflags
[i
] = audit_ops
[f
->op
];
656 case AUDIT_SUBJ_USER
:
657 case AUDIT_SUBJ_ROLE
:
658 case AUDIT_SUBJ_TYPE
:
664 case AUDIT_OBJ_LEV_LOW
:
665 case AUDIT_OBJ_LEV_HIGH
:
666 data
->buflen
+= data
->values
[i
] =
667 audit_pack_string(&bufp
, f
->lsm_str
);
670 data
->buflen
+= data
->values
[i
] =
671 audit_pack_string(&bufp
,
672 audit_watch_path(krule
->watch
));
675 data
->buflen
+= data
->values
[i
] =
676 audit_pack_string(&bufp
,
677 audit_tree_path(krule
->tree
));
679 case AUDIT_FILTERKEY
:
680 data
->buflen
+= data
->values
[i
] =
681 audit_pack_string(&bufp
, krule
->filterkey
);
684 data
->buflen
+= data
->values
[i
] =
685 audit_pack_string(&bufp
, audit_mark_path(krule
->exe
));
687 case AUDIT_LOGINUID_SET
:
688 if (krule
->pflags
& AUDIT_LOGINUID_LEGACY
&& !f
->val
) {
689 data
->fields
[i
] = AUDIT_LOGINUID
;
690 data
->values
[i
] = AUDIT_UID_UNSET
;
693 fallthrough
; /* if set */
695 data
->values
[i
] = f
->val
;
698 for (i
= 0; i
< AUDIT_BITMASK_SIZE
; i
++)
699 data
->mask
[i
] = krule
->mask
[i
];
704 /* Compare two rules in kernel format. Considered success if rules
706 static int audit_compare_rule(struct audit_krule
*a
, struct audit_krule
*b
)
710 if (a
->flags
!= b
->flags
||
711 a
->pflags
!= b
->pflags
||
712 a
->listnr
!= b
->listnr
||
713 a
->action
!= b
->action
||
714 a
->field_count
!= b
->field_count
)
717 for (i
= 0; i
< a
->field_count
; i
++) {
718 if (a
->fields
[i
].type
!= b
->fields
[i
].type
||
719 a
->fields
[i
].op
!= b
->fields
[i
].op
)
722 switch (a
->fields
[i
].type
) {
723 case AUDIT_SUBJ_USER
:
724 case AUDIT_SUBJ_ROLE
:
725 case AUDIT_SUBJ_TYPE
:
731 case AUDIT_OBJ_LEV_LOW
:
732 case AUDIT_OBJ_LEV_HIGH
:
733 if (strcmp(a
->fields
[i
].lsm_str
, b
->fields
[i
].lsm_str
))
737 if (strcmp(audit_watch_path(a
->watch
),
738 audit_watch_path(b
->watch
)))
742 if (strcmp(audit_tree_path(a
->tree
),
743 audit_tree_path(b
->tree
)))
746 case AUDIT_FILTERKEY
:
747 /* both filterkeys exist based on above type compare */
748 if (strcmp(a
->filterkey
, b
->filterkey
))
752 /* both paths exist based on above type compare */
753 if (strcmp(audit_mark_path(a
->exe
),
754 audit_mark_path(b
->exe
)))
763 if (!uid_eq(a
->fields
[i
].uid
, b
->fields
[i
].uid
))
771 if (!gid_eq(a
->fields
[i
].gid
, b
->fields
[i
].gid
))
775 if (a
->fields
[i
].val
!= b
->fields
[i
].val
)
780 for (i
= 0; i
< AUDIT_BITMASK_SIZE
; i
++)
781 if (a
->mask
[i
] != b
->mask
[i
])
787 /* Duplicate LSM field information. The lsm_rule is opaque, so must be
789 static inline int audit_dupe_lsm_field(struct audit_field
*df
,
790 struct audit_field
*sf
)
795 /* our own copy of lsm_str */
796 lsm_str
= kstrdup(sf
->lsm_str
, GFP_KERNEL
);
797 if (unlikely(!lsm_str
))
799 df
->lsm_str
= lsm_str
;
801 /* our own (refreshed) copy of lsm_rule */
802 ret
= security_audit_rule_init(df
->type
, df
->op
, df
->lsm_str
,
803 (void **)&df
->lsm_rule
, GFP_KERNEL
);
804 /* Keep currently invalid fields around in case they
805 * become valid after a policy reload. */
806 if (ret
== -EINVAL
) {
807 pr_warn("audit rule for LSM \'%s\' is invalid\n",
815 /* Duplicate an audit rule. This will be a deep copy with the exception
816 * of the watch - that pointer is carried over. The LSM specific fields
817 * will be updated in the copy. The point is to be able to replace the old
818 * rule with the new rule in the filterlist, then free the old rule.
819 * The rlist element is undefined; list manipulations are handled apart from
820 * the initial copy. */
821 struct audit_entry
*audit_dupe_rule(struct audit_krule
*old
)
823 u32 fcount
= old
->field_count
;
824 struct audit_entry
*entry
;
825 struct audit_krule
*new;
829 entry
= audit_init_entry(fcount
);
830 if (unlikely(!entry
))
831 return ERR_PTR(-ENOMEM
);
834 new->flags
= old
->flags
;
835 new->pflags
= old
->pflags
;
836 new->listnr
= old
->listnr
;
837 new->action
= old
->action
;
838 for (i
= 0; i
< AUDIT_BITMASK_SIZE
; i
++)
839 new->mask
[i
] = old
->mask
[i
];
840 new->prio
= old
->prio
;
841 new->buflen
= old
->buflen
;
842 new->inode_f
= old
->inode_f
;
843 new->field_count
= old
->field_count
;
846 * note that we are OK with not refcounting here; audit_match_tree()
847 * never dereferences tree and we can't get false positives there
848 * since we'd have to have rule gone from the list *and* removed
849 * before the chunks found by lookup had been allocated, i.e. before
850 * the beginning of list scan.
852 new->tree
= old
->tree
;
853 memcpy(new->fields
, old
->fields
, sizeof(struct audit_field
) * fcount
);
855 /* deep copy this information, updating the lsm_rule fields, because
856 * the originals will all be freed when the old rule is freed. */
857 for (i
= 0; i
< fcount
; i
++) {
858 switch (new->fields
[i
].type
) {
859 case AUDIT_SUBJ_USER
:
860 case AUDIT_SUBJ_ROLE
:
861 case AUDIT_SUBJ_TYPE
:
867 case AUDIT_OBJ_LEV_LOW
:
868 case AUDIT_OBJ_LEV_HIGH
:
869 err
= audit_dupe_lsm_field(&new->fields
[i
],
872 case AUDIT_FILTERKEY
:
873 fk
= kstrdup(old
->filterkey
, GFP_KERNEL
);
880 err
= audit_dupe_exe(new, old
);
885 audit_remove_mark(new->exe
);
886 audit_free_rule(entry
);
892 audit_get_watch(old
->watch
);
893 new->watch
= old
->watch
;
899 /* Find an existing audit rule.
900 * Caller must hold audit_filter_mutex to prevent stale rule data. */
901 static struct audit_entry
*audit_find_rule(struct audit_entry
*entry
,
902 struct list_head
**p
)
904 struct audit_entry
*e
, *found
= NULL
;
905 struct list_head
*list
;
908 if (entry
->rule
.inode_f
) {
909 h
= audit_hash_ino(entry
->rule
.inode_f
->val
);
910 *p
= list
= &audit_inode_hash
[h
];
911 } else if (entry
->rule
.watch
) {
912 /* we don't know the inode number, so must walk entire hash */
913 for (h
= 0; h
< AUDIT_INODE_BUCKETS
; h
++) {
914 list
= &audit_inode_hash
[h
];
915 list_for_each_entry(e
, list
, list
)
916 if (!audit_compare_rule(&entry
->rule
, &e
->rule
)) {
923 *p
= list
= &audit_filter_list
[entry
->rule
.listnr
];
926 list_for_each_entry(e
, list
, list
)
927 if (!audit_compare_rule(&entry
->rule
, &e
->rule
)) {
936 static u64 prio_low
= ~0ULL/2;
937 static u64 prio_high
= ~0ULL/2 - 1;
939 /* Add rule to given filterlist if not a duplicate. */
940 static inline int audit_add_rule(struct audit_entry
*entry
)
942 struct audit_entry
*e
;
943 struct audit_watch
*watch
= entry
->rule
.watch
;
944 struct audit_tree
*tree
= entry
->rule
.tree
;
945 struct list_head
*list
;
947 #ifdef CONFIG_AUDITSYSCALL
950 /* If any of these, don't count towards total */
951 switch (entry
->rule
.listnr
) {
952 case AUDIT_FILTER_USER
:
953 case AUDIT_FILTER_EXCLUDE
:
954 case AUDIT_FILTER_FS
:
959 mutex_lock(&audit_filter_mutex
);
960 e
= audit_find_rule(entry
, &list
);
962 mutex_unlock(&audit_filter_mutex
);
964 /* normally audit_add_tree_rule() will free it on failure */
966 audit_put_tree(tree
);
971 /* audit_filter_mutex is dropped and re-taken during this call */
972 err
= audit_add_watch(&entry
->rule
, &list
);
974 mutex_unlock(&audit_filter_mutex
);
976 * normally audit_add_tree_rule() will free it
980 audit_put_tree(tree
);
985 err
= audit_add_tree_rule(&entry
->rule
);
987 mutex_unlock(&audit_filter_mutex
);
992 entry
->rule
.prio
= ~0ULL;
993 if (entry
->rule
.listnr
== AUDIT_FILTER_EXIT
||
994 entry
->rule
.listnr
== AUDIT_FILTER_URING_EXIT
) {
995 if (entry
->rule
.flags
& AUDIT_FILTER_PREPEND
)
996 entry
->rule
.prio
= ++prio_high
;
998 entry
->rule
.prio
= --prio_low
;
1001 if (entry
->rule
.flags
& AUDIT_FILTER_PREPEND
) {
1002 list_add(&entry
->rule
.list
,
1003 &audit_rules_list
[entry
->rule
.listnr
]);
1004 list_add_rcu(&entry
->list
, list
);
1005 entry
->rule
.flags
&= ~AUDIT_FILTER_PREPEND
;
1007 list_add_tail(&entry
->rule
.list
,
1008 &audit_rules_list
[entry
->rule
.listnr
]);
1009 list_add_tail_rcu(&entry
->list
, list
);
1011 #ifdef CONFIG_AUDITSYSCALL
1015 if (!audit_match_signal(entry
))
1018 mutex_unlock(&audit_filter_mutex
);
1023 /* Remove an existing rule from filterlist. */
1024 int audit_del_rule(struct audit_entry
*entry
)
1026 struct audit_entry
*e
;
1027 struct audit_tree
*tree
= entry
->rule
.tree
;
1028 struct list_head
*list
;
1030 #ifdef CONFIG_AUDITSYSCALL
1033 /* If any of these, don't count towards total */
1034 switch (entry
->rule
.listnr
) {
1035 case AUDIT_FILTER_USER
:
1036 case AUDIT_FILTER_EXCLUDE
:
1037 case AUDIT_FILTER_FS
:
1042 mutex_lock(&audit_filter_mutex
);
1043 e
= audit_find_rule(entry
, &list
);
1050 audit_remove_watch_rule(&e
->rule
);
1053 audit_remove_tree_rule(&e
->rule
);
1056 audit_remove_mark_rule(&e
->rule
);
1058 #ifdef CONFIG_AUDITSYSCALL
1062 if (!audit_match_signal(entry
))
1066 list_del_rcu(&e
->list
);
1067 list_del(&e
->rule
.list
);
1068 call_rcu(&e
->rcu
, audit_free_rule_rcu
);
1071 mutex_unlock(&audit_filter_mutex
);
1074 audit_put_tree(tree
); /* that's the temporary one */
1079 /* List rules using struct audit_rule_data. */
1080 static void audit_list_rules(int seq
, struct sk_buff_head
*q
)
1082 struct sk_buff
*skb
;
1083 struct audit_krule
*r
;
1086 /* This is a blocking read, so use audit_filter_mutex instead of rcu
1087 * iterator to sync with list writers. */
1088 for (i
= 0; i
< AUDIT_NR_FILTERS
; i
++) {
1089 list_for_each_entry(r
, &audit_rules_list
[i
], list
) {
1090 struct audit_rule_data
*data
;
1092 data
= audit_krule_to_data(r
);
1093 if (unlikely(!data
))
1095 skb
= audit_make_reply(seq
, AUDIT_LIST_RULES
, 0, 1,
1097 struct_size(data
, buf
, data
->buflen
));
1099 skb_queue_tail(q
, skb
);
1103 skb
= audit_make_reply(seq
, AUDIT_LIST_RULES
, 1, 1, NULL
, 0);
1105 skb_queue_tail(q
, skb
);
1108 /* Log rule additions and removals */
1109 static void audit_log_rule_change(char *action
, struct audit_krule
*rule
, int res
)
1111 struct audit_buffer
*ab
;
1116 ab
= audit_log_start(audit_context(), GFP_KERNEL
, AUDIT_CONFIG_CHANGE
);
1119 audit_log_session_info(ab
);
1120 audit_log_task_context(ab
);
1121 audit_log_format(ab
, " op=%s", action
);
1122 audit_log_key(ab
, rule
->filterkey
);
1123 audit_log_format(ab
, " list=%d res=%d", rule
->listnr
, res
);
1128 * audit_rule_change - apply all rules to the specified message type
1129 * @type: audit message type
1130 * @seq: netlink audit message sequence (serial) number
1131 * @data: payload data
1132 * @datasz: size of payload data
1134 int audit_rule_change(int type
, int seq
, void *data
, size_t datasz
)
1137 struct audit_entry
*entry
;
1140 case AUDIT_ADD_RULE
:
1141 entry
= audit_data_to_entry(data
, datasz
);
1143 return PTR_ERR(entry
);
1144 err
= audit_add_rule(entry
);
1145 audit_log_rule_change("add_rule", &entry
->rule
, !err
);
1147 case AUDIT_DEL_RULE
:
1148 entry
= audit_data_to_entry(data
, datasz
);
1150 return PTR_ERR(entry
);
1151 err
= audit_del_rule(entry
);
1152 audit_log_rule_change("remove_rule", &entry
->rule
, !err
);
1159 if (err
|| type
== AUDIT_DEL_RULE
) {
1160 if (entry
->rule
.exe
)
1161 audit_remove_mark(entry
->rule
.exe
);
1162 audit_free_rule(entry
);
1169 * audit_list_rules_send - list the audit rules
1170 * @request_skb: skb of request we are replying to (used to target the reply)
1171 * @seq: netlink audit message sequence (serial) number
1173 int audit_list_rules_send(struct sk_buff
*request_skb
, int seq
)
1175 struct task_struct
*tsk
;
1176 struct audit_netlink_list
*dest
;
1178 /* We can't just spew out the rules here because we might fill
1179 * the available socket buffer space and deadlock waiting for
1180 * auditctl to read from it... which isn't ever going to
1181 * happen if we're actually running in the context of auditctl
1182 * trying to _send_ the stuff */
1184 dest
= kmalloc(sizeof(*dest
), GFP_KERNEL
);
1187 dest
->net
= get_net(sock_net(NETLINK_CB(request_skb
).sk
));
1188 dest
->portid
= NETLINK_CB(request_skb
).portid
;
1189 skb_queue_head_init(&dest
->q
);
1191 mutex_lock(&audit_filter_mutex
);
1192 audit_list_rules(seq
, &dest
->q
);
1193 mutex_unlock(&audit_filter_mutex
);
1195 tsk
= kthread_run(audit_send_list_thread
, dest
, "audit_send_list");
1197 skb_queue_purge(&dest
->q
);
1200 return PTR_ERR(tsk
);
1206 int audit_comparator(u32 left
, u32 op
, u32 right
)
1210 return (left
== right
);
1211 case Audit_not_equal
:
1212 return (left
!= right
);
1214 return (left
< right
);
1216 return (left
<= right
);
1218 return (left
> right
);
1220 return (left
>= right
);
1222 return (left
& right
);
1224 return ((left
& right
) == right
);
1230 int audit_uid_comparator(kuid_t left
, u32 op
, kuid_t right
)
1234 return uid_eq(left
, right
);
1235 case Audit_not_equal
:
1236 return !uid_eq(left
, right
);
1238 return uid_lt(left
, right
);
1240 return uid_lte(left
, right
);
1242 return uid_gt(left
, right
);
1244 return uid_gte(left
, right
);
1252 int audit_gid_comparator(kgid_t left
, u32 op
, kgid_t right
)
1256 return gid_eq(left
, right
);
1257 case Audit_not_equal
:
1258 return !gid_eq(left
, right
);
1260 return gid_lt(left
, right
);
1262 return gid_lte(left
, right
);
1264 return gid_gt(left
, right
);
1266 return gid_gte(left
, right
);
1275 * parent_len - find the length of the parent portion of a pathname
1276 * @path: pathname of which to determine length
1278 int parent_len(const char *path
)
1283 plen
= strlen(path
);
1288 /* disregard trailing slashes */
1289 p
= path
+ plen
- 1;
1290 while ((*p
== '/') && (p
> path
))
1293 /* walk backward until we find the next slash or hit beginning */
1294 while ((*p
!= '/') && (p
> path
))
1297 /* did we find a slash? Then increment to include it in path */
1305 * audit_compare_dname_path - compare given dentry name with last component in
1306 * given path. Return of 0 indicates a match.
1307 * @dname: dentry name that we're comparing
1308 * @path: full pathname that we're comparing
1309 * @parentlen: length of the parent if known. Passing in AUDIT_NAME_FULL
1310 * here indicates that we must compute this value.
1312 int audit_compare_dname_path(const struct qstr
*dname
, const char *path
, int parentlen
)
1318 pathlen
= strlen(path
);
1322 parentlen
= parentlen
== AUDIT_NAME_FULL
? parent_len(path
) : parentlen
;
1323 if (pathlen
- parentlen
!= dlen
)
1326 p
= path
+ parentlen
;
1328 return strncmp(p
, dname
->name
, dlen
);
1331 int audit_filter(int msgtype
, unsigned int listtype
)
1333 struct audit_entry
*e
;
1334 int ret
= 1; /* Audit by default */
1337 list_for_each_entry_rcu(e
, &audit_filter_list
[listtype
], list
) {
1340 for (i
= 0; i
< e
->rule
.field_count
; i
++) {
1341 struct audit_field
*f
= &e
->rule
.fields
[i
];
1347 pid
= task_tgid_nr(current
);
1348 result
= audit_comparator(pid
, f
->op
, f
->val
);
1351 result
= audit_uid_comparator(current_uid(), f
->op
, f
->uid
);
1354 result
= audit_gid_comparator(current_gid(), f
->op
, f
->gid
);
1356 case AUDIT_LOGINUID
:
1357 result
= audit_uid_comparator(audit_get_loginuid(current
),
1360 case AUDIT_LOGINUID_SET
:
1361 result
= audit_comparator(audit_loginuid_set(current
),
1365 result
= audit_comparator(msgtype
, f
->op
, f
->val
);
1367 case AUDIT_SUBJ_USER
:
1368 case AUDIT_SUBJ_ROLE
:
1369 case AUDIT_SUBJ_TYPE
:
1370 case AUDIT_SUBJ_SEN
:
1371 case AUDIT_SUBJ_CLR
:
1373 security_current_getsecid_subj(&sid
);
1374 result
= security_audit_rule_match(sid
,
1375 f
->type
, f
->op
, f
->lsm_rule
);
1379 result
= audit_exe_compare(current
, e
->rule
.exe
);
1380 if (f
->op
== Audit_not_equal
)
1384 goto unlock_and_return
;
1386 if (result
< 0) /* error */
1387 goto unlock_and_return
;
1392 if (e
->rule
.action
== AUDIT_NEVER
|| listtype
== AUDIT_FILTER_EXCLUDE
)
1402 static int update_lsm_rule(struct audit_krule
*r
)
1404 struct audit_entry
*entry
= container_of(r
, struct audit_entry
, rule
);
1405 struct audit_entry
*nentry
;
1408 if (!security_audit_rule_known(r
))
1411 nentry
= audit_dupe_rule(r
);
1412 if (entry
->rule
.exe
)
1413 audit_remove_mark(entry
->rule
.exe
);
1414 if (IS_ERR(nentry
)) {
1415 /* save the first error encountered for the
1417 err
= PTR_ERR(nentry
);
1418 audit_panic("error updating LSM filters");
1420 list_del(&r
->rlist
);
1421 list_del_rcu(&entry
->list
);
1424 if (r
->watch
|| r
->tree
)
1425 list_replace_init(&r
->rlist
, &nentry
->rule
.rlist
);
1426 list_replace_rcu(&entry
->list
, &nentry
->list
);
1427 list_replace(&r
->list
, &nentry
->rule
.list
);
1429 call_rcu(&entry
->rcu
, audit_free_rule_rcu
);
1434 /* This function will re-initialize the lsm_rule field of all applicable rules.
1435 * It will traverse the filter lists serarching for rules that contain LSM
1436 * specific filter fields. When such a rule is found, it is copied, the
1437 * LSM field is re-initialized, and the old rule is replaced with the
1439 int audit_update_lsm_rules(void)
1441 struct audit_krule
*r
, *n
;
1444 /* audit_filter_mutex synchronizes the writers */
1445 mutex_lock(&audit_filter_mutex
);
1447 for (i
= 0; i
< AUDIT_NR_FILTERS
; i
++) {
1448 list_for_each_entry_safe(r
, n
, &audit_rules_list
[i
], list
) {
1449 int res
= update_lsm_rule(r
);
1454 mutex_unlock(&audit_filter_mutex
);