1 /* audit.c -- Auditing support
2 * Gateway between the kernel (e.g., selinux) and the user-space audit daemon.
3 * System-call specific features have moved to auditsc.c
5 * Copyright 2003-2007 Red Hat Inc., Durham, North Carolina.
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License
19 * along with this program; if not, write to the Free Software
20 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
22 * Written by Rickard E. (Rik) Faith <faith@redhat.com>
24 * Goals: 1) Integrate fully with Security Modules.
25 * 2) Minimal run-time overhead:
26 * a) Minimal when syscall auditing is disabled (audit_enable=0).
27 * b) Small when syscall auditing is enabled and no audit record
28 * is generated (defer as much work as possible to record
30 * i) context is allocated,
31 * ii) names from getname are stored without a copy, and
32 * iii) inode information stored from path_lookup.
33 * 3) Ability to disable syscall auditing at boot time (audit=0).
34 * 4) Usable by other parts of the kernel (if audit_log* is called,
35 * then a syscall record will be generated automatically for the
37 * 5) Netlink interface to user-space.
38 * 6) Support low-overhead kernel-based filtering to minimize the
39 * information that must be passed to user-space.
41 * Example user-space utilities: http://people.redhat.com/sgrubb/audit/
44 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
46 #include <linux/file.h>
47 #include <linux/init.h>
48 #include <linux/types.h>
49 #include <linux/atomic.h>
51 #include <linux/export.h>
52 #include <linux/slab.h>
53 #include <linux/err.h>
54 #include <linux/kthread.h>
55 #include <linux/kernel.h>
56 #include <linux/syscalls.h>
58 #include <linux/audit.h>
61 #include <net/netlink.h>
62 #include <linux/skbuff.h>
63 #ifdef CONFIG_SECURITY
64 #include <linux/security.h>
66 #include <linux/freezer.h>
67 #include <linux/tty.h>
68 #include <linux/pid_namespace.h>
69 #include <net/netns/generic.h>
73 /* No auditing will take place until audit_initialized == AUDIT_INITIALIZED.
74 * (Initialization happens after skb_init is called.) */
75 #define AUDIT_DISABLED -1
76 #define AUDIT_UNINITIALIZED 0
77 #define AUDIT_INITIALIZED 1
78 static int audit_initialized
;
82 #define AUDIT_LOCKED 2
84 u32 audit_ever_enabled
;
86 EXPORT_SYMBOL_GPL(audit_enabled
);
88 /* Default state when kernel boots without any parameters. */
89 static u32 audit_default
;
91 /* If auditing cannot proceed, audit_failure selects what happens. */
92 static u32 audit_failure
= AUDIT_FAIL_PRINTK
;
95 * If audit records are to be written to the netlink socket, audit_pid
96 * contains the pid of the auditd process and audit_nlk_portid contains
97 * the portid to use to send netlink messages to that process.
100 static __u32 audit_nlk_portid
;
102 /* If audit_rate_limit is non-zero, limit the rate of sending audit records
103 * to that number per second. This prevents DoS attacks, but results in
104 * audit records being dropped. */
105 static u32 audit_rate_limit
;
107 /* Number of outstanding audit_buffers allowed.
108 * When set to zero, this means unlimited. */
109 static u32 audit_backlog_limit
= 64;
110 #define AUDIT_BACKLOG_WAIT_TIME (60 * HZ)
111 static u32 audit_backlog_wait_time_master
= AUDIT_BACKLOG_WAIT_TIME
;
112 static u32 audit_backlog_wait_time
= AUDIT_BACKLOG_WAIT_TIME
;
114 /* The identity of the user shutting down the audit system. */
115 kuid_t audit_sig_uid
= INVALID_UID
;
116 pid_t audit_sig_pid
= -1;
117 u32 audit_sig_sid
= 0;
119 /* Records can be lost in several ways:
120 0) [suppressed in audit_alloc]
121 1) out of memory in audit_log_start [kmalloc of struct audit_buffer]
122 2) out of memory in audit_log_move [alloc_skb]
123 3) suppressed due to audit_rate_limit
124 4) suppressed due to audit_backlog_limit
126 static atomic_t audit_lost
= ATOMIC_INIT(0);
128 /* The netlink socket. */
129 static struct sock
*audit_sock
;
130 static int audit_net_id
;
132 /* Hash for inode-based rules */
133 struct list_head audit_inode_hash
[AUDIT_INODE_BUCKETS
];
135 /* The audit_freelist is a list of pre-allocated audit buffers (if more
136 * than AUDIT_MAXFREE are in use, the audit buffer is freed instead of
137 * being placed on the freelist). */
138 static DEFINE_SPINLOCK(audit_freelist_lock
);
139 static int audit_freelist_count
;
140 static LIST_HEAD(audit_freelist
);
142 static struct sk_buff_head audit_skb_queue
;
143 /* queue of skbs to send to auditd when/if it comes back */
144 static struct sk_buff_head audit_skb_hold_queue
;
145 static struct task_struct
*kauditd_task
;
146 static DECLARE_WAIT_QUEUE_HEAD(kauditd_wait
);
147 static DECLARE_WAIT_QUEUE_HEAD(audit_backlog_wait
);
149 static struct audit_features af
= {.vers
= AUDIT_FEATURE_VERSION
,
154 static char *audit_feature_names
[2] = {
155 "only_unset_loginuid",
156 "loginuid_immutable",
160 /* Serialize requests from userspace. */
161 DEFINE_MUTEX(audit_cmd_mutex
);
163 /* AUDIT_BUFSIZ is the size of the temporary buffer used for formatting
164 * audit records. Since printk uses a 1024 byte buffer, this buffer
165 * should be at least that large. */
166 #define AUDIT_BUFSIZ 1024
168 /* AUDIT_MAXFREE is the number of empty audit_buffers we keep on the
169 * audit_freelist. Doing so eliminates many kmalloc/kfree calls. */
170 #define AUDIT_MAXFREE (2*NR_CPUS)
172 /* The audit_buffer is used when formatting an audit record. The caller
173 * locks briefly to get the record off the freelist or to allocate the
174 * buffer, and locks briefly to send the buffer to the netlink layer or
175 * to place it on a transmit queue. Multiple audit_buffers can be in
176 * use simultaneously. */
177 struct audit_buffer
{
178 struct list_head list
;
179 struct sk_buff
*skb
; /* formatted skb ready to send */
180 struct audit_context
*ctx
; /* NULL or associated context */
190 static void audit_set_portid(struct audit_buffer
*ab
, __u32 portid
)
193 struct nlmsghdr
*nlh
= nlmsg_hdr(ab
->skb
);
194 nlh
->nlmsg_pid
= portid
;
198 void audit_panic(const char *message
)
200 switch (audit_failure
) {
201 case AUDIT_FAIL_SILENT
:
203 case AUDIT_FAIL_PRINTK
:
204 if (printk_ratelimit())
205 pr_err("%s\n", message
);
207 case AUDIT_FAIL_PANIC
:
208 /* test audit_pid since printk is always losey, why bother? */
210 panic("audit: %s\n", message
);
215 static inline int audit_rate_check(void)
217 static unsigned long last_check
= 0;
218 static int messages
= 0;
219 static DEFINE_SPINLOCK(lock
);
222 unsigned long elapsed
;
225 if (!audit_rate_limit
) return 1;
227 spin_lock_irqsave(&lock
, flags
);
228 if (++messages
< audit_rate_limit
) {
232 elapsed
= now
- last_check
;
239 spin_unlock_irqrestore(&lock
, flags
);
245 * audit_log_lost - conditionally log lost audit message event
246 * @message: the message stating reason for lost audit message
248 * Emit at least 1 message per second, even if audit_rate_check is
250 * Always increment the lost messages counter.
252 void audit_log_lost(const char *message
)
254 static unsigned long last_msg
= 0;
255 static DEFINE_SPINLOCK(lock
);
260 atomic_inc(&audit_lost
);
262 print
= (audit_failure
== AUDIT_FAIL_PANIC
|| !audit_rate_limit
);
265 spin_lock_irqsave(&lock
, flags
);
267 if (now
- last_msg
> HZ
) {
271 spin_unlock_irqrestore(&lock
, flags
);
275 if (printk_ratelimit())
276 pr_warn("audit_lost=%u audit_rate_limit=%u audit_backlog_limit=%u\n",
277 atomic_read(&audit_lost
),
279 audit_backlog_limit
);
280 audit_panic(message
);
284 static int audit_log_config_change(char *function_name
, u32
new, u32 old
,
287 struct audit_buffer
*ab
;
290 ab
= audit_log_start(NULL
, GFP_KERNEL
, AUDIT_CONFIG_CHANGE
);
293 audit_log_format(ab
, "%s=%u old=%u", function_name
, new, old
);
294 audit_log_session_info(ab
);
295 rc
= audit_log_task_context(ab
);
297 allow_changes
= 0; /* Something weird, deny request */
298 audit_log_format(ab
, " res=%d", allow_changes
);
303 static int audit_do_config_change(char *function_name
, u32
*to_change
, u32
new)
305 int allow_changes
, rc
= 0;
306 u32 old
= *to_change
;
308 /* check if we are locked */
309 if (audit_enabled
== AUDIT_LOCKED
)
314 if (audit_enabled
!= AUDIT_OFF
) {
315 rc
= audit_log_config_change(function_name
, new, old
, allow_changes
);
320 /* If we are allowed, make the change */
321 if (allow_changes
== 1)
323 /* Not allowed, update reason */
329 static int audit_set_rate_limit(u32 limit
)
331 return audit_do_config_change("audit_rate_limit", &audit_rate_limit
, limit
);
334 static int audit_set_backlog_limit(u32 limit
)
336 return audit_do_config_change("audit_backlog_limit", &audit_backlog_limit
, limit
);
339 static int audit_set_backlog_wait_time(u32 timeout
)
341 return audit_do_config_change("audit_backlog_wait_time",
342 &audit_backlog_wait_time_master
, timeout
);
345 static int audit_set_enabled(u32 state
)
348 if (state
> AUDIT_LOCKED
)
351 rc
= audit_do_config_change("audit_enabled", &audit_enabled
, state
);
353 audit_ever_enabled
|= !!state
;
358 static int audit_set_failure(u32 state
)
360 if (state
!= AUDIT_FAIL_SILENT
361 && state
!= AUDIT_FAIL_PRINTK
362 && state
!= AUDIT_FAIL_PANIC
)
365 return audit_do_config_change("audit_failure", &audit_failure
, state
);
369 * Queue skbs to be sent to auditd when/if it comes back. These skbs should
370 * already have been sent via prink/syslog and so if these messages are dropped
371 * it is not a huge concern since we already passed the audit_log_lost()
372 * notification and stuff. This is just nice to get audit messages during
373 * boot before auditd is running or messages generated while auditd is stopped.
374 * This only holds messages is audit_default is set, aka booting with audit=1
375 * or building your kernel that way.
377 static void audit_hold_skb(struct sk_buff
*skb
)
380 (!audit_backlog_limit
||
381 skb_queue_len(&audit_skb_hold_queue
) < audit_backlog_limit
))
382 skb_queue_tail(&audit_skb_hold_queue
, skb
);
388 * For one reason or another this nlh isn't getting delivered to the userspace
389 * audit daemon, just send it to printk.
391 static void audit_printk_skb(struct sk_buff
*skb
)
393 struct nlmsghdr
*nlh
= nlmsg_hdr(skb
);
394 char *data
= nlmsg_data(nlh
);
396 if (nlh
->nlmsg_type
!= AUDIT_EOE
) {
397 if (printk_ratelimit())
398 pr_notice("type=%d %s\n", nlh
->nlmsg_type
, data
);
400 audit_log_lost("printk limit exceeded");
406 static void kauditd_send_skb(struct sk_buff
*skb
)
410 #define AUDITD_RETRIES 5
413 /* take a reference in case we can't send it and we want to hold it */
415 err
= netlink_unicast(audit_sock
, skb
, audit_nlk_portid
, 0);
417 pr_err("netlink_unicast sending to audit_pid=%d returned error: %d\n",
420 if (err
== -ECONNREFUSED
|| err
== -EPERM
421 || ++attempts
>= AUDITD_RETRIES
) {
424 snprintf(s
, sizeof(s
), "audit_pid=%d reset", audit_pid
);
429 pr_warn("re-scheduling(#%d) write to audit_pid=%d\n",
430 attempts
, audit_pid
);
431 set_current_state(TASK_INTERRUPTIBLE
);
433 __set_current_state(TASK_RUNNING
);
437 /* we might get lucky and get this in the next auditd */
440 /* drop the extra reference if sent ok */
445 * kauditd_send_multicast_skb - send the skb to multicast userspace listeners
447 * This function doesn't consume an skb as might be expected since it has to
450 static void kauditd_send_multicast_skb(struct sk_buff
*skb
, gfp_t gfp_mask
)
452 struct sk_buff
*copy
;
453 struct audit_net
*aunet
= net_generic(&init_net
, audit_net_id
);
454 struct sock
*sock
= aunet
->nlsk
;
456 if (!netlink_has_listeners(sock
, AUDIT_NLGRP_READLOG
))
460 * The seemingly wasteful skb_copy() rather than bumping the refcount
461 * using skb_get() is necessary because non-standard mods are made to
462 * the skb by the original kaudit unicast socket send routine. The
463 * existing auditd daemon assumes this breakage. Fixing this would
464 * require co-ordinating a change in the established protocol between
465 * the kaudit kernel subsystem and the auditd userspace code. There is
466 * no reason for new multicast clients to continue with this
469 copy
= skb_copy(skb
, gfp_mask
);
473 nlmsg_multicast(sock
, copy
, 0, AUDIT_NLGRP_READLOG
, gfp_mask
);
477 * flush_hold_queue - empty the hold queue if auditd appears
479 * If auditd just started, drain the queue of messages already
480 * sent to syslog/printk. Remember loss here is ok. We already
481 * called audit_log_lost() if it didn't go out normally. so the
482 * race between the skb_dequeue and the next check for audit_pid
485 * If you ever find kauditd to be too slow we can get a perf win
486 * by doing our own locking and keeping better track if there
487 * are messages in this queue. I don't see the need now, but
488 * in 5 years when I want to play with this again I'll see this
489 * note and still have no friggin idea what i'm thinking today.
491 static void flush_hold_queue(void)
495 if (!audit_default
|| !audit_pid
)
498 skb
= skb_dequeue(&audit_skb_hold_queue
);
502 while (skb
&& audit_pid
) {
503 kauditd_send_skb(skb
);
504 skb
= skb_dequeue(&audit_skb_hold_queue
);
508 * if auditd just disappeared but we
509 * dequeued an skb we need to drop ref
514 static int kauditd_thread(void *dummy
)
517 while (!kthread_should_stop()) {
522 skb
= skb_dequeue(&audit_skb_queue
);
525 if (!audit_backlog_limit
||
526 (skb_queue_len(&audit_skb_queue
) <= audit_backlog_limit
))
527 wake_up(&audit_backlog_wait
);
529 kauditd_send_skb(skb
);
531 audit_printk_skb(skb
);
535 wait_event_freezable(kauditd_wait
, skb_queue_len(&audit_skb_queue
));
540 int audit_send_list(void *_dest
)
542 struct audit_netlink_list
*dest
= _dest
;
544 struct net
*net
= dest
->net
;
545 struct audit_net
*aunet
= net_generic(net
, audit_net_id
);
547 /* wait for parent to finish and send an ACK */
548 mutex_lock(&audit_cmd_mutex
);
549 mutex_unlock(&audit_cmd_mutex
);
551 while ((skb
= __skb_dequeue(&dest
->q
)) != NULL
)
552 netlink_unicast(aunet
->nlsk
, skb
, dest
->portid
, 0);
560 struct sk_buff
*audit_make_reply(__u32 portid
, int seq
, int type
, int done
,
561 int multi
, const void *payload
, int size
)
564 struct nlmsghdr
*nlh
;
566 int flags
= multi
? NLM_F_MULTI
: 0;
567 int t
= done
? NLMSG_DONE
: type
;
569 skb
= nlmsg_new(size
, GFP_KERNEL
);
573 nlh
= nlmsg_put(skb
, portid
, seq
, t
, size
, flags
);
576 data
= nlmsg_data(nlh
);
577 memcpy(data
, payload
, size
);
585 static int audit_send_reply_thread(void *arg
)
587 struct audit_reply
*reply
= (struct audit_reply
*)arg
;
588 struct net
*net
= reply
->net
;
589 struct audit_net
*aunet
= net_generic(net
, audit_net_id
);
591 mutex_lock(&audit_cmd_mutex
);
592 mutex_unlock(&audit_cmd_mutex
);
594 /* Ignore failure. It'll only happen if the sender goes away,
595 because our timeout is set to infinite. */
596 netlink_unicast(aunet
->nlsk
, reply
->skb
, reply
->portid
, 0);
602 * audit_send_reply - send an audit reply message via netlink
603 * @request_skb: skb of request we are replying to (used to target the reply)
604 * @seq: sequence number
605 * @type: audit message type
606 * @done: done (last) flag
607 * @multi: multi-part message flag
608 * @payload: payload data
609 * @size: payload size
611 * Allocates an skb, builds the netlink message, and sends it to the port id.
612 * No failure notifications.
614 static void audit_send_reply(struct sk_buff
*request_skb
, int seq
, int type
, int done
,
615 int multi
, const void *payload
, int size
)
617 u32 portid
= NETLINK_CB(request_skb
).portid
;
618 struct net
*net
= sock_net(NETLINK_CB(request_skb
).sk
);
620 struct task_struct
*tsk
;
621 struct audit_reply
*reply
= kmalloc(sizeof(struct audit_reply
),
627 skb
= audit_make_reply(portid
, seq
, type
, done
, multi
, payload
, size
);
631 reply
->net
= get_net(net
);
632 reply
->portid
= portid
;
635 tsk
= kthread_run(audit_send_reply_thread
, reply
, "audit_send_reply");
644 * Check for appropriate CAP_AUDIT_ capabilities on incoming audit
647 static int audit_netlink_ok(struct sk_buff
*skb
, u16 msg_type
)
651 /* Only support initial user namespace for now. */
653 * We return ECONNREFUSED because it tricks userspace into thinking
654 * that audit was not configured into the kernel. Lots of users
655 * configure their PAM stack (because that's what the distro does)
656 * to reject login if unable to send messages to audit. If we return
657 * ECONNREFUSED the PAM stack thinks the kernel does not have audit
658 * configured in and will let login proceed. If we return EPERM
659 * userspace will reject all logins. This should be removed when we
660 * support non init namespaces!!
662 if (current_user_ns() != &init_user_ns
)
663 return -ECONNREFUSED
;
672 case AUDIT_GET_FEATURE
:
673 case AUDIT_SET_FEATURE
:
674 case AUDIT_LIST_RULES
:
677 case AUDIT_SIGNAL_INFO
:
681 case AUDIT_MAKE_EQUIV
:
682 /* Only support auditd and auditctl in initial pid namespace
684 if (task_active_pid_ns(current
) != &init_pid_ns
)
687 if (!netlink_capable(skb
, CAP_AUDIT_CONTROL
))
691 case AUDIT_FIRST_USER_MSG
... AUDIT_LAST_USER_MSG
:
692 case AUDIT_FIRST_USER_MSG2
... AUDIT_LAST_USER_MSG2
:
693 if (!netlink_capable(skb
, CAP_AUDIT_WRITE
))
696 default: /* bad msg */
703 static void audit_log_common_recv_msg(struct audit_buffer
**ab
, u16 msg_type
)
705 uid_t uid
= from_kuid(&init_user_ns
, current_uid());
706 pid_t pid
= task_tgid_nr(current
);
708 if (!audit_enabled
&& msg_type
!= AUDIT_USER_AVC
) {
713 *ab
= audit_log_start(NULL
, GFP_KERNEL
, msg_type
);
716 audit_log_format(*ab
, "pid=%d uid=%u", pid
, uid
);
717 audit_log_session_info(*ab
);
718 audit_log_task_context(*ab
);
721 int is_audit_feature_set(int i
)
723 return af
.features
& AUDIT_FEATURE_TO_MASK(i
);
727 static int audit_get_feature(struct sk_buff
*skb
)
731 seq
= nlmsg_hdr(skb
)->nlmsg_seq
;
733 audit_send_reply(skb
, seq
, AUDIT_GET_FEATURE
, 0, 0, &af
, sizeof(af
));
738 static void audit_log_feature_change(int which
, u32 old_feature
, u32 new_feature
,
739 u32 old_lock
, u32 new_lock
, int res
)
741 struct audit_buffer
*ab
;
743 if (audit_enabled
== AUDIT_OFF
)
746 ab
= audit_log_start(NULL
, GFP_KERNEL
, AUDIT_FEATURE_CHANGE
);
747 audit_log_task_info(ab
, current
);
748 audit_log_format(ab
, " feature=%s old=%u new=%u old_lock=%u new_lock=%u res=%d",
749 audit_feature_names
[which
], !!old_feature
, !!new_feature
,
750 !!old_lock
, !!new_lock
, res
);
754 static int audit_set_feature(struct sk_buff
*skb
)
756 struct audit_features
*uaf
;
759 BUILD_BUG_ON(AUDIT_LAST_FEATURE
+ 1 > ARRAY_SIZE(audit_feature_names
));
760 uaf
= nlmsg_data(nlmsg_hdr(skb
));
762 /* if there is ever a version 2 we should handle that here */
764 for (i
= 0; i
<= AUDIT_LAST_FEATURE
; i
++) {
765 u32 feature
= AUDIT_FEATURE_TO_MASK(i
);
766 u32 old_feature
, new_feature
, old_lock
, new_lock
;
768 /* if we are not changing this feature, move along */
769 if (!(feature
& uaf
->mask
))
772 old_feature
= af
.features
& feature
;
773 new_feature
= uaf
->features
& feature
;
774 new_lock
= (uaf
->lock
| af
.lock
) & feature
;
775 old_lock
= af
.lock
& feature
;
777 /* are we changing a locked feature? */
778 if (old_lock
&& (new_feature
!= old_feature
)) {
779 audit_log_feature_change(i
, old_feature
, new_feature
,
780 old_lock
, new_lock
, 0);
784 /* nothing invalid, do the changes */
785 for (i
= 0; i
<= AUDIT_LAST_FEATURE
; i
++) {
786 u32 feature
= AUDIT_FEATURE_TO_MASK(i
);
787 u32 old_feature
, new_feature
, old_lock
, new_lock
;
789 /* if we are not changing this feature, move along */
790 if (!(feature
& uaf
->mask
))
793 old_feature
= af
.features
& feature
;
794 new_feature
= uaf
->features
& feature
;
795 old_lock
= af
.lock
& feature
;
796 new_lock
= (uaf
->lock
| af
.lock
) & feature
;
798 if (new_feature
!= old_feature
)
799 audit_log_feature_change(i
, old_feature
, new_feature
,
800 old_lock
, new_lock
, 1);
803 af
.features
|= feature
;
805 af
.features
&= ~feature
;
812 static int audit_receive_msg(struct sk_buff
*skb
, struct nlmsghdr
*nlh
)
817 struct audit_buffer
*ab
;
818 u16 msg_type
= nlh
->nlmsg_type
;
819 struct audit_sig_info
*sig_data
;
823 err
= audit_netlink_ok(skb
, msg_type
);
827 /* As soon as there's any sign of userspace auditd,
828 * start kauditd to talk to it */
830 kauditd_task
= kthread_run(kauditd_thread
, NULL
, "kauditd");
831 if (IS_ERR(kauditd_task
)) {
832 err
= PTR_ERR(kauditd_task
);
837 seq
= nlh
->nlmsg_seq
;
838 data
= nlmsg_data(nlh
);
842 struct audit_status s
;
843 memset(&s
, 0, sizeof(s
));
844 s
.enabled
= audit_enabled
;
845 s
.failure
= audit_failure
;
847 s
.rate_limit
= audit_rate_limit
;
848 s
.backlog_limit
= audit_backlog_limit
;
849 s
.lost
= atomic_read(&audit_lost
);
850 s
.backlog
= skb_queue_len(&audit_skb_queue
);
851 s
.feature_bitmap
= AUDIT_FEATURE_BITMAP_ALL
;
852 s
.backlog_wait_time
= audit_backlog_wait_time_master
;
853 audit_send_reply(skb
, seq
, AUDIT_GET
, 0, 0, &s
, sizeof(s
));
857 struct audit_status s
;
858 memset(&s
, 0, sizeof(s
));
859 /* guard against past and future API changes */
860 memcpy(&s
, data
, min_t(size_t, sizeof(s
), nlmsg_len(nlh
)));
861 if (s
.mask
& AUDIT_STATUS_ENABLED
) {
862 err
= audit_set_enabled(s
.enabled
);
866 if (s
.mask
& AUDIT_STATUS_FAILURE
) {
867 err
= audit_set_failure(s
.failure
);
871 if (s
.mask
& AUDIT_STATUS_PID
) {
874 if ((!new_pid
) && (task_tgid_vnr(current
) != audit_pid
))
876 if (audit_enabled
!= AUDIT_OFF
)
877 audit_log_config_change("audit_pid", new_pid
, audit_pid
, 1);
879 audit_nlk_portid
= NETLINK_CB(skb
).portid
;
880 audit_sock
= skb
->sk
;
882 if (s
.mask
& AUDIT_STATUS_RATE_LIMIT
) {
883 err
= audit_set_rate_limit(s
.rate_limit
);
887 if (s
.mask
& AUDIT_STATUS_BACKLOG_LIMIT
) {
888 err
= audit_set_backlog_limit(s
.backlog_limit
);
892 if (s
.mask
& AUDIT_STATUS_BACKLOG_WAIT_TIME
) {
893 if (sizeof(s
) > (size_t)nlh
->nlmsg_len
)
895 if (s
.backlog_wait_time
> 10*AUDIT_BACKLOG_WAIT_TIME
)
897 err
= audit_set_backlog_wait_time(s
.backlog_wait_time
);
903 case AUDIT_GET_FEATURE
:
904 err
= audit_get_feature(skb
);
908 case AUDIT_SET_FEATURE
:
909 err
= audit_set_feature(skb
);
914 case AUDIT_FIRST_USER_MSG
... AUDIT_LAST_USER_MSG
:
915 case AUDIT_FIRST_USER_MSG2
... AUDIT_LAST_USER_MSG2
:
916 if (!audit_enabled
&& msg_type
!= AUDIT_USER_AVC
)
919 err
= audit_filter_user(msg_type
);
920 if (err
== 1) { /* match or error */
922 if (msg_type
== AUDIT_USER_TTY
) {
923 err
= tty_audit_push();
927 mutex_unlock(&audit_cmd_mutex
);
928 audit_log_common_recv_msg(&ab
, msg_type
);
929 if (msg_type
!= AUDIT_USER_TTY
)
930 audit_log_format(ab
, " msg='%.*s'",
931 AUDIT_MESSAGE_TEXT_MAX
,
936 audit_log_format(ab
, " data=");
937 size
= nlmsg_len(nlh
);
939 ((unsigned char *)data
)[size
- 1] == '\0')
941 audit_log_n_untrustedstring(ab
, data
, size
);
943 audit_set_portid(ab
, NETLINK_CB(skb
).portid
);
945 mutex_lock(&audit_cmd_mutex
);
950 if (nlmsg_len(nlh
) < sizeof(struct audit_rule_data
))
952 if (audit_enabled
== AUDIT_LOCKED
) {
953 audit_log_common_recv_msg(&ab
, AUDIT_CONFIG_CHANGE
);
954 audit_log_format(ab
, " audit_enabled=%d res=0", audit_enabled
);
958 err
= audit_rule_change(msg_type
, NETLINK_CB(skb
).portid
,
959 seq
, data
, nlmsg_len(nlh
));
961 case AUDIT_LIST_RULES
:
962 err
= audit_list_rules_send(skb
, seq
);
966 audit_log_common_recv_msg(&ab
, AUDIT_CONFIG_CHANGE
);
967 audit_log_format(ab
, " op=trim res=1");
970 case AUDIT_MAKE_EQUIV
: {
973 size_t msglen
= nlmsg_len(nlh
);
977 if (msglen
< 2 * sizeof(u32
))
979 memcpy(sizes
, bufp
, 2 * sizeof(u32
));
980 bufp
+= 2 * sizeof(u32
);
981 msglen
-= 2 * sizeof(u32
);
982 old
= audit_unpack_string(&bufp
, &msglen
, sizes
[0]);
987 new = audit_unpack_string(&bufp
, &msglen
, sizes
[1]);
993 /* OK, here comes... */
994 err
= audit_tag_tree(old
, new);
996 audit_log_common_recv_msg(&ab
, AUDIT_CONFIG_CHANGE
);
998 audit_log_format(ab
, " op=make_equiv old=");
999 audit_log_untrustedstring(ab
, old
);
1000 audit_log_format(ab
, " new=");
1001 audit_log_untrustedstring(ab
, new);
1002 audit_log_format(ab
, " res=%d", !err
);
1008 case AUDIT_SIGNAL_INFO
:
1010 if (audit_sig_sid
) {
1011 err
= security_secid_to_secctx(audit_sig_sid
, &ctx
, &len
);
1015 sig_data
= kmalloc(sizeof(*sig_data
) + len
, GFP_KERNEL
);
1018 security_release_secctx(ctx
, len
);
1021 sig_data
->uid
= from_kuid(&init_user_ns
, audit_sig_uid
);
1022 sig_data
->pid
= audit_sig_pid
;
1023 if (audit_sig_sid
) {
1024 memcpy(sig_data
->ctx
, ctx
, len
);
1025 security_release_secctx(ctx
, len
);
1027 audit_send_reply(skb
, seq
, AUDIT_SIGNAL_INFO
, 0, 0,
1028 sig_data
, sizeof(*sig_data
) + len
);
1031 case AUDIT_TTY_GET
: {
1032 struct audit_tty_status s
;
1035 t
= READ_ONCE(current
->signal
->audit_tty
);
1036 s
.enabled
= t
& AUDIT_TTY_ENABLE
;
1037 s
.log_passwd
= !!(t
& AUDIT_TTY_LOG_PASSWD
);
1039 audit_send_reply(skb
, seq
, AUDIT_TTY_GET
, 0, 0, &s
, sizeof(s
));
1042 case AUDIT_TTY_SET
: {
1043 struct audit_tty_status s
, old
;
1044 struct audit_buffer
*ab
;
1047 memset(&s
, 0, sizeof(s
));
1048 /* guard against past and future API changes */
1049 memcpy(&s
, data
, min_t(size_t, sizeof(s
), nlmsg_len(nlh
)));
1050 /* check if new data is valid */
1051 if ((s
.enabled
!= 0 && s
.enabled
!= 1) ||
1052 (s
.log_passwd
!= 0 && s
.log_passwd
!= 1))
1056 t
= READ_ONCE(current
->signal
->audit_tty
);
1058 t
= s
.enabled
| (-s
.log_passwd
& AUDIT_TTY_LOG_PASSWD
);
1059 t
= xchg(¤t
->signal
->audit_tty
, t
);
1061 old
.enabled
= t
& AUDIT_TTY_ENABLE
;
1062 old
.log_passwd
= !!(t
& AUDIT_TTY_LOG_PASSWD
);
1064 audit_log_common_recv_msg(&ab
, AUDIT_CONFIG_CHANGE
);
1065 audit_log_format(ab
, " op=tty_set old-enabled=%d new-enabled=%d"
1066 " old-log_passwd=%d new-log_passwd=%d res=%d",
1067 old
.enabled
, s
.enabled
, old
.log_passwd
,
1068 s
.log_passwd
, !err
);
1077 return err
< 0 ? err
: 0;
1081 * Get message from skb. Each message is processed by audit_receive_msg.
1082 * Malformed skbs with wrong length are discarded silently.
1084 static void audit_receive_skb(struct sk_buff
*skb
)
1086 struct nlmsghdr
*nlh
;
1088 * len MUST be signed for nlmsg_next to be able to dec it below 0
1089 * if the nlmsg_len was not aligned
1094 nlh
= nlmsg_hdr(skb
);
1097 while (nlmsg_ok(nlh
, len
)) {
1098 err
= audit_receive_msg(skb
, nlh
);
1099 /* if err or if this message says it wants a response */
1100 if (err
|| (nlh
->nlmsg_flags
& NLM_F_ACK
))
1101 netlink_ack(skb
, nlh
, err
);
1103 nlh
= nlmsg_next(nlh
, &len
);
1107 /* Receive messages from netlink socket. */
1108 static void audit_receive(struct sk_buff
*skb
)
1110 mutex_lock(&audit_cmd_mutex
);
1111 audit_receive_skb(skb
);
1112 mutex_unlock(&audit_cmd_mutex
);
1115 /* Run custom bind function on netlink socket group connect or bind requests. */
1116 static int audit_bind(struct net
*net
, int group
)
1118 if (!capable(CAP_AUDIT_READ
))
1124 static int __net_init
audit_net_init(struct net
*net
)
1126 struct netlink_kernel_cfg cfg
= {
1127 .input
= audit_receive
,
1129 .flags
= NL_CFG_F_NONROOT_RECV
,
1130 .groups
= AUDIT_NLGRP_MAX
,
1133 struct audit_net
*aunet
= net_generic(net
, audit_net_id
);
1135 aunet
->nlsk
= netlink_kernel_create(net
, NETLINK_AUDIT
, &cfg
);
1136 if (aunet
->nlsk
== NULL
) {
1137 audit_panic("cannot initialize netlink socket in namespace");
1140 aunet
->nlsk
->sk_sndtimeo
= MAX_SCHEDULE_TIMEOUT
;
1144 static void __net_exit
audit_net_exit(struct net
*net
)
1146 struct audit_net
*aunet
= net_generic(net
, audit_net_id
);
1147 struct sock
*sock
= aunet
->nlsk
;
1148 if (sock
== audit_sock
) {
1153 RCU_INIT_POINTER(aunet
->nlsk
, NULL
);
1155 netlink_kernel_release(sock
);
1158 static struct pernet_operations audit_net_ops __net_initdata
= {
1159 .init
= audit_net_init
,
1160 .exit
= audit_net_exit
,
1161 .id
= &audit_net_id
,
1162 .size
= sizeof(struct audit_net
),
1165 /* Initialize audit support at boot time. */
1166 static int __init
audit_init(void)
1170 if (audit_initialized
== AUDIT_DISABLED
)
1173 pr_info("initializing netlink subsys (%s)\n",
1174 audit_default
? "enabled" : "disabled");
1175 register_pernet_subsys(&audit_net_ops
);
1177 skb_queue_head_init(&audit_skb_queue
);
1178 skb_queue_head_init(&audit_skb_hold_queue
);
1179 audit_initialized
= AUDIT_INITIALIZED
;
1180 audit_enabled
= audit_default
;
1181 audit_ever_enabled
|= !!audit_default
;
1183 audit_log(NULL
, GFP_KERNEL
, AUDIT_KERNEL
, "initialized");
1185 for (i
= 0; i
< AUDIT_INODE_BUCKETS
; i
++)
1186 INIT_LIST_HEAD(&audit_inode_hash
[i
]);
1190 __initcall(audit_init
);
1192 /* Process kernel command-line parameter at boot time. audit=0 or audit=1. */
1193 static int __init
audit_enable(char *str
)
1195 audit_default
= !!simple_strtol(str
, NULL
, 0);
1197 audit_initialized
= AUDIT_DISABLED
;
1199 pr_info("%s\n", audit_default
?
1200 "enabled (after initialization)" : "disabled (until reboot)");
1204 __setup("audit=", audit_enable
);
1206 /* Process kernel command-line parameter at boot time.
1207 * audit_backlog_limit=<n> */
1208 static int __init
audit_backlog_limit_set(char *str
)
1210 u32 audit_backlog_limit_arg
;
1212 pr_info("audit_backlog_limit: ");
1213 if (kstrtouint(str
, 0, &audit_backlog_limit_arg
)) {
1214 pr_cont("using default of %u, unable to parse %s\n",
1215 audit_backlog_limit
, str
);
1219 audit_backlog_limit
= audit_backlog_limit_arg
;
1220 pr_cont("%d\n", audit_backlog_limit
);
1224 __setup("audit_backlog_limit=", audit_backlog_limit_set
);
1226 static void audit_buffer_free(struct audit_buffer
*ab
)
1228 unsigned long flags
;
1234 spin_lock_irqsave(&audit_freelist_lock
, flags
);
1235 if (audit_freelist_count
> AUDIT_MAXFREE
)
1238 audit_freelist_count
++;
1239 list_add(&ab
->list
, &audit_freelist
);
1241 spin_unlock_irqrestore(&audit_freelist_lock
, flags
);
1244 static struct audit_buffer
* audit_buffer_alloc(struct audit_context
*ctx
,
1245 gfp_t gfp_mask
, int type
)
1247 unsigned long flags
;
1248 struct audit_buffer
*ab
= NULL
;
1249 struct nlmsghdr
*nlh
;
1251 spin_lock_irqsave(&audit_freelist_lock
, flags
);
1252 if (!list_empty(&audit_freelist
)) {
1253 ab
= list_entry(audit_freelist
.next
,
1254 struct audit_buffer
, list
);
1255 list_del(&ab
->list
);
1256 --audit_freelist_count
;
1258 spin_unlock_irqrestore(&audit_freelist_lock
, flags
);
1261 ab
= kmalloc(sizeof(*ab
), gfp_mask
);
1267 ab
->gfp_mask
= gfp_mask
;
1269 ab
->skb
= nlmsg_new(AUDIT_BUFSIZ
, gfp_mask
);
1273 nlh
= nlmsg_put(ab
->skb
, 0, 0, type
, 0, 0);
1283 audit_buffer_free(ab
);
1288 * audit_serial - compute a serial number for the audit record
1290 * Compute a serial number for the audit record. Audit records are
1291 * written to user-space as soon as they are generated, so a complete
1292 * audit record may be written in several pieces. The timestamp of the
1293 * record and this serial number are used by the user-space tools to
1294 * determine which pieces belong to the same audit record. The
1295 * (timestamp,serial) tuple is unique for each syscall and is live from
1296 * syscall entry to syscall exit.
1298 * NOTE: Another possibility is to store the formatted records off the
1299 * audit context (for those records that have a context), and emit them
1300 * all at syscall exit. However, this could delay the reporting of
1301 * significant errors until syscall exit (or never, if the system
1304 unsigned int audit_serial(void)
1306 static atomic_t serial
= ATOMIC_INIT(0);
1308 return atomic_add_return(1, &serial
);
1311 static inline void audit_get_stamp(struct audit_context
*ctx
,
1312 struct timespec
*t
, unsigned int *serial
)
1314 if (!ctx
|| !auditsc_get_stamp(ctx
, t
, serial
)) {
1316 *serial
= audit_serial();
1321 * Wait for auditd to drain the queue a little
1323 static long wait_for_auditd(long sleep_time
)
1325 DECLARE_WAITQUEUE(wait
, current
);
1326 set_current_state(TASK_UNINTERRUPTIBLE
);
1327 add_wait_queue_exclusive(&audit_backlog_wait
, &wait
);
1329 if (audit_backlog_limit
&&
1330 skb_queue_len(&audit_skb_queue
) > audit_backlog_limit
)
1331 sleep_time
= schedule_timeout(sleep_time
);
1333 __set_current_state(TASK_RUNNING
);
1334 remove_wait_queue(&audit_backlog_wait
, &wait
);
1340 * audit_log_start - obtain an audit buffer
1341 * @ctx: audit_context (may be NULL)
1342 * @gfp_mask: type of allocation
1343 * @type: audit message type
1345 * Returns audit_buffer pointer on success or NULL on error.
1347 * Obtain an audit buffer. This routine does locking to obtain the
1348 * audit buffer, but then no locking is required for calls to
1349 * audit_log_*format. If the task (ctx) is a task that is currently in a
1350 * syscall, then the syscall is marked as auditable and an audit record
1351 * will be written at syscall exit. If there is no associated task, then
1352 * task context (ctx) should be NULL.
1354 struct audit_buffer
*audit_log_start(struct audit_context
*ctx
, gfp_t gfp_mask
,
1357 struct audit_buffer
*ab
= NULL
;
1359 unsigned int uninitialized_var(serial
);
1360 int reserve
= 5; /* Allow atomic callers to go up to five
1361 entries over the normal backlog limit */
1362 unsigned long timeout_start
= jiffies
;
1364 if (audit_initialized
!= AUDIT_INITIALIZED
)
1367 if (unlikely(audit_filter_type(type
)))
1370 if (gfp_mask
& __GFP_DIRECT_RECLAIM
) {
1371 if (audit_pid
&& audit_pid
== current
->tgid
)
1372 gfp_mask
&= ~__GFP_DIRECT_RECLAIM
;
1377 while (audit_backlog_limit
1378 && skb_queue_len(&audit_skb_queue
) > audit_backlog_limit
+ reserve
) {
1379 if (gfp_mask
& __GFP_DIRECT_RECLAIM
&& audit_backlog_wait_time
) {
1382 sleep_time
= timeout_start
+ audit_backlog_wait_time
- jiffies
;
1383 if (sleep_time
> 0) {
1384 sleep_time
= wait_for_auditd(sleep_time
);
1389 if (audit_rate_check() && printk_ratelimit())
1390 pr_warn("audit_backlog=%d > audit_backlog_limit=%d\n",
1391 skb_queue_len(&audit_skb_queue
),
1392 audit_backlog_limit
);
1393 audit_log_lost("backlog limit exceeded");
1394 audit_backlog_wait_time
= 0;
1395 wake_up(&audit_backlog_wait
);
1399 if (!reserve
&& !audit_backlog_wait_time
)
1400 audit_backlog_wait_time
= audit_backlog_wait_time_master
;
1402 ab
= audit_buffer_alloc(ctx
, gfp_mask
, type
);
1404 audit_log_lost("out of memory in audit_log_start");
1408 audit_get_stamp(ab
->ctx
, &t
, &serial
);
1410 audit_log_format(ab
, "audit(%lu.%03lu:%u): ",
1411 t
.tv_sec
, t
.tv_nsec
/1000000, serial
);
1416 * audit_expand - expand skb in the audit buffer
1418 * @extra: space to add at tail of the skb
1420 * Returns 0 (no space) on failed expansion, or available space if
1423 static inline int audit_expand(struct audit_buffer
*ab
, int extra
)
1425 struct sk_buff
*skb
= ab
->skb
;
1426 int oldtail
= skb_tailroom(skb
);
1427 int ret
= pskb_expand_head(skb
, 0, extra
, ab
->gfp_mask
);
1428 int newtail
= skb_tailroom(skb
);
1431 audit_log_lost("out of memory in audit_expand");
1435 skb
->truesize
+= newtail
- oldtail
;
1440 * Format an audit message into the audit buffer. If there isn't enough
1441 * room in the audit buffer, more room will be allocated and vsnprint
1442 * will be called a second time. Currently, we assume that a printk
1443 * can't format message larger than 1024 bytes, so we don't either.
1445 static void audit_log_vformat(struct audit_buffer
*ab
, const char *fmt
,
1449 struct sk_buff
*skb
;
1457 avail
= skb_tailroom(skb
);
1459 avail
= audit_expand(ab
, AUDIT_BUFSIZ
);
1463 va_copy(args2
, args
);
1464 len
= vsnprintf(skb_tail_pointer(skb
), avail
, fmt
, args
);
1466 /* The printk buffer is 1024 bytes long, so if we get
1467 * here and AUDIT_BUFSIZ is at least 1024, then we can
1468 * log everything that printk could have logged. */
1469 avail
= audit_expand(ab
,
1470 max_t(unsigned, AUDIT_BUFSIZ
, 1+len
-avail
));
1473 len
= vsnprintf(skb_tail_pointer(skb
), avail
, fmt
, args2
);
1484 * audit_log_format - format a message into the audit buffer.
1486 * @fmt: format string
1487 * @...: optional parameters matching @fmt string
1489 * All the work is done in audit_log_vformat.
1491 void audit_log_format(struct audit_buffer
*ab
, const char *fmt
, ...)
1497 va_start(args
, fmt
);
1498 audit_log_vformat(ab
, fmt
, args
);
1503 * audit_log_hex - convert a buffer to hex and append it to the audit skb
1504 * @ab: the audit_buffer
1505 * @buf: buffer to convert to hex
1506 * @len: length of @buf to be converted
1508 * No return value; failure to expand is silently ignored.
1510 * This function will take the passed buf and convert it into a string of
1511 * ascii hex digits. The new string is placed onto the skb.
1513 void audit_log_n_hex(struct audit_buffer
*ab
, const unsigned char *buf
,
1516 int i
, avail
, new_len
;
1518 struct sk_buff
*skb
;
1525 avail
= skb_tailroom(skb
);
1527 if (new_len
>= avail
) {
1528 /* Round the buffer request up to the next multiple */
1529 new_len
= AUDIT_BUFSIZ
*(((new_len
-avail
)/AUDIT_BUFSIZ
) + 1);
1530 avail
= audit_expand(ab
, new_len
);
1535 ptr
= skb_tail_pointer(skb
);
1536 for (i
= 0; i
< len
; i
++)
1537 ptr
= hex_byte_pack_upper(ptr
, buf
[i
]);
1539 skb_put(skb
, len
<< 1); /* new string is twice the old string */
1543 * Format a string of no more than slen characters into the audit buffer,
1544 * enclosed in quote marks.
1546 void audit_log_n_string(struct audit_buffer
*ab
, const char *string
,
1551 struct sk_buff
*skb
;
1558 avail
= skb_tailroom(skb
);
1559 new_len
= slen
+ 3; /* enclosing quotes + null terminator */
1560 if (new_len
> avail
) {
1561 avail
= audit_expand(ab
, new_len
);
1565 ptr
= skb_tail_pointer(skb
);
1567 memcpy(ptr
, string
, slen
);
1571 skb_put(skb
, slen
+ 2); /* don't include null terminator */
1575 * audit_string_contains_control - does a string need to be logged in hex
1576 * @string: string to be checked
1577 * @len: max length of the string to check
1579 bool audit_string_contains_control(const char *string
, size_t len
)
1581 const unsigned char *p
;
1582 for (p
= string
; p
< (const unsigned char *)string
+ len
; p
++) {
1583 if (*p
== '"' || *p
< 0x21 || *p
> 0x7e)
1590 * audit_log_n_untrustedstring - log a string that may contain random characters
1592 * @len: length of string (not including trailing null)
1593 * @string: string to be logged
1595 * This code will escape a string that is passed to it if the string
1596 * contains a control character, unprintable character, double quote mark,
1597 * or a space. Unescaped strings will start and end with a double quote mark.
1598 * Strings that are escaped are printed in hex (2 digits per char).
1600 * The caller specifies the number of characters in the string to log, which may
1601 * or may not be the entire string.
1603 void audit_log_n_untrustedstring(struct audit_buffer
*ab
, const char *string
,
1606 if (audit_string_contains_control(string
, len
))
1607 audit_log_n_hex(ab
, string
, len
);
1609 audit_log_n_string(ab
, string
, len
);
1613 * audit_log_untrustedstring - log a string that may contain random characters
1615 * @string: string to be logged
1617 * Same as audit_log_n_untrustedstring(), except that strlen is used to
1618 * determine string length.
1620 void audit_log_untrustedstring(struct audit_buffer
*ab
, const char *string
)
1622 audit_log_n_untrustedstring(ab
, string
, strlen(string
));
1625 /* This is a helper-function to print the escaped d_path */
1626 void audit_log_d_path(struct audit_buffer
*ab
, const char *prefix
,
1627 const struct path
*path
)
1632 audit_log_format(ab
, "%s", prefix
);
1634 /* We will allow 11 spaces for ' (deleted)' to be appended */
1635 pathname
= kmalloc(PATH_MAX
+11, ab
->gfp_mask
);
1637 audit_log_string(ab
, "<no_memory>");
1640 p
= d_path(path
, pathname
, PATH_MAX
+11);
1641 if (IS_ERR(p
)) { /* Should never happen since we send PATH_MAX */
1642 /* FIXME: can we save some information here? */
1643 audit_log_string(ab
, "<too_long>");
1645 audit_log_untrustedstring(ab
, p
);
1649 void audit_log_session_info(struct audit_buffer
*ab
)
1651 unsigned int sessionid
= audit_get_sessionid(current
);
1652 uid_t auid
= from_kuid(&init_user_ns
, audit_get_loginuid(current
));
1654 audit_log_format(ab
, " auid=%u ses=%u", auid
, sessionid
);
1657 void audit_log_key(struct audit_buffer
*ab
, char *key
)
1659 audit_log_format(ab
, " key=");
1661 audit_log_untrustedstring(ab
, key
);
1663 audit_log_format(ab
, "(null)");
1666 void audit_log_cap(struct audit_buffer
*ab
, char *prefix
, kernel_cap_t
*cap
)
1670 audit_log_format(ab
, " %s=", prefix
);
1671 CAP_FOR_EACH_U32(i
) {
1672 audit_log_format(ab
, "%08x",
1673 cap
->cap
[CAP_LAST_U32
- i
]);
1677 static void audit_log_fcaps(struct audit_buffer
*ab
, struct audit_names
*name
)
1679 kernel_cap_t
*perm
= &name
->fcap
.permitted
;
1680 kernel_cap_t
*inh
= &name
->fcap
.inheritable
;
1683 if (!cap_isclear(*perm
)) {
1684 audit_log_cap(ab
, "cap_fp", perm
);
1687 if (!cap_isclear(*inh
)) {
1688 audit_log_cap(ab
, "cap_fi", inh
);
1693 audit_log_format(ab
, " cap_fe=%d cap_fver=%x",
1694 name
->fcap
.fE
, name
->fcap_ver
);
1697 static inline int audit_copy_fcaps(struct audit_names
*name
,
1698 const struct dentry
*dentry
)
1700 struct cpu_vfs_cap_data caps
;
1706 rc
= get_vfs_caps_from_disk(dentry
, &caps
);
1710 name
->fcap
.permitted
= caps
.permitted
;
1711 name
->fcap
.inheritable
= caps
.inheritable
;
1712 name
->fcap
.fE
= !!(caps
.magic_etc
& VFS_CAP_FLAGS_EFFECTIVE
);
1713 name
->fcap_ver
= (caps
.magic_etc
& VFS_CAP_REVISION_MASK
) >>
1714 VFS_CAP_REVISION_SHIFT
;
1719 /* Copy inode data into an audit_names. */
1720 void audit_copy_inode(struct audit_names
*name
, const struct dentry
*dentry
,
1721 struct inode
*inode
)
1723 name
->ino
= inode
->i_ino
;
1724 name
->dev
= inode
->i_sb
->s_dev
;
1725 name
->mode
= inode
->i_mode
;
1726 name
->uid
= inode
->i_uid
;
1727 name
->gid
= inode
->i_gid
;
1728 name
->rdev
= inode
->i_rdev
;
1729 security_inode_getsecid(inode
, &name
->osid
);
1730 audit_copy_fcaps(name
, dentry
);
1734 * audit_log_name - produce AUDIT_PATH record from struct audit_names
1735 * @context: audit_context for the task
1736 * @n: audit_names structure with reportable details
1737 * @path: optional path to report instead of audit_names->name
1738 * @record_num: record number to report when handling a list of names
1739 * @call_panic: optional pointer to int that will be updated if secid fails
1741 void audit_log_name(struct audit_context
*context
, struct audit_names
*n
,
1742 struct path
*path
, int record_num
, int *call_panic
)
1744 struct audit_buffer
*ab
;
1745 ab
= audit_log_start(context
, GFP_KERNEL
, AUDIT_PATH
);
1749 audit_log_format(ab
, "item=%d", record_num
);
1752 audit_log_d_path(ab
, " name=", path
);
1754 switch (n
->name_len
) {
1755 case AUDIT_NAME_FULL
:
1756 /* log the full path */
1757 audit_log_format(ab
, " name=");
1758 audit_log_untrustedstring(ab
, n
->name
->name
);
1761 /* name was specified as a relative path and the
1762 * directory component is the cwd */
1763 audit_log_d_path(ab
, " name=", &context
->pwd
);
1766 /* log the name's directory component */
1767 audit_log_format(ab
, " name=");
1768 audit_log_n_untrustedstring(ab
, n
->name
->name
,
1772 audit_log_format(ab
, " name=(null)");
1774 if (n
->ino
!= AUDIT_INO_UNSET
)
1775 audit_log_format(ab
, " inode=%lu"
1776 " dev=%02x:%02x mode=%#ho"
1777 " ouid=%u ogid=%u rdev=%02x:%02x",
1782 from_kuid(&init_user_ns
, n
->uid
),
1783 from_kgid(&init_user_ns
, n
->gid
),
1789 if (security_secid_to_secctx(
1790 n
->osid
, &ctx
, &len
)) {
1791 audit_log_format(ab
, " osid=%u", n
->osid
);
1795 audit_log_format(ab
, " obj=%s", ctx
);
1796 security_release_secctx(ctx
, len
);
1800 /* log the audit_names record type */
1801 audit_log_format(ab
, " nametype=");
1803 case AUDIT_TYPE_NORMAL
:
1804 audit_log_format(ab
, "NORMAL");
1806 case AUDIT_TYPE_PARENT
:
1807 audit_log_format(ab
, "PARENT");
1809 case AUDIT_TYPE_CHILD_DELETE
:
1810 audit_log_format(ab
, "DELETE");
1812 case AUDIT_TYPE_CHILD_CREATE
:
1813 audit_log_format(ab
, "CREATE");
1816 audit_log_format(ab
, "UNKNOWN");
1820 audit_log_fcaps(ab
, n
);
1824 int audit_log_task_context(struct audit_buffer
*ab
)
1831 security_task_getsecid(current
, &sid
);
1835 error
= security_secid_to_secctx(sid
, &ctx
, &len
);
1837 if (error
!= -EINVAL
)
1842 audit_log_format(ab
, " subj=%s", ctx
);
1843 security_release_secctx(ctx
, len
);
1847 audit_panic("error in audit_log_task_context");
1850 EXPORT_SYMBOL(audit_log_task_context
);
1852 void audit_log_d_path_exe(struct audit_buffer
*ab
,
1853 struct mm_struct
*mm
)
1855 struct file
*exe_file
;
1860 exe_file
= get_mm_exe_file(mm
);
1864 audit_log_d_path(ab
, " exe=", &exe_file
->f_path
);
1868 audit_log_format(ab
, " exe=(null)");
1871 void audit_log_task_info(struct audit_buffer
*ab
, struct task_struct
*tsk
)
1873 const struct cred
*cred
;
1874 char comm
[sizeof(tsk
->comm
)];
1880 /* tsk == current */
1881 cred
= current_cred();
1883 spin_lock_irq(&tsk
->sighand
->siglock
);
1884 if (tsk
->signal
&& tsk
->signal
->tty
&& tsk
->signal
->tty
->name
)
1885 tty
= tsk
->signal
->tty
->name
;
1888 spin_unlock_irq(&tsk
->sighand
->siglock
);
1890 audit_log_format(ab
,
1891 " ppid=%d pid=%d auid=%u uid=%u gid=%u"
1892 " euid=%u suid=%u fsuid=%u"
1893 " egid=%u sgid=%u fsgid=%u tty=%s ses=%u",
1896 from_kuid(&init_user_ns
, audit_get_loginuid(tsk
)),
1897 from_kuid(&init_user_ns
, cred
->uid
),
1898 from_kgid(&init_user_ns
, cred
->gid
),
1899 from_kuid(&init_user_ns
, cred
->euid
),
1900 from_kuid(&init_user_ns
, cred
->suid
),
1901 from_kuid(&init_user_ns
, cred
->fsuid
),
1902 from_kgid(&init_user_ns
, cred
->egid
),
1903 from_kgid(&init_user_ns
, cred
->sgid
),
1904 from_kgid(&init_user_ns
, cred
->fsgid
),
1905 tty
, audit_get_sessionid(tsk
));
1907 audit_log_format(ab
, " comm=");
1908 audit_log_untrustedstring(ab
, get_task_comm(comm
, tsk
));
1910 audit_log_d_path_exe(ab
, tsk
->mm
);
1911 audit_log_task_context(ab
);
1913 EXPORT_SYMBOL(audit_log_task_info
);
1916 * audit_log_link_denied - report a link restriction denial
1917 * @operation: specific link operation
1918 * @link: the path that triggered the restriction
1920 void audit_log_link_denied(const char *operation
, struct path
*link
)
1922 struct audit_buffer
*ab
;
1923 struct audit_names
*name
;
1925 name
= kzalloc(sizeof(*name
), GFP_NOFS
);
1929 /* Generate AUDIT_ANOM_LINK with subject, operation, outcome. */
1930 ab
= audit_log_start(current
->audit_context
, GFP_KERNEL
,
1934 audit_log_format(ab
, "op=%s", operation
);
1935 audit_log_task_info(ab
, current
);
1936 audit_log_format(ab
, " res=0");
1939 /* Generate AUDIT_PATH record with object. */
1940 name
->type
= AUDIT_TYPE_NORMAL
;
1941 audit_copy_inode(name
, link
->dentry
, d_backing_inode(link
->dentry
));
1942 audit_log_name(current
->audit_context
, name
, link
, 0, NULL
);
1948 * audit_log_end - end one audit record
1949 * @ab: the audit_buffer
1951 * netlink_unicast() cannot be called inside an irq context because it blocks
1952 * (last arg, flags, is not set to MSG_DONTWAIT), so the audit buffer is placed
1953 * on a queue and a tasklet is scheduled to remove them from the queue outside
1954 * the irq context. May be called in any context.
1956 void audit_log_end(struct audit_buffer
*ab
)
1960 if (!audit_rate_check()) {
1961 audit_log_lost("rate limit exceeded");
1963 struct nlmsghdr
*nlh
= nlmsg_hdr(ab
->skb
);
1965 nlh
->nlmsg_len
= ab
->skb
->len
;
1966 kauditd_send_multicast_skb(ab
->skb
, ab
->gfp_mask
);
1969 * The original kaudit unicast socket sends up messages with
1970 * nlmsg_len set to the payload length rather than the entire
1971 * message length. This breaks the standard set by netlink.
1972 * The existing auditd daemon assumes this breakage. Fixing
1973 * this would require co-ordinating a change in the established
1974 * protocol between the kaudit kernel subsystem and the auditd
1977 nlh
->nlmsg_len
-= NLMSG_HDRLEN
;
1980 skb_queue_tail(&audit_skb_queue
, ab
->skb
);
1981 wake_up_interruptible(&kauditd_wait
);
1983 audit_printk_skb(ab
->skb
);
1987 audit_buffer_free(ab
);
1991 * audit_log - Log an audit record
1992 * @ctx: audit context
1993 * @gfp_mask: type of allocation
1994 * @type: audit message type
1995 * @fmt: format string to use
1996 * @...: variable parameters matching the format string
1998 * This is a convenience function that calls audit_log_start,
1999 * audit_log_vformat, and audit_log_end. It may be called
2002 void audit_log(struct audit_context
*ctx
, gfp_t gfp_mask
, int type
,
2003 const char *fmt
, ...)
2005 struct audit_buffer
*ab
;
2008 ab
= audit_log_start(ctx
, gfp_mask
, type
);
2010 va_start(args
, fmt
);
2011 audit_log_vformat(ab
, fmt
, args
);
2017 #ifdef CONFIG_SECURITY
2019 * audit_log_secctx - Converts and logs SELinux context
2021 * @secid: security number
2023 * This is a helper function that calls security_secid_to_secctx to convert
2024 * secid to secctx and then adds the (converted) SELinux context to the audit
2025 * log by calling audit_log_format, thus also preventing leak of internal secid
2026 * to userspace. If secid cannot be converted audit_panic is called.
2028 void audit_log_secctx(struct audit_buffer
*ab
, u32 secid
)
2033 if (security_secid_to_secctx(secid
, &secctx
, &len
)) {
2034 audit_panic("Cannot convert secid to context");
2036 audit_log_format(ab
, " obj=%s", secctx
);
2037 security_release_secctx(secctx
, len
);
2040 EXPORT_SYMBOL(audit_log_secctx
);
2043 EXPORT_SYMBOL(audit_log_start
);
2044 EXPORT_SYMBOL(audit_log_end
);
2045 EXPORT_SYMBOL(audit_log_format
);
2046 EXPORT_SYMBOL(audit_log
);