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>
57 #include <linux/spinlock.h>
58 #include <linux/rcupdate.h>
59 #include <linux/mutex.h>
60 #include <linux/gfp.h>
62 #include <linux/audit.h>
65 #include <net/netlink.h>
66 #include <linux/skbuff.h>
67 #ifdef CONFIG_SECURITY
68 #include <linux/security.h>
70 #include <linux/freezer.h>
71 #include <linux/pid_namespace.h>
72 #include <net/netns/generic.h>
76 /* No auditing will take place until audit_initialized == AUDIT_INITIALIZED.
77 * (Initialization happens after skb_init is called.) */
78 #define AUDIT_DISABLED -1
79 #define AUDIT_UNINITIALIZED 0
80 #define AUDIT_INITIALIZED 1
81 static int audit_initialized
;
85 #define AUDIT_LOCKED 2
87 u32 audit_ever_enabled
;
89 EXPORT_SYMBOL_GPL(audit_enabled
);
91 /* Default state when kernel boots without any parameters. */
92 static u32 audit_default
;
94 /* If auditing cannot proceed, audit_failure selects what happens. */
95 static u32 audit_failure
= AUDIT_FAIL_PRINTK
;
97 /* private audit network namespace index */
98 static unsigned int audit_net_id
;
101 * struct audit_net - audit private network namespace data
102 * @sk: communication socket
109 * struct auditd_connection - kernel/auditd connection state
111 * @portid: netlink portid
112 * @net: the associated network namespace
113 * @lock: spinlock to protect write access
116 * This struct is RCU protected; you must either hold the RCU lock for reading
117 * or the included spinlock for writing.
119 static struct auditd_connection
{
126 /* If audit_rate_limit is non-zero, limit the rate of sending audit records
127 * to that number per second. This prevents DoS attacks, but results in
128 * audit records being dropped. */
129 static u32 audit_rate_limit
;
131 /* Number of outstanding audit_buffers allowed.
132 * When set to zero, this means unlimited. */
133 static u32 audit_backlog_limit
= 64;
134 #define AUDIT_BACKLOG_WAIT_TIME (60 * HZ)
135 static u32 audit_backlog_wait_time
= AUDIT_BACKLOG_WAIT_TIME
;
137 /* The identity of the user shutting down the audit system. */
138 kuid_t audit_sig_uid
= INVALID_UID
;
139 pid_t audit_sig_pid
= -1;
140 u32 audit_sig_sid
= 0;
142 /* Records can be lost in several ways:
143 0) [suppressed in audit_alloc]
144 1) out of memory in audit_log_start [kmalloc of struct audit_buffer]
145 2) out of memory in audit_log_move [alloc_skb]
146 3) suppressed due to audit_rate_limit
147 4) suppressed due to audit_backlog_limit
149 static atomic_t audit_lost
= ATOMIC_INIT(0);
151 /* Hash for inode-based rules */
152 struct list_head audit_inode_hash
[AUDIT_INODE_BUCKETS
];
154 /* The audit_freelist is a list of pre-allocated audit buffers (if more
155 * than AUDIT_MAXFREE are in use, the audit buffer is freed instead of
156 * being placed on the freelist). */
157 static DEFINE_SPINLOCK(audit_freelist_lock
);
158 static int audit_freelist_count
;
159 static LIST_HEAD(audit_freelist
);
161 /* queue msgs to send via kauditd_task */
162 static struct sk_buff_head audit_queue
;
163 /* queue msgs due to temporary unicast send problems */
164 static struct sk_buff_head audit_retry_queue
;
165 /* queue msgs waiting for new auditd connection */
166 static struct sk_buff_head audit_hold_queue
;
168 /* queue servicing thread */
169 static struct task_struct
*kauditd_task
;
170 static DECLARE_WAIT_QUEUE_HEAD(kauditd_wait
);
172 /* waitqueue for callers who are blocked on the audit backlog */
173 static DECLARE_WAIT_QUEUE_HEAD(audit_backlog_wait
);
175 static struct audit_features af
= {.vers
= AUDIT_FEATURE_VERSION
,
180 static char *audit_feature_names
[2] = {
181 "only_unset_loginuid",
182 "loginuid_immutable",
186 /* Serialize requests from userspace. */
187 DEFINE_MUTEX(audit_cmd_mutex
);
189 /* AUDIT_BUFSIZ is the size of the temporary buffer used for formatting
190 * audit records. Since printk uses a 1024 byte buffer, this buffer
191 * should be at least that large. */
192 #define AUDIT_BUFSIZ 1024
194 /* AUDIT_MAXFREE is the number of empty audit_buffers we keep on the
195 * audit_freelist. Doing so eliminates many kmalloc/kfree calls. */
196 #define AUDIT_MAXFREE (2*NR_CPUS)
198 /* The audit_buffer is used when formatting an audit record. The caller
199 * locks briefly to get the record off the freelist or to allocate the
200 * buffer, and locks briefly to send the buffer to the netlink layer or
201 * to place it on a transmit queue. Multiple audit_buffers can be in
202 * use simultaneously. */
203 struct audit_buffer
{
204 struct list_head list
;
205 struct sk_buff
*skb
; /* formatted skb ready to send */
206 struct audit_context
*ctx
; /* NULL or associated context */
217 * auditd_test_task - Check to see if a given task is an audit daemon
218 * @task: the task to check
221 * Return 1 if the task is a registered audit daemon, 0 otherwise.
223 int auditd_test_task(const struct task_struct
*task
)
228 rc
= (auditd_conn
.pid
&& task
->tgid
== auditd_conn
.pid
? 1 : 0);
235 * audit_get_sk - Return the audit socket for the given network namespace
236 * @net: the destination network namespace
239 * Returns the sock pointer if valid, NULL otherwise. The caller must ensure
240 * that a reference is held for the network namespace while the sock is in use.
242 static struct sock
*audit_get_sk(const struct net
*net
)
244 struct audit_net
*aunet
;
249 aunet
= net_generic(net
, audit_net_id
);
253 static void audit_set_portid(struct audit_buffer
*ab
, __u32 portid
)
256 struct nlmsghdr
*nlh
= nlmsg_hdr(ab
->skb
);
257 nlh
->nlmsg_pid
= portid
;
261 void audit_panic(const char *message
)
263 switch (audit_failure
) {
264 case AUDIT_FAIL_SILENT
:
266 case AUDIT_FAIL_PRINTK
:
267 if (printk_ratelimit())
268 pr_err("%s\n", message
);
270 case AUDIT_FAIL_PANIC
:
271 panic("audit: %s\n", message
);
276 static inline int audit_rate_check(void)
278 static unsigned long last_check
= 0;
279 static int messages
= 0;
280 static DEFINE_SPINLOCK(lock
);
283 unsigned long elapsed
;
286 if (!audit_rate_limit
) return 1;
288 spin_lock_irqsave(&lock
, flags
);
289 if (++messages
< audit_rate_limit
) {
293 elapsed
= now
- last_check
;
300 spin_unlock_irqrestore(&lock
, flags
);
306 * audit_log_lost - conditionally log lost audit message event
307 * @message: the message stating reason for lost audit message
309 * Emit at least 1 message per second, even if audit_rate_check is
311 * Always increment the lost messages counter.
313 void audit_log_lost(const char *message
)
315 static unsigned long last_msg
= 0;
316 static DEFINE_SPINLOCK(lock
);
321 atomic_inc(&audit_lost
);
323 print
= (audit_failure
== AUDIT_FAIL_PANIC
|| !audit_rate_limit
);
326 spin_lock_irqsave(&lock
, flags
);
328 if (now
- last_msg
> HZ
) {
332 spin_unlock_irqrestore(&lock
, flags
);
336 if (printk_ratelimit())
337 pr_warn("audit_lost=%u audit_rate_limit=%u audit_backlog_limit=%u\n",
338 atomic_read(&audit_lost
),
340 audit_backlog_limit
);
341 audit_panic(message
);
345 static int audit_log_config_change(char *function_name
, u32
new, u32 old
,
348 struct audit_buffer
*ab
;
351 ab
= audit_log_start(NULL
, GFP_KERNEL
, AUDIT_CONFIG_CHANGE
);
354 audit_log_format(ab
, "%s=%u old=%u", function_name
, new, old
);
355 audit_log_session_info(ab
);
356 rc
= audit_log_task_context(ab
);
358 allow_changes
= 0; /* Something weird, deny request */
359 audit_log_format(ab
, " res=%d", allow_changes
);
364 static int audit_do_config_change(char *function_name
, u32
*to_change
, u32
new)
366 int allow_changes
, rc
= 0;
367 u32 old
= *to_change
;
369 /* check if we are locked */
370 if (audit_enabled
== AUDIT_LOCKED
)
375 if (audit_enabled
!= AUDIT_OFF
) {
376 rc
= audit_log_config_change(function_name
, new, old
, allow_changes
);
381 /* If we are allowed, make the change */
382 if (allow_changes
== 1)
384 /* Not allowed, update reason */
390 static int audit_set_rate_limit(u32 limit
)
392 return audit_do_config_change("audit_rate_limit", &audit_rate_limit
, limit
);
395 static int audit_set_backlog_limit(u32 limit
)
397 return audit_do_config_change("audit_backlog_limit", &audit_backlog_limit
, limit
);
400 static int audit_set_backlog_wait_time(u32 timeout
)
402 return audit_do_config_change("audit_backlog_wait_time",
403 &audit_backlog_wait_time
, timeout
);
406 static int audit_set_enabled(u32 state
)
409 if (state
> AUDIT_LOCKED
)
412 rc
= audit_do_config_change("audit_enabled", &audit_enabled
, state
);
414 audit_ever_enabled
|= !!state
;
419 static int audit_set_failure(u32 state
)
421 if (state
!= AUDIT_FAIL_SILENT
422 && state
!= AUDIT_FAIL_PRINTK
423 && state
!= AUDIT_FAIL_PANIC
)
426 return audit_do_config_change("audit_failure", &audit_failure
, state
);
430 * auditd_set - Set/Reset the auditd connection state
432 * @portid: auditd netlink portid
433 * @net: auditd network namespace pointer
436 * This function will obtain and drop network namespace references as
439 static void auditd_set(int pid
, u32 portid
, struct net
*net
)
443 spin_lock_irqsave(&auditd_conn
.lock
, flags
);
444 auditd_conn
.pid
= pid
;
445 auditd_conn
.portid
= portid
;
447 put_net(auditd_conn
.net
);
449 auditd_conn
.net
= get_net(net
);
451 auditd_conn
.net
= NULL
;
452 spin_unlock_irqrestore(&auditd_conn
.lock
, flags
);
456 * kauditd_print_skb - Print the audit record to the ring buffer
459 * Whatever the reason, this packet may not make it to the auditd connection
460 * so write it via printk so the information isn't completely lost.
462 static void kauditd_printk_skb(struct sk_buff
*skb
)
464 struct nlmsghdr
*nlh
= nlmsg_hdr(skb
);
465 char *data
= nlmsg_data(nlh
);
467 if (nlh
->nlmsg_type
!= AUDIT_EOE
&& printk_ratelimit())
468 pr_notice("type=%d %s\n", nlh
->nlmsg_type
, data
);
472 * kauditd_rehold_skb - Handle a audit record send failure in the hold queue
476 * This should only be used by the kauditd_thread when it fails to flush the
479 static void kauditd_rehold_skb(struct sk_buff
*skb
)
481 /* put the record back in the queue at the same place */
482 skb_queue_head(&audit_hold_queue
, skb
);
486 * kauditd_hold_skb - Queue an audit record, waiting for auditd
490 * Queue the audit record, waiting for an instance of auditd. When this
491 * function is called we haven't given up yet on sending the record, but things
492 * are not looking good. The first thing we want to do is try to write the
493 * record via printk and then see if we want to try and hold on to the record
494 * and queue it, if we have room. If we want to hold on to the record, but we
495 * don't have room, record a record lost message.
497 static void kauditd_hold_skb(struct sk_buff
*skb
)
499 /* at this point it is uncertain if we will ever send this to auditd so
500 * try to send the message via printk before we go any further */
501 kauditd_printk_skb(skb
);
503 /* can we just silently drop the message? */
504 if (!audit_default
) {
509 /* if we have room, queue the message */
510 if (!audit_backlog_limit
||
511 skb_queue_len(&audit_hold_queue
) < audit_backlog_limit
) {
512 skb_queue_tail(&audit_hold_queue
, skb
);
516 /* we have no other options - drop the message */
517 audit_log_lost("kauditd hold queue overflow");
522 * kauditd_retry_skb - Queue an audit record, attempt to send again to auditd
526 * Not as serious as kauditd_hold_skb() as we still have a connected auditd,
527 * but for some reason we are having problems sending it audit records so
528 * queue the given record and attempt to resend.
530 static void kauditd_retry_skb(struct sk_buff
*skb
)
532 /* NOTE: because records should only live in the retry queue for a
533 * short period of time, before either being sent or moved to the hold
534 * queue, we don't currently enforce a limit on this queue */
535 skb_queue_tail(&audit_retry_queue
, skb
);
539 * auditd_reset - Disconnect the auditd connection
542 * Break the auditd/kauditd connection and move all the queued records into the
543 * hold queue in case auditd reconnects.
545 static void auditd_reset(void)
549 /* if it isn't already broken, break the connection */
552 auditd_set(0, 0, NULL
);
555 /* flush all of the main and retry queues to the hold queue */
556 while ((skb
= skb_dequeue(&audit_retry_queue
)))
557 kauditd_hold_skb(skb
);
558 while ((skb
= skb_dequeue(&audit_queue
)))
559 kauditd_hold_skb(skb
);
563 * auditd_send_unicast_skb - Send a record via unicast to auditd
567 * Send a skb to the audit daemon, returns positive/zero values on success and
568 * negative values on failure; in all cases the skb will be consumed by this
569 * function. If the send results in -ECONNREFUSED the connection with auditd
570 * will be reset. This function may sleep so callers should not hold any locks
571 * where this would cause a problem.
573 static int auditd_send_unicast_skb(struct sk_buff
*skb
)
580 /* NOTE: we can't call netlink_unicast while in the RCU section so
581 * take a reference to the network namespace and grab local
582 * copies of the namespace, the sock, and the portid; the
583 * namespace and sock aren't going to go away while we hold a
584 * reference and if the portid does become invalid after the RCU
585 * section netlink_unicast() should safely return an error */
588 if (!auditd_conn
.pid
) {
593 net
= auditd_conn
.net
;
595 sk
= audit_get_sk(net
);
596 portid
= auditd_conn
.portid
;
599 rc
= netlink_unicast(sk
, skb
, portid
, 0);
607 if (rc
== -ECONNREFUSED
)
613 * kauditd_send_queue - Helper for kauditd_thread to flush skb queues
614 * @sk: the sending sock
615 * @portid: the netlink destination
616 * @queue: the skb queue to process
617 * @retry_limit: limit on number of netlink unicast failures
618 * @skb_hook: per-skb hook for additional processing
619 * @err_hook: hook called if the skb fails the netlink unicast send
622 * Run through the given queue and attempt to send the audit records to auditd,
623 * returns zero on success, negative values on failure. It is up to the caller
624 * to ensure that the @sk is valid for the duration of this function.
627 static int kauditd_send_queue(struct sock
*sk
, u32 portid
,
628 struct sk_buff_head
*queue
,
629 unsigned int retry_limit
,
630 void (*skb_hook
)(struct sk_buff
*skb
),
631 void (*err_hook
)(struct sk_buff
*skb
))
635 static unsigned int failed
= 0;
637 /* NOTE: kauditd_thread takes care of all our locking, we just use
638 * the netlink info passed to us (e.g. sk and portid) */
640 while ((skb
= skb_dequeue(queue
))) {
641 /* call the skb_hook for each skb we touch */
645 /* can we send to anyone via unicast? */
652 /* grab an extra skb reference in case of error */
654 rc
= netlink_unicast(sk
, skb
, portid
, 0);
656 /* fatal failure for our queue flush attempt? */
657 if (++failed
>= retry_limit
||
658 rc
== -ECONNREFUSED
|| rc
== -EPERM
) {
659 /* yes - error processing for the queue */
665 /* keep processing with the skb_hook */
668 /* no - requeue to preserve ordering */
669 skb_queue_head(queue
, skb
);
671 /* it worked - drop the extra reference and continue */
678 return (rc
>= 0 ? 0 : rc
);
682 * kauditd_send_multicast_skb - Send a record to any multicast listeners
686 * Write a multicast message to anyone listening in the initial network
687 * namespace. This function doesn't consume an skb as might be expected since
688 * it has to copy it anyways.
690 static void kauditd_send_multicast_skb(struct sk_buff
*skb
)
692 struct sk_buff
*copy
;
693 struct sock
*sock
= audit_get_sk(&init_net
);
694 struct nlmsghdr
*nlh
;
696 /* NOTE: we are not taking an additional reference for init_net since
697 * we don't have to worry about it going away */
699 if (!netlink_has_listeners(sock
, AUDIT_NLGRP_READLOG
))
703 * The seemingly wasteful skb_copy() rather than bumping the refcount
704 * using skb_get() is necessary because non-standard mods are made to
705 * the skb by the original kaudit unicast socket send routine. The
706 * existing auditd daemon assumes this breakage. Fixing this would
707 * require co-ordinating a change in the established protocol between
708 * the kaudit kernel subsystem and the auditd userspace code. There is
709 * no reason for new multicast clients to continue with this
712 copy
= skb_copy(skb
, GFP_KERNEL
);
715 nlh
= nlmsg_hdr(copy
);
716 nlh
->nlmsg_len
= skb
->len
;
718 nlmsg_multicast(sock
, copy
, 0, AUDIT_NLGRP_READLOG
, GFP_KERNEL
);
722 * kauditd_thread - Worker thread to send audit records to userspace
725 static int kauditd_thread(void *dummy
)
729 struct net
*net
= NULL
;
730 struct sock
*sk
= NULL
;
732 #define UNICAST_RETRIES 5
735 while (!kthread_should_stop()) {
736 /* NOTE: see the lock comments in auditd_send_unicast_skb() */
738 if (!auditd_conn
.pid
) {
742 net
= auditd_conn
.net
;
744 sk
= audit_get_sk(net
);
745 portid
= auditd_conn
.portid
;
748 /* attempt to flush the hold queue */
749 rc
= kauditd_send_queue(sk
, portid
,
750 &audit_hold_queue
, UNICAST_RETRIES
,
751 NULL
, kauditd_rehold_skb
);
758 /* attempt to flush the retry queue */
759 rc
= kauditd_send_queue(sk
, portid
,
760 &audit_retry_queue
, UNICAST_RETRIES
,
761 NULL
, kauditd_hold_skb
);
769 /* process the main queue - do the multicast send and attempt
770 * unicast, dump failed record sends to the retry queue; if
771 * sk == NULL due to previous failures we will just do the
772 * multicast send and move the record to the retry queue */
773 rc
= kauditd_send_queue(sk
, portid
, &audit_queue
, 1,
774 kauditd_send_multicast_skb
,
776 if (sk
== NULL
|| rc
< 0)
780 /* drop our netns reference, no auditd sends past this line */
786 /* we have processed all the queues so wake everyone */
787 wake_up(&audit_backlog_wait
);
789 /* NOTE: we want to wake up if there is anything on the queue,
790 * regardless of if an auditd is connected, as we need to
791 * do the multicast send and rotate records from the
792 * main queue to the retry/hold queues */
793 wait_event_freezable(kauditd_wait
,
794 (skb_queue_len(&audit_queue
) ? 1 : 0));
800 int audit_send_list(void *_dest
)
802 struct audit_netlink_list
*dest
= _dest
;
804 struct sock
*sk
= audit_get_sk(dest
->net
);
806 /* wait for parent to finish and send an ACK */
807 mutex_lock(&audit_cmd_mutex
);
808 mutex_unlock(&audit_cmd_mutex
);
810 while ((skb
= __skb_dequeue(&dest
->q
)) != NULL
)
811 netlink_unicast(sk
, skb
, dest
->portid
, 0);
819 struct sk_buff
*audit_make_reply(__u32 portid
, int seq
, int type
, int done
,
820 int multi
, const void *payload
, int size
)
823 struct nlmsghdr
*nlh
;
825 int flags
= multi
? NLM_F_MULTI
: 0;
826 int t
= done
? NLMSG_DONE
: type
;
828 skb
= nlmsg_new(size
, GFP_KERNEL
);
832 nlh
= nlmsg_put(skb
, portid
, seq
, t
, size
, flags
);
835 data
= nlmsg_data(nlh
);
836 memcpy(data
, payload
, size
);
844 static int audit_send_reply_thread(void *arg
)
846 struct audit_reply
*reply
= (struct audit_reply
*)arg
;
847 struct sock
*sk
= audit_get_sk(reply
->net
);
849 mutex_lock(&audit_cmd_mutex
);
850 mutex_unlock(&audit_cmd_mutex
);
852 /* Ignore failure. It'll only happen if the sender goes away,
853 because our timeout is set to infinite. */
854 netlink_unicast(sk
, reply
->skb
, reply
->portid
, 0);
861 * audit_send_reply - send an audit reply message via netlink
862 * @request_skb: skb of request we are replying to (used to target the reply)
863 * @seq: sequence number
864 * @type: audit message type
865 * @done: done (last) flag
866 * @multi: multi-part message flag
867 * @payload: payload data
868 * @size: payload size
870 * Allocates an skb, builds the netlink message, and sends it to the port id.
871 * No failure notifications.
873 static void audit_send_reply(struct sk_buff
*request_skb
, int seq
, int type
, int done
,
874 int multi
, const void *payload
, int size
)
876 u32 portid
= NETLINK_CB(request_skb
).portid
;
877 struct net
*net
= sock_net(NETLINK_CB(request_skb
).sk
);
879 struct task_struct
*tsk
;
880 struct audit_reply
*reply
= kmalloc(sizeof(struct audit_reply
),
886 skb
= audit_make_reply(portid
, seq
, type
, done
, multi
, payload
, size
);
890 reply
->net
= get_net(net
);
891 reply
->portid
= portid
;
894 tsk
= kthread_run(audit_send_reply_thread
, reply
, "audit_send_reply");
903 * Check for appropriate CAP_AUDIT_ capabilities on incoming audit
906 static int audit_netlink_ok(struct sk_buff
*skb
, u16 msg_type
)
910 /* Only support initial user namespace for now. */
912 * We return ECONNREFUSED because it tricks userspace into thinking
913 * that audit was not configured into the kernel. Lots of users
914 * configure their PAM stack (because that's what the distro does)
915 * to reject login if unable to send messages to audit. If we return
916 * ECONNREFUSED the PAM stack thinks the kernel does not have audit
917 * configured in and will let login proceed. If we return EPERM
918 * userspace will reject all logins. This should be removed when we
919 * support non init namespaces!!
921 if (current_user_ns() != &init_user_ns
)
922 return -ECONNREFUSED
;
931 case AUDIT_GET_FEATURE
:
932 case AUDIT_SET_FEATURE
:
933 case AUDIT_LIST_RULES
:
936 case AUDIT_SIGNAL_INFO
:
940 case AUDIT_MAKE_EQUIV
:
941 /* Only support auditd and auditctl in initial pid namespace
943 if (task_active_pid_ns(current
) != &init_pid_ns
)
946 if (!netlink_capable(skb
, CAP_AUDIT_CONTROL
))
950 case AUDIT_FIRST_USER_MSG
... AUDIT_LAST_USER_MSG
:
951 case AUDIT_FIRST_USER_MSG2
... AUDIT_LAST_USER_MSG2
:
952 if (!netlink_capable(skb
, CAP_AUDIT_WRITE
))
955 default: /* bad msg */
962 static void audit_log_common_recv_msg(struct audit_buffer
**ab
, u16 msg_type
)
964 uid_t uid
= from_kuid(&init_user_ns
, current_uid());
965 pid_t pid
= task_tgid_nr(current
);
967 if (!audit_enabled
&& msg_type
!= AUDIT_USER_AVC
) {
972 *ab
= audit_log_start(NULL
, GFP_KERNEL
, msg_type
);
975 audit_log_format(*ab
, "pid=%d uid=%u", pid
, uid
);
976 audit_log_session_info(*ab
);
977 audit_log_task_context(*ab
);
980 int is_audit_feature_set(int i
)
982 return af
.features
& AUDIT_FEATURE_TO_MASK(i
);
986 static int audit_get_feature(struct sk_buff
*skb
)
990 seq
= nlmsg_hdr(skb
)->nlmsg_seq
;
992 audit_send_reply(skb
, seq
, AUDIT_GET_FEATURE
, 0, 0, &af
, sizeof(af
));
997 static void audit_log_feature_change(int which
, u32 old_feature
, u32 new_feature
,
998 u32 old_lock
, u32 new_lock
, int res
)
1000 struct audit_buffer
*ab
;
1002 if (audit_enabled
== AUDIT_OFF
)
1005 ab
= audit_log_start(NULL
, GFP_KERNEL
, AUDIT_FEATURE_CHANGE
);
1006 audit_log_task_info(ab
, current
);
1007 audit_log_format(ab
, " feature=%s old=%u new=%u old_lock=%u new_lock=%u res=%d",
1008 audit_feature_names
[which
], !!old_feature
, !!new_feature
,
1009 !!old_lock
, !!new_lock
, res
);
1013 static int audit_set_feature(struct sk_buff
*skb
)
1015 struct audit_features
*uaf
;
1018 BUILD_BUG_ON(AUDIT_LAST_FEATURE
+ 1 > ARRAY_SIZE(audit_feature_names
));
1019 uaf
= nlmsg_data(nlmsg_hdr(skb
));
1021 /* if there is ever a version 2 we should handle that here */
1023 for (i
= 0; i
<= AUDIT_LAST_FEATURE
; i
++) {
1024 u32 feature
= AUDIT_FEATURE_TO_MASK(i
);
1025 u32 old_feature
, new_feature
, old_lock
, new_lock
;
1027 /* if we are not changing this feature, move along */
1028 if (!(feature
& uaf
->mask
))
1031 old_feature
= af
.features
& feature
;
1032 new_feature
= uaf
->features
& feature
;
1033 new_lock
= (uaf
->lock
| af
.lock
) & feature
;
1034 old_lock
= af
.lock
& feature
;
1036 /* are we changing a locked feature? */
1037 if (old_lock
&& (new_feature
!= old_feature
)) {
1038 audit_log_feature_change(i
, old_feature
, new_feature
,
1039 old_lock
, new_lock
, 0);
1043 /* nothing invalid, do the changes */
1044 for (i
= 0; i
<= AUDIT_LAST_FEATURE
; i
++) {
1045 u32 feature
= AUDIT_FEATURE_TO_MASK(i
);
1046 u32 old_feature
, new_feature
, old_lock
, new_lock
;
1048 /* if we are not changing this feature, move along */
1049 if (!(feature
& uaf
->mask
))
1052 old_feature
= af
.features
& feature
;
1053 new_feature
= uaf
->features
& feature
;
1054 old_lock
= af
.lock
& feature
;
1055 new_lock
= (uaf
->lock
| af
.lock
) & feature
;
1057 if (new_feature
!= old_feature
)
1058 audit_log_feature_change(i
, old_feature
, new_feature
,
1059 old_lock
, new_lock
, 1);
1062 af
.features
|= feature
;
1064 af
.features
&= ~feature
;
1065 af
.lock
|= new_lock
;
1071 static int audit_replace(pid_t pid
)
1073 struct sk_buff
*skb
;
1075 skb
= audit_make_reply(0, 0, AUDIT_REPLACE
, 0, 0, &pid
, sizeof(pid
));
1078 return auditd_send_unicast_skb(skb
);
1081 static int audit_receive_msg(struct sk_buff
*skb
, struct nlmsghdr
*nlh
)
1086 struct audit_buffer
*ab
;
1087 u16 msg_type
= nlh
->nlmsg_type
;
1088 struct audit_sig_info
*sig_data
;
1092 err
= audit_netlink_ok(skb
, msg_type
);
1096 seq
= nlh
->nlmsg_seq
;
1097 data
= nlmsg_data(nlh
);
1101 struct audit_status s
;
1102 memset(&s
, 0, sizeof(s
));
1103 s
.enabled
= audit_enabled
;
1104 s
.failure
= audit_failure
;
1106 s
.pid
= auditd_conn
.pid
;
1108 s
.rate_limit
= audit_rate_limit
;
1109 s
.backlog_limit
= audit_backlog_limit
;
1110 s
.lost
= atomic_read(&audit_lost
);
1111 s
.backlog
= skb_queue_len(&audit_queue
);
1112 s
.feature_bitmap
= AUDIT_FEATURE_BITMAP_ALL
;
1113 s
.backlog_wait_time
= audit_backlog_wait_time
;
1114 audit_send_reply(skb
, seq
, AUDIT_GET
, 0, 0, &s
, sizeof(s
));
1118 struct audit_status s
;
1119 memset(&s
, 0, sizeof(s
));
1120 /* guard against past and future API changes */
1121 memcpy(&s
, data
, min_t(size_t, sizeof(s
), nlmsg_len(nlh
)));
1122 if (s
.mask
& AUDIT_STATUS_ENABLED
) {
1123 err
= audit_set_enabled(s
.enabled
);
1127 if (s
.mask
& AUDIT_STATUS_FAILURE
) {
1128 err
= audit_set_failure(s
.failure
);
1132 if (s
.mask
& AUDIT_STATUS_PID
) {
1133 /* NOTE: we are using task_tgid_vnr() below because
1134 * the s.pid value is relative to the namespace
1135 * of the caller; at present this doesn't matter
1136 * much since you can really only run auditd
1137 * from the initial pid namespace, but something
1138 * to keep in mind if this changes */
1139 int new_pid
= s
.pid
;
1141 pid_t requesting_pid
= task_tgid_vnr(current
);
1143 /* test the auditd connection */
1144 audit_replace(requesting_pid
);
1147 auditd_pid
= auditd_conn
.pid
;
1148 /* only the current auditd can unregister itself */
1149 if ((!new_pid
) && (requesting_pid
!= auditd_pid
)) {
1151 audit_log_config_change("audit_pid", new_pid
,
1155 /* replacing a healthy auditd is not allowed */
1156 if (auditd_pid
&& new_pid
) {
1158 audit_log_config_change("audit_pid", new_pid
,
1164 if (audit_enabled
!= AUDIT_OFF
)
1165 audit_log_config_change("audit_pid", new_pid
,
1169 /* register a new auditd connection */
1171 NETLINK_CB(skb
).portid
,
1172 sock_net(NETLINK_CB(skb
).sk
));
1173 /* try to process any backlog */
1174 wake_up_interruptible(&kauditd_wait
);
1176 /* unregister the auditd connection */
1179 if (s
.mask
& AUDIT_STATUS_RATE_LIMIT
) {
1180 err
= audit_set_rate_limit(s
.rate_limit
);
1184 if (s
.mask
& AUDIT_STATUS_BACKLOG_LIMIT
) {
1185 err
= audit_set_backlog_limit(s
.backlog_limit
);
1189 if (s
.mask
& AUDIT_STATUS_BACKLOG_WAIT_TIME
) {
1190 if (sizeof(s
) > (size_t)nlh
->nlmsg_len
)
1192 if (s
.backlog_wait_time
> 10*AUDIT_BACKLOG_WAIT_TIME
)
1194 err
= audit_set_backlog_wait_time(s
.backlog_wait_time
);
1200 case AUDIT_GET_FEATURE
:
1201 err
= audit_get_feature(skb
);
1205 case AUDIT_SET_FEATURE
:
1206 err
= audit_set_feature(skb
);
1211 case AUDIT_FIRST_USER_MSG
... AUDIT_LAST_USER_MSG
:
1212 case AUDIT_FIRST_USER_MSG2
... AUDIT_LAST_USER_MSG2
:
1213 if (!audit_enabled
&& msg_type
!= AUDIT_USER_AVC
)
1216 err
= audit_filter(msg_type
, AUDIT_FILTER_USER
);
1217 if (err
== 1) { /* match or error */
1219 if (msg_type
== AUDIT_USER_TTY
) {
1220 err
= tty_audit_push();
1224 audit_log_common_recv_msg(&ab
, msg_type
);
1225 if (msg_type
!= AUDIT_USER_TTY
)
1226 audit_log_format(ab
, " msg='%.*s'",
1227 AUDIT_MESSAGE_TEXT_MAX
,
1232 audit_log_format(ab
, " data=");
1233 size
= nlmsg_len(nlh
);
1235 ((unsigned char *)data
)[size
- 1] == '\0')
1237 audit_log_n_untrustedstring(ab
, data
, size
);
1239 audit_set_portid(ab
, NETLINK_CB(skb
).portid
);
1243 case AUDIT_ADD_RULE
:
1244 case AUDIT_DEL_RULE
:
1245 if (nlmsg_len(nlh
) < sizeof(struct audit_rule_data
))
1247 if (audit_enabled
== AUDIT_LOCKED
) {
1248 audit_log_common_recv_msg(&ab
, AUDIT_CONFIG_CHANGE
);
1249 audit_log_format(ab
, " audit_enabled=%d res=0", audit_enabled
);
1253 err
= audit_rule_change(msg_type
, NETLINK_CB(skb
).portid
,
1254 seq
, data
, nlmsg_len(nlh
));
1256 case AUDIT_LIST_RULES
:
1257 err
= audit_list_rules_send(skb
, seq
);
1261 audit_log_common_recv_msg(&ab
, AUDIT_CONFIG_CHANGE
);
1262 audit_log_format(ab
, " op=trim res=1");
1265 case AUDIT_MAKE_EQUIV
: {
1268 size_t msglen
= nlmsg_len(nlh
);
1272 if (msglen
< 2 * sizeof(u32
))
1274 memcpy(sizes
, bufp
, 2 * sizeof(u32
));
1275 bufp
+= 2 * sizeof(u32
);
1276 msglen
-= 2 * sizeof(u32
);
1277 old
= audit_unpack_string(&bufp
, &msglen
, sizes
[0]);
1282 new = audit_unpack_string(&bufp
, &msglen
, sizes
[1]);
1288 /* OK, here comes... */
1289 err
= audit_tag_tree(old
, new);
1291 audit_log_common_recv_msg(&ab
, AUDIT_CONFIG_CHANGE
);
1293 audit_log_format(ab
, " op=make_equiv old=");
1294 audit_log_untrustedstring(ab
, old
);
1295 audit_log_format(ab
, " new=");
1296 audit_log_untrustedstring(ab
, new);
1297 audit_log_format(ab
, " res=%d", !err
);
1303 case AUDIT_SIGNAL_INFO
:
1305 if (audit_sig_sid
) {
1306 err
= security_secid_to_secctx(audit_sig_sid
, &ctx
, &len
);
1310 sig_data
= kmalloc(sizeof(*sig_data
) + len
, GFP_KERNEL
);
1313 security_release_secctx(ctx
, len
);
1316 sig_data
->uid
= from_kuid(&init_user_ns
, audit_sig_uid
);
1317 sig_data
->pid
= audit_sig_pid
;
1318 if (audit_sig_sid
) {
1319 memcpy(sig_data
->ctx
, ctx
, len
);
1320 security_release_secctx(ctx
, len
);
1322 audit_send_reply(skb
, seq
, AUDIT_SIGNAL_INFO
, 0, 0,
1323 sig_data
, sizeof(*sig_data
) + len
);
1326 case AUDIT_TTY_GET
: {
1327 struct audit_tty_status s
;
1330 t
= READ_ONCE(current
->signal
->audit_tty
);
1331 s
.enabled
= t
& AUDIT_TTY_ENABLE
;
1332 s
.log_passwd
= !!(t
& AUDIT_TTY_LOG_PASSWD
);
1334 audit_send_reply(skb
, seq
, AUDIT_TTY_GET
, 0, 0, &s
, sizeof(s
));
1337 case AUDIT_TTY_SET
: {
1338 struct audit_tty_status s
, old
;
1339 struct audit_buffer
*ab
;
1342 memset(&s
, 0, sizeof(s
));
1343 /* guard against past and future API changes */
1344 memcpy(&s
, data
, min_t(size_t, sizeof(s
), nlmsg_len(nlh
)));
1345 /* check if new data is valid */
1346 if ((s
.enabled
!= 0 && s
.enabled
!= 1) ||
1347 (s
.log_passwd
!= 0 && s
.log_passwd
!= 1))
1351 t
= READ_ONCE(current
->signal
->audit_tty
);
1353 t
= s
.enabled
| (-s
.log_passwd
& AUDIT_TTY_LOG_PASSWD
);
1354 t
= xchg(¤t
->signal
->audit_tty
, t
);
1356 old
.enabled
= t
& AUDIT_TTY_ENABLE
;
1357 old
.log_passwd
= !!(t
& AUDIT_TTY_LOG_PASSWD
);
1359 audit_log_common_recv_msg(&ab
, AUDIT_CONFIG_CHANGE
);
1360 audit_log_format(ab
, " op=tty_set old-enabled=%d new-enabled=%d"
1361 " old-log_passwd=%d new-log_passwd=%d res=%d",
1362 old
.enabled
, s
.enabled
, old
.log_passwd
,
1363 s
.log_passwd
, !err
);
1372 return err
< 0 ? err
: 0;
1376 * Get message from skb. Each message is processed by audit_receive_msg.
1377 * Malformed skbs with wrong length are discarded silently.
1379 static void audit_receive_skb(struct sk_buff
*skb
)
1381 struct nlmsghdr
*nlh
;
1383 * len MUST be signed for nlmsg_next to be able to dec it below 0
1384 * if the nlmsg_len was not aligned
1389 nlh
= nlmsg_hdr(skb
);
1392 while (nlmsg_ok(nlh
, len
)) {
1393 err
= audit_receive_msg(skb
, nlh
);
1394 /* if err or if this message says it wants a response */
1395 if (err
|| (nlh
->nlmsg_flags
& NLM_F_ACK
))
1396 netlink_ack(skb
, nlh
, err
);
1398 nlh
= nlmsg_next(nlh
, &len
);
1402 /* Receive messages from netlink socket. */
1403 static void audit_receive(struct sk_buff
*skb
)
1405 mutex_lock(&audit_cmd_mutex
);
1406 audit_receive_skb(skb
);
1407 mutex_unlock(&audit_cmd_mutex
);
1410 /* Run custom bind function on netlink socket group connect or bind requests. */
1411 static int audit_bind(struct net
*net
, int group
)
1413 if (!capable(CAP_AUDIT_READ
))
1419 static int __net_init
audit_net_init(struct net
*net
)
1421 struct netlink_kernel_cfg cfg
= {
1422 .input
= audit_receive
,
1424 .flags
= NL_CFG_F_NONROOT_RECV
,
1425 .groups
= AUDIT_NLGRP_MAX
,
1428 struct audit_net
*aunet
= net_generic(net
, audit_net_id
);
1430 aunet
->sk
= netlink_kernel_create(net
, NETLINK_AUDIT
, &cfg
);
1431 if (aunet
->sk
== NULL
) {
1432 audit_panic("cannot initialize netlink socket in namespace");
1435 aunet
->sk
->sk_sndtimeo
= MAX_SCHEDULE_TIMEOUT
;
1440 static void __net_exit
audit_net_exit(struct net
*net
)
1442 struct audit_net
*aunet
= net_generic(net
, audit_net_id
);
1445 if (net
== auditd_conn
.net
)
1449 netlink_kernel_release(aunet
->sk
);
1452 static struct pernet_operations audit_net_ops __net_initdata
= {
1453 .init
= audit_net_init
,
1454 .exit
= audit_net_exit
,
1455 .id
= &audit_net_id
,
1456 .size
= sizeof(struct audit_net
),
1459 /* Initialize audit support at boot time. */
1460 static int __init
audit_init(void)
1464 if (audit_initialized
== AUDIT_DISABLED
)
1467 memset(&auditd_conn
, 0, sizeof(auditd_conn
));
1468 spin_lock_init(&auditd_conn
.lock
);
1470 skb_queue_head_init(&audit_queue
);
1471 skb_queue_head_init(&audit_retry_queue
);
1472 skb_queue_head_init(&audit_hold_queue
);
1474 for (i
= 0; i
< AUDIT_INODE_BUCKETS
; i
++)
1475 INIT_LIST_HEAD(&audit_inode_hash
[i
]);
1477 pr_info("initializing netlink subsys (%s)\n",
1478 audit_default
? "enabled" : "disabled");
1479 register_pernet_subsys(&audit_net_ops
);
1481 audit_initialized
= AUDIT_INITIALIZED
;
1482 audit_enabled
= audit_default
;
1483 audit_ever_enabled
|= !!audit_default
;
1485 kauditd_task
= kthread_run(kauditd_thread
, NULL
, "kauditd");
1486 if (IS_ERR(kauditd_task
)) {
1487 int err
= PTR_ERR(kauditd_task
);
1488 panic("audit: failed to start the kauditd thread (%d)\n", err
);
1491 audit_log(NULL
, GFP_KERNEL
, AUDIT_KERNEL
, "initialized");
1495 __initcall(audit_init
);
1497 /* Process kernel command-line parameter at boot time. audit=0 or audit=1. */
1498 static int __init
audit_enable(char *str
)
1500 audit_default
= !!simple_strtol(str
, NULL
, 0);
1502 audit_initialized
= AUDIT_DISABLED
;
1504 pr_info("%s\n", audit_default
?
1505 "enabled (after initialization)" : "disabled (until reboot)");
1509 __setup("audit=", audit_enable
);
1511 /* Process kernel command-line parameter at boot time.
1512 * audit_backlog_limit=<n> */
1513 static int __init
audit_backlog_limit_set(char *str
)
1515 u32 audit_backlog_limit_arg
;
1517 pr_info("audit_backlog_limit: ");
1518 if (kstrtouint(str
, 0, &audit_backlog_limit_arg
)) {
1519 pr_cont("using default of %u, unable to parse %s\n",
1520 audit_backlog_limit
, str
);
1524 audit_backlog_limit
= audit_backlog_limit_arg
;
1525 pr_cont("%d\n", audit_backlog_limit
);
1529 __setup("audit_backlog_limit=", audit_backlog_limit_set
);
1531 static void audit_buffer_free(struct audit_buffer
*ab
)
1533 unsigned long flags
;
1539 spin_lock_irqsave(&audit_freelist_lock
, flags
);
1540 if (audit_freelist_count
> AUDIT_MAXFREE
)
1543 audit_freelist_count
++;
1544 list_add(&ab
->list
, &audit_freelist
);
1546 spin_unlock_irqrestore(&audit_freelist_lock
, flags
);
1549 static struct audit_buffer
* audit_buffer_alloc(struct audit_context
*ctx
,
1550 gfp_t gfp_mask
, int type
)
1552 unsigned long flags
;
1553 struct audit_buffer
*ab
= NULL
;
1554 struct nlmsghdr
*nlh
;
1556 spin_lock_irqsave(&audit_freelist_lock
, flags
);
1557 if (!list_empty(&audit_freelist
)) {
1558 ab
= list_entry(audit_freelist
.next
,
1559 struct audit_buffer
, list
);
1560 list_del(&ab
->list
);
1561 --audit_freelist_count
;
1563 spin_unlock_irqrestore(&audit_freelist_lock
, flags
);
1566 ab
= kmalloc(sizeof(*ab
), gfp_mask
);
1572 ab
->gfp_mask
= gfp_mask
;
1574 ab
->skb
= nlmsg_new(AUDIT_BUFSIZ
, gfp_mask
);
1578 nlh
= nlmsg_put(ab
->skb
, 0, 0, type
, 0, 0);
1588 audit_buffer_free(ab
);
1593 * audit_serial - compute a serial number for the audit record
1595 * Compute a serial number for the audit record. Audit records are
1596 * written to user-space as soon as they are generated, so a complete
1597 * audit record may be written in several pieces. The timestamp of the
1598 * record and this serial number are used by the user-space tools to
1599 * determine which pieces belong to the same audit record. The
1600 * (timestamp,serial) tuple is unique for each syscall and is live from
1601 * syscall entry to syscall exit.
1603 * NOTE: Another possibility is to store the formatted records off the
1604 * audit context (for those records that have a context), and emit them
1605 * all at syscall exit. However, this could delay the reporting of
1606 * significant errors until syscall exit (or never, if the system
1609 unsigned int audit_serial(void)
1611 static atomic_t serial
= ATOMIC_INIT(0);
1613 return atomic_add_return(1, &serial
);
1616 static inline void audit_get_stamp(struct audit_context
*ctx
,
1617 struct timespec
*t
, unsigned int *serial
)
1619 if (!ctx
|| !auditsc_get_stamp(ctx
, t
, serial
)) {
1621 *serial
= audit_serial();
1626 * audit_log_start - obtain an audit buffer
1627 * @ctx: audit_context (may be NULL)
1628 * @gfp_mask: type of allocation
1629 * @type: audit message type
1631 * Returns audit_buffer pointer on success or NULL on error.
1633 * Obtain an audit buffer. This routine does locking to obtain the
1634 * audit buffer, but then no locking is required for calls to
1635 * audit_log_*format. If the task (ctx) is a task that is currently in a
1636 * syscall, then the syscall is marked as auditable and an audit record
1637 * will be written at syscall exit. If there is no associated task, then
1638 * task context (ctx) should be NULL.
1640 struct audit_buffer
*audit_log_start(struct audit_context
*ctx
, gfp_t gfp_mask
,
1643 struct audit_buffer
*ab
;
1645 unsigned int uninitialized_var(serial
);
1647 if (audit_initialized
!= AUDIT_INITIALIZED
)
1650 if (unlikely(!audit_filter(type
, AUDIT_FILTER_TYPE
)))
1653 /* NOTE: don't ever fail/sleep on these two conditions:
1654 * 1. auditd generated record - since we need auditd to drain the
1655 * queue; also, when we are checking for auditd, compare PIDs using
1656 * task_tgid_vnr() since auditd_pid is set in audit_receive_msg()
1657 * using a PID anchored in the caller's namespace
1658 * 2. generator holding the audit_cmd_mutex - we don't want to block
1659 * while holding the mutex */
1660 if (!(auditd_test_task(current
) ||
1661 (current
== __mutex_owner(&audit_cmd_mutex
)))) {
1662 long stime
= audit_backlog_wait_time
;
1664 while (audit_backlog_limit
&&
1665 (skb_queue_len(&audit_queue
) > audit_backlog_limit
)) {
1666 /* wake kauditd to try and flush the queue */
1667 wake_up_interruptible(&kauditd_wait
);
1669 /* sleep if we are allowed and we haven't exhausted our
1670 * backlog wait limit */
1671 if (gfpflags_allow_blocking(gfp_mask
) && (stime
> 0)) {
1672 DECLARE_WAITQUEUE(wait
, current
);
1674 add_wait_queue_exclusive(&audit_backlog_wait
,
1676 set_current_state(TASK_UNINTERRUPTIBLE
);
1677 stime
= schedule_timeout(stime
);
1678 remove_wait_queue(&audit_backlog_wait
, &wait
);
1680 if (audit_rate_check() && printk_ratelimit())
1681 pr_warn("audit_backlog=%d > audit_backlog_limit=%d\n",
1682 skb_queue_len(&audit_queue
),
1683 audit_backlog_limit
);
1684 audit_log_lost("backlog limit exceeded");
1690 ab
= audit_buffer_alloc(ctx
, gfp_mask
, type
);
1692 audit_log_lost("out of memory in audit_log_start");
1696 audit_get_stamp(ab
->ctx
, &t
, &serial
);
1697 audit_log_format(ab
, "audit(%lu.%03lu:%u): ",
1698 t
.tv_sec
, t
.tv_nsec
/1000000, serial
);
1704 * audit_expand - expand skb in the audit buffer
1706 * @extra: space to add at tail of the skb
1708 * Returns 0 (no space) on failed expansion, or available space if
1711 static inline int audit_expand(struct audit_buffer
*ab
, int extra
)
1713 struct sk_buff
*skb
= ab
->skb
;
1714 int oldtail
= skb_tailroom(skb
);
1715 int ret
= pskb_expand_head(skb
, 0, extra
, ab
->gfp_mask
);
1716 int newtail
= skb_tailroom(skb
);
1719 audit_log_lost("out of memory in audit_expand");
1723 skb
->truesize
+= newtail
- oldtail
;
1728 * Format an audit message into the audit buffer. If there isn't enough
1729 * room in the audit buffer, more room will be allocated and vsnprint
1730 * will be called a second time. Currently, we assume that a printk
1731 * can't format message larger than 1024 bytes, so we don't either.
1733 static void audit_log_vformat(struct audit_buffer
*ab
, const char *fmt
,
1737 struct sk_buff
*skb
;
1745 avail
= skb_tailroom(skb
);
1747 avail
= audit_expand(ab
, AUDIT_BUFSIZ
);
1751 va_copy(args2
, args
);
1752 len
= vsnprintf(skb_tail_pointer(skb
), avail
, fmt
, args
);
1754 /* The printk buffer is 1024 bytes long, so if we get
1755 * here and AUDIT_BUFSIZ is at least 1024, then we can
1756 * log everything that printk could have logged. */
1757 avail
= audit_expand(ab
,
1758 max_t(unsigned, AUDIT_BUFSIZ
, 1+len
-avail
));
1761 len
= vsnprintf(skb_tail_pointer(skb
), avail
, fmt
, args2
);
1772 * audit_log_format - format a message into the audit buffer.
1774 * @fmt: format string
1775 * @...: optional parameters matching @fmt string
1777 * All the work is done in audit_log_vformat.
1779 void audit_log_format(struct audit_buffer
*ab
, const char *fmt
, ...)
1785 va_start(args
, fmt
);
1786 audit_log_vformat(ab
, fmt
, args
);
1791 * audit_log_hex - convert a buffer to hex and append it to the audit skb
1792 * @ab: the audit_buffer
1793 * @buf: buffer to convert to hex
1794 * @len: length of @buf to be converted
1796 * No return value; failure to expand is silently ignored.
1798 * This function will take the passed buf and convert it into a string of
1799 * ascii hex digits. The new string is placed onto the skb.
1801 void audit_log_n_hex(struct audit_buffer
*ab
, const unsigned char *buf
,
1804 int i
, avail
, new_len
;
1806 struct sk_buff
*skb
;
1813 avail
= skb_tailroom(skb
);
1815 if (new_len
>= avail
) {
1816 /* Round the buffer request up to the next multiple */
1817 new_len
= AUDIT_BUFSIZ
*(((new_len
-avail
)/AUDIT_BUFSIZ
) + 1);
1818 avail
= audit_expand(ab
, new_len
);
1823 ptr
= skb_tail_pointer(skb
);
1824 for (i
= 0; i
< len
; i
++)
1825 ptr
= hex_byte_pack_upper(ptr
, buf
[i
]);
1827 skb_put(skb
, len
<< 1); /* new string is twice the old string */
1831 * Format a string of no more than slen characters into the audit buffer,
1832 * enclosed in quote marks.
1834 void audit_log_n_string(struct audit_buffer
*ab
, const char *string
,
1839 struct sk_buff
*skb
;
1846 avail
= skb_tailroom(skb
);
1847 new_len
= slen
+ 3; /* enclosing quotes + null terminator */
1848 if (new_len
> avail
) {
1849 avail
= audit_expand(ab
, new_len
);
1853 ptr
= skb_tail_pointer(skb
);
1855 memcpy(ptr
, string
, slen
);
1859 skb_put(skb
, slen
+ 2); /* don't include null terminator */
1863 * audit_string_contains_control - does a string need to be logged in hex
1864 * @string: string to be checked
1865 * @len: max length of the string to check
1867 bool audit_string_contains_control(const char *string
, size_t len
)
1869 const unsigned char *p
;
1870 for (p
= string
; p
< (const unsigned char *)string
+ len
; p
++) {
1871 if (*p
== '"' || *p
< 0x21 || *p
> 0x7e)
1878 * audit_log_n_untrustedstring - log a string that may contain random characters
1880 * @len: length of string (not including trailing null)
1881 * @string: string to be logged
1883 * This code will escape a string that is passed to it if the string
1884 * contains a control character, unprintable character, double quote mark,
1885 * or a space. Unescaped strings will start and end with a double quote mark.
1886 * Strings that are escaped are printed in hex (2 digits per char).
1888 * The caller specifies the number of characters in the string to log, which may
1889 * or may not be the entire string.
1891 void audit_log_n_untrustedstring(struct audit_buffer
*ab
, const char *string
,
1894 if (audit_string_contains_control(string
, len
))
1895 audit_log_n_hex(ab
, string
, len
);
1897 audit_log_n_string(ab
, string
, len
);
1901 * audit_log_untrustedstring - log a string that may contain random characters
1903 * @string: string to be logged
1905 * Same as audit_log_n_untrustedstring(), except that strlen is used to
1906 * determine string length.
1908 void audit_log_untrustedstring(struct audit_buffer
*ab
, const char *string
)
1910 audit_log_n_untrustedstring(ab
, string
, strlen(string
));
1913 /* This is a helper-function to print the escaped d_path */
1914 void audit_log_d_path(struct audit_buffer
*ab
, const char *prefix
,
1915 const struct path
*path
)
1920 audit_log_format(ab
, "%s", prefix
);
1922 /* We will allow 11 spaces for ' (deleted)' to be appended */
1923 pathname
= kmalloc(PATH_MAX
+11, ab
->gfp_mask
);
1925 audit_log_string(ab
, "<no_memory>");
1928 p
= d_path(path
, pathname
, PATH_MAX
+11);
1929 if (IS_ERR(p
)) { /* Should never happen since we send PATH_MAX */
1930 /* FIXME: can we save some information here? */
1931 audit_log_string(ab
, "<too_long>");
1933 audit_log_untrustedstring(ab
, p
);
1937 void audit_log_session_info(struct audit_buffer
*ab
)
1939 unsigned int sessionid
= audit_get_sessionid(current
);
1940 uid_t auid
= from_kuid(&init_user_ns
, audit_get_loginuid(current
));
1942 audit_log_format(ab
, " auid=%u ses=%u", auid
, sessionid
);
1945 void audit_log_key(struct audit_buffer
*ab
, char *key
)
1947 audit_log_format(ab
, " key=");
1949 audit_log_untrustedstring(ab
, key
);
1951 audit_log_format(ab
, "(null)");
1954 void audit_log_cap(struct audit_buffer
*ab
, char *prefix
, kernel_cap_t
*cap
)
1958 audit_log_format(ab
, " %s=", prefix
);
1959 CAP_FOR_EACH_U32(i
) {
1960 audit_log_format(ab
, "%08x",
1961 cap
->cap
[CAP_LAST_U32
- i
]);
1965 static void audit_log_fcaps(struct audit_buffer
*ab
, struct audit_names
*name
)
1967 kernel_cap_t
*perm
= &name
->fcap
.permitted
;
1968 kernel_cap_t
*inh
= &name
->fcap
.inheritable
;
1971 if (!cap_isclear(*perm
)) {
1972 audit_log_cap(ab
, "cap_fp", perm
);
1975 if (!cap_isclear(*inh
)) {
1976 audit_log_cap(ab
, "cap_fi", inh
);
1981 audit_log_format(ab
, " cap_fe=%d cap_fver=%x",
1982 name
->fcap
.fE
, name
->fcap_ver
);
1985 static inline int audit_copy_fcaps(struct audit_names
*name
,
1986 const struct dentry
*dentry
)
1988 struct cpu_vfs_cap_data caps
;
1994 rc
= get_vfs_caps_from_disk(dentry
, &caps
);
1998 name
->fcap
.permitted
= caps
.permitted
;
1999 name
->fcap
.inheritable
= caps
.inheritable
;
2000 name
->fcap
.fE
= !!(caps
.magic_etc
& VFS_CAP_FLAGS_EFFECTIVE
);
2001 name
->fcap_ver
= (caps
.magic_etc
& VFS_CAP_REVISION_MASK
) >>
2002 VFS_CAP_REVISION_SHIFT
;
2007 /* Copy inode data into an audit_names. */
2008 void audit_copy_inode(struct audit_names
*name
, const struct dentry
*dentry
,
2009 struct inode
*inode
)
2011 name
->ino
= inode
->i_ino
;
2012 name
->dev
= inode
->i_sb
->s_dev
;
2013 name
->mode
= inode
->i_mode
;
2014 name
->uid
= inode
->i_uid
;
2015 name
->gid
= inode
->i_gid
;
2016 name
->rdev
= inode
->i_rdev
;
2017 security_inode_getsecid(inode
, &name
->osid
);
2018 audit_copy_fcaps(name
, dentry
);
2022 * audit_log_name - produce AUDIT_PATH record from struct audit_names
2023 * @context: audit_context for the task
2024 * @n: audit_names structure with reportable details
2025 * @path: optional path to report instead of audit_names->name
2026 * @record_num: record number to report when handling a list of names
2027 * @call_panic: optional pointer to int that will be updated if secid fails
2029 void audit_log_name(struct audit_context
*context
, struct audit_names
*n
,
2030 const struct path
*path
, int record_num
, int *call_panic
)
2032 struct audit_buffer
*ab
;
2033 ab
= audit_log_start(context
, GFP_KERNEL
, AUDIT_PATH
);
2037 audit_log_format(ab
, "item=%d", record_num
);
2040 audit_log_d_path(ab
, " name=", path
);
2042 switch (n
->name_len
) {
2043 case AUDIT_NAME_FULL
:
2044 /* log the full path */
2045 audit_log_format(ab
, " name=");
2046 audit_log_untrustedstring(ab
, n
->name
->name
);
2049 /* name was specified as a relative path and the
2050 * directory component is the cwd */
2051 audit_log_d_path(ab
, " name=", &context
->pwd
);
2054 /* log the name's directory component */
2055 audit_log_format(ab
, " name=");
2056 audit_log_n_untrustedstring(ab
, n
->name
->name
,
2060 audit_log_format(ab
, " name=(null)");
2062 if (n
->ino
!= AUDIT_INO_UNSET
)
2063 audit_log_format(ab
, " inode=%lu"
2064 " dev=%02x:%02x mode=%#ho"
2065 " ouid=%u ogid=%u rdev=%02x:%02x",
2070 from_kuid(&init_user_ns
, n
->uid
),
2071 from_kgid(&init_user_ns
, n
->gid
),
2077 if (security_secid_to_secctx(
2078 n
->osid
, &ctx
, &len
)) {
2079 audit_log_format(ab
, " osid=%u", n
->osid
);
2083 audit_log_format(ab
, " obj=%s", ctx
);
2084 security_release_secctx(ctx
, len
);
2088 /* log the audit_names record type */
2089 audit_log_format(ab
, " nametype=");
2091 case AUDIT_TYPE_NORMAL
:
2092 audit_log_format(ab
, "NORMAL");
2094 case AUDIT_TYPE_PARENT
:
2095 audit_log_format(ab
, "PARENT");
2097 case AUDIT_TYPE_CHILD_DELETE
:
2098 audit_log_format(ab
, "DELETE");
2100 case AUDIT_TYPE_CHILD_CREATE
:
2101 audit_log_format(ab
, "CREATE");
2104 audit_log_format(ab
, "UNKNOWN");
2108 audit_log_fcaps(ab
, n
);
2112 int audit_log_task_context(struct audit_buffer
*ab
)
2119 security_task_getsecid(current
, &sid
);
2123 error
= security_secid_to_secctx(sid
, &ctx
, &len
);
2125 if (error
!= -EINVAL
)
2130 audit_log_format(ab
, " subj=%s", ctx
);
2131 security_release_secctx(ctx
, len
);
2135 audit_panic("error in audit_log_task_context");
2138 EXPORT_SYMBOL(audit_log_task_context
);
2140 void audit_log_d_path_exe(struct audit_buffer
*ab
,
2141 struct mm_struct
*mm
)
2143 struct file
*exe_file
;
2148 exe_file
= get_mm_exe_file(mm
);
2152 audit_log_d_path(ab
, " exe=", &exe_file
->f_path
);
2156 audit_log_format(ab
, " exe=(null)");
2159 struct tty_struct
*audit_get_tty(struct task_struct
*tsk
)
2161 struct tty_struct
*tty
= NULL
;
2162 unsigned long flags
;
2164 spin_lock_irqsave(&tsk
->sighand
->siglock
, flags
);
2166 tty
= tty_kref_get(tsk
->signal
->tty
);
2167 spin_unlock_irqrestore(&tsk
->sighand
->siglock
, flags
);
2171 void audit_put_tty(struct tty_struct
*tty
)
2176 void audit_log_task_info(struct audit_buffer
*ab
, struct task_struct
*tsk
)
2178 const struct cred
*cred
;
2179 char comm
[sizeof(tsk
->comm
)];
2180 struct tty_struct
*tty
;
2185 /* tsk == current */
2186 cred
= current_cred();
2187 tty
= audit_get_tty(tsk
);
2188 audit_log_format(ab
,
2189 " ppid=%d pid=%d auid=%u uid=%u gid=%u"
2190 " euid=%u suid=%u fsuid=%u"
2191 " egid=%u sgid=%u fsgid=%u tty=%s ses=%u",
2194 from_kuid(&init_user_ns
, audit_get_loginuid(tsk
)),
2195 from_kuid(&init_user_ns
, cred
->uid
),
2196 from_kgid(&init_user_ns
, cred
->gid
),
2197 from_kuid(&init_user_ns
, cred
->euid
),
2198 from_kuid(&init_user_ns
, cred
->suid
),
2199 from_kuid(&init_user_ns
, cred
->fsuid
),
2200 from_kgid(&init_user_ns
, cred
->egid
),
2201 from_kgid(&init_user_ns
, cred
->sgid
),
2202 from_kgid(&init_user_ns
, cred
->fsgid
),
2203 tty
? tty_name(tty
) : "(none)",
2204 audit_get_sessionid(tsk
));
2206 audit_log_format(ab
, " comm=");
2207 audit_log_untrustedstring(ab
, get_task_comm(comm
, tsk
));
2208 audit_log_d_path_exe(ab
, tsk
->mm
);
2209 audit_log_task_context(ab
);
2211 EXPORT_SYMBOL(audit_log_task_info
);
2214 * audit_log_link_denied - report a link restriction denial
2215 * @operation: specific link operation
2216 * @link: the path that triggered the restriction
2218 void audit_log_link_denied(const char *operation
, const struct path
*link
)
2220 struct audit_buffer
*ab
;
2221 struct audit_names
*name
;
2223 name
= kzalloc(sizeof(*name
), GFP_NOFS
);
2227 /* Generate AUDIT_ANOM_LINK with subject, operation, outcome. */
2228 ab
= audit_log_start(current
->audit_context
, GFP_KERNEL
,
2232 audit_log_format(ab
, "op=%s", operation
);
2233 audit_log_task_info(ab
, current
);
2234 audit_log_format(ab
, " res=0");
2237 /* Generate AUDIT_PATH record with object. */
2238 name
->type
= AUDIT_TYPE_NORMAL
;
2239 audit_copy_inode(name
, link
->dentry
, d_backing_inode(link
->dentry
));
2240 audit_log_name(current
->audit_context
, name
, link
, 0, NULL
);
2246 * audit_log_end - end one audit record
2247 * @ab: the audit_buffer
2249 * We can not do a netlink send inside an irq context because it blocks (last
2250 * arg, flags, is not set to MSG_DONTWAIT), so the audit buffer is placed on a
2251 * queue and a tasklet is scheduled to remove them from the queue outside the
2252 * irq context. May be called in any context.
2254 void audit_log_end(struct audit_buffer
*ab
)
2256 struct sk_buff
*skb
;
2257 struct nlmsghdr
*nlh
;
2262 if (audit_rate_check()) {
2266 /* setup the netlink header, see the comments in
2267 * kauditd_send_multicast_skb() for length quirks */
2268 nlh
= nlmsg_hdr(skb
);
2269 nlh
->nlmsg_len
= skb
->len
- NLMSG_HDRLEN
;
2271 /* queue the netlink packet and poke the kauditd thread */
2272 skb_queue_tail(&audit_queue
, skb
);
2273 wake_up_interruptible(&kauditd_wait
);
2275 audit_log_lost("rate limit exceeded");
2277 audit_buffer_free(ab
);
2281 * audit_log - Log an audit record
2282 * @ctx: audit context
2283 * @gfp_mask: type of allocation
2284 * @type: audit message type
2285 * @fmt: format string to use
2286 * @...: variable parameters matching the format string
2288 * This is a convenience function that calls audit_log_start,
2289 * audit_log_vformat, and audit_log_end. It may be called
2292 void audit_log(struct audit_context
*ctx
, gfp_t gfp_mask
, int type
,
2293 const char *fmt
, ...)
2295 struct audit_buffer
*ab
;
2298 ab
= audit_log_start(ctx
, gfp_mask
, type
);
2300 va_start(args
, fmt
);
2301 audit_log_vformat(ab
, fmt
, args
);
2307 #ifdef CONFIG_SECURITY
2309 * audit_log_secctx - Converts and logs SELinux context
2311 * @secid: security number
2313 * This is a helper function that calls security_secid_to_secctx to convert
2314 * secid to secctx and then adds the (converted) SELinux context to the audit
2315 * log by calling audit_log_format, thus also preventing leak of internal secid
2316 * to userspace. If secid cannot be converted audit_panic is called.
2318 void audit_log_secctx(struct audit_buffer
*ab
, u32 secid
)
2323 if (security_secid_to_secctx(secid
, &secctx
, &len
)) {
2324 audit_panic("Cannot convert secid to context");
2326 audit_log_format(ab
, " obj=%s", secctx
);
2327 security_release_secctx(secctx
, len
);
2330 EXPORT_SYMBOL(audit_log_secctx
);
2333 EXPORT_SYMBOL(audit_log_start
);
2334 EXPORT_SYMBOL(audit_log_end
);
2335 EXPORT_SYMBOL(audit_log_format
);
2336 EXPORT_SYMBOL(audit_log
);