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
4 *
5 * Copyright 2003-2007 Red Hat Inc., Durham, North Carolina.
6 * All Rights Reserved.
7 *
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.
12 *
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.
17 *
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
21 *
22 * Written by Rickard E. (Rik) Faith <faith@redhat.com>
23 *
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
29 * generation time):
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
36 * current syscall).
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.
40 *
41 * Audit userspace, documentation, tests, and bug/issue trackers:
42 * https://github.com/linux-audit
43 */
44
45#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
46
47#include <linux/file.h>
48#include <linux/init.h>
49#include <linux/types.h>
50#include <linux/atomic.h>
51#include <linux/mm.h>
52#include <linux/export.h>
53#include <linux/slab.h>
54#include <linux/err.h>
55#include <linux/kthread.h>
56#include <linux/kernel.h>
57#include <linux/syscalls.h>
58#include <linux/spinlock.h>
59#include <linux/rcupdate.h>
60#include <linux/mutex.h>
61#include <linux/gfp.h>
62#include <linux/pid.h>
63#include <linux/slab.h>
64
65#include <linux/audit.h>
66
67#include <net/sock.h>
68#include <net/netlink.h>
69#include <linux/skbuff.h>
70#ifdef CONFIG_SECURITY
71#include <linux/security.h>
72#endif
73#include <linux/freezer.h>
74#include <linux/pid_namespace.h>
75#include <net/netns/generic.h>
76
77#include "audit.h"
78
79/* No auditing will take place until audit_initialized == AUDIT_INITIALIZED.
80 * (Initialization happens after skb_init is called.) */
81#define AUDIT_DISABLED -1
82#define AUDIT_UNINITIALIZED 0
83#define AUDIT_INITIALIZED 1
84static int audit_initialized;
85
86u32 audit_enabled = AUDIT_OFF;
87bool audit_ever_enabled = !!AUDIT_OFF;
88
89EXPORT_SYMBOL_GPL(audit_enabled);
90
91/* Default state when kernel boots without any parameters. */
92static u32 audit_default = AUDIT_OFF;
93
94/* If auditing cannot proceed, audit_failure selects what happens. */
95static u32 audit_failure = AUDIT_FAIL_PRINTK;
96
97/* private audit network namespace index */
98static unsigned int audit_net_id;
99
100/**
101 * struct audit_net - audit private network namespace data
102 * @sk: communication socket
103 */
104struct audit_net {
105 struct sock *sk;
106};
107
108/**
109 * struct auditd_connection - kernel/auditd connection state
110 * @pid: auditd PID
111 * @portid: netlink portid
112 * @net: the associated network namespace
113 * @rcu: RCU head
114 *
115 * Description:
116 * This struct is RCU protected; you must either hold the RCU lock for reading
117 * or the associated spinlock for writing.
118 */
119static struct auditd_connection {
120 struct pid *pid;
121 u32 portid;
122 struct net *net;
123 struct rcu_head rcu;
124} *auditd_conn = NULL;
125static DEFINE_SPINLOCK(auditd_conn_lock);
126
127/* If audit_rate_limit is non-zero, limit the rate of sending audit records
128 * to that number per second. This prevents DoS attacks, but results in
129 * audit records being dropped. */
130static u32 audit_rate_limit;
131
132/* Number of outstanding audit_buffers allowed.
133 * When set to zero, this means unlimited. */
134static u32 audit_backlog_limit = 64;
135#define AUDIT_BACKLOG_WAIT_TIME (60 * HZ)
136static u32 audit_backlog_wait_time = AUDIT_BACKLOG_WAIT_TIME;
137
138/* The identity of the user shutting down the audit system. */
139kuid_t audit_sig_uid = INVALID_UID;
140pid_t audit_sig_pid = -1;
141u32 audit_sig_sid = 0;
142
143/* Records can be lost in several ways:
144 0) [suppressed in audit_alloc]
145 1) out of memory in audit_log_start [kmalloc of struct audit_buffer]
146 2) out of memory in audit_log_move [alloc_skb]
147 3) suppressed due to audit_rate_limit
148 4) suppressed due to audit_backlog_limit
149*/
150static atomic_t audit_lost = ATOMIC_INIT(0);
151
152/* Hash for inode-based rules */
153struct list_head audit_inode_hash[AUDIT_INODE_BUCKETS];
154
155static struct kmem_cache *audit_buffer_cache;
156
157/* queue msgs to send via kauditd_task */
158static struct sk_buff_head audit_queue;
159/* queue msgs due to temporary unicast send problems */
160static struct sk_buff_head audit_retry_queue;
161/* queue msgs waiting for new auditd connection */
162static struct sk_buff_head audit_hold_queue;
163
164/* queue servicing thread */
165static struct task_struct *kauditd_task;
166static DECLARE_WAIT_QUEUE_HEAD(kauditd_wait);
167
168/* waitqueue for callers who are blocked on the audit backlog */
169static DECLARE_WAIT_QUEUE_HEAD(audit_backlog_wait);
170
171static struct audit_features af = {.vers = AUDIT_FEATURE_VERSION,
172 .mask = -1,
173 .features = 0,
174 .lock = 0,};
175
176static char *audit_feature_names[2] = {
177 "only_unset_loginuid",
178 "loginuid_immutable",
179};
180
181/**
182 * struct audit_ctl_mutex - serialize requests from userspace
183 * @lock: the mutex used for locking
184 * @owner: the task which owns the lock
185 *
186 * Description:
187 * This is the lock struct used to ensure we only process userspace requests
188 * in an orderly fashion. We can't simply use a mutex/lock here because we
189 * need to track lock ownership so we don't end up blocking the lock owner in
190 * audit_log_start() or similar.
191 */
192static struct audit_ctl_mutex {
193 struct mutex lock;
194 void *owner;
195} audit_cmd_mutex;
196
197/* AUDIT_BUFSIZ is the size of the temporary buffer used for formatting
198 * audit records. Since printk uses a 1024 byte buffer, this buffer
199 * should be at least that large. */
200#define AUDIT_BUFSIZ 1024
201
202/* The audit_buffer is used when formatting an audit record. The caller
203 * locks briefly to get the record off the freelist or to allocate the
204 * buffer, and locks briefly to send the buffer to the netlink layer or
205 * to place it on a transmit queue. Multiple audit_buffers can be in
206 * use simultaneously. */
207struct audit_buffer {
208 struct sk_buff *skb; /* formatted skb ready to send */
209 struct audit_context *ctx; /* NULL or associated context */
210 gfp_t gfp_mask;
211};
212
213struct audit_reply {
214 __u32 portid;
215 struct net *net;
216 struct sk_buff *skb;
217};
218
219/**
220 * auditd_test_task - Check to see if a given task is an audit daemon
221 * @task: the task to check
222 *
223 * Description:
224 * Return 1 if the task is a registered audit daemon, 0 otherwise.
225 */
226int auditd_test_task(struct task_struct *task)
227{
228 int rc;
229 struct auditd_connection *ac;
230
231 rcu_read_lock();
232 ac = rcu_dereference(auditd_conn);
233 rc = (ac && ac->pid == task_tgid(task) ? 1 : 0);
234 rcu_read_unlock();
235
236 return rc;
237}
238
239/**
240 * audit_ctl_lock - Take the audit control lock
241 */
242void audit_ctl_lock(void)
243{
244 mutex_lock(&audit_cmd_mutex.lock);
245 audit_cmd_mutex.owner = current;
246}
247
248/**
249 * audit_ctl_unlock - Drop the audit control lock
250 */
251void audit_ctl_unlock(void)
252{
253 audit_cmd_mutex.owner = NULL;
254 mutex_unlock(&audit_cmd_mutex.lock);
255}
256
257/**
258 * audit_ctl_owner_current - Test to see if the current task owns the lock
259 *
260 * Description:
261 * Return true if the current task owns the audit control lock, false if it
262 * doesn't own the lock.
263 */
264static bool audit_ctl_owner_current(void)
265{
266 return (current == audit_cmd_mutex.owner);
267}
268
269/**
270 * auditd_pid_vnr - Return the auditd PID relative to the namespace
271 *
272 * Description:
273 * Returns the PID in relation to the namespace, 0 on failure.
274 */
275static pid_t auditd_pid_vnr(void)
276{
277 pid_t pid;
278 const struct auditd_connection *ac;
279
280 rcu_read_lock();
281 ac = rcu_dereference(auditd_conn);
282 if (!ac || !ac->pid)
283 pid = 0;
284 else
285 pid = pid_vnr(ac->pid);
286 rcu_read_unlock();
287
288 return pid;
289}
290
291/**
292 * audit_get_sk - Return the audit socket for the given network namespace
293 * @net: the destination network namespace
294 *
295 * Description:
296 * Returns the sock pointer if valid, NULL otherwise. The caller must ensure
297 * that a reference is held for the network namespace while the sock is in use.
298 */
299static struct sock *audit_get_sk(const struct net *net)
300{
301 struct audit_net *aunet;
302
303 if (!net)
304 return NULL;
305
306 aunet = net_generic(net, audit_net_id);
307 return aunet->sk;
308}
309
310void audit_panic(const char *message)
311{
312 switch (audit_failure) {
313 case AUDIT_FAIL_SILENT:
314 break;
315 case AUDIT_FAIL_PRINTK:
316 if (printk_ratelimit())
317 pr_err("%s\n", message);
318 break;
319 case AUDIT_FAIL_PANIC:
320 panic("audit: %s\n", message);
321 break;
322 }
323}
324
325static inline int audit_rate_check(void)
326{
327 static unsigned long last_check = 0;
328 static int messages = 0;
329 static DEFINE_SPINLOCK(lock);
330 unsigned long flags;
331 unsigned long now;
332 unsigned long elapsed;
333 int retval = 0;
334
335 if (!audit_rate_limit) return 1;
336
337 spin_lock_irqsave(&lock, flags);
338 if (++messages < audit_rate_limit) {
339 retval = 1;
340 } else {
341 now = jiffies;
342 elapsed = now - last_check;
343 if (elapsed > HZ) {
344 last_check = now;
345 messages = 0;
346 retval = 1;
347 }
348 }
349 spin_unlock_irqrestore(&lock, flags);
350
351 return retval;
352}
353
354/**
355 * audit_log_lost - conditionally log lost audit message event
356 * @message: the message stating reason for lost audit message
357 *
358 * Emit at least 1 message per second, even if audit_rate_check is
359 * throttling.
360 * Always increment the lost messages counter.
361*/
362void audit_log_lost(const char *message)
363{
364 static unsigned long last_msg = 0;
365 static DEFINE_SPINLOCK(lock);
366 unsigned long flags;
367 unsigned long now;
368 int print;
369
370 atomic_inc(&audit_lost);
371
372 print = (audit_failure == AUDIT_FAIL_PANIC || !audit_rate_limit);
373
374 if (!print) {
375 spin_lock_irqsave(&lock, flags);
376 now = jiffies;
377 if (now - last_msg > HZ) {
378 print = 1;
379 last_msg = now;
380 }
381 spin_unlock_irqrestore(&lock, flags);
382 }
383
384 if (print) {
385 if (printk_ratelimit())
386 pr_warn("audit_lost=%u audit_rate_limit=%u audit_backlog_limit=%u\n",
387 atomic_read(&audit_lost),
388 audit_rate_limit,
389 audit_backlog_limit);
390 audit_panic(message);
391 }
392}
393
394static int audit_log_config_change(char *function_name, u32 new, u32 old,
395 int allow_changes)
396{
397 struct audit_buffer *ab;
398 int rc = 0;
399
400 ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
401 if (unlikely(!ab))
402 return rc;
403 audit_log_format(ab, "%s=%u old=%u", function_name, new, old);
404 audit_log_session_info(ab);
405 rc = audit_log_task_context(ab);
406 if (rc)
407 allow_changes = 0; /* Something weird, deny request */
408 audit_log_format(ab, " res=%d", allow_changes);
409 audit_log_end(ab);
410 return rc;
411}
412
413static int audit_do_config_change(char *function_name, u32 *to_change, u32 new)
414{
415 int allow_changes, rc = 0;
416 u32 old = *to_change;
417
418 /* check if we are locked */
419 if (audit_enabled == AUDIT_LOCKED)
420 allow_changes = 0;
421 else
422 allow_changes = 1;
423
424 if (audit_enabled != AUDIT_OFF) {
425 rc = audit_log_config_change(function_name, new, old, allow_changes);
426 if (rc)
427 allow_changes = 0;
428 }
429
430 /* If we are allowed, make the change */
431 if (allow_changes == 1)
432 *to_change = new;
433 /* Not allowed, update reason */
434 else if (rc == 0)
435 rc = -EPERM;
436 return rc;
437}
438
439static int audit_set_rate_limit(u32 limit)
440{
441 return audit_do_config_change("audit_rate_limit", &audit_rate_limit, limit);
442}
443
444static int audit_set_backlog_limit(u32 limit)
445{
446 return audit_do_config_change("audit_backlog_limit", &audit_backlog_limit, limit);
447}
448
449static int audit_set_backlog_wait_time(u32 timeout)
450{
451 return audit_do_config_change("audit_backlog_wait_time",
452 &audit_backlog_wait_time, timeout);
453}
454
455static int audit_set_enabled(u32 state)
456{
457 int rc;
458 if (state > AUDIT_LOCKED)
459 return -EINVAL;
460
461 rc = audit_do_config_change("audit_enabled", &audit_enabled, state);
462 if (!rc)
463 audit_ever_enabled |= !!state;
464
465 return rc;
466}
467
468static int audit_set_failure(u32 state)
469{
470 if (state != AUDIT_FAIL_SILENT
471 && state != AUDIT_FAIL_PRINTK
472 && state != AUDIT_FAIL_PANIC)
473 return -EINVAL;
474
475 return audit_do_config_change("audit_failure", &audit_failure, state);
476}
477
478/**
479 * auditd_conn_free - RCU helper to release an auditd connection struct
480 * @rcu: RCU head
481 *
482 * Description:
483 * Drop any references inside the auditd connection tracking struct and free
484 * the memory.
485 */
486static void auditd_conn_free(struct rcu_head *rcu)
487{
488 struct auditd_connection *ac;
489
490 ac = container_of(rcu, struct auditd_connection, rcu);
491 put_pid(ac->pid);
492 put_net(ac->net);
493 kfree(ac);
494}
495
496/**
497 * auditd_set - Set/Reset the auditd connection state
498 * @pid: auditd PID
499 * @portid: auditd netlink portid
500 * @net: auditd network namespace pointer
501 *
502 * Description:
503 * This function will obtain and drop network namespace references as
504 * necessary. Returns zero on success, negative values on failure.
505 */
506static int auditd_set(struct pid *pid, u32 portid, struct net *net)
507{
508 unsigned long flags;
509 struct auditd_connection *ac_old, *ac_new;
510
511 if (!pid || !net)
512 return -EINVAL;
513
514 ac_new = kzalloc(sizeof(*ac_new), GFP_KERNEL);
515 if (!ac_new)
516 return -ENOMEM;
517 ac_new->pid = get_pid(pid);
518 ac_new->portid = portid;
519 ac_new->net = get_net(net);
520
521 spin_lock_irqsave(&auditd_conn_lock, flags);
522 ac_old = rcu_dereference_protected(auditd_conn,
523 lockdep_is_held(&auditd_conn_lock));
524 rcu_assign_pointer(auditd_conn, ac_new);
525 spin_unlock_irqrestore(&auditd_conn_lock, flags);
526
527 if (ac_old)
528 call_rcu(&ac_old->rcu, auditd_conn_free);
529
530 return 0;
531}
532
533/**
534 * kauditd_print_skb - Print the audit record to the ring buffer
535 * @skb: audit record
536 *
537 * Whatever the reason, this packet may not make it to the auditd connection
538 * so write it via printk so the information isn't completely lost.
539 */
540static void kauditd_printk_skb(struct sk_buff *skb)
541{
542 struct nlmsghdr *nlh = nlmsg_hdr(skb);
543 char *data = nlmsg_data(nlh);
544
545 if (nlh->nlmsg_type != AUDIT_EOE && printk_ratelimit())
546 pr_notice("type=%d %s\n", nlh->nlmsg_type, data);
547}
548
549/**
550 * kauditd_rehold_skb - Handle a audit record send failure in the hold queue
551 * @skb: audit record
552 *
553 * Description:
554 * This should only be used by the kauditd_thread when it fails to flush the
555 * hold queue.
556 */
557static void kauditd_rehold_skb(struct sk_buff *skb)
558{
559 /* put the record back in the queue at the same place */
560 skb_queue_head(&audit_hold_queue, skb);
561}
562
563/**
564 * kauditd_hold_skb - Queue an audit record, waiting for auditd
565 * @skb: audit record
566 *
567 * Description:
568 * Queue the audit record, waiting for an instance of auditd. When this
569 * function is called we haven't given up yet on sending the record, but things
570 * are not looking good. The first thing we want to do is try to write the
571 * record via printk and then see if we want to try and hold on to the record
572 * and queue it, if we have room. If we want to hold on to the record, but we
573 * don't have room, record a record lost message.
574 */
575static void kauditd_hold_skb(struct sk_buff *skb)
576{
577 /* at this point it is uncertain if we will ever send this to auditd so
578 * try to send the message via printk before we go any further */
579 kauditd_printk_skb(skb);
580
581 /* can we just silently drop the message? */
582 if (!audit_default) {
583 kfree_skb(skb);
584 return;
585 }
586
587 /* if we have room, queue the message */
588 if (!audit_backlog_limit ||
589 skb_queue_len(&audit_hold_queue) < audit_backlog_limit) {
590 skb_queue_tail(&audit_hold_queue, skb);
591 return;
592 }
593
594 /* we have no other options - drop the message */
595 audit_log_lost("kauditd hold queue overflow");
596 kfree_skb(skb);
597}
598
599/**
600 * kauditd_retry_skb - Queue an audit record, attempt to send again to auditd
601 * @skb: audit record
602 *
603 * Description:
604 * Not as serious as kauditd_hold_skb() as we still have a connected auditd,
605 * but for some reason we are having problems sending it audit records so
606 * queue the given record and attempt to resend.
607 */
608static void kauditd_retry_skb(struct sk_buff *skb)
609{
610 /* NOTE: because records should only live in the retry queue for a
611 * short period of time, before either being sent or moved to the hold
612 * queue, we don't currently enforce a limit on this queue */
613 skb_queue_tail(&audit_retry_queue, skb);
614}
615
616/**
617 * auditd_reset - Disconnect the auditd connection
618 * @ac: auditd connection state
619 *
620 * Description:
621 * Break the auditd/kauditd connection and move all the queued records into the
622 * hold queue in case auditd reconnects. It is important to note that the @ac
623 * pointer should never be dereferenced inside this function as it may be NULL
624 * or invalid, you can only compare the memory address! If @ac is NULL then
625 * the connection will always be reset.
626 */
627static void auditd_reset(const struct auditd_connection *ac)
628{
629 unsigned long flags;
630 struct sk_buff *skb;
631 struct auditd_connection *ac_old;
632
633 /* if it isn't already broken, break the connection */
634 spin_lock_irqsave(&auditd_conn_lock, flags);
635 ac_old = rcu_dereference_protected(auditd_conn,
636 lockdep_is_held(&auditd_conn_lock));
637 if (ac && ac != ac_old) {
638 /* someone already registered a new auditd connection */
639 spin_unlock_irqrestore(&auditd_conn_lock, flags);
640 return;
641 }
642 rcu_assign_pointer(auditd_conn, NULL);
643 spin_unlock_irqrestore(&auditd_conn_lock, flags);
644
645 if (ac_old)
646 call_rcu(&ac_old->rcu, auditd_conn_free);
647
648 /* flush the retry queue to the hold queue, but don't touch the main
649 * queue since we need to process that normally for multicast */
650 while ((skb = skb_dequeue(&audit_retry_queue)))
651 kauditd_hold_skb(skb);
652}
653
654/**
655 * auditd_send_unicast_skb - Send a record via unicast to auditd
656 * @skb: audit record
657 *
658 * Description:
659 * Send a skb to the audit daemon, returns positive/zero values on success and
660 * negative values on failure; in all cases the skb will be consumed by this
661 * function. If the send results in -ECONNREFUSED the connection with auditd
662 * will be reset. This function may sleep so callers should not hold any locks
663 * where this would cause a problem.
664 */
665static int auditd_send_unicast_skb(struct sk_buff *skb)
666{
667 int rc;
668 u32 portid;
669 struct net *net;
670 struct sock *sk;
671 struct auditd_connection *ac;
672
673 /* NOTE: we can't call netlink_unicast while in the RCU section so
674 * take a reference to the network namespace and grab local
675 * copies of the namespace, the sock, and the portid; the
676 * namespace and sock aren't going to go away while we hold a
677 * reference and if the portid does become invalid after the RCU
678 * section netlink_unicast() should safely return an error */
679
680 rcu_read_lock();
681 ac = rcu_dereference(auditd_conn);
682 if (!ac) {
683 rcu_read_unlock();
684 kfree_skb(skb);
685 rc = -ECONNREFUSED;
686 goto err;
687 }
688 net = get_net(ac->net);
689 sk = audit_get_sk(net);
690 portid = ac->portid;
691 rcu_read_unlock();
692
693 rc = netlink_unicast(sk, skb, portid, 0);
694 put_net(net);
695 if (rc < 0)
696 goto err;
697
698 return rc;
699
700err:
701 if (ac && rc == -ECONNREFUSED)
702 auditd_reset(ac);
703 return rc;
704}
705
706/**
707 * kauditd_send_queue - Helper for kauditd_thread to flush skb queues
708 * @sk: the sending sock
709 * @portid: the netlink destination
710 * @queue: the skb queue to process
711 * @retry_limit: limit on number of netlink unicast failures
712 * @skb_hook: per-skb hook for additional processing
713 * @err_hook: hook called if the skb fails the netlink unicast send
714 *
715 * Description:
716 * Run through the given queue and attempt to send the audit records to auditd,
717 * returns zero on success, negative values on failure. It is up to the caller
718 * to ensure that the @sk is valid for the duration of this function.
719 *
720 */
721static int kauditd_send_queue(struct sock *sk, u32 portid,
722 struct sk_buff_head *queue,
723 unsigned int retry_limit,
724 void (*skb_hook)(struct sk_buff *skb),
725 void (*err_hook)(struct sk_buff *skb))
726{
727 int rc = 0;
728 struct sk_buff *skb;
729 static unsigned int failed = 0;
730
731 /* NOTE: kauditd_thread takes care of all our locking, we just use
732 * the netlink info passed to us (e.g. sk and portid) */
733
734 while ((skb = skb_dequeue(queue))) {
735 /* call the skb_hook for each skb we touch */
736 if (skb_hook)
737 (*skb_hook)(skb);
738
739 /* can we send to anyone via unicast? */
740 if (!sk) {
741 if (err_hook)
742 (*err_hook)(skb);
743 continue;
744 }
745
746 /* grab an extra skb reference in case of error */
747 skb_get(skb);
748 rc = netlink_unicast(sk, skb, portid, 0);
749 if (rc < 0) {
750 /* fatal failure for our queue flush attempt? */
751 if (++failed >= retry_limit ||
752 rc == -ECONNREFUSED || rc == -EPERM) {
753 /* yes - error processing for the queue */
754 sk = NULL;
755 if (err_hook)
756 (*err_hook)(skb);
757 if (!skb_hook)
758 goto out;
759 /* keep processing with the skb_hook */
760 continue;
761 } else
762 /* no - requeue to preserve ordering */
763 skb_queue_head(queue, skb);
764 } else {
765 /* it worked - drop the extra reference and continue */
766 consume_skb(skb);
767 failed = 0;
768 }
769 }
770
771out:
772 return (rc >= 0 ? 0 : rc);
773}
774
775/*
776 * kauditd_send_multicast_skb - Send a record to any multicast listeners
777 * @skb: audit record
778 *
779 * Description:
780 * Write a multicast message to anyone listening in the initial network
781 * namespace. This function doesn't consume an skb as might be expected since
782 * it has to copy it anyways.
783 */
784static void kauditd_send_multicast_skb(struct sk_buff *skb)
785{
786 struct sk_buff *copy;
787 struct sock *sock = audit_get_sk(&init_net);
788 struct nlmsghdr *nlh;
789
790 /* NOTE: we are not taking an additional reference for init_net since
791 * we don't have to worry about it going away */
792
793 if (!netlink_has_listeners(sock, AUDIT_NLGRP_READLOG))
794 return;
795
796 /*
797 * The seemingly wasteful skb_copy() rather than bumping the refcount
798 * using skb_get() is necessary because non-standard mods are made to
799 * the skb by the original kaudit unicast socket send routine. The
800 * existing auditd daemon assumes this breakage. Fixing this would
801 * require co-ordinating a change in the established protocol between
802 * the kaudit kernel subsystem and the auditd userspace code. There is
803 * no reason for new multicast clients to continue with this
804 * non-compliance.
805 */
806 copy = skb_copy(skb, GFP_KERNEL);
807 if (!copy)
808 return;
809 nlh = nlmsg_hdr(copy);
810 nlh->nlmsg_len = skb->len;
811
812 nlmsg_multicast(sock, copy, 0, AUDIT_NLGRP_READLOG, GFP_KERNEL);
813}
814
815/**
816 * kauditd_thread - Worker thread to send audit records to userspace
817 * @dummy: unused
818 */
819static int kauditd_thread(void *dummy)
820{
821 int rc;
822 u32 portid = 0;
823 struct net *net = NULL;
824 struct sock *sk = NULL;
825 struct auditd_connection *ac;
826
827#define UNICAST_RETRIES 5
828
829 set_freezable();
830 while (!kthread_should_stop()) {
831 /* NOTE: see the lock comments in auditd_send_unicast_skb() */
832 rcu_read_lock();
833 ac = rcu_dereference(auditd_conn);
834 if (!ac) {
835 rcu_read_unlock();
836 goto main_queue;
837 }
838 net = get_net(ac->net);
839 sk = audit_get_sk(net);
840 portid = ac->portid;
841 rcu_read_unlock();
842
843 /* attempt to flush the hold queue */
844 rc = kauditd_send_queue(sk, portid,
845 &audit_hold_queue, UNICAST_RETRIES,
846 NULL, kauditd_rehold_skb);
847 if (ac && rc < 0) {
848 sk = NULL;
849 auditd_reset(ac);
850 goto main_queue;
851 }
852
853 /* attempt to flush the retry queue */
854 rc = kauditd_send_queue(sk, portid,
855 &audit_retry_queue, UNICAST_RETRIES,
856 NULL, kauditd_hold_skb);
857 if (ac && rc < 0) {
858 sk = NULL;
859 auditd_reset(ac);
860 goto main_queue;
861 }
862
863main_queue:
864 /* process the main queue - do the multicast send and attempt
865 * unicast, dump failed record sends to the retry queue; if
866 * sk == NULL due to previous failures we will just do the
867 * multicast send and move the record to the hold queue */
868 rc = kauditd_send_queue(sk, portid, &audit_queue, 1,
869 kauditd_send_multicast_skb,
870 (sk ?
871 kauditd_retry_skb : kauditd_hold_skb));
872 if (ac && rc < 0)
873 auditd_reset(ac);
874 sk = NULL;
875
876 /* drop our netns reference, no auditd sends past this line */
877 if (net) {
878 put_net(net);
879 net = NULL;
880 }
881
882 /* we have processed all the queues so wake everyone */
883 wake_up(&audit_backlog_wait);
884
885 /* NOTE: we want to wake up if there is anything on the queue,
886 * regardless of if an auditd is connected, as we need to
887 * do the multicast send and rotate records from the
888 * main queue to the retry/hold queues */
889 wait_event_freezable(kauditd_wait,
890 (skb_queue_len(&audit_queue) ? 1 : 0));
891 }
892
893 return 0;
894}
895
896int audit_send_list(void *_dest)
897{
898 struct audit_netlink_list *dest = _dest;
899 struct sk_buff *skb;
900 struct sock *sk = audit_get_sk(dest->net);
901
902 /* wait for parent to finish and send an ACK */
903 audit_ctl_lock();
904 audit_ctl_unlock();
905
906 while ((skb = __skb_dequeue(&dest->q)) != NULL)
907 netlink_unicast(sk, skb, dest->portid, 0);
908
909 put_net(dest->net);
910 kfree(dest);
911
912 return 0;
913}
914
915struct sk_buff *audit_make_reply(int seq, int type, int done,
916 int multi, const void *payload, int size)
917{
918 struct sk_buff *skb;
919 struct nlmsghdr *nlh;
920 void *data;
921 int flags = multi ? NLM_F_MULTI : 0;
922 int t = done ? NLMSG_DONE : type;
923
924 skb = nlmsg_new(size, GFP_KERNEL);
925 if (!skb)
926 return NULL;
927
928 nlh = nlmsg_put(skb, 0, seq, t, size, flags);
929 if (!nlh)
930 goto out_kfree_skb;
931 data = nlmsg_data(nlh);
932 memcpy(data, payload, size);
933 return skb;
934
935out_kfree_skb:
936 kfree_skb(skb);
937 return NULL;
938}
939
940static int audit_send_reply_thread(void *arg)
941{
942 struct audit_reply *reply = (struct audit_reply *)arg;
943 struct sock *sk = audit_get_sk(reply->net);
944
945 audit_ctl_lock();
946 audit_ctl_unlock();
947
948 /* Ignore failure. It'll only happen if the sender goes away,
949 because our timeout is set to infinite. */
950 netlink_unicast(sk, reply->skb, reply->portid, 0);
951 put_net(reply->net);
952 kfree(reply);
953 return 0;
954}
955
956/**
957 * audit_send_reply - send an audit reply message via netlink
958 * @request_skb: skb of request we are replying to (used to target the reply)
959 * @seq: sequence number
960 * @type: audit message type
961 * @done: done (last) flag
962 * @multi: multi-part message flag
963 * @payload: payload data
964 * @size: payload size
965 *
966 * Allocates an skb, builds the netlink message, and sends it to the port id.
967 * No failure notifications.
968 */
969static void audit_send_reply(struct sk_buff *request_skb, int seq, int type, int done,
970 int multi, const void *payload, int size)
971{
972 struct net *net = sock_net(NETLINK_CB(request_skb).sk);
973 struct sk_buff *skb;
974 struct task_struct *tsk;
975 struct audit_reply *reply = kmalloc(sizeof(struct audit_reply),
976 GFP_KERNEL);
977
978 if (!reply)
979 return;
980
981 skb = audit_make_reply(seq, type, done, multi, payload, size);
982 if (!skb)
983 goto out;
984
985 reply->net = get_net(net);
986 reply->portid = NETLINK_CB(request_skb).portid;
987 reply->skb = skb;
988
989 tsk = kthread_run(audit_send_reply_thread, reply, "audit_send_reply");
990 if (!IS_ERR(tsk))
991 return;
992 kfree_skb(skb);
993out:
994 kfree(reply);
995}
996
997/*
998 * Check for appropriate CAP_AUDIT_ capabilities on incoming audit
999 * control messages.
1000 */
1001static int audit_netlink_ok(struct sk_buff *skb, u16 msg_type)
1002{
1003 int err = 0;
1004
1005 /* Only support initial user namespace for now. */
1006 /*
1007 * We return ECONNREFUSED because it tricks userspace into thinking
1008 * that audit was not configured into the kernel. Lots of users
1009 * configure their PAM stack (because that's what the distro does)
1010 * to reject login if unable to send messages to audit. If we return
1011 * ECONNREFUSED the PAM stack thinks the kernel does not have audit
1012 * configured in and will let login proceed. If we return EPERM
1013 * userspace will reject all logins. This should be removed when we
1014 * support non init namespaces!!
1015 */
1016 if (current_user_ns() != &init_user_ns)
1017 return -ECONNREFUSED;
1018
1019 switch (msg_type) {
1020 case AUDIT_LIST:
1021 case AUDIT_ADD:
1022 case AUDIT_DEL:
1023 return -EOPNOTSUPP;
1024 case AUDIT_GET:
1025 case AUDIT_SET:
1026 case AUDIT_GET_FEATURE:
1027 case AUDIT_SET_FEATURE:
1028 case AUDIT_LIST_RULES:
1029 case AUDIT_ADD_RULE:
1030 case AUDIT_DEL_RULE:
1031 case AUDIT_SIGNAL_INFO:
1032 case AUDIT_TTY_GET:
1033 case AUDIT_TTY_SET:
1034 case AUDIT_TRIM:
1035 case AUDIT_MAKE_EQUIV:
1036 /* Only support auditd and auditctl in initial pid namespace
1037 * for now. */
1038 if (task_active_pid_ns(current) != &init_pid_ns)
1039 return -EPERM;
1040
1041 if (!netlink_capable(skb, CAP_AUDIT_CONTROL))
1042 err = -EPERM;
1043 break;
1044 case AUDIT_USER:
1045 case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG:
1046 case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2:
1047 if (!netlink_capable(skb, CAP_AUDIT_WRITE))
1048 err = -EPERM;
1049 break;
1050 default: /* bad msg */
1051 err = -EINVAL;
1052 }
1053
1054 return err;
1055}
1056
1057static void audit_log_common_recv_msg(struct audit_buffer **ab, u16 msg_type)
1058{
1059 uid_t uid = from_kuid(&init_user_ns, current_uid());
1060 pid_t pid = task_tgid_nr(current);
1061
1062 if (!audit_enabled && msg_type != AUDIT_USER_AVC) {
1063 *ab = NULL;
1064 return;
1065 }
1066
1067 *ab = audit_log_start(NULL, GFP_KERNEL, msg_type);
1068 if (unlikely(!*ab))
1069 return;
1070 audit_log_format(*ab, "pid=%d uid=%u", pid, uid);
1071 audit_log_session_info(*ab);
1072 audit_log_task_context(*ab);
1073}
1074
1075int is_audit_feature_set(int i)
1076{
1077 return af.features & AUDIT_FEATURE_TO_MASK(i);
1078}
1079
1080
1081static int audit_get_feature(struct sk_buff *skb)
1082{
1083 u32 seq;
1084
1085 seq = nlmsg_hdr(skb)->nlmsg_seq;
1086
1087 audit_send_reply(skb, seq, AUDIT_GET_FEATURE, 0, 0, &af, sizeof(af));
1088
1089 return 0;
1090}
1091
1092static void audit_log_feature_change(int which, u32 old_feature, u32 new_feature,
1093 u32 old_lock, u32 new_lock, int res)
1094{
1095 struct audit_buffer *ab;
1096
1097 if (audit_enabled == AUDIT_OFF)
1098 return;
1099 ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_FEATURE_CHANGE);
1100 if (!ab)
1101 return;
1102 audit_log_task_info(ab, current);
1103 audit_log_format(ab, " feature=%s old=%u new=%u old_lock=%u new_lock=%u res=%d",
1104 audit_feature_names[which], !!old_feature, !!new_feature,
1105 !!old_lock, !!new_lock, res);
1106 audit_log_end(ab);
1107}
1108
1109static int audit_set_feature(struct sk_buff *skb)
1110{
1111 struct audit_features *uaf;
1112 int i;
1113
1114 BUILD_BUG_ON(AUDIT_LAST_FEATURE + 1 > ARRAY_SIZE(audit_feature_names));
1115 uaf = nlmsg_data(nlmsg_hdr(skb));
1116
1117 /* if there is ever a version 2 we should handle that here */
1118
1119 for (i = 0; i <= AUDIT_LAST_FEATURE; i++) {
1120 u32 feature = AUDIT_FEATURE_TO_MASK(i);
1121 u32 old_feature, new_feature, old_lock, new_lock;
1122
1123 /* if we are not changing this feature, move along */
1124 if (!(feature & uaf->mask))
1125 continue;
1126
1127 old_feature = af.features & feature;
1128 new_feature = uaf->features & feature;
1129 new_lock = (uaf->lock | af.lock) & feature;
1130 old_lock = af.lock & feature;
1131
1132 /* are we changing a locked feature? */
1133 if (old_lock && (new_feature != old_feature)) {
1134 audit_log_feature_change(i, old_feature, new_feature,
1135 old_lock, new_lock, 0);
1136 return -EPERM;
1137 }
1138 }
1139 /* nothing invalid, do the changes */
1140 for (i = 0; i <= AUDIT_LAST_FEATURE; i++) {
1141 u32 feature = AUDIT_FEATURE_TO_MASK(i);
1142 u32 old_feature, new_feature, old_lock, new_lock;
1143
1144 /* if we are not changing this feature, move along */
1145 if (!(feature & uaf->mask))
1146 continue;
1147
1148 old_feature = af.features & feature;
1149 new_feature = uaf->features & feature;
1150 old_lock = af.lock & feature;
1151 new_lock = (uaf->lock | af.lock) & feature;
1152
1153 if (new_feature != old_feature)
1154 audit_log_feature_change(i, old_feature, new_feature,
1155 old_lock, new_lock, 1);
1156
1157 if (new_feature)
1158 af.features |= feature;
1159 else
1160 af.features &= ~feature;
1161 af.lock |= new_lock;
1162 }
1163
1164 return 0;
1165}
1166
1167static int audit_replace(struct pid *pid)
1168{
1169 pid_t pvnr;
1170 struct sk_buff *skb;
1171
1172 pvnr = pid_vnr(pid);
1173 skb = audit_make_reply(0, AUDIT_REPLACE, 0, 0, &pvnr, sizeof(pvnr));
1174 if (!skb)
1175 return -ENOMEM;
1176 return auditd_send_unicast_skb(skb);
1177}
1178
1179static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
1180{
1181 u32 seq;
1182 void *data;
1183 int err;
1184 struct audit_buffer *ab;
1185 u16 msg_type = nlh->nlmsg_type;
1186 struct audit_sig_info *sig_data;
1187 char *ctx = NULL;
1188 u32 len;
1189
1190 err = audit_netlink_ok(skb, msg_type);
1191 if (err)
1192 return err;
1193
1194 seq = nlh->nlmsg_seq;
1195 data = nlmsg_data(nlh);
1196
1197 switch (msg_type) {
1198 case AUDIT_GET: {
1199 struct audit_status s;
1200 memset(&s, 0, sizeof(s));
1201 s.enabled = audit_enabled;
1202 s.failure = audit_failure;
1203 /* NOTE: use pid_vnr() so the PID is relative to the current
1204 * namespace */
1205 s.pid = auditd_pid_vnr();
1206 s.rate_limit = audit_rate_limit;
1207 s.backlog_limit = audit_backlog_limit;
1208 s.lost = atomic_read(&audit_lost);
1209 s.backlog = skb_queue_len(&audit_queue);
1210 s.feature_bitmap = AUDIT_FEATURE_BITMAP_ALL;
1211 s.backlog_wait_time = audit_backlog_wait_time;
1212 audit_send_reply(skb, seq, AUDIT_GET, 0, 0, &s, sizeof(s));
1213 break;
1214 }
1215 case AUDIT_SET: {
1216 struct audit_status s;
1217 memset(&s, 0, sizeof(s));
1218 /* guard against past and future API changes */
1219 memcpy(&s, data, min_t(size_t, sizeof(s), nlmsg_len(nlh)));
1220 if (s.mask & AUDIT_STATUS_ENABLED) {
1221 err = audit_set_enabled(s.enabled);
1222 if (err < 0)
1223 return err;
1224 }
1225 if (s.mask & AUDIT_STATUS_FAILURE) {
1226 err = audit_set_failure(s.failure);
1227 if (err < 0)
1228 return err;
1229 }
1230 if (s.mask & AUDIT_STATUS_PID) {
1231 /* NOTE: we are using the vnr PID functions below
1232 * because the s.pid value is relative to the
1233 * namespace of the caller; at present this
1234 * doesn't matter much since you can really only
1235 * run auditd from the initial pid namespace, but
1236 * something to keep in mind if this changes */
1237 pid_t new_pid = s.pid;
1238 pid_t auditd_pid;
1239 struct pid *req_pid = task_tgid(current);
1240
1241 /* Sanity check - PID values must match. Setting
1242 * pid to 0 is how auditd ends auditing. */
1243 if (new_pid && (new_pid != pid_vnr(req_pid)))
1244 return -EINVAL;
1245
1246 /* test the auditd connection */
1247 audit_replace(req_pid);
1248
1249 auditd_pid = auditd_pid_vnr();
1250 if (auditd_pid) {
1251 /* replacing a healthy auditd is not allowed */
1252 if (new_pid) {
1253 audit_log_config_change("audit_pid",
1254 new_pid, auditd_pid, 0);
1255 return -EEXIST;
1256 }
1257 /* only current auditd can unregister itself */
1258 if (pid_vnr(req_pid) != auditd_pid) {
1259 audit_log_config_change("audit_pid",
1260 new_pid, auditd_pid, 0);
1261 return -EACCES;
1262 }
1263 }
1264
1265 if (new_pid) {
1266 /* register a new auditd connection */
1267 err = auditd_set(req_pid,
1268 NETLINK_CB(skb).portid,
1269 sock_net(NETLINK_CB(skb).sk));
1270 if (audit_enabled != AUDIT_OFF)
1271 audit_log_config_change("audit_pid",
1272 new_pid,
1273 auditd_pid,
1274 err ? 0 : 1);
1275 if (err)
1276 return err;
1277
1278 /* try to process any backlog */
1279 wake_up_interruptible(&kauditd_wait);
1280 } else {
1281 if (audit_enabled != AUDIT_OFF)
1282 audit_log_config_change("audit_pid",
1283 new_pid,
1284 auditd_pid, 1);
1285
1286 /* unregister the auditd connection */
1287 auditd_reset(NULL);
1288 }
1289 }
1290 if (s.mask & AUDIT_STATUS_RATE_LIMIT) {
1291 err = audit_set_rate_limit(s.rate_limit);
1292 if (err < 0)
1293 return err;
1294 }
1295 if (s.mask & AUDIT_STATUS_BACKLOG_LIMIT) {
1296 err = audit_set_backlog_limit(s.backlog_limit);
1297 if (err < 0)
1298 return err;
1299 }
1300 if (s.mask & AUDIT_STATUS_BACKLOG_WAIT_TIME) {
1301 if (sizeof(s) > (size_t)nlh->nlmsg_len)
1302 return -EINVAL;
1303 if (s.backlog_wait_time > 10*AUDIT_BACKLOG_WAIT_TIME)
1304 return -EINVAL;
1305 err = audit_set_backlog_wait_time(s.backlog_wait_time);
1306 if (err < 0)
1307 return err;
1308 }
1309 if (s.mask == AUDIT_STATUS_LOST) {
1310 u32 lost = atomic_xchg(&audit_lost, 0);
1311
1312 audit_log_config_change("lost", 0, lost, 1);
1313 return lost;
1314 }
1315 break;
1316 }
1317 case AUDIT_GET_FEATURE:
1318 err = audit_get_feature(skb);
1319 if (err)
1320 return err;
1321 break;
1322 case AUDIT_SET_FEATURE:
1323 err = audit_set_feature(skb);
1324 if (err)
1325 return err;
1326 break;
1327 case AUDIT_USER:
1328 case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG:
1329 case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2:
1330 if (!audit_enabled && msg_type != AUDIT_USER_AVC)
1331 return 0;
1332
1333 err = audit_filter(msg_type, AUDIT_FILTER_USER);
1334 if (err == 1) { /* match or error */
1335 err = 0;
1336 if (msg_type == AUDIT_USER_TTY) {
1337 err = tty_audit_push();
1338 if (err)
1339 break;
1340 }
1341 audit_log_common_recv_msg(&ab, msg_type);
1342 if (msg_type != AUDIT_USER_TTY)
1343 audit_log_format(ab, " msg='%.*s'",
1344 AUDIT_MESSAGE_TEXT_MAX,
1345 (char *)data);
1346 else {
1347 int size;
1348
1349 audit_log_format(ab, " data=");
1350 size = nlmsg_len(nlh);
1351 if (size > 0 &&
1352 ((unsigned char *)data)[size - 1] == '\0')
1353 size--;
1354 audit_log_n_untrustedstring(ab, data, size);
1355 }
1356 audit_log_end(ab);
1357 }
1358 break;
1359 case AUDIT_ADD_RULE:
1360 case AUDIT_DEL_RULE:
1361 if (nlmsg_len(nlh) < sizeof(struct audit_rule_data))
1362 return -EINVAL;
1363 if (audit_enabled == AUDIT_LOCKED) {
1364 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE);
1365 audit_log_format(ab, " audit_enabled=%d res=0", audit_enabled);
1366 audit_log_end(ab);
1367 return -EPERM;
1368 }
1369 err = audit_rule_change(msg_type, seq, data, nlmsg_len(nlh));
1370 break;
1371 case AUDIT_LIST_RULES:
1372 err = audit_list_rules_send(skb, seq);
1373 break;
1374 case AUDIT_TRIM:
1375 audit_trim_trees();
1376 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE);
1377 audit_log_format(ab, " op=trim res=1");
1378 audit_log_end(ab);
1379 break;
1380 case AUDIT_MAKE_EQUIV: {
1381 void *bufp = data;
1382 u32 sizes[2];
1383 size_t msglen = nlmsg_len(nlh);
1384 char *old, *new;
1385
1386 err = -EINVAL;
1387 if (msglen < 2 * sizeof(u32))
1388 break;
1389 memcpy(sizes, bufp, 2 * sizeof(u32));
1390 bufp += 2 * sizeof(u32);
1391 msglen -= 2 * sizeof(u32);
1392 old = audit_unpack_string(&bufp, &msglen, sizes[0]);
1393 if (IS_ERR(old)) {
1394 err = PTR_ERR(old);
1395 break;
1396 }
1397 new = audit_unpack_string(&bufp, &msglen, sizes[1]);
1398 if (IS_ERR(new)) {
1399 err = PTR_ERR(new);
1400 kfree(old);
1401 break;
1402 }
1403 /* OK, here comes... */
1404 err = audit_tag_tree(old, new);
1405
1406 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE);
1407
1408 audit_log_format(ab, " op=make_equiv old=");
1409 audit_log_untrustedstring(ab, old);
1410 audit_log_format(ab, " new=");
1411 audit_log_untrustedstring(ab, new);
1412 audit_log_format(ab, " res=%d", !err);
1413 audit_log_end(ab);
1414 kfree(old);
1415 kfree(new);
1416 break;
1417 }
1418 case AUDIT_SIGNAL_INFO:
1419 len = 0;
1420 if (audit_sig_sid) {
1421 err = security_secid_to_secctx(audit_sig_sid, &ctx, &len);
1422 if (err)
1423 return err;
1424 }
1425 sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL);
1426 if (!sig_data) {
1427 if (audit_sig_sid)
1428 security_release_secctx(ctx, len);
1429 return -ENOMEM;
1430 }
1431 sig_data->uid = from_kuid(&init_user_ns, audit_sig_uid);
1432 sig_data->pid = audit_sig_pid;
1433 if (audit_sig_sid) {
1434 memcpy(sig_data->ctx, ctx, len);
1435 security_release_secctx(ctx, len);
1436 }
1437 audit_send_reply(skb, seq, AUDIT_SIGNAL_INFO, 0, 0,
1438 sig_data, sizeof(*sig_data) + len);
1439 kfree(sig_data);
1440 break;
1441 case AUDIT_TTY_GET: {
1442 struct audit_tty_status s;
1443 unsigned int t;
1444
1445 t = READ_ONCE(current->signal->audit_tty);
1446 s.enabled = t & AUDIT_TTY_ENABLE;
1447 s.log_passwd = !!(t & AUDIT_TTY_LOG_PASSWD);
1448
1449 audit_send_reply(skb, seq, AUDIT_TTY_GET, 0, 0, &s, sizeof(s));
1450 break;
1451 }
1452 case AUDIT_TTY_SET: {
1453 struct audit_tty_status s, old;
1454 struct audit_buffer *ab;
1455 unsigned int t;
1456
1457 memset(&s, 0, sizeof(s));
1458 /* guard against past and future API changes */
1459 memcpy(&s, data, min_t(size_t, sizeof(s), nlmsg_len(nlh)));
1460 /* check if new data is valid */
1461 if ((s.enabled != 0 && s.enabled != 1) ||
1462 (s.log_passwd != 0 && s.log_passwd != 1))
1463 err = -EINVAL;
1464
1465 if (err)
1466 t = READ_ONCE(current->signal->audit_tty);
1467 else {
1468 t = s.enabled | (-s.log_passwd & AUDIT_TTY_LOG_PASSWD);
1469 t = xchg(&current->signal->audit_tty, t);
1470 }
1471 old.enabled = t & AUDIT_TTY_ENABLE;
1472 old.log_passwd = !!(t & AUDIT_TTY_LOG_PASSWD);
1473
1474 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE);
1475 audit_log_format(ab, " op=tty_set old-enabled=%d new-enabled=%d"
1476 " old-log_passwd=%d new-log_passwd=%d res=%d",
1477 old.enabled, s.enabled, old.log_passwd,
1478 s.log_passwd, !err);
1479 audit_log_end(ab);
1480 break;
1481 }
1482 default:
1483 err = -EINVAL;
1484 break;
1485 }
1486
1487 return err < 0 ? err : 0;
1488}
1489
1490/**
1491 * audit_receive - receive messages from a netlink control socket
1492 * @skb: the message buffer
1493 *
1494 * Parse the provided skb and deal with any messages that may be present,
1495 * malformed skbs are discarded.
1496 */
1497static void audit_receive(struct sk_buff *skb)
1498{
1499 struct nlmsghdr *nlh;
1500 /*
1501 * len MUST be signed for nlmsg_next to be able to dec it below 0
1502 * if the nlmsg_len was not aligned
1503 */
1504 int len;
1505 int err;
1506
1507 nlh = nlmsg_hdr(skb);
1508 len = skb->len;
1509
1510 audit_ctl_lock();
1511 while (nlmsg_ok(nlh, len)) {
1512 err = audit_receive_msg(skb, nlh);
1513 /* if err or if this message says it wants a response */
1514 if (err || (nlh->nlmsg_flags & NLM_F_ACK))
1515 netlink_ack(skb, nlh, err, NULL);
1516
1517 nlh = nlmsg_next(nlh, &len);
1518 }
1519 audit_ctl_unlock();
1520}
1521
1522/* Run custom bind function on netlink socket group connect or bind requests. */
1523static int audit_bind(struct net *net, int group)
1524{
1525 if (!capable(CAP_AUDIT_READ))
1526 return -EPERM;
1527
1528 return 0;
1529}
1530
1531static int __net_init audit_net_init(struct net *net)
1532{
1533 struct netlink_kernel_cfg cfg = {
1534 .input = audit_receive,
1535 .bind = audit_bind,
1536 .flags = NL_CFG_F_NONROOT_RECV,
1537 .groups = AUDIT_NLGRP_MAX,
1538 };
1539
1540 struct audit_net *aunet = net_generic(net, audit_net_id);
1541
1542 aunet->sk = netlink_kernel_create(net, NETLINK_AUDIT, &cfg);
1543 if (aunet->sk == NULL) {
1544 audit_panic("cannot initialize netlink socket in namespace");
1545 return -ENOMEM;
1546 }
1547 aunet->sk->sk_sndtimeo = MAX_SCHEDULE_TIMEOUT;
1548
1549 return 0;
1550}
1551
1552static void __net_exit audit_net_exit(struct net *net)
1553{
1554 struct audit_net *aunet = net_generic(net, audit_net_id);
1555
1556 /* NOTE: you would think that we would want to check the auditd
1557 * connection and potentially reset it here if it lives in this
1558 * namespace, but since the auditd connection tracking struct holds a
1559 * reference to this namespace (see auditd_set()) we are only ever
1560 * going to get here after that connection has been released */
1561
1562 netlink_kernel_release(aunet->sk);
1563}
1564
1565static struct pernet_operations audit_net_ops __net_initdata = {
1566 .init = audit_net_init,
1567 .exit = audit_net_exit,
1568 .id = &audit_net_id,
1569 .size = sizeof(struct audit_net),
1570};
1571
1572/* Initialize audit support at boot time. */
1573static int __init audit_init(void)
1574{
1575 int i;
1576
1577 if (audit_initialized == AUDIT_DISABLED)
1578 return 0;
1579
1580 audit_buffer_cache = kmem_cache_create("audit_buffer",
1581 sizeof(struct audit_buffer),
1582 0, SLAB_PANIC, NULL);
1583
1584 skb_queue_head_init(&audit_queue);
1585 skb_queue_head_init(&audit_retry_queue);
1586 skb_queue_head_init(&audit_hold_queue);
1587
1588 for (i = 0; i < AUDIT_INODE_BUCKETS; i++)
1589 INIT_LIST_HEAD(&audit_inode_hash[i]);
1590
1591 mutex_init(&audit_cmd_mutex.lock);
1592 audit_cmd_mutex.owner = NULL;
1593
1594 pr_info("initializing netlink subsys (%s)\n",
1595 audit_default ? "enabled" : "disabled");
1596 register_pernet_subsys(&audit_net_ops);
1597
1598 audit_initialized = AUDIT_INITIALIZED;
1599
1600 kauditd_task = kthread_run(kauditd_thread, NULL, "kauditd");
1601 if (IS_ERR(kauditd_task)) {
1602 int err = PTR_ERR(kauditd_task);
1603 panic("audit: failed to start the kauditd thread (%d)\n", err);
1604 }
1605
1606 audit_log(NULL, GFP_KERNEL, AUDIT_KERNEL,
1607 "state=initialized audit_enabled=%u res=1",
1608 audit_enabled);
1609
1610 return 0;
1611}
1612postcore_initcall(audit_init);
1613
1614/*
1615 * Process kernel command-line parameter at boot time.
1616 * audit={0|off} or audit={1|on}.
1617 */
1618static int __init audit_enable(char *str)
1619{
1620 if (!strcasecmp(str, "off") || !strcmp(str, "0"))
1621 audit_default = AUDIT_OFF;
1622 else if (!strcasecmp(str, "on") || !strcmp(str, "1"))
1623 audit_default = AUDIT_ON;
1624 else {
1625 pr_err("audit: invalid 'audit' parameter value (%s)\n", str);
1626 audit_default = AUDIT_ON;
1627 }
1628
1629 if (audit_default == AUDIT_OFF)
1630 audit_initialized = AUDIT_DISABLED;
1631 if (audit_set_enabled(audit_default))
1632 pr_err("audit: error setting audit state (%d)\n",
1633 audit_default);
1634
1635 pr_info("%s\n", audit_default ?
1636 "enabled (after initialization)" : "disabled (until reboot)");
1637
1638 return 1;
1639}
1640__setup("audit=", audit_enable);
1641
1642/* Process kernel command-line parameter at boot time.
1643 * audit_backlog_limit=<n> */
1644static int __init audit_backlog_limit_set(char *str)
1645{
1646 u32 audit_backlog_limit_arg;
1647
1648 pr_info("audit_backlog_limit: ");
1649 if (kstrtouint(str, 0, &audit_backlog_limit_arg)) {
1650 pr_cont("using default of %u, unable to parse %s\n",
1651 audit_backlog_limit, str);
1652 return 1;
1653 }
1654
1655 audit_backlog_limit = audit_backlog_limit_arg;
1656 pr_cont("%d\n", audit_backlog_limit);
1657
1658 return 1;
1659}
1660__setup("audit_backlog_limit=", audit_backlog_limit_set);
1661
1662static void audit_buffer_free(struct audit_buffer *ab)
1663{
1664 if (!ab)
1665 return;
1666
1667 kfree_skb(ab->skb);
1668 kmem_cache_free(audit_buffer_cache, ab);
1669}
1670
1671static struct audit_buffer *audit_buffer_alloc(struct audit_context *ctx,
1672 gfp_t gfp_mask, int type)
1673{
1674 struct audit_buffer *ab;
1675
1676 ab = kmem_cache_alloc(audit_buffer_cache, gfp_mask);
1677 if (!ab)
1678 return NULL;
1679
1680 ab->skb = nlmsg_new(AUDIT_BUFSIZ, gfp_mask);
1681 if (!ab->skb)
1682 goto err;
1683 if (!nlmsg_put(ab->skb, 0, 0, type, 0, 0))
1684 goto err;
1685
1686 ab->ctx = ctx;
1687 ab->gfp_mask = gfp_mask;
1688
1689 return ab;
1690
1691err:
1692 audit_buffer_free(ab);
1693 return NULL;
1694}
1695
1696/**
1697 * audit_serial - compute a serial number for the audit record
1698 *
1699 * Compute a serial number for the audit record. Audit records are
1700 * written to user-space as soon as they are generated, so a complete
1701 * audit record may be written in several pieces. The timestamp of the
1702 * record and this serial number are used by the user-space tools to
1703 * determine which pieces belong to the same audit record. The
1704 * (timestamp,serial) tuple is unique for each syscall and is live from
1705 * syscall entry to syscall exit.
1706 *
1707 * NOTE: Another possibility is to store the formatted records off the
1708 * audit context (for those records that have a context), and emit them
1709 * all at syscall exit. However, this could delay the reporting of
1710 * significant errors until syscall exit (or never, if the system
1711 * halts).
1712 */
1713unsigned int audit_serial(void)
1714{
1715 static atomic_t serial = ATOMIC_INIT(0);
1716
1717 return atomic_add_return(1, &serial);
1718}
1719
1720static inline void audit_get_stamp(struct audit_context *ctx,
1721 struct timespec64 *t, unsigned int *serial)
1722{
1723 if (!ctx || !auditsc_get_stamp(ctx, t, serial)) {
1724 ktime_get_coarse_real_ts64(t);
1725 *serial = audit_serial();
1726 }
1727}
1728
1729/**
1730 * audit_log_start - obtain an audit buffer
1731 * @ctx: audit_context (may be NULL)
1732 * @gfp_mask: type of allocation
1733 * @type: audit message type
1734 *
1735 * Returns audit_buffer pointer on success or NULL on error.
1736 *
1737 * Obtain an audit buffer. This routine does locking to obtain the
1738 * audit buffer, but then no locking is required for calls to
1739 * audit_log_*format. If the task (ctx) is a task that is currently in a
1740 * syscall, then the syscall is marked as auditable and an audit record
1741 * will be written at syscall exit. If there is no associated task, then
1742 * task context (ctx) should be NULL.
1743 */
1744struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask,
1745 int type)
1746{
1747 struct audit_buffer *ab;
1748 struct timespec64 t;
1749 unsigned int uninitialized_var(serial);
1750
1751 if (audit_initialized != AUDIT_INITIALIZED)
1752 return NULL;
1753
1754 if (unlikely(!audit_filter(type, AUDIT_FILTER_EXCLUDE)))
1755 return NULL;
1756
1757 /* NOTE: don't ever fail/sleep on these two conditions:
1758 * 1. auditd generated record - since we need auditd to drain the
1759 * queue; also, when we are checking for auditd, compare PIDs using
1760 * task_tgid_vnr() since auditd_pid is set in audit_receive_msg()
1761 * using a PID anchored in the caller's namespace
1762 * 2. generator holding the audit_cmd_mutex - we don't want to block
1763 * while holding the mutex */
1764 if (!(auditd_test_task(current) || audit_ctl_owner_current())) {
1765 long stime = audit_backlog_wait_time;
1766
1767 while (audit_backlog_limit &&
1768 (skb_queue_len(&audit_queue) > audit_backlog_limit)) {
1769 /* wake kauditd to try and flush the queue */
1770 wake_up_interruptible(&kauditd_wait);
1771
1772 /* sleep if we are allowed and we haven't exhausted our
1773 * backlog wait limit */
1774 if (gfpflags_allow_blocking(gfp_mask) && (stime > 0)) {
1775 DECLARE_WAITQUEUE(wait, current);
1776
1777 add_wait_queue_exclusive(&audit_backlog_wait,
1778 &wait);
1779 set_current_state(TASK_UNINTERRUPTIBLE);
1780 stime = schedule_timeout(stime);
1781 remove_wait_queue(&audit_backlog_wait, &wait);
1782 } else {
1783 if (audit_rate_check() && printk_ratelimit())
1784 pr_warn("audit_backlog=%d > audit_backlog_limit=%d\n",
1785 skb_queue_len(&audit_queue),
1786 audit_backlog_limit);
1787 audit_log_lost("backlog limit exceeded");
1788 return NULL;
1789 }
1790 }
1791 }
1792
1793 ab = audit_buffer_alloc(ctx, gfp_mask, type);
1794 if (!ab) {
1795 audit_log_lost("out of memory in audit_log_start");
1796 return NULL;
1797 }
1798
1799 audit_get_stamp(ab->ctx, &t, &serial);
1800 audit_log_format(ab, "audit(%llu.%03lu:%u): ",
1801 (unsigned long long)t.tv_sec, t.tv_nsec/1000000, serial);
1802
1803 return ab;
1804}
1805
1806/**
1807 * audit_expand - expand skb in the audit buffer
1808 * @ab: audit_buffer
1809 * @extra: space to add at tail of the skb
1810 *
1811 * Returns 0 (no space) on failed expansion, or available space if
1812 * successful.
1813 */
1814static inline int audit_expand(struct audit_buffer *ab, int extra)
1815{
1816 struct sk_buff *skb = ab->skb;
1817 int oldtail = skb_tailroom(skb);
1818 int ret = pskb_expand_head(skb, 0, extra, ab->gfp_mask);
1819 int newtail = skb_tailroom(skb);
1820
1821 if (ret < 0) {
1822 audit_log_lost("out of memory in audit_expand");
1823 return 0;
1824 }
1825
1826 skb->truesize += newtail - oldtail;
1827 return newtail;
1828}
1829
1830/*
1831 * Format an audit message into the audit buffer. If there isn't enough
1832 * room in the audit buffer, more room will be allocated and vsnprint
1833 * will be called a second time. Currently, we assume that a printk
1834 * can't format message larger than 1024 bytes, so we don't either.
1835 */
1836static void audit_log_vformat(struct audit_buffer *ab, const char *fmt,
1837 va_list args)
1838{
1839 int len, avail;
1840 struct sk_buff *skb;
1841 va_list args2;
1842
1843 if (!ab)
1844 return;
1845
1846 BUG_ON(!ab->skb);
1847 skb = ab->skb;
1848 avail = skb_tailroom(skb);
1849 if (avail == 0) {
1850 avail = audit_expand(ab, AUDIT_BUFSIZ);
1851 if (!avail)
1852 goto out;
1853 }
1854 va_copy(args2, args);
1855 len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args);
1856 if (len >= avail) {
1857 /* The printk buffer is 1024 bytes long, so if we get
1858 * here and AUDIT_BUFSIZ is at least 1024, then we can
1859 * log everything that printk could have logged. */
1860 avail = audit_expand(ab,
1861 max_t(unsigned, AUDIT_BUFSIZ, 1+len-avail));
1862 if (!avail)
1863 goto out_va_end;
1864 len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args2);
1865 }
1866 if (len > 0)
1867 skb_put(skb, len);
1868out_va_end:
1869 va_end(args2);
1870out:
1871 return;
1872}
1873
1874/**
1875 * audit_log_format - format a message into the audit buffer.
1876 * @ab: audit_buffer
1877 * @fmt: format string
1878 * @...: optional parameters matching @fmt string
1879 *
1880 * All the work is done in audit_log_vformat.
1881 */
1882void audit_log_format(struct audit_buffer *ab, const char *fmt, ...)
1883{
1884 va_list args;
1885
1886 if (!ab)
1887 return;
1888 va_start(args, fmt);
1889 audit_log_vformat(ab, fmt, args);
1890 va_end(args);
1891}
1892
1893/**
1894 * audit_log_n_hex - convert a buffer to hex and append it to the audit skb
1895 * @ab: the audit_buffer
1896 * @buf: buffer to convert to hex
1897 * @len: length of @buf to be converted
1898 *
1899 * No return value; failure to expand is silently ignored.
1900 *
1901 * This function will take the passed buf and convert it into a string of
1902 * ascii hex digits. The new string is placed onto the skb.
1903 */
1904void audit_log_n_hex(struct audit_buffer *ab, const unsigned char *buf,
1905 size_t len)
1906{
1907 int i, avail, new_len;
1908 unsigned char *ptr;
1909 struct sk_buff *skb;
1910
1911 if (!ab)
1912 return;
1913
1914 BUG_ON(!ab->skb);
1915 skb = ab->skb;
1916 avail = skb_tailroom(skb);
1917 new_len = len<<1;
1918 if (new_len >= avail) {
1919 /* Round the buffer request up to the next multiple */
1920 new_len = AUDIT_BUFSIZ*(((new_len-avail)/AUDIT_BUFSIZ) + 1);
1921 avail = audit_expand(ab, new_len);
1922 if (!avail)
1923 return;
1924 }
1925
1926 ptr = skb_tail_pointer(skb);
1927 for (i = 0; i < len; i++)
1928 ptr = hex_byte_pack_upper(ptr, buf[i]);
1929 *ptr = 0;
1930 skb_put(skb, len << 1); /* new string is twice the old string */
1931}
1932
1933/*
1934 * Format a string of no more than slen characters into the audit buffer,
1935 * enclosed in quote marks.
1936 */
1937void audit_log_n_string(struct audit_buffer *ab, const char *string,
1938 size_t slen)
1939{
1940 int avail, new_len;
1941 unsigned char *ptr;
1942 struct sk_buff *skb;
1943
1944 if (!ab)
1945 return;
1946
1947 BUG_ON(!ab->skb);
1948 skb = ab->skb;
1949 avail = skb_tailroom(skb);
1950 new_len = slen + 3; /* enclosing quotes + null terminator */
1951 if (new_len > avail) {
1952 avail = audit_expand(ab, new_len);
1953 if (!avail)
1954 return;
1955 }
1956 ptr = skb_tail_pointer(skb);
1957 *ptr++ = '"';
1958 memcpy(ptr, string, slen);
1959 ptr += slen;
1960 *ptr++ = '"';
1961 *ptr = 0;
1962 skb_put(skb, slen + 2); /* don't include null terminator */
1963}
1964
1965/**
1966 * audit_string_contains_control - does a string need to be logged in hex
1967 * @string: string to be checked
1968 * @len: max length of the string to check
1969 */
1970bool audit_string_contains_control(const char *string, size_t len)
1971{
1972 const unsigned char *p;
1973 for (p = string; p < (const unsigned char *)string + len; p++) {
1974 if (*p == '"' || *p < 0x21 || *p > 0x7e)
1975 return true;
1976 }
1977 return false;
1978}
1979
1980/**
1981 * audit_log_n_untrustedstring - log a string that may contain random characters
1982 * @ab: audit_buffer
1983 * @len: length of string (not including trailing null)
1984 * @string: string to be logged
1985 *
1986 * This code will escape a string that is passed to it if the string
1987 * contains a control character, unprintable character, double quote mark,
1988 * or a space. Unescaped strings will start and end with a double quote mark.
1989 * Strings that are escaped are printed in hex (2 digits per char).
1990 *
1991 * The caller specifies the number of characters in the string to log, which may
1992 * or may not be the entire string.
1993 */
1994void audit_log_n_untrustedstring(struct audit_buffer *ab, const char *string,
1995 size_t len)
1996{
1997 if (audit_string_contains_control(string, len))
1998 audit_log_n_hex(ab, string, len);
1999 else
2000 audit_log_n_string(ab, string, len);
2001}
2002
2003/**
2004 * audit_log_untrustedstring - log a string that may contain random characters
2005 * @ab: audit_buffer
2006 * @string: string to be logged
2007 *
2008 * Same as audit_log_n_untrustedstring(), except that strlen is used to
2009 * determine string length.
2010 */
2011void audit_log_untrustedstring(struct audit_buffer *ab, const char *string)
2012{
2013 audit_log_n_untrustedstring(ab, string, strlen(string));
2014}
2015
2016/* This is a helper-function to print the escaped d_path */
2017void audit_log_d_path(struct audit_buffer *ab, const char *prefix,
2018 const struct path *path)
2019{
2020 char *p, *pathname;
2021
2022 if (prefix)
2023 audit_log_format(ab, "%s", prefix);
2024
2025 /* We will allow 11 spaces for ' (deleted)' to be appended */
2026 pathname = kmalloc(PATH_MAX+11, ab->gfp_mask);
2027 if (!pathname) {
2028 audit_log_string(ab, "<no_memory>");
2029 return;
2030 }
2031 p = d_path(path, pathname, PATH_MAX+11);
2032 if (IS_ERR(p)) { /* Should never happen since we send PATH_MAX */
2033 /* FIXME: can we save some information here? */
2034 audit_log_string(ab, "<too_long>");
2035 } else
2036 audit_log_untrustedstring(ab, p);
2037 kfree(pathname);
2038}
2039
2040void audit_log_session_info(struct audit_buffer *ab)
2041{
2042 unsigned int sessionid = audit_get_sessionid(current);
2043 uid_t auid = from_kuid(&init_user_ns, audit_get_loginuid(current));
2044
2045 audit_log_format(ab, " auid=%u ses=%u", auid, sessionid);
2046}
2047
2048void audit_log_key(struct audit_buffer *ab, char *key)
2049{
2050 audit_log_format(ab, " key=");
2051 if (key)
2052 audit_log_untrustedstring(ab, key);
2053 else
2054 audit_log_format(ab, "(null)");
2055}
2056
2057void audit_log_cap(struct audit_buffer *ab, char *prefix, kernel_cap_t *cap)
2058{
2059 int i;
2060
2061 audit_log_format(ab, " %s=", prefix);
2062 CAP_FOR_EACH_U32(i) {
2063 audit_log_format(ab, "%08x",
2064 cap->cap[CAP_LAST_U32 - i]);
2065 }
2066}
2067
2068static void audit_log_fcaps(struct audit_buffer *ab, struct audit_names *name)
2069{
2070 audit_log_cap(ab, "cap_fp", &name->fcap.permitted);
2071 audit_log_cap(ab, "cap_fi", &name->fcap.inheritable);
2072 audit_log_format(ab, " cap_fe=%d cap_fver=%x",
2073 name->fcap.fE, name->fcap_ver);
2074}
2075
2076static inline int audit_copy_fcaps(struct audit_names *name,
2077 const struct dentry *dentry)
2078{
2079 struct cpu_vfs_cap_data caps;
2080 int rc;
2081
2082 if (!dentry)
2083 return 0;
2084
2085 rc = get_vfs_caps_from_disk(dentry, &caps);
2086 if (rc)
2087 return rc;
2088
2089 name->fcap.permitted = caps.permitted;
2090 name->fcap.inheritable = caps.inheritable;
2091 name->fcap.fE = !!(caps.magic_etc & VFS_CAP_FLAGS_EFFECTIVE);
2092 name->fcap_ver = (caps.magic_etc & VFS_CAP_REVISION_MASK) >>
2093 VFS_CAP_REVISION_SHIFT;
2094
2095 return 0;
2096}
2097
2098/* Copy inode data into an audit_names. */
2099void audit_copy_inode(struct audit_names *name, const struct dentry *dentry,
2100 struct inode *inode)
2101{
2102 name->ino = inode->i_ino;
2103 name->dev = inode->i_sb->s_dev;
2104 name->mode = inode->i_mode;
2105 name->uid = inode->i_uid;
2106 name->gid = inode->i_gid;
2107 name->rdev = inode->i_rdev;
2108 security_inode_getsecid(inode, &name->osid);
2109 audit_copy_fcaps(name, dentry);
2110}
2111
2112/**
2113 * audit_log_name - produce AUDIT_PATH record from struct audit_names
2114 * @context: audit_context for the task
2115 * @n: audit_names structure with reportable details
2116 * @path: optional path to report instead of audit_names->name
2117 * @record_num: record number to report when handling a list of names
2118 * @call_panic: optional pointer to int that will be updated if secid fails
2119 */
2120void audit_log_name(struct audit_context *context, struct audit_names *n,
2121 const struct path *path, int record_num, int *call_panic)
2122{
2123 struct audit_buffer *ab;
2124 ab = audit_log_start(context, GFP_KERNEL, AUDIT_PATH);
2125 if (!ab)
2126 return;
2127
2128 audit_log_format(ab, "item=%d", record_num);
2129
2130 if (path)
2131 audit_log_d_path(ab, " name=", path);
2132 else if (n->name) {
2133 switch (n->name_len) {
2134 case AUDIT_NAME_FULL:
2135 /* log the full path */
2136 audit_log_format(ab, " name=");
2137 audit_log_untrustedstring(ab, n->name->name);
2138 break;
2139 case 0:
2140 /* name was specified as a relative path and the
2141 * directory component is the cwd */
2142 audit_log_d_path(ab, " name=", &context->pwd);
2143 break;
2144 default:
2145 /* log the name's directory component */
2146 audit_log_format(ab, " name=");
2147 audit_log_n_untrustedstring(ab, n->name->name,
2148 n->name_len);
2149 }
2150 } else
2151 audit_log_format(ab, " name=(null)");
2152
2153 if (n->ino != AUDIT_INO_UNSET)
2154 audit_log_format(ab, " inode=%lu"
2155 " dev=%02x:%02x mode=%#ho"
2156 " ouid=%u ogid=%u rdev=%02x:%02x",
2157 n->ino,
2158 MAJOR(n->dev),
2159 MINOR(n->dev),
2160 n->mode,
2161 from_kuid(&init_user_ns, n->uid),
2162 from_kgid(&init_user_ns, n->gid),
2163 MAJOR(n->rdev),
2164 MINOR(n->rdev));
2165 if (n->osid != 0) {
2166 char *ctx = NULL;
2167 u32 len;
2168 if (security_secid_to_secctx(
2169 n->osid, &ctx, &len)) {
2170 audit_log_format(ab, " osid=%u", n->osid);
2171 if (call_panic)
2172 *call_panic = 2;
2173 } else {
2174 audit_log_format(ab, " obj=%s", ctx);
2175 security_release_secctx(ctx, len);
2176 }
2177 }
2178
2179 /* log the audit_names record type */
2180 audit_log_format(ab, " nametype=");
2181 switch(n->type) {
2182 case AUDIT_TYPE_NORMAL:
2183 audit_log_format(ab, "NORMAL");
2184 break;
2185 case AUDIT_TYPE_PARENT:
2186 audit_log_format(ab, "PARENT");
2187 break;
2188 case AUDIT_TYPE_CHILD_DELETE:
2189 audit_log_format(ab, "DELETE");
2190 break;
2191 case AUDIT_TYPE_CHILD_CREATE:
2192 audit_log_format(ab, "CREATE");
2193 break;
2194 default:
2195 audit_log_format(ab, "UNKNOWN");
2196 break;
2197 }
2198
2199 audit_log_fcaps(ab, n);
2200 audit_log_end(ab);
2201}
2202
2203int audit_log_task_context(struct audit_buffer *ab)
2204{
2205 char *ctx = NULL;
2206 unsigned len;
2207 int error;
2208 u32 sid;
2209
2210 security_task_getsecid(current, &sid);
2211 if (!sid)
2212 return 0;
2213
2214 error = security_secid_to_secctx(sid, &ctx, &len);
2215 if (error) {
2216 if (error != -EINVAL)
2217 goto error_path;
2218 return 0;
2219 }
2220
2221 audit_log_format(ab, " subj=%s", ctx);
2222 security_release_secctx(ctx, len);
2223 return 0;
2224
2225error_path:
2226 audit_panic("error in audit_log_task_context");
2227 return error;
2228}
2229EXPORT_SYMBOL(audit_log_task_context);
2230
2231void audit_log_d_path_exe(struct audit_buffer *ab,
2232 struct mm_struct *mm)
2233{
2234 struct file *exe_file;
2235
2236 if (!mm)
2237 goto out_null;
2238
2239 exe_file = get_mm_exe_file(mm);
2240 if (!exe_file)
2241 goto out_null;
2242
2243 audit_log_d_path(ab, " exe=", &exe_file->f_path);
2244 fput(exe_file);
2245 return;
2246out_null:
2247 audit_log_format(ab, " exe=(null)");
2248}
2249
2250struct tty_struct *audit_get_tty(struct task_struct *tsk)
2251{
2252 struct tty_struct *tty = NULL;
2253 unsigned long flags;
2254
2255 spin_lock_irqsave(&tsk->sighand->siglock, flags);
2256 if (tsk->signal)
2257 tty = tty_kref_get(tsk->signal->tty);
2258 spin_unlock_irqrestore(&tsk->sighand->siglock, flags);
2259 return tty;
2260}
2261
2262void audit_put_tty(struct tty_struct *tty)
2263{
2264 tty_kref_put(tty);
2265}
2266
2267void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk)
2268{
2269 const struct cred *cred;
2270 char comm[sizeof(tsk->comm)];
2271 struct tty_struct *tty;
2272
2273 if (!ab)
2274 return;
2275
2276 /* tsk == current */
2277 cred = current_cred();
2278 tty = audit_get_tty(tsk);
2279 audit_log_format(ab,
2280 " ppid=%d pid=%d auid=%u uid=%u gid=%u"
2281 " euid=%u suid=%u fsuid=%u"
2282 " egid=%u sgid=%u fsgid=%u tty=%s ses=%u",
2283 task_ppid_nr(tsk),
2284 task_tgid_nr(tsk),
2285 from_kuid(&init_user_ns, audit_get_loginuid(tsk)),
2286 from_kuid(&init_user_ns, cred->uid),
2287 from_kgid(&init_user_ns, cred->gid),
2288 from_kuid(&init_user_ns, cred->euid),
2289 from_kuid(&init_user_ns, cred->suid),
2290 from_kuid(&init_user_ns, cred->fsuid),
2291 from_kgid(&init_user_ns, cred->egid),
2292 from_kgid(&init_user_ns, cred->sgid),
2293 from_kgid(&init_user_ns, cred->fsgid),
2294 tty ? tty_name(tty) : "(none)",
2295 audit_get_sessionid(tsk));
2296 audit_put_tty(tty);
2297 audit_log_format(ab, " comm=");
2298 audit_log_untrustedstring(ab, get_task_comm(comm, tsk));
2299 audit_log_d_path_exe(ab, tsk->mm);
2300 audit_log_task_context(ab);
2301}
2302EXPORT_SYMBOL(audit_log_task_info);
2303
2304/**
2305 * audit_log_link_denied - report a link restriction denial
2306 * @operation: specific link operation
2307 */
2308void audit_log_link_denied(const char *operation)
2309{
2310 struct audit_buffer *ab;
2311
2312 if (!audit_enabled || audit_dummy_context())
2313 return;
2314
2315 /* Generate AUDIT_ANOM_LINK with subject, operation, outcome. */
2316 ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_ANOM_LINK);
2317 if (!ab)
2318 return;
2319 audit_log_format(ab, "op=%s", operation);
2320 audit_log_task_info(ab, current);
2321 audit_log_format(ab, " res=0");
2322 audit_log_end(ab);
2323}
2324
2325/**
2326 * audit_log_end - end one audit record
2327 * @ab: the audit_buffer
2328 *
2329 * We can not do a netlink send inside an irq context because it blocks (last
2330 * arg, flags, is not set to MSG_DONTWAIT), so the audit buffer is placed on a
2331 * queue and a tasklet is scheduled to remove them from the queue outside the
2332 * irq context. May be called in any context.
2333 */
2334void audit_log_end(struct audit_buffer *ab)
2335{
2336 struct sk_buff *skb;
2337 struct nlmsghdr *nlh;
2338
2339 if (!ab)
2340 return;
2341
2342 if (audit_rate_check()) {
2343 skb = ab->skb;
2344 ab->skb = NULL;
2345
2346 /* setup the netlink header, see the comments in
2347 * kauditd_send_multicast_skb() for length quirks */
2348 nlh = nlmsg_hdr(skb);
2349 nlh->nlmsg_len = skb->len - NLMSG_HDRLEN;
2350
2351 /* queue the netlink packet and poke the kauditd thread */
2352 skb_queue_tail(&audit_queue, skb);
2353 wake_up_interruptible(&kauditd_wait);
2354 } else
2355 audit_log_lost("rate limit exceeded");
2356
2357 audit_buffer_free(ab);
2358}
2359
2360/**
2361 * audit_log - Log an audit record
2362 * @ctx: audit context
2363 * @gfp_mask: type of allocation
2364 * @type: audit message type
2365 * @fmt: format string to use
2366 * @...: variable parameters matching the format string
2367 *
2368 * This is a convenience function that calls audit_log_start,
2369 * audit_log_vformat, and audit_log_end. It may be called
2370 * in any context.
2371 */
2372void audit_log(struct audit_context *ctx, gfp_t gfp_mask, int type,
2373 const char *fmt, ...)
2374{
2375 struct audit_buffer *ab;
2376 va_list args;
2377
2378 ab = audit_log_start(ctx, gfp_mask, type);
2379 if (ab) {
2380 va_start(args, fmt);
2381 audit_log_vformat(ab, fmt, args);
2382 va_end(args);
2383 audit_log_end(ab);
2384 }
2385}
2386
2387EXPORT_SYMBOL(audit_log_start);
2388EXPORT_SYMBOL(audit_log_end);
2389EXPORT_SYMBOL(audit_log_format);
2390EXPORT_SYMBOL(audit_log);
2391