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31
32#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
33
34#include <linux/file.h>
35#include <linux/init.h>
36#include <linux/types.h>
37#include <linux/atomic.h>
38#include <linux/mm.h>
39#include <linux/export.h>
40#include <linux/slab.h>
41#include <linux/err.h>
42#include <linux/kthread.h>
43#include <linux/kernel.h>
44#include <linux/syscalls.h>
45#include <linux/spinlock.h>
46#include <linux/rcupdate.h>
47#include <linux/mutex.h>
48#include <linux/gfp.h>
49#include <linux/pid.h>
50
51#include <linux/audit.h>
52
53#include <net/sock.h>
54#include <net/netlink.h>
55#include <linux/skbuff.h>
56#ifdef CONFIG_SECURITY
57#include <linux/security.h>
58#endif
59#include <linux/freezer.h>
60#include <linux/pid_namespace.h>
61#include <net/netns/generic.h>
62
63#include "audit.h"
64
65
66
67#define AUDIT_DISABLED -1
68#define AUDIT_UNINITIALIZED 0
69#define AUDIT_INITIALIZED 1
70static int audit_initialized;
71
72u32 audit_enabled = AUDIT_OFF;
73bool audit_ever_enabled = !!AUDIT_OFF;
74
75EXPORT_SYMBOL_GPL(audit_enabled);
76
77
78static u32 audit_default = AUDIT_OFF;
79
80
81static u32 audit_failure = AUDIT_FAIL_PRINTK;
82
83
84static unsigned int audit_net_id;
85
86
87
88
89
90struct audit_net {
91 struct sock *sk;
92};
93
94
95
96
97
98
99
100
101
102
103
104
105struct auditd_connection {
106 struct pid *pid;
107 u32 portid;
108 struct net *net;
109 struct rcu_head rcu;
110};
111static struct auditd_connection __rcu *auditd_conn;
112static DEFINE_SPINLOCK(auditd_conn_lock);
113
114
115
116
117static u32 audit_rate_limit;
118
119
120
121static u32 audit_backlog_limit = 64;
122#define AUDIT_BACKLOG_WAIT_TIME (60 * HZ)
123static u32 audit_backlog_wait_time = AUDIT_BACKLOG_WAIT_TIME;
124
125
126kuid_t audit_sig_uid = INVALID_UID;
127pid_t audit_sig_pid = -1;
128u32 audit_sig_sid = 0;
129
130
131
132
133
134
135
136
137static atomic_t audit_lost = ATOMIC_INIT(0);
138
139
140
141
142static atomic_t audit_backlog_wait_time_actual = ATOMIC_INIT(0);
143
144
145struct list_head audit_inode_hash[AUDIT_INODE_BUCKETS];
146
147static struct kmem_cache *audit_buffer_cache;
148
149
150static struct sk_buff_head audit_queue;
151
152static struct sk_buff_head audit_retry_queue;
153
154static struct sk_buff_head audit_hold_queue;
155
156
157static struct task_struct *kauditd_task;
158static DECLARE_WAIT_QUEUE_HEAD(kauditd_wait);
159
160
161static DECLARE_WAIT_QUEUE_HEAD(audit_backlog_wait);
162
163static struct audit_features af = {.vers = AUDIT_FEATURE_VERSION,
164 .mask = -1,
165 .features = 0,
166 .lock = 0,};
167
168static char *audit_feature_names[2] = {
169 "only_unset_loginuid",
170 "loginuid_immutable",
171};
172
173
174
175
176
177
178
179
180
181
182
183
184static struct audit_ctl_mutex {
185 struct mutex lock;
186 void *owner;
187} audit_cmd_mutex;
188
189
190
191
192#define AUDIT_BUFSIZ 1024
193
194
195
196
197
198
199struct audit_buffer {
200 struct sk_buff *skb;
201 struct audit_context *ctx;
202 gfp_t gfp_mask;
203};
204
205struct audit_reply {
206 __u32 portid;
207 struct net *net;
208 struct sk_buff *skb;
209};
210
211
212
213
214
215
216
217
218int auditd_test_task(struct task_struct *task)
219{
220 int rc;
221 struct auditd_connection *ac;
222
223 rcu_read_lock();
224 ac = rcu_dereference(auditd_conn);
225 rc = (ac && ac->pid == task_tgid(task) ? 1 : 0);
226 rcu_read_unlock();
227
228 return rc;
229}
230
231
232
233
234void audit_ctl_lock(void)
235{
236 mutex_lock(&audit_cmd_mutex.lock);
237 audit_cmd_mutex.owner = current;
238}
239
240
241
242
243void audit_ctl_unlock(void)
244{
245 audit_cmd_mutex.owner = NULL;
246 mutex_unlock(&audit_cmd_mutex.lock);
247}
248
249
250
251
252
253
254
255
256static bool audit_ctl_owner_current(void)
257{
258 return (current == audit_cmd_mutex.owner);
259}
260
261
262
263
264
265
266
267static pid_t auditd_pid_vnr(void)
268{
269 pid_t pid;
270 const struct auditd_connection *ac;
271
272 rcu_read_lock();
273 ac = rcu_dereference(auditd_conn);
274 if (!ac || !ac->pid)
275 pid = 0;
276 else
277 pid = pid_vnr(ac->pid);
278 rcu_read_unlock();
279
280 return pid;
281}
282
283
284
285
286
287
288
289
290
291static struct sock *audit_get_sk(const struct net *net)
292{
293 struct audit_net *aunet;
294
295 if (!net)
296 return NULL;
297
298 aunet = net_generic(net, audit_net_id);
299 return aunet->sk;
300}
301
302void audit_panic(const char *message)
303{
304 switch (audit_failure) {
305 case AUDIT_FAIL_SILENT:
306 break;
307 case AUDIT_FAIL_PRINTK:
308 if (printk_ratelimit())
309 pr_err("%s\n", message);
310 break;
311 case AUDIT_FAIL_PANIC:
312 panic("audit: %s\n", message);
313 break;
314 }
315}
316
317static inline int audit_rate_check(void)
318{
319 static unsigned long last_check = 0;
320 static int messages = 0;
321 static DEFINE_SPINLOCK(lock);
322 unsigned long flags;
323 unsigned long now;
324 unsigned long elapsed;
325 int retval = 0;
326
327 if (!audit_rate_limit) return 1;
328
329 spin_lock_irqsave(&lock, flags);
330 if (++messages < audit_rate_limit) {
331 retval = 1;
332 } else {
333 now = jiffies;
334 elapsed = now - last_check;
335 if (elapsed > HZ) {
336 last_check = now;
337 messages = 0;
338 retval = 1;
339 }
340 }
341 spin_unlock_irqrestore(&lock, flags);
342
343 return retval;
344}
345
346
347
348
349
350
351
352
353
354void audit_log_lost(const char *message)
355{
356 static unsigned long last_msg = 0;
357 static DEFINE_SPINLOCK(lock);
358 unsigned long flags;
359 unsigned long now;
360 int print;
361
362 atomic_inc(&audit_lost);
363
364 print = (audit_failure == AUDIT_FAIL_PANIC || !audit_rate_limit);
365
366 if (!print) {
367 spin_lock_irqsave(&lock, flags);
368 now = jiffies;
369 if (now - last_msg > HZ) {
370 print = 1;
371 last_msg = now;
372 }
373 spin_unlock_irqrestore(&lock, flags);
374 }
375
376 if (print) {
377 if (printk_ratelimit())
378 pr_warn("audit_lost=%u audit_rate_limit=%u audit_backlog_limit=%u\n",
379 atomic_read(&audit_lost),
380 audit_rate_limit,
381 audit_backlog_limit);
382 audit_panic(message);
383 }
384}
385
386static int audit_log_config_change(char *function_name, u32 new, u32 old,
387 int allow_changes)
388{
389 struct audit_buffer *ab;
390 int rc = 0;
391
392 ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_CONFIG_CHANGE);
393 if (unlikely(!ab))
394 return rc;
395 audit_log_format(ab, "op=set %s=%u old=%u ", function_name, new, old);
396 audit_log_session_info(ab);
397 rc = audit_log_task_context(ab);
398 if (rc)
399 allow_changes = 0;
400 audit_log_format(ab, " res=%d", allow_changes);
401 audit_log_end(ab);
402 return rc;
403}
404
405static int audit_do_config_change(char *function_name, u32 *to_change, u32 new)
406{
407 int allow_changes, rc = 0;
408 u32 old = *to_change;
409
410
411 if (audit_enabled == AUDIT_LOCKED)
412 allow_changes = 0;
413 else
414 allow_changes = 1;
415
416 if (audit_enabled != AUDIT_OFF) {
417 rc = audit_log_config_change(function_name, new, old, allow_changes);
418 if (rc)
419 allow_changes = 0;
420 }
421
422
423 if (allow_changes == 1)
424 *to_change = new;
425
426 else if (rc == 0)
427 rc = -EPERM;
428 return rc;
429}
430
431static int audit_set_rate_limit(u32 limit)
432{
433 return audit_do_config_change("audit_rate_limit", &audit_rate_limit, limit);
434}
435
436static int audit_set_backlog_limit(u32 limit)
437{
438 return audit_do_config_change("audit_backlog_limit", &audit_backlog_limit, limit);
439}
440
441static int audit_set_backlog_wait_time(u32 timeout)
442{
443 return audit_do_config_change("audit_backlog_wait_time",
444 &audit_backlog_wait_time, timeout);
445}
446
447static int audit_set_enabled(u32 state)
448{
449 int rc;
450 if (state > AUDIT_LOCKED)
451 return -EINVAL;
452
453 rc = audit_do_config_change("audit_enabled", &audit_enabled, state);
454 if (!rc)
455 audit_ever_enabled |= !!state;
456
457 return rc;
458}
459
460static int audit_set_failure(u32 state)
461{
462 if (state != AUDIT_FAIL_SILENT
463 && state != AUDIT_FAIL_PRINTK
464 && state != AUDIT_FAIL_PANIC)
465 return -EINVAL;
466
467 return audit_do_config_change("audit_failure", &audit_failure, state);
468}
469
470
471
472
473
474
475
476
477
478static void auditd_conn_free(struct rcu_head *rcu)
479{
480 struct auditd_connection *ac;
481
482 ac = container_of(rcu, struct auditd_connection, rcu);
483 put_pid(ac->pid);
484 put_net(ac->net);
485 kfree(ac);
486}
487
488
489
490
491
492
493
494
495
496
497
498static int auditd_set(struct pid *pid, u32 portid, struct net *net)
499{
500 unsigned long flags;
501 struct auditd_connection *ac_old, *ac_new;
502
503 if (!pid || !net)
504 return -EINVAL;
505
506 ac_new = kzalloc(sizeof(*ac_new), GFP_KERNEL);
507 if (!ac_new)
508 return -ENOMEM;
509 ac_new->pid = get_pid(pid);
510 ac_new->portid = portid;
511 ac_new->net = get_net(net);
512
513 spin_lock_irqsave(&auditd_conn_lock, flags);
514 ac_old = rcu_dereference_protected(auditd_conn,
515 lockdep_is_held(&auditd_conn_lock));
516 rcu_assign_pointer(auditd_conn, ac_new);
517 spin_unlock_irqrestore(&auditd_conn_lock, flags);
518
519 if (ac_old)
520 call_rcu(&ac_old->rcu, auditd_conn_free);
521
522 return 0;
523}
524
525
526
527
528
529
530
531
532static void kauditd_printk_skb(struct sk_buff *skb)
533{
534 struct nlmsghdr *nlh = nlmsg_hdr(skb);
535 char *data = nlmsg_data(nlh);
536
537 if (nlh->nlmsg_type != AUDIT_EOE && printk_ratelimit())
538 pr_notice("type=%d %s\n", nlh->nlmsg_type, data);
539}
540
541
542
543
544
545
546
547
548
549static void kauditd_rehold_skb(struct sk_buff *skb)
550{
551
552 skb_queue_head(&audit_hold_queue, skb);
553}
554
555
556
557
558
559
560
561
562
563
564
565
566
567static void kauditd_hold_skb(struct sk_buff *skb)
568{
569
570
571 kauditd_printk_skb(skb);
572
573
574 if (!audit_default) {
575 kfree_skb(skb);
576 return;
577 }
578
579
580 if (!audit_backlog_limit ||
581 skb_queue_len(&audit_hold_queue) < audit_backlog_limit) {
582 skb_queue_tail(&audit_hold_queue, skb);
583 return;
584 }
585
586
587 audit_log_lost("kauditd hold queue overflow");
588 kfree_skb(skb);
589}
590
591
592
593
594
595
596
597
598
599
600static void kauditd_retry_skb(struct sk_buff *skb)
601{
602
603
604
605 skb_queue_tail(&audit_retry_queue, skb);
606}
607
608
609
610
611
612
613
614
615
616
617
618
619static void auditd_reset(const struct auditd_connection *ac)
620{
621 unsigned long flags;
622 struct sk_buff *skb;
623 struct auditd_connection *ac_old;
624
625
626 spin_lock_irqsave(&auditd_conn_lock, flags);
627 ac_old = rcu_dereference_protected(auditd_conn,
628 lockdep_is_held(&auditd_conn_lock));
629 if (ac && ac != ac_old) {
630
631 spin_unlock_irqrestore(&auditd_conn_lock, flags);
632 return;
633 }
634 rcu_assign_pointer(auditd_conn, NULL);
635 spin_unlock_irqrestore(&auditd_conn_lock, flags);
636
637 if (ac_old)
638 call_rcu(&ac_old->rcu, auditd_conn_free);
639
640
641
642 while ((skb = skb_dequeue(&audit_retry_queue)))
643 kauditd_hold_skb(skb);
644}
645
646
647
648
649
650
651
652
653
654
655
656
657static int auditd_send_unicast_skb(struct sk_buff *skb)
658{
659 int rc;
660 u32 portid;
661 struct net *net;
662 struct sock *sk;
663 struct auditd_connection *ac;
664
665
666
667
668
669
670
671
672 rcu_read_lock();
673 ac = rcu_dereference(auditd_conn);
674 if (!ac) {
675 rcu_read_unlock();
676 kfree_skb(skb);
677 rc = -ECONNREFUSED;
678 goto err;
679 }
680 net = get_net(ac->net);
681 sk = audit_get_sk(net);
682 portid = ac->portid;
683 rcu_read_unlock();
684
685 rc = netlink_unicast(sk, skb, portid, 0);
686 put_net(net);
687 if (rc < 0)
688 goto err;
689
690 return rc;
691
692err:
693 if (ac && rc == -ECONNREFUSED)
694 auditd_reset(ac);
695 return rc;
696}
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713static int kauditd_send_queue(struct sock *sk, u32 portid,
714 struct sk_buff_head *queue,
715 unsigned int retry_limit,
716 void (*skb_hook)(struct sk_buff *skb),
717 void (*err_hook)(struct sk_buff *skb))
718{
719 int rc = 0;
720 struct sk_buff *skb;
721 static unsigned int failed = 0;
722
723
724
725
726 while ((skb = skb_dequeue(queue))) {
727
728 if (skb_hook)
729 (*skb_hook)(skb);
730
731
732 if (!sk) {
733 if (err_hook)
734 (*err_hook)(skb);
735 continue;
736 }
737
738
739 skb_get(skb);
740 rc = netlink_unicast(sk, skb, portid, 0);
741 if (rc < 0) {
742
743 if (++failed >= retry_limit ||
744 rc == -ECONNREFUSED || rc == -EPERM) {
745
746 sk = NULL;
747 if (err_hook)
748 (*err_hook)(skb);
749 if (!skb_hook)
750 goto out;
751
752 continue;
753 } else
754
755 skb_queue_head(queue, skb);
756 } else {
757
758 consume_skb(skb);
759 failed = 0;
760 }
761 }
762
763out:
764 return (rc >= 0 ? 0 : rc);
765}
766
767
768
769
770
771
772
773
774
775
776static void kauditd_send_multicast_skb(struct sk_buff *skb)
777{
778 struct sk_buff *copy;
779 struct sock *sock = audit_get_sk(&init_net);
780 struct nlmsghdr *nlh;
781
782
783
784
785 if (!netlink_has_listeners(sock, AUDIT_NLGRP_READLOG))
786 return;
787
788
789
790
791
792
793
794
795
796
797
798 copy = skb_copy(skb, GFP_KERNEL);
799 if (!copy)
800 return;
801 nlh = nlmsg_hdr(copy);
802 nlh->nlmsg_len = skb->len;
803
804 nlmsg_multicast(sock, copy, 0, AUDIT_NLGRP_READLOG, GFP_KERNEL);
805}
806
807
808
809
810
811static int kauditd_thread(void *dummy)
812{
813 int rc;
814 u32 portid = 0;
815 struct net *net = NULL;
816 struct sock *sk = NULL;
817 struct auditd_connection *ac;
818
819#define UNICAST_RETRIES 5
820
821 set_freezable();
822 while (!kthread_should_stop()) {
823
824 rcu_read_lock();
825 ac = rcu_dereference(auditd_conn);
826 if (!ac) {
827 rcu_read_unlock();
828 goto main_queue;
829 }
830 net = get_net(ac->net);
831 sk = audit_get_sk(net);
832 portid = ac->portid;
833 rcu_read_unlock();
834
835
836 rc = kauditd_send_queue(sk, portid,
837 &audit_hold_queue, UNICAST_RETRIES,
838 NULL, kauditd_rehold_skb);
839 if (rc < 0) {
840 sk = NULL;
841 auditd_reset(ac);
842 goto main_queue;
843 }
844
845
846 rc = kauditd_send_queue(sk, portid,
847 &audit_retry_queue, UNICAST_RETRIES,
848 NULL, kauditd_hold_skb);
849 if (rc < 0) {
850 sk = NULL;
851 auditd_reset(ac);
852 goto main_queue;
853 }
854
855main_queue:
856
857
858
859
860 rc = kauditd_send_queue(sk, portid, &audit_queue, 1,
861 kauditd_send_multicast_skb,
862 (sk ?
863 kauditd_retry_skb : kauditd_hold_skb));
864 if (ac && rc < 0)
865 auditd_reset(ac);
866 sk = NULL;
867
868
869 if (net) {
870 put_net(net);
871 net = NULL;
872 }
873
874
875 wake_up(&audit_backlog_wait);
876
877
878
879
880
881 wait_event_freezable(kauditd_wait,
882 (skb_queue_len(&audit_queue) ? 1 : 0));
883 }
884
885 return 0;
886}
887
888int audit_send_list_thread(void *_dest)
889{
890 struct audit_netlink_list *dest = _dest;
891 struct sk_buff *skb;
892 struct sock *sk = audit_get_sk(dest->net);
893
894
895 audit_ctl_lock();
896 audit_ctl_unlock();
897
898 while ((skb = __skb_dequeue(&dest->q)) != NULL)
899 netlink_unicast(sk, skb, dest->portid, 0);
900
901 put_net(dest->net);
902 kfree(dest);
903
904 return 0;
905}
906
907struct sk_buff *audit_make_reply(int seq, int type, int done,
908 int multi, const void *payload, int size)
909{
910 struct sk_buff *skb;
911 struct nlmsghdr *nlh;
912 void *data;
913 int flags = multi ? NLM_F_MULTI : 0;
914 int t = done ? NLMSG_DONE : type;
915
916 skb = nlmsg_new(size, GFP_KERNEL);
917 if (!skb)
918 return NULL;
919
920 nlh = nlmsg_put(skb, 0, seq, t, size, flags);
921 if (!nlh)
922 goto out_kfree_skb;
923 data = nlmsg_data(nlh);
924 memcpy(data, payload, size);
925 return skb;
926
927out_kfree_skb:
928 kfree_skb(skb);
929 return NULL;
930}
931
932static void audit_free_reply(struct audit_reply *reply)
933{
934 if (!reply)
935 return;
936
937 if (reply->skb)
938 kfree_skb(reply->skb);
939 if (reply->net)
940 put_net(reply->net);
941 kfree(reply);
942}
943
944static int audit_send_reply_thread(void *arg)
945{
946 struct audit_reply *reply = (struct audit_reply *)arg;
947
948 audit_ctl_lock();
949 audit_ctl_unlock();
950
951
952
953 netlink_unicast(audit_get_sk(reply->net), reply->skb, reply->portid, 0);
954 reply->skb = NULL;
955 audit_free_reply(reply);
956 return 0;
957}
958
959
960
961
962
963
964
965
966
967
968
969
970
971static void audit_send_reply(struct sk_buff *request_skb, int seq, int type, int done,
972 int multi, const void *payload, int size)
973{
974 struct task_struct *tsk;
975 struct audit_reply *reply;
976
977 reply = kzalloc(sizeof(*reply), GFP_KERNEL);
978 if (!reply)
979 return;
980
981 reply->skb = audit_make_reply(seq, type, done, multi, payload, size);
982 if (!reply->skb)
983 goto err;
984 reply->net = get_net(sock_net(NETLINK_CB(request_skb).sk));
985 reply->portid = NETLINK_CB(request_skb).portid;
986
987 tsk = kthread_run(audit_send_reply_thread, reply, "audit_send_reply");
988 if (IS_ERR(tsk))
989 goto err;
990
991 return;
992
993err:
994 audit_free_reply(reply);
995}
996
997
998
999
1000
1001static int audit_netlink_ok(struct sk_buff *skb, u16 msg_type)
1002{
1003 int err = 0;
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
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
1037
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:
1051 err = -EINVAL;
1052 }
1053
1054 return err;
1055}
1056
1057static void audit_log_common_recv_msg(struct audit_context *context,
1058 struct audit_buffer **ab, u16 msg_type)
1059{
1060 uid_t uid = from_kuid(&init_user_ns, current_uid());
1061 pid_t pid = task_tgid_nr(current);
1062
1063 if (!audit_enabled && msg_type != AUDIT_USER_AVC) {
1064 *ab = NULL;
1065 return;
1066 }
1067
1068 *ab = audit_log_start(context, GFP_KERNEL, msg_type);
1069 if (unlikely(!*ab))
1070 return;
1071 audit_log_format(*ab, "pid=%d uid=%u ", pid, uid);
1072 audit_log_session_info(*ab);
1073 audit_log_task_context(*ab);
1074}
1075
1076static inline void audit_log_user_recv_msg(struct audit_buffer **ab,
1077 u16 msg_type)
1078{
1079 audit_log_common_recv_msg(NULL, ab, msg_type);
1080}
1081
1082int is_audit_feature_set(int i)
1083{
1084 return af.features & AUDIT_FEATURE_TO_MASK(i);
1085}
1086
1087
1088static int audit_get_feature(struct sk_buff *skb)
1089{
1090 u32 seq;
1091
1092 seq = nlmsg_hdr(skb)->nlmsg_seq;
1093
1094 audit_send_reply(skb, seq, AUDIT_GET_FEATURE, 0, 0, &af, sizeof(af));
1095
1096 return 0;
1097}
1098
1099static void audit_log_feature_change(int which, u32 old_feature, u32 new_feature,
1100 u32 old_lock, u32 new_lock, int res)
1101{
1102 struct audit_buffer *ab;
1103
1104 if (audit_enabled == AUDIT_OFF)
1105 return;
1106
1107 ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_FEATURE_CHANGE);
1108 if (!ab)
1109 return;
1110 audit_log_task_info(ab);
1111 audit_log_format(ab, " feature=%s old=%u new=%u old_lock=%u new_lock=%u res=%d",
1112 audit_feature_names[which], !!old_feature, !!new_feature,
1113 !!old_lock, !!new_lock, res);
1114 audit_log_end(ab);
1115}
1116
1117static int audit_set_feature(struct audit_features *uaf)
1118{
1119 int i;
1120
1121 BUILD_BUG_ON(AUDIT_LAST_FEATURE + 1 > ARRAY_SIZE(audit_feature_names));
1122
1123
1124
1125 for (i = 0; i <= AUDIT_LAST_FEATURE; i++) {
1126 u32 feature = AUDIT_FEATURE_TO_MASK(i);
1127 u32 old_feature, new_feature, old_lock, new_lock;
1128
1129
1130 if (!(feature & uaf->mask))
1131 continue;
1132
1133 old_feature = af.features & feature;
1134 new_feature = uaf->features & feature;
1135 new_lock = (uaf->lock | af.lock) & feature;
1136 old_lock = af.lock & feature;
1137
1138
1139 if (old_lock && (new_feature != old_feature)) {
1140 audit_log_feature_change(i, old_feature, new_feature,
1141 old_lock, new_lock, 0);
1142 return -EPERM;
1143 }
1144 }
1145
1146 for (i = 0; i <= AUDIT_LAST_FEATURE; i++) {
1147 u32 feature = AUDIT_FEATURE_TO_MASK(i);
1148 u32 old_feature, new_feature, old_lock, new_lock;
1149
1150
1151 if (!(feature & uaf->mask))
1152 continue;
1153
1154 old_feature = af.features & feature;
1155 new_feature = uaf->features & feature;
1156 old_lock = af.lock & feature;
1157 new_lock = (uaf->lock | af.lock) & feature;
1158
1159 if (new_feature != old_feature)
1160 audit_log_feature_change(i, old_feature, new_feature,
1161 old_lock, new_lock, 1);
1162
1163 if (new_feature)
1164 af.features |= feature;
1165 else
1166 af.features &= ~feature;
1167 af.lock |= new_lock;
1168 }
1169
1170 return 0;
1171}
1172
1173static int audit_replace(struct pid *pid)
1174{
1175 pid_t pvnr;
1176 struct sk_buff *skb;
1177
1178 pvnr = pid_vnr(pid);
1179 skb = audit_make_reply(0, AUDIT_REPLACE, 0, 0, &pvnr, sizeof(pvnr));
1180 if (!skb)
1181 return -ENOMEM;
1182 return auditd_send_unicast_skb(skb);
1183}
1184
1185static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
1186{
1187 u32 seq;
1188 void *data;
1189 int data_len;
1190 int err;
1191 struct audit_buffer *ab;
1192 u16 msg_type = nlh->nlmsg_type;
1193 struct audit_sig_info *sig_data;
1194 char *ctx = NULL;
1195 u32 len;
1196
1197 err = audit_netlink_ok(skb, msg_type);
1198 if (err)
1199 return err;
1200
1201 seq = nlh->nlmsg_seq;
1202 data = nlmsg_data(nlh);
1203 data_len = nlmsg_len(nlh);
1204
1205 switch (msg_type) {
1206 case AUDIT_GET: {
1207 struct audit_status s;
1208 memset(&s, 0, sizeof(s));
1209 s.enabled = audit_enabled;
1210 s.failure = audit_failure;
1211
1212
1213 s.pid = auditd_pid_vnr();
1214 s.rate_limit = audit_rate_limit;
1215 s.backlog_limit = audit_backlog_limit;
1216 s.lost = atomic_read(&audit_lost);
1217 s.backlog = skb_queue_len(&audit_queue);
1218 s.feature_bitmap = AUDIT_FEATURE_BITMAP_ALL;
1219 s.backlog_wait_time = audit_backlog_wait_time;
1220 s.backlog_wait_time_actual = atomic_read(&audit_backlog_wait_time_actual);
1221 audit_send_reply(skb, seq, AUDIT_GET, 0, 0, &s, sizeof(s));
1222 break;
1223 }
1224 case AUDIT_SET: {
1225 struct audit_status s;
1226 memset(&s, 0, sizeof(s));
1227
1228 memcpy(&s, data, min_t(size_t, sizeof(s), data_len));
1229 if (s.mask & AUDIT_STATUS_ENABLED) {
1230 err = audit_set_enabled(s.enabled);
1231 if (err < 0)
1232 return err;
1233 }
1234 if (s.mask & AUDIT_STATUS_FAILURE) {
1235 err = audit_set_failure(s.failure);
1236 if (err < 0)
1237 return err;
1238 }
1239 if (s.mask & AUDIT_STATUS_PID) {
1240
1241
1242
1243
1244
1245
1246 pid_t new_pid = s.pid;
1247 pid_t auditd_pid;
1248 struct pid *req_pid = task_tgid(current);
1249
1250
1251
1252 if (new_pid && (new_pid != pid_vnr(req_pid)))
1253 return -EINVAL;
1254
1255
1256 audit_replace(req_pid);
1257
1258 auditd_pid = auditd_pid_vnr();
1259 if (auditd_pid) {
1260
1261 if (new_pid) {
1262 audit_log_config_change("audit_pid",
1263 new_pid, auditd_pid, 0);
1264 return -EEXIST;
1265 }
1266
1267 if (pid_vnr(req_pid) != auditd_pid) {
1268 audit_log_config_change("audit_pid",
1269 new_pid, auditd_pid, 0);
1270 return -EACCES;
1271 }
1272 }
1273
1274 if (new_pid) {
1275
1276 err = auditd_set(req_pid,
1277 NETLINK_CB(skb).portid,
1278 sock_net(NETLINK_CB(skb).sk));
1279 if (audit_enabled != AUDIT_OFF)
1280 audit_log_config_change("audit_pid",
1281 new_pid,
1282 auditd_pid,
1283 err ? 0 : 1);
1284 if (err)
1285 return err;
1286
1287
1288 wake_up_interruptible(&kauditd_wait);
1289 } else {
1290 if (audit_enabled != AUDIT_OFF)
1291 audit_log_config_change("audit_pid",
1292 new_pid,
1293 auditd_pid, 1);
1294
1295
1296 auditd_reset(NULL);
1297 }
1298 }
1299 if (s.mask & AUDIT_STATUS_RATE_LIMIT) {
1300 err = audit_set_rate_limit(s.rate_limit);
1301 if (err < 0)
1302 return err;
1303 }
1304 if (s.mask & AUDIT_STATUS_BACKLOG_LIMIT) {
1305 err = audit_set_backlog_limit(s.backlog_limit);
1306 if (err < 0)
1307 return err;
1308 }
1309 if (s.mask & AUDIT_STATUS_BACKLOG_WAIT_TIME) {
1310 if (sizeof(s) > (size_t)nlh->nlmsg_len)
1311 return -EINVAL;
1312 if (s.backlog_wait_time > 10*AUDIT_BACKLOG_WAIT_TIME)
1313 return -EINVAL;
1314 err = audit_set_backlog_wait_time(s.backlog_wait_time);
1315 if (err < 0)
1316 return err;
1317 }
1318 if (s.mask == AUDIT_STATUS_LOST) {
1319 u32 lost = atomic_xchg(&audit_lost, 0);
1320
1321 audit_log_config_change("lost", 0, lost, 1);
1322 return lost;
1323 }
1324 if (s.mask == AUDIT_STATUS_BACKLOG_WAIT_TIME_ACTUAL) {
1325 u32 actual = atomic_xchg(&audit_backlog_wait_time_actual, 0);
1326
1327 audit_log_config_change("backlog_wait_time_actual", 0, actual, 1);
1328 return actual;
1329 }
1330 break;
1331 }
1332 case AUDIT_GET_FEATURE:
1333 err = audit_get_feature(skb);
1334 if (err)
1335 return err;
1336 break;
1337 case AUDIT_SET_FEATURE:
1338 if (data_len < sizeof(struct audit_features))
1339 return -EINVAL;
1340 err = audit_set_feature(data);
1341 if (err)
1342 return err;
1343 break;
1344 case AUDIT_USER:
1345 case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG:
1346 case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2:
1347 if (!audit_enabled && msg_type != AUDIT_USER_AVC)
1348 return 0;
1349
1350 if (data_len < 2)
1351 return -EINVAL;
1352
1353 err = audit_filter(msg_type, AUDIT_FILTER_USER);
1354 if (err == 1) {
1355 char *str = data;
1356
1357 err = 0;
1358 if (msg_type == AUDIT_USER_TTY) {
1359 err = tty_audit_push();
1360 if (err)
1361 break;
1362 }
1363 audit_log_user_recv_msg(&ab, msg_type);
1364 if (msg_type != AUDIT_USER_TTY) {
1365
1366 str[data_len - 1] = '\0';
1367 audit_log_format(ab, " msg='%.*s'",
1368 AUDIT_MESSAGE_TEXT_MAX,
1369 str);
1370 } else {
1371 audit_log_format(ab, " data=");
1372 if (data_len > 0 && str[data_len - 1] == '\0')
1373 data_len--;
1374 audit_log_n_untrustedstring(ab, str, data_len);
1375 }
1376 audit_log_end(ab);
1377 }
1378 break;
1379 case AUDIT_ADD_RULE:
1380 case AUDIT_DEL_RULE:
1381 if (data_len < sizeof(struct audit_rule_data))
1382 return -EINVAL;
1383 if (audit_enabled == AUDIT_LOCKED) {
1384 audit_log_common_recv_msg(audit_context(), &ab,
1385 AUDIT_CONFIG_CHANGE);
1386 audit_log_format(ab, " op=%s audit_enabled=%d res=0",
1387 msg_type == AUDIT_ADD_RULE ?
1388 "add_rule" : "remove_rule",
1389 audit_enabled);
1390 audit_log_end(ab);
1391 return -EPERM;
1392 }
1393 err = audit_rule_change(msg_type, seq, data, data_len);
1394 break;
1395 case AUDIT_LIST_RULES:
1396 err = audit_list_rules_send(skb, seq);
1397 break;
1398 case AUDIT_TRIM:
1399 audit_trim_trees();
1400 audit_log_common_recv_msg(audit_context(), &ab,
1401 AUDIT_CONFIG_CHANGE);
1402 audit_log_format(ab, " op=trim res=1");
1403 audit_log_end(ab);
1404 break;
1405 case AUDIT_MAKE_EQUIV: {
1406 void *bufp = data;
1407 u32 sizes[2];
1408 size_t msglen = data_len;
1409 char *old, *new;
1410
1411 err = -EINVAL;
1412 if (msglen < 2 * sizeof(u32))
1413 break;
1414 memcpy(sizes, bufp, 2 * sizeof(u32));
1415 bufp += 2 * sizeof(u32);
1416 msglen -= 2 * sizeof(u32);
1417 old = audit_unpack_string(&bufp, &msglen, sizes[0]);
1418 if (IS_ERR(old)) {
1419 err = PTR_ERR(old);
1420 break;
1421 }
1422 new = audit_unpack_string(&bufp, &msglen, sizes[1]);
1423 if (IS_ERR(new)) {
1424 err = PTR_ERR(new);
1425 kfree(old);
1426 break;
1427 }
1428
1429 err = audit_tag_tree(old, new);
1430
1431 audit_log_common_recv_msg(audit_context(), &ab,
1432 AUDIT_CONFIG_CHANGE);
1433 audit_log_format(ab, " op=make_equiv old=");
1434 audit_log_untrustedstring(ab, old);
1435 audit_log_format(ab, " new=");
1436 audit_log_untrustedstring(ab, new);
1437 audit_log_format(ab, " res=%d", !err);
1438 audit_log_end(ab);
1439 kfree(old);
1440 kfree(new);
1441 break;
1442 }
1443 case AUDIT_SIGNAL_INFO:
1444 len = 0;
1445 if (audit_sig_sid) {
1446 err = security_secid_to_secctx(audit_sig_sid, &ctx, &len);
1447 if (err)
1448 return err;
1449 }
1450 sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL);
1451 if (!sig_data) {
1452 if (audit_sig_sid)
1453 security_release_secctx(ctx, len);
1454 return -ENOMEM;
1455 }
1456 sig_data->uid = from_kuid(&init_user_ns, audit_sig_uid);
1457 sig_data->pid = audit_sig_pid;
1458 if (audit_sig_sid) {
1459 memcpy(sig_data->ctx, ctx, len);
1460 security_release_secctx(ctx, len);
1461 }
1462 audit_send_reply(skb, seq, AUDIT_SIGNAL_INFO, 0, 0,
1463 sig_data, sizeof(*sig_data) + len);
1464 kfree(sig_data);
1465 break;
1466 case AUDIT_TTY_GET: {
1467 struct audit_tty_status s;
1468 unsigned int t;
1469
1470 t = READ_ONCE(current->signal->audit_tty);
1471 s.enabled = t & AUDIT_TTY_ENABLE;
1472 s.log_passwd = !!(t & AUDIT_TTY_LOG_PASSWD);
1473
1474 audit_send_reply(skb, seq, AUDIT_TTY_GET, 0, 0, &s, sizeof(s));
1475 break;
1476 }
1477 case AUDIT_TTY_SET: {
1478 struct audit_tty_status s, old;
1479 struct audit_buffer *ab;
1480 unsigned int t;
1481
1482 memset(&s, 0, sizeof(s));
1483
1484 memcpy(&s, data, min_t(size_t, sizeof(s), data_len));
1485
1486 if ((s.enabled != 0 && s.enabled != 1) ||
1487 (s.log_passwd != 0 && s.log_passwd != 1))
1488 err = -EINVAL;
1489
1490 if (err)
1491 t = READ_ONCE(current->signal->audit_tty);
1492 else {
1493 t = s.enabled | (-s.log_passwd & AUDIT_TTY_LOG_PASSWD);
1494 t = xchg(¤t->signal->audit_tty, t);
1495 }
1496 old.enabled = t & AUDIT_TTY_ENABLE;
1497 old.log_passwd = !!(t & AUDIT_TTY_LOG_PASSWD);
1498
1499 audit_log_common_recv_msg(audit_context(), &ab,
1500 AUDIT_CONFIG_CHANGE);
1501 audit_log_format(ab, " op=tty_set old-enabled=%d new-enabled=%d"
1502 " old-log_passwd=%d new-log_passwd=%d res=%d",
1503 old.enabled, s.enabled, old.log_passwd,
1504 s.log_passwd, !err);
1505 audit_log_end(ab);
1506 break;
1507 }
1508 default:
1509 err = -EINVAL;
1510 break;
1511 }
1512
1513 return err < 0 ? err : 0;
1514}
1515
1516
1517
1518
1519
1520
1521
1522
1523static void audit_receive(struct sk_buff *skb)
1524{
1525 struct nlmsghdr *nlh;
1526
1527
1528
1529
1530 int len;
1531 int err;
1532
1533 nlh = nlmsg_hdr(skb);
1534 len = skb->len;
1535
1536 audit_ctl_lock();
1537 while (nlmsg_ok(nlh, len)) {
1538 err = audit_receive_msg(skb, nlh);
1539
1540 if (err || (nlh->nlmsg_flags & NLM_F_ACK))
1541 netlink_ack(skb, nlh, err, NULL);
1542
1543 nlh = nlmsg_next(nlh, &len);
1544 }
1545 audit_ctl_unlock();
1546}
1547
1548
1549static void audit_log_multicast(int group, const char *op, int err)
1550{
1551 const struct cred *cred;
1552 struct tty_struct *tty;
1553 char comm[sizeof(current->comm)];
1554 struct audit_buffer *ab;
1555
1556 if (!audit_enabled)
1557 return;
1558
1559 ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_EVENT_LISTENER);
1560 if (!ab)
1561 return;
1562
1563 cred = current_cred();
1564 tty = audit_get_tty();
1565 audit_log_format(ab, "pid=%u uid=%u auid=%u tty=%s ses=%u",
1566 task_pid_nr(current),
1567 from_kuid(&init_user_ns, cred->uid),
1568 from_kuid(&init_user_ns, audit_get_loginuid(current)),
1569 tty ? tty_name(tty) : "(none)",
1570 audit_get_sessionid(current));
1571 audit_put_tty(tty);
1572 audit_log_task_context(ab);
1573 audit_log_format(ab, " comm=");
1574 audit_log_untrustedstring(ab, get_task_comm(comm, current));
1575 audit_log_d_path_exe(ab, current->mm);
1576 audit_log_format(ab, " nl-mcgrp=%d op=%s res=%d", group, op, !err);
1577 audit_log_end(ab);
1578}
1579
1580
1581static int audit_multicast_bind(struct net *net, int group)
1582{
1583 int err = 0;
1584
1585 if (!capable(CAP_AUDIT_READ))
1586 err = -EPERM;
1587 audit_log_multicast(group, "connect", err);
1588 return err;
1589}
1590
1591static void audit_multicast_unbind(struct net *net, int group)
1592{
1593 audit_log_multicast(group, "disconnect", 0);
1594}
1595
1596static int __net_init audit_net_init(struct net *net)
1597{
1598 struct netlink_kernel_cfg cfg = {
1599 .input = audit_receive,
1600 .bind = audit_multicast_bind,
1601 .unbind = audit_multicast_unbind,
1602 .flags = NL_CFG_F_NONROOT_RECV,
1603 .groups = AUDIT_NLGRP_MAX,
1604 };
1605
1606 struct audit_net *aunet = net_generic(net, audit_net_id);
1607
1608 aunet->sk = netlink_kernel_create(net, NETLINK_AUDIT, &cfg);
1609 if (aunet->sk == NULL) {
1610 audit_panic("cannot initialize netlink socket in namespace");
1611 return -ENOMEM;
1612 }
1613 aunet->sk->sk_sndtimeo = MAX_SCHEDULE_TIMEOUT;
1614
1615 return 0;
1616}
1617
1618static void __net_exit audit_net_exit(struct net *net)
1619{
1620 struct audit_net *aunet = net_generic(net, audit_net_id);
1621
1622
1623
1624
1625
1626
1627
1628 netlink_kernel_release(aunet->sk);
1629}
1630
1631static struct pernet_operations audit_net_ops __net_initdata = {
1632 .init = audit_net_init,
1633 .exit = audit_net_exit,
1634 .id = &audit_net_id,
1635 .size = sizeof(struct audit_net),
1636};
1637
1638
1639static int __init audit_init(void)
1640{
1641 int i;
1642
1643 if (audit_initialized == AUDIT_DISABLED)
1644 return 0;
1645
1646 audit_buffer_cache = kmem_cache_create("audit_buffer",
1647 sizeof(struct audit_buffer),
1648 0, SLAB_PANIC, NULL);
1649
1650 skb_queue_head_init(&audit_queue);
1651 skb_queue_head_init(&audit_retry_queue);
1652 skb_queue_head_init(&audit_hold_queue);
1653
1654 for (i = 0; i < AUDIT_INODE_BUCKETS; i++)
1655 INIT_LIST_HEAD(&audit_inode_hash[i]);
1656
1657 mutex_init(&audit_cmd_mutex.lock);
1658 audit_cmd_mutex.owner = NULL;
1659
1660 pr_info("initializing netlink subsys (%s)\n",
1661 audit_default ? "enabled" : "disabled");
1662 register_pernet_subsys(&audit_net_ops);
1663
1664 audit_initialized = AUDIT_INITIALIZED;
1665
1666 kauditd_task = kthread_run(kauditd_thread, NULL, "kauditd");
1667 if (IS_ERR(kauditd_task)) {
1668 int err = PTR_ERR(kauditd_task);
1669 panic("audit: failed to start the kauditd thread (%d)\n", err);
1670 }
1671
1672 audit_log(NULL, GFP_KERNEL, AUDIT_KERNEL,
1673 "state=initialized audit_enabled=%u res=1",
1674 audit_enabled);
1675
1676 return 0;
1677}
1678postcore_initcall(audit_init);
1679
1680
1681
1682
1683
1684static int __init audit_enable(char *str)
1685{
1686 if (!strcasecmp(str, "off") || !strcmp(str, "0"))
1687 audit_default = AUDIT_OFF;
1688 else if (!strcasecmp(str, "on") || !strcmp(str, "1"))
1689 audit_default = AUDIT_ON;
1690 else {
1691 pr_err("audit: invalid 'audit' parameter value (%s)\n", str);
1692 audit_default = AUDIT_ON;
1693 }
1694
1695 if (audit_default == AUDIT_OFF)
1696 audit_initialized = AUDIT_DISABLED;
1697 if (audit_set_enabled(audit_default))
1698 pr_err("audit: error setting audit state (%d)\n",
1699 audit_default);
1700
1701 pr_info("%s\n", audit_default ?
1702 "enabled (after initialization)" : "disabled (until reboot)");
1703
1704 return 1;
1705}
1706__setup("audit=", audit_enable);
1707
1708
1709
1710static int __init audit_backlog_limit_set(char *str)
1711{
1712 u32 audit_backlog_limit_arg;
1713
1714 pr_info("audit_backlog_limit: ");
1715 if (kstrtouint(str, 0, &audit_backlog_limit_arg)) {
1716 pr_cont("using default of %u, unable to parse %s\n",
1717 audit_backlog_limit, str);
1718 return 1;
1719 }
1720
1721 audit_backlog_limit = audit_backlog_limit_arg;
1722 pr_cont("%d\n", audit_backlog_limit);
1723
1724 return 1;
1725}
1726__setup("audit_backlog_limit=", audit_backlog_limit_set);
1727
1728static void audit_buffer_free(struct audit_buffer *ab)
1729{
1730 if (!ab)
1731 return;
1732
1733 kfree_skb(ab->skb);
1734 kmem_cache_free(audit_buffer_cache, ab);
1735}
1736
1737static struct audit_buffer *audit_buffer_alloc(struct audit_context *ctx,
1738 gfp_t gfp_mask, int type)
1739{
1740 struct audit_buffer *ab;
1741
1742 ab = kmem_cache_alloc(audit_buffer_cache, gfp_mask);
1743 if (!ab)
1744 return NULL;
1745
1746 ab->skb = nlmsg_new(AUDIT_BUFSIZ, gfp_mask);
1747 if (!ab->skb)
1748 goto err;
1749 if (!nlmsg_put(ab->skb, 0, 0, type, 0, 0))
1750 goto err;
1751
1752 ab->ctx = ctx;
1753 ab->gfp_mask = gfp_mask;
1754
1755 return ab;
1756
1757err:
1758 audit_buffer_free(ab);
1759 return NULL;
1760}
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779unsigned int audit_serial(void)
1780{
1781 static atomic_t serial = ATOMIC_INIT(0);
1782
1783 return atomic_add_return(1, &serial);
1784}
1785
1786static inline void audit_get_stamp(struct audit_context *ctx,
1787 struct timespec64 *t, unsigned int *serial)
1788{
1789 if (!ctx || !auditsc_get_stamp(ctx, t, serial)) {
1790 ktime_get_coarse_real_ts64(t);
1791 *serial = audit_serial();
1792 }
1793}
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask,
1811 int type)
1812{
1813 struct audit_buffer *ab;
1814 struct timespec64 t;
1815 unsigned int serial;
1816
1817 if (audit_initialized != AUDIT_INITIALIZED)
1818 return NULL;
1819
1820 if (unlikely(!audit_filter(type, AUDIT_FILTER_EXCLUDE)))
1821 return NULL;
1822
1823
1824
1825
1826
1827
1828
1829
1830 if (!(auditd_test_task(current) || audit_ctl_owner_current())) {
1831 long stime = audit_backlog_wait_time;
1832
1833 while (audit_backlog_limit &&
1834 (skb_queue_len(&audit_queue) > audit_backlog_limit)) {
1835
1836 wake_up_interruptible(&kauditd_wait);
1837
1838
1839
1840 if (gfpflags_allow_blocking(gfp_mask) && (stime > 0)) {
1841 long rtime = stime;
1842
1843 DECLARE_WAITQUEUE(wait, current);
1844
1845 add_wait_queue_exclusive(&audit_backlog_wait,
1846 &wait);
1847 set_current_state(TASK_UNINTERRUPTIBLE);
1848 stime = schedule_timeout(rtime);
1849 atomic_add(rtime - stime, &audit_backlog_wait_time_actual);
1850 remove_wait_queue(&audit_backlog_wait, &wait);
1851 } else {
1852 if (audit_rate_check() && printk_ratelimit())
1853 pr_warn("audit_backlog=%d > audit_backlog_limit=%d\n",
1854 skb_queue_len(&audit_queue),
1855 audit_backlog_limit);
1856 audit_log_lost("backlog limit exceeded");
1857 return NULL;
1858 }
1859 }
1860 }
1861
1862 ab = audit_buffer_alloc(ctx, gfp_mask, type);
1863 if (!ab) {
1864 audit_log_lost("out of memory in audit_log_start");
1865 return NULL;
1866 }
1867
1868 audit_get_stamp(ab->ctx, &t, &serial);
1869 audit_log_format(ab, "audit(%llu.%03lu:%u): ",
1870 (unsigned long long)t.tv_sec, t.tv_nsec/1000000, serial);
1871
1872 return ab;
1873}
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883static inline int audit_expand(struct audit_buffer *ab, int extra)
1884{
1885 struct sk_buff *skb = ab->skb;
1886 int oldtail = skb_tailroom(skb);
1887 int ret = pskb_expand_head(skb, 0, extra, ab->gfp_mask);
1888 int newtail = skb_tailroom(skb);
1889
1890 if (ret < 0) {
1891 audit_log_lost("out of memory in audit_expand");
1892 return 0;
1893 }
1894
1895 skb->truesize += newtail - oldtail;
1896 return newtail;
1897}
1898
1899
1900
1901
1902
1903
1904
1905static void audit_log_vformat(struct audit_buffer *ab, const char *fmt,
1906 va_list args)
1907{
1908 int len, avail;
1909 struct sk_buff *skb;
1910 va_list args2;
1911
1912 if (!ab)
1913 return;
1914
1915 BUG_ON(!ab->skb);
1916 skb = ab->skb;
1917 avail = skb_tailroom(skb);
1918 if (avail == 0) {
1919 avail = audit_expand(ab, AUDIT_BUFSIZ);
1920 if (!avail)
1921 goto out;
1922 }
1923 va_copy(args2, args);
1924 len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args);
1925 if (len >= avail) {
1926
1927
1928
1929 avail = audit_expand(ab,
1930 max_t(unsigned, AUDIT_BUFSIZ, 1+len-avail));
1931 if (!avail)
1932 goto out_va_end;
1933 len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args2);
1934 }
1935 if (len > 0)
1936 skb_put(skb, len);
1937out_va_end:
1938 va_end(args2);
1939out:
1940 return;
1941}
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951void audit_log_format(struct audit_buffer *ab, const char *fmt, ...)
1952{
1953 va_list args;
1954
1955 if (!ab)
1956 return;
1957 va_start(args, fmt);
1958 audit_log_vformat(ab, fmt, args);
1959 va_end(args);
1960}
1961
1962
1963
1964
1965
1966
1967
1968
1969
1970
1971
1972
1973void audit_log_n_hex(struct audit_buffer *ab, const unsigned char *buf,
1974 size_t len)
1975{
1976 int i, avail, new_len;
1977 unsigned char *ptr;
1978 struct sk_buff *skb;
1979
1980 if (!ab)
1981 return;
1982
1983 BUG_ON(!ab->skb);
1984 skb = ab->skb;
1985 avail = skb_tailroom(skb);
1986 new_len = len<<1;
1987 if (new_len >= avail) {
1988
1989 new_len = AUDIT_BUFSIZ*(((new_len-avail)/AUDIT_BUFSIZ) + 1);
1990 avail = audit_expand(ab, new_len);
1991 if (!avail)
1992 return;
1993 }
1994
1995 ptr = skb_tail_pointer(skb);
1996 for (i = 0; i < len; i++)
1997 ptr = hex_byte_pack_upper(ptr, buf[i]);
1998 *ptr = 0;
1999 skb_put(skb, len << 1);
2000}
2001
2002
2003
2004
2005
2006void audit_log_n_string(struct audit_buffer *ab, const char *string,
2007 size_t slen)
2008{
2009 int avail, new_len;
2010 unsigned char *ptr;
2011 struct sk_buff *skb;
2012
2013 if (!ab)
2014 return;
2015
2016 BUG_ON(!ab->skb);
2017 skb = ab->skb;
2018 avail = skb_tailroom(skb);
2019 new_len = slen + 3;
2020 if (new_len > avail) {
2021 avail = audit_expand(ab, new_len);
2022 if (!avail)
2023 return;
2024 }
2025 ptr = skb_tail_pointer(skb);
2026 *ptr++ = '"';
2027 memcpy(ptr, string, slen);
2028 ptr += slen;
2029 *ptr++ = '"';
2030 *ptr = 0;
2031 skb_put(skb, slen + 2);
2032}
2033
2034
2035
2036
2037
2038
2039bool audit_string_contains_control(const char *string, size_t len)
2040{
2041 const unsigned char *p;
2042 for (p = string; p < (const unsigned char *)string + len; p++) {
2043 if (*p == '"' || *p < 0x21 || *p > 0x7e)
2044 return true;
2045 }
2046 return false;
2047}
2048
2049
2050
2051
2052
2053
2054
2055
2056
2057
2058
2059
2060
2061
2062
2063void audit_log_n_untrustedstring(struct audit_buffer *ab, const char *string,
2064 size_t len)
2065{
2066 if (audit_string_contains_control(string, len))
2067 audit_log_n_hex(ab, string, len);
2068 else
2069 audit_log_n_string(ab, string, len);
2070}
2071
2072
2073
2074
2075
2076
2077
2078
2079
2080void audit_log_untrustedstring(struct audit_buffer *ab, const char *string)
2081{
2082 audit_log_n_untrustedstring(ab, string, strlen(string));
2083}
2084
2085
2086void audit_log_d_path(struct audit_buffer *ab, const char *prefix,
2087 const struct path *path)
2088{
2089 char *p, *pathname;
2090
2091 if (prefix)
2092 audit_log_format(ab, "%s", prefix);
2093
2094
2095 pathname = kmalloc(PATH_MAX+11, ab->gfp_mask);
2096 if (!pathname) {
2097 audit_log_format(ab, "\"<no_memory>\"");
2098 return;
2099 }
2100 p = d_path(path, pathname, PATH_MAX+11);
2101 if (IS_ERR(p)) {
2102
2103 audit_log_format(ab, "\"<too_long>\"");
2104 } else
2105 audit_log_untrustedstring(ab, p);
2106 kfree(pathname);
2107}
2108
2109void audit_log_session_info(struct audit_buffer *ab)
2110{
2111 unsigned int sessionid = audit_get_sessionid(current);
2112 uid_t auid = from_kuid(&init_user_ns, audit_get_loginuid(current));
2113
2114 audit_log_format(ab, "auid=%u ses=%u", auid, sessionid);
2115}
2116
2117void audit_log_key(struct audit_buffer *ab, char *key)
2118{
2119 audit_log_format(ab, " key=");
2120 if (key)
2121 audit_log_untrustedstring(ab, key);
2122 else
2123 audit_log_format(ab, "(null)");
2124}
2125
2126int audit_log_task_context(struct audit_buffer *ab)
2127{
2128 char *ctx = NULL;
2129 unsigned len;
2130 int error;
2131 u32 sid;
2132
2133 security_task_getsecid(current, &sid);
2134 if (!sid)
2135 return 0;
2136
2137 error = security_secid_to_secctx(sid, &ctx, &len);
2138 if (error) {
2139 if (error != -EINVAL)
2140 goto error_path;
2141 return 0;
2142 }
2143
2144 audit_log_format(ab, " subj=%s", ctx);
2145 security_release_secctx(ctx, len);
2146 return 0;
2147
2148error_path:
2149 audit_panic("error in audit_log_task_context");
2150 return error;
2151}
2152EXPORT_SYMBOL(audit_log_task_context);
2153
2154void audit_log_d_path_exe(struct audit_buffer *ab,
2155 struct mm_struct *mm)
2156{
2157 struct file *exe_file;
2158
2159 if (!mm)
2160 goto out_null;
2161
2162 exe_file = get_mm_exe_file(mm);
2163 if (!exe_file)
2164 goto out_null;
2165
2166 audit_log_d_path(ab, " exe=", &exe_file->f_path);
2167 fput(exe_file);
2168 return;
2169out_null:
2170 audit_log_format(ab, " exe=(null)");
2171}
2172
2173struct tty_struct *audit_get_tty(void)
2174{
2175 struct tty_struct *tty = NULL;
2176 unsigned long flags;
2177
2178 spin_lock_irqsave(¤t->sighand->siglock, flags);
2179 if (current->signal)
2180 tty = tty_kref_get(current->signal->tty);
2181 spin_unlock_irqrestore(¤t->sighand->siglock, flags);
2182 return tty;
2183}
2184
2185void audit_put_tty(struct tty_struct *tty)
2186{
2187 tty_kref_put(tty);
2188}
2189
2190void audit_log_task_info(struct audit_buffer *ab)
2191{
2192 const struct cred *cred;
2193 char comm[sizeof(current->comm)];
2194 struct tty_struct *tty;
2195
2196 if (!ab)
2197 return;
2198
2199 cred = current_cred();
2200 tty = audit_get_tty();
2201 audit_log_format(ab,
2202 " ppid=%d pid=%d auid=%u uid=%u gid=%u"
2203 " euid=%u suid=%u fsuid=%u"
2204 " egid=%u sgid=%u fsgid=%u tty=%s ses=%u",
2205 task_ppid_nr(current),
2206 task_tgid_nr(current),
2207 from_kuid(&init_user_ns, audit_get_loginuid(current)),
2208 from_kuid(&init_user_ns, cred->uid),
2209 from_kgid(&init_user_ns, cred->gid),
2210 from_kuid(&init_user_ns, cred->euid),
2211 from_kuid(&init_user_ns, cred->suid),
2212 from_kuid(&init_user_ns, cred->fsuid),
2213 from_kgid(&init_user_ns, cred->egid),
2214 from_kgid(&init_user_ns, cred->sgid),
2215 from_kgid(&init_user_ns, cred->fsgid),
2216 tty ? tty_name(tty) : "(none)",
2217 audit_get_sessionid(current));
2218 audit_put_tty(tty);
2219 audit_log_format(ab, " comm=");
2220 audit_log_untrustedstring(ab, get_task_comm(comm, current));
2221 audit_log_d_path_exe(ab, current->mm);
2222 audit_log_task_context(ab);
2223}
2224EXPORT_SYMBOL(audit_log_task_info);
2225
2226
2227
2228
2229
2230
2231void audit_log_path_denied(int type, const char *operation)
2232{
2233 struct audit_buffer *ab;
2234
2235 if (!audit_enabled || audit_dummy_context())
2236 return;
2237
2238
2239 ab = audit_log_start(audit_context(), GFP_KERNEL, type);
2240 if (!ab)
2241 return;
2242 audit_log_format(ab, "op=%s", operation);
2243 audit_log_task_info(ab);
2244 audit_log_format(ab, " res=0");
2245 audit_log_end(ab);
2246}
2247
2248
2249static atomic_t session_id = ATOMIC_INIT(0);
2250
2251static int audit_set_loginuid_perm(kuid_t loginuid)
2252{
2253
2254 if (!audit_loginuid_set(current))
2255 return 0;
2256
2257 if (is_audit_feature_set(AUDIT_FEATURE_LOGINUID_IMMUTABLE))
2258 return -EPERM;
2259
2260 if (!capable(CAP_AUDIT_CONTROL))
2261 return -EPERM;
2262
2263 if (is_audit_feature_set(AUDIT_FEATURE_ONLY_UNSET_LOGINUID)
2264 && uid_valid(loginuid))
2265 return -EPERM;
2266 return 0;
2267}
2268
2269static void audit_log_set_loginuid(kuid_t koldloginuid, kuid_t kloginuid,
2270 unsigned int oldsessionid,
2271 unsigned int sessionid, int rc)
2272{
2273 struct audit_buffer *ab;
2274 uid_t uid, oldloginuid, loginuid;
2275 struct tty_struct *tty;
2276
2277 if (!audit_enabled)
2278 return;
2279
2280 ab = audit_log_start(audit_context(), GFP_KERNEL, AUDIT_LOGIN);
2281 if (!ab)
2282 return;
2283
2284 uid = from_kuid(&init_user_ns, task_uid(current));
2285 oldloginuid = from_kuid(&init_user_ns, koldloginuid);
2286 loginuid = from_kuid(&init_user_ns, kloginuid),
2287 tty = audit_get_tty();
2288
2289 audit_log_format(ab, "pid=%d uid=%u", task_tgid_nr(current), uid);
2290 audit_log_task_context(ab);
2291 audit_log_format(ab, " old-auid=%u auid=%u tty=%s old-ses=%u ses=%u res=%d",
2292 oldloginuid, loginuid, tty ? tty_name(tty) : "(none)",
2293 oldsessionid, sessionid, !rc);
2294 audit_put_tty(tty);
2295 audit_log_end(ab);
2296}
2297
2298
2299
2300
2301
2302
2303
2304
2305
2306int audit_set_loginuid(kuid_t loginuid)
2307{
2308 unsigned int oldsessionid, sessionid = AUDIT_SID_UNSET;
2309 kuid_t oldloginuid;
2310 int rc;
2311
2312 oldloginuid = audit_get_loginuid(current);
2313 oldsessionid = audit_get_sessionid(current);
2314
2315 rc = audit_set_loginuid_perm(loginuid);
2316 if (rc)
2317 goto out;
2318
2319
2320 if (uid_valid(loginuid)) {
2321 sessionid = (unsigned int)atomic_inc_return(&session_id);
2322 if (unlikely(sessionid == AUDIT_SID_UNSET))
2323 sessionid = (unsigned int)atomic_inc_return(&session_id);
2324 }
2325
2326 current->sessionid = sessionid;
2327 current->loginuid = loginuid;
2328out:
2329 audit_log_set_loginuid(oldloginuid, loginuid, oldsessionid, sessionid, rc);
2330 return rc;
2331}
2332
2333
2334
2335
2336
2337
2338
2339
2340
2341int audit_signal_info(int sig, struct task_struct *t)
2342{
2343 kuid_t uid = current_uid(), auid;
2344
2345 if (auditd_test_task(t) &&
2346 (sig == SIGTERM || sig == SIGHUP ||
2347 sig == SIGUSR1 || sig == SIGUSR2)) {
2348 audit_sig_pid = task_tgid_nr(current);
2349 auid = audit_get_loginuid(current);
2350 if (uid_valid(auid))
2351 audit_sig_uid = auid;
2352 else
2353 audit_sig_uid = uid;
2354 security_task_getsecid(current, &audit_sig_sid);
2355 }
2356
2357 return audit_signal_info_syscall(t);
2358}
2359
2360
2361
2362
2363
2364
2365
2366
2367
2368
2369void audit_log_end(struct audit_buffer *ab)
2370{
2371 struct sk_buff *skb;
2372 struct nlmsghdr *nlh;
2373
2374 if (!ab)
2375 return;
2376
2377 if (audit_rate_check()) {
2378 skb = ab->skb;
2379 ab->skb = NULL;
2380
2381
2382
2383 nlh = nlmsg_hdr(skb);
2384 nlh->nlmsg_len = skb->len - NLMSG_HDRLEN;
2385
2386
2387 skb_queue_tail(&audit_queue, skb);
2388 wake_up_interruptible(&kauditd_wait);
2389 } else
2390 audit_log_lost("rate limit exceeded");
2391
2392 audit_buffer_free(ab);
2393}
2394
2395
2396
2397
2398
2399
2400
2401
2402
2403
2404
2405
2406
2407void audit_log(struct audit_context *ctx, gfp_t gfp_mask, int type,
2408 const char *fmt, ...)
2409{
2410 struct audit_buffer *ab;
2411 va_list args;
2412
2413 ab = audit_log_start(ctx, gfp_mask, type);
2414 if (ab) {
2415 va_start(args, fmt);
2416 audit_log_vformat(ab, fmt, args);
2417 va_end(args);
2418 audit_log_end(ab);
2419 }
2420}
2421
2422EXPORT_SYMBOL(audit_log_start);
2423EXPORT_SYMBOL(audit_log_end);
2424EXPORT_SYMBOL(audit_log_format);
2425EXPORT_SYMBOL(audit_log);
2426