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44#include <linux/init.h>
45#include <asm/types.h>
46#include <linux/atomic.h>
47#include <linux/mm.h>
48#include <linux/export.h>
49#include <linux/slab.h>
50#include <linux/err.h>
51#include <linux/kthread.h>
52#include <linux/kernel.h>
53#include <linux/syscalls.h>
54
55#include <linux/audit.h>
56
57#include <net/sock.h>
58#include <net/netlink.h>
59#include <linux/skbuff.h>
60#ifdef CONFIG_SECURITY
61#include <linux/security.h>
62#endif
63#include <net/netlink.h>
64#include <linux/freezer.h>
65#include <linux/tty.h>
66#include <linux/pid_namespace.h>
67
68#include "audit.h"
69
70
71
72#define AUDIT_DISABLED -1
73#define AUDIT_UNINITIALIZED 0
74#define AUDIT_INITIALIZED 1
75static int audit_initialized;
76
77#define AUDIT_OFF 0
78#define AUDIT_ON 1
79#define AUDIT_LOCKED 2
80int audit_enabled;
81int audit_ever_enabled;
82
83EXPORT_SYMBOL_GPL(audit_enabled);
84
85
86static int audit_default;
87
88
89static int audit_failure = AUDIT_FAIL_PRINTK;
90
91
92
93
94
95
96int audit_pid;
97static int audit_nlk_portid;
98
99
100
101
102static int audit_rate_limit;
103
104
105static int audit_backlog_limit = 64;
106static int audit_backlog_wait_time = 60 * HZ;
107static int audit_backlog_wait_overflow = 0;
108
109
110kuid_t audit_sig_uid = INVALID_UID;
111pid_t audit_sig_pid = -1;
112u32 audit_sig_sid = 0;
113
114
115
116
117
118
119
120
121static atomic_t audit_lost = ATOMIC_INIT(0);
122
123
124static struct sock *audit_sock;
125
126
127struct list_head audit_inode_hash[AUDIT_INODE_BUCKETS];
128
129
130
131
132static DEFINE_SPINLOCK(audit_freelist_lock);
133static int audit_freelist_count;
134static LIST_HEAD(audit_freelist);
135
136static struct sk_buff_head audit_skb_queue;
137
138static struct sk_buff_head audit_skb_hold_queue;
139static struct task_struct *kauditd_task;
140static DECLARE_WAIT_QUEUE_HEAD(kauditd_wait);
141static DECLARE_WAIT_QUEUE_HEAD(audit_backlog_wait);
142
143
144DEFINE_MUTEX(audit_cmd_mutex);
145
146
147
148
149#define AUDIT_BUFSIZ 1024
150
151
152
153#define AUDIT_MAXFREE (2*NR_CPUS)
154
155
156
157
158
159
160struct audit_buffer {
161 struct list_head list;
162 struct sk_buff *skb;
163 struct audit_context *ctx;
164 gfp_t gfp_mask;
165};
166
167struct audit_reply {
168 int pid;
169 struct sk_buff *skb;
170};
171
172static void audit_set_pid(struct audit_buffer *ab, pid_t pid)
173{
174 if (ab) {
175 struct nlmsghdr *nlh = nlmsg_hdr(ab->skb);
176 nlh->nlmsg_pid = pid;
177 }
178}
179
180void audit_panic(const char *message)
181{
182 switch (audit_failure)
183 {
184 case AUDIT_FAIL_SILENT:
185 break;
186 case AUDIT_FAIL_PRINTK:
187 if (printk_ratelimit())
188 printk(KERN_ERR "audit: %s\n", message);
189 break;
190 case AUDIT_FAIL_PANIC:
191
192 if (audit_pid)
193 panic("audit: %s\n", message);
194 break;
195 }
196}
197
198static inline int audit_rate_check(void)
199{
200 static unsigned long last_check = 0;
201 static int messages = 0;
202 static DEFINE_SPINLOCK(lock);
203 unsigned long flags;
204 unsigned long now;
205 unsigned long elapsed;
206 int retval = 0;
207
208 if (!audit_rate_limit) return 1;
209
210 spin_lock_irqsave(&lock, flags);
211 if (++messages < audit_rate_limit) {
212 retval = 1;
213 } else {
214 now = jiffies;
215 elapsed = now - last_check;
216 if (elapsed > HZ) {
217 last_check = now;
218 messages = 0;
219 retval = 1;
220 }
221 }
222 spin_unlock_irqrestore(&lock, flags);
223
224 return retval;
225}
226
227
228
229
230
231
232
233
234
235void audit_log_lost(const char *message)
236{
237 static unsigned long last_msg = 0;
238 static DEFINE_SPINLOCK(lock);
239 unsigned long flags;
240 unsigned long now;
241 int print;
242
243 atomic_inc(&audit_lost);
244
245 print = (audit_failure == AUDIT_FAIL_PANIC || !audit_rate_limit);
246
247 if (!print) {
248 spin_lock_irqsave(&lock, flags);
249 now = jiffies;
250 if (now - last_msg > HZ) {
251 print = 1;
252 last_msg = now;
253 }
254 spin_unlock_irqrestore(&lock, flags);
255 }
256
257 if (print) {
258 if (printk_ratelimit())
259 printk(KERN_WARNING
260 "audit: audit_lost=%d audit_rate_limit=%d "
261 "audit_backlog_limit=%d\n",
262 atomic_read(&audit_lost),
263 audit_rate_limit,
264 audit_backlog_limit);
265 audit_panic(message);
266 }
267}
268
269static int audit_log_config_change(char *function_name, int new, int old,
270 int allow_changes)
271{
272 struct audit_buffer *ab;
273 int rc = 0;
274
275 ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
276 if (unlikely(!ab))
277 return rc;
278 audit_log_format(ab, "%s=%d old=%d", function_name, new, old);
279 audit_log_session_info(ab);
280 rc = audit_log_task_context(ab);
281 if (rc)
282 allow_changes = 0;
283 audit_log_format(ab, " res=%d", allow_changes);
284 audit_log_end(ab);
285 return rc;
286}
287
288static int audit_do_config_change(char *function_name, int *to_change, int new)
289{
290 int allow_changes, rc = 0, old = *to_change;
291
292
293 if (audit_enabled == AUDIT_LOCKED)
294 allow_changes = 0;
295 else
296 allow_changes = 1;
297
298 if (audit_enabled != AUDIT_OFF) {
299 rc = audit_log_config_change(function_name, new, old, allow_changes);
300 if (rc)
301 allow_changes = 0;
302 }
303
304
305 if (allow_changes == 1)
306 *to_change = new;
307
308 else if (rc == 0)
309 rc = -EPERM;
310 return rc;
311}
312
313static int audit_set_rate_limit(int limit)
314{
315 return audit_do_config_change("audit_rate_limit", &audit_rate_limit, limit);
316}
317
318static int audit_set_backlog_limit(int limit)
319{
320 return audit_do_config_change("audit_backlog_limit", &audit_backlog_limit, limit);
321}
322
323static int audit_set_enabled(int state)
324{
325 int rc;
326 if (state < AUDIT_OFF || state > AUDIT_LOCKED)
327 return -EINVAL;
328
329 rc = audit_do_config_change("audit_enabled", &audit_enabled, state);
330 if (!rc)
331 audit_ever_enabled |= !!state;
332
333 return rc;
334}
335
336static int audit_set_failure(int state)
337{
338 if (state != AUDIT_FAIL_SILENT
339 && state != AUDIT_FAIL_PRINTK
340 && state != AUDIT_FAIL_PANIC)
341 return -EINVAL;
342
343 return audit_do_config_change("audit_failure", &audit_failure, state);
344}
345
346
347
348
349
350
351
352
353
354
355static void audit_hold_skb(struct sk_buff *skb)
356{
357 if (audit_default &&
358 skb_queue_len(&audit_skb_hold_queue) < audit_backlog_limit)
359 skb_queue_tail(&audit_skb_hold_queue, skb);
360 else
361 kfree_skb(skb);
362}
363
364
365
366
367
368static void audit_printk_skb(struct sk_buff *skb)
369{
370 struct nlmsghdr *nlh = nlmsg_hdr(skb);
371 char *data = nlmsg_data(nlh);
372
373 if (nlh->nlmsg_type != AUDIT_EOE) {
374 if (printk_ratelimit())
375 printk(KERN_NOTICE "type=%d %s\n", nlh->nlmsg_type, data);
376 else
377 audit_log_lost("printk limit exceeded\n");
378 }
379
380 audit_hold_skb(skb);
381}
382
383static void kauditd_send_skb(struct sk_buff *skb)
384{
385 int err;
386
387 skb_get(skb);
388 err = netlink_unicast(audit_sock, skb, audit_nlk_portid, 0);
389 if (err < 0) {
390 BUG_ON(err != -ECONNREFUSED);
391 printk(KERN_ERR "audit: *NO* daemon at audit_pid=%d\n", audit_pid);
392 audit_log_lost("auditd disappeared\n");
393 audit_pid = 0;
394
395 audit_hold_skb(skb);
396 } else
397
398 consume_skb(skb);
399}
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416static void flush_hold_queue(void)
417{
418 struct sk_buff *skb;
419
420 if (!audit_default || !audit_pid)
421 return;
422
423 skb = skb_dequeue(&audit_skb_hold_queue);
424 if (likely(!skb))
425 return;
426
427 while (skb && audit_pid) {
428 kauditd_send_skb(skb);
429 skb = skb_dequeue(&audit_skb_hold_queue);
430 }
431
432
433
434
435
436 if (skb)
437 consume_skb(skb);
438}
439
440static int kauditd_thread(void *dummy)
441{
442 set_freezable();
443 while (!kthread_should_stop()) {
444 struct sk_buff *skb;
445 DECLARE_WAITQUEUE(wait, current);
446
447 flush_hold_queue();
448
449 skb = skb_dequeue(&audit_skb_queue);
450 wake_up(&audit_backlog_wait);
451 if (skb) {
452 if (audit_pid)
453 kauditd_send_skb(skb);
454 else
455 audit_printk_skb(skb);
456 continue;
457 }
458 set_current_state(TASK_INTERRUPTIBLE);
459 add_wait_queue(&kauditd_wait, &wait);
460
461 if (!skb_queue_len(&audit_skb_queue)) {
462 try_to_freeze();
463 schedule();
464 }
465
466 __set_current_state(TASK_RUNNING);
467 remove_wait_queue(&kauditd_wait, &wait);
468 }
469 return 0;
470}
471
472int audit_send_list(void *_dest)
473{
474 struct audit_netlink_list *dest = _dest;
475 int pid = dest->pid;
476 struct sk_buff *skb;
477
478
479 mutex_lock(&audit_cmd_mutex);
480 mutex_unlock(&audit_cmd_mutex);
481
482 while ((skb = __skb_dequeue(&dest->q)) != NULL)
483 netlink_unicast(audit_sock, skb, pid, 0);
484
485 kfree(dest);
486
487 return 0;
488}
489
490struct sk_buff *audit_make_reply(int pid, int seq, int type, int done,
491 int multi, const void *payload, int size)
492{
493 struct sk_buff *skb;
494 struct nlmsghdr *nlh;
495 void *data;
496 int flags = multi ? NLM_F_MULTI : 0;
497 int t = done ? NLMSG_DONE : type;
498
499 skb = nlmsg_new(size, GFP_KERNEL);
500 if (!skb)
501 return NULL;
502
503 nlh = nlmsg_put(skb, pid, seq, t, size, flags);
504 if (!nlh)
505 goto out_kfree_skb;
506 data = nlmsg_data(nlh);
507 memcpy(data, payload, size);
508 return skb;
509
510out_kfree_skb:
511 kfree_skb(skb);
512 return NULL;
513}
514
515static int audit_send_reply_thread(void *arg)
516{
517 struct audit_reply *reply = (struct audit_reply *)arg;
518
519 mutex_lock(&audit_cmd_mutex);
520 mutex_unlock(&audit_cmd_mutex);
521
522
523
524 netlink_unicast(audit_sock, reply->skb, reply->pid, 0);
525 kfree(reply);
526 return 0;
527}
528
529
530
531
532
533
534
535
536
537
538
539
540
541static void audit_send_reply(int pid, int seq, int type, int done, int multi,
542 const void *payload, int size)
543{
544 struct sk_buff *skb;
545 struct task_struct *tsk;
546 struct audit_reply *reply = kmalloc(sizeof(struct audit_reply),
547 GFP_KERNEL);
548
549 if (!reply)
550 return;
551
552 skb = audit_make_reply(pid, seq, type, done, multi, payload, size);
553 if (!skb)
554 goto out;
555
556 reply->pid = pid;
557 reply->skb = skb;
558
559 tsk = kthread_run(audit_send_reply_thread, reply, "audit_send_reply");
560 if (!IS_ERR(tsk))
561 return;
562 kfree_skb(skb);
563out:
564 kfree(reply);
565}
566
567
568
569
570
571static int audit_netlink_ok(struct sk_buff *skb, u16 msg_type)
572{
573 int err = 0;
574
575
576 if ((current_user_ns() != &init_user_ns) ||
577 (task_active_pid_ns(current) != &init_pid_ns))
578 return -EPERM;
579
580 switch (msg_type) {
581 case AUDIT_LIST:
582 case AUDIT_ADD:
583 case AUDIT_DEL:
584 return -EOPNOTSUPP;
585 case AUDIT_GET:
586 case AUDIT_SET:
587 case AUDIT_LIST_RULES:
588 case AUDIT_ADD_RULE:
589 case AUDIT_DEL_RULE:
590 case AUDIT_SIGNAL_INFO:
591 case AUDIT_TTY_GET:
592 case AUDIT_TTY_SET:
593 case AUDIT_TRIM:
594 case AUDIT_MAKE_EQUIV:
595 if (!capable(CAP_AUDIT_CONTROL))
596 err = -EPERM;
597 break;
598 case AUDIT_USER:
599 case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG:
600 case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2:
601 if (!capable(CAP_AUDIT_WRITE))
602 err = -EPERM;
603 break;
604 default:
605 err = -EINVAL;
606 }
607
608 return err;
609}
610
611static int audit_log_common_recv_msg(struct audit_buffer **ab, u16 msg_type)
612{
613 int rc = 0;
614 uid_t uid = from_kuid(&init_user_ns, current_uid());
615
616 if (!audit_enabled) {
617 *ab = NULL;
618 return rc;
619 }
620
621 *ab = audit_log_start(NULL, GFP_KERNEL, msg_type);
622 if (unlikely(!*ab))
623 return rc;
624 audit_log_format(*ab, "pid=%d uid=%u", task_tgid_vnr(current), uid);
625 audit_log_session_info(*ab);
626 audit_log_task_context(*ab);
627
628 return rc;
629}
630
631static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
632{
633 u32 seq;
634 void *data;
635 struct audit_status *status_get, status_set;
636 int err;
637 struct audit_buffer *ab;
638 u16 msg_type = nlh->nlmsg_type;
639 struct audit_sig_info *sig_data;
640 char *ctx = NULL;
641 u32 len;
642
643 err = audit_netlink_ok(skb, msg_type);
644 if (err)
645 return err;
646
647
648
649 if (!kauditd_task) {
650 kauditd_task = kthread_run(kauditd_thread, NULL, "kauditd");
651 if (IS_ERR(kauditd_task)) {
652 err = PTR_ERR(kauditd_task);
653 kauditd_task = NULL;
654 return err;
655 }
656 }
657 seq = nlh->nlmsg_seq;
658 data = nlmsg_data(nlh);
659
660 switch (msg_type) {
661 case AUDIT_GET:
662 status_set.enabled = audit_enabled;
663 status_set.failure = audit_failure;
664 status_set.pid = audit_pid;
665 status_set.rate_limit = audit_rate_limit;
666 status_set.backlog_limit = audit_backlog_limit;
667 status_set.lost = atomic_read(&audit_lost);
668 status_set.backlog = skb_queue_len(&audit_skb_queue);
669 audit_send_reply(NETLINK_CB(skb).portid, seq, AUDIT_GET, 0, 0,
670 &status_set, sizeof(status_set));
671 break;
672 case AUDIT_SET:
673 if (nlh->nlmsg_len < sizeof(struct audit_status))
674 return -EINVAL;
675 status_get = (struct audit_status *)data;
676 if (status_get->mask & AUDIT_STATUS_ENABLED) {
677 err = audit_set_enabled(status_get->enabled);
678 if (err < 0)
679 return err;
680 }
681 if (status_get->mask & AUDIT_STATUS_FAILURE) {
682 err = audit_set_failure(status_get->failure);
683 if (err < 0)
684 return err;
685 }
686 if (status_get->mask & AUDIT_STATUS_PID) {
687 int new_pid = status_get->pid;
688
689 if (audit_enabled != AUDIT_OFF)
690 audit_log_config_change("audit_pid", new_pid, audit_pid, 1);
691 audit_pid = new_pid;
692 audit_nlk_portid = NETLINK_CB(skb).portid;
693 }
694 if (status_get->mask & AUDIT_STATUS_RATE_LIMIT) {
695 err = audit_set_rate_limit(status_get->rate_limit);
696 if (err < 0)
697 return err;
698 }
699 if (status_get->mask & AUDIT_STATUS_BACKLOG_LIMIT)
700 err = audit_set_backlog_limit(status_get->backlog_limit);
701 break;
702 case AUDIT_USER:
703 case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG:
704 case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2:
705 if (!audit_enabled && msg_type != AUDIT_USER_AVC)
706 return 0;
707
708 err = audit_filter_user(msg_type);
709 if (err == 1) {
710 err = 0;
711 if (msg_type == AUDIT_USER_TTY) {
712 err = tty_audit_push_current();
713 if (err)
714 break;
715 }
716 audit_log_common_recv_msg(&ab, msg_type);
717 if (msg_type != AUDIT_USER_TTY)
718 audit_log_format(ab, " msg='%.1024s'",
719 (char *)data);
720 else {
721 int size;
722
723 audit_log_format(ab, " data=");
724 size = nlmsg_len(nlh);
725 if (size > 0 &&
726 ((unsigned char *)data)[size - 1] == '\0')
727 size--;
728 audit_log_n_untrustedstring(ab, data, size);
729 }
730 audit_set_pid(ab, NETLINK_CB(skb).portid);
731 audit_log_end(ab);
732 }
733 break;
734 case AUDIT_ADD_RULE:
735 case AUDIT_DEL_RULE:
736 if (nlmsg_len(nlh) < sizeof(struct audit_rule_data))
737 return -EINVAL;
738 if (audit_enabled == AUDIT_LOCKED) {
739 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE);
740 audit_log_format(ab, " audit_enabled=%d res=0", audit_enabled);
741 audit_log_end(ab);
742 return -EPERM;
743 }
744
745 case AUDIT_LIST_RULES:
746 err = audit_receive_filter(msg_type, NETLINK_CB(skb).portid,
747 seq, data, nlmsg_len(nlh));
748 break;
749 case AUDIT_TRIM:
750 audit_trim_trees();
751 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE);
752 audit_log_format(ab, " op=trim res=1");
753 audit_log_end(ab);
754 break;
755 case AUDIT_MAKE_EQUIV: {
756 void *bufp = data;
757 u32 sizes[2];
758 size_t msglen = nlmsg_len(nlh);
759 char *old, *new;
760
761 err = -EINVAL;
762 if (msglen < 2 * sizeof(u32))
763 break;
764 memcpy(sizes, bufp, 2 * sizeof(u32));
765 bufp += 2 * sizeof(u32);
766 msglen -= 2 * sizeof(u32);
767 old = audit_unpack_string(&bufp, &msglen, sizes[0]);
768 if (IS_ERR(old)) {
769 err = PTR_ERR(old);
770 break;
771 }
772 new = audit_unpack_string(&bufp, &msglen, sizes[1]);
773 if (IS_ERR(new)) {
774 err = PTR_ERR(new);
775 kfree(old);
776 break;
777 }
778
779 err = audit_tag_tree(old, new);
780
781 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE);
782
783 audit_log_format(ab, " op=make_equiv old=");
784 audit_log_untrustedstring(ab, old);
785 audit_log_format(ab, " new=");
786 audit_log_untrustedstring(ab, new);
787 audit_log_format(ab, " res=%d", !err);
788 audit_log_end(ab);
789 kfree(old);
790 kfree(new);
791 break;
792 }
793 case AUDIT_SIGNAL_INFO:
794 len = 0;
795 if (audit_sig_sid) {
796 err = security_secid_to_secctx(audit_sig_sid, &ctx, &len);
797 if (err)
798 return err;
799 }
800 sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL);
801 if (!sig_data) {
802 if (audit_sig_sid)
803 security_release_secctx(ctx, len);
804 return -ENOMEM;
805 }
806 sig_data->uid = from_kuid(&init_user_ns, audit_sig_uid);
807 sig_data->pid = audit_sig_pid;
808 if (audit_sig_sid) {
809 memcpy(sig_data->ctx, ctx, len);
810 security_release_secctx(ctx, len);
811 }
812 audit_send_reply(NETLINK_CB(skb).portid, seq, AUDIT_SIGNAL_INFO,
813 0, 0, sig_data, sizeof(*sig_data) + len);
814 kfree(sig_data);
815 break;
816 case AUDIT_TTY_GET: {
817 struct audit_tty_status s;
818 struct task_struct *tsk = current;
819
820 spin_lock(&tsk->sighand->siglock);
821 s.enabled = tsk->signal->audit_tty != 0;
822 s.log_passwd = tsk->signal->audit_tty_log_passwd;
823 spin_unlock(&tsk->sighand->siglock);
824
825 audit_send_reply(NETLINK_CB(skb).portid, seq,
826 AUDIT_TTY_GET, 0, 0, &s, sizeof(s));
827 break;
828 }
829 case AUDIT_TTY_SET: {
830 struct audit_tty_status s;
831 struct task_struct *tsk = current;
832
833 memset(&s, 0, sizeof(s));
834
835 memcpy(&s, data, min(sizeof(s), (size_t)nlh->nlmsg_len));
836 if ((s.enabled != 0 && s.enabled != 1) ||
837 (s.log_passwd != 0 && s.log_passwd != 1))
838 return -EINVAL;
839
840 spin_lock(&tsk->sighand->siglock);
841 tsk->signal->audit_tty = s.enabled;
842 tsk->signal->audit_tty_log_passwd = s.log_passwd;
843 spin_unlock(&tsk->sighand->siglock);
844 break;
845 }
846 default:
847 err = -EINVAL;
848 break;
849 }
850
851 return err < 0 ? err : 0;
852}
853
854
855
856
857
858static void audit_receive_skb(struct sk_buff *skb)
859{
860 struct nlmsghdr *nlh;
861
862
863
864
865 int len;
866 int err;
867
868 nlh = nlmsg_hdr(skb);
869 len = skb->len;
870
871 while (nlmsg_ok(nlh, len)) {
872 err = audit_receive_msg(skb, nlh);
873
874 if (err || (nlh->nlmsg_flags & NLM_F_ACK))
875 netlink_ack(skb, nlh, err);
876
877 nlh = nlmsg_next(nlh, &len);
878 }
879}
880
881
882static void audit_receive(struct sk_buff *skb)
883{
884 mutex_lock(&audit_cmd_mutex);
885 audit_receive_skb(skb);
886 mutex_unlock(&audit_cmd_mutex);
887}
888
889
890static int __init audit_init(void)
891{
892 int i;
893 struct netlink_kernel_cfg cfg = {
894 .input = audit_receive,
895 };
896
897 if (audit_initialized == AUDIT_DISABLED)
898 return 0;
899
900 printk(KERN_INFO "audit: initializing netlink socket (%s)\n",
901 audit_default ? "enabled" : "disabled");
902 audit_sock = netlink_kernel_create(&init_net, NETLINK_AUDIT, &cfg);
903 if (!audit_sock)
904 audit_panic("cannot initialize netlink socket");
905 else
906 audit_sock->sk_sndtimeo = MAX_SCHEDULE_TIMEOUT;
907
908 skb_queue_head_init(&audit_skb_queue);
909 skb_queue_head_init(&audit_skb_hold_queue);
910 audit_initialized = AUDIT_INITIALIZED;
911 audit_enabled = audit_default;
912 audit_ever_enabled |= !!audit_default;
913
914 audit_log(NULL, GFP_KERNEL, AUDIT_KERNEL, "initialized");
915
916 for (i = 0; i < AUDIT_INODE_BUCKETS; i++)
917 INIT_LIST_HEAD(&audit_inode_hash[i]);
918
919 return 0;
920}
921__initcall(audit_init);
922
923
924static int __init audit_enable(char *str)
925{
926 audit_default = !!simple_strtol(str, NULL, 0);
927 if (!audit_default)
928 audit_initialized = AUDIT_DISABLED;
929
930 printk(KERN_INFO "audit: %s", audit_default ? "enabled" : "disabled");
931
932 if (audit_initialized == AUDIT_INITIALIZED) {
933 audit_enabled = audit_default;
934 audit_ever_enabled |= !!audit_default;
935 } else if (audit_initialized == AUDIT_UNINITIALIZED) {
936 printk(" (after initialization)");
937 } else {
938 printk(" (until reboot)");
939 }
940 printk("\n");
941
942 return 1;
943}
944
945__setup("audit=", audit_enable);
946
947static void audit_buffer_free(struct audit_buffer *ab)
948{
949 unsigned long flags;
950
951 if (!ab)
952 return;
953
954 if (ab->skb)
955 kfree_skb(ab->skb);
956
957 spin_lock_irqsave(&audit_freelist_lock, flags);
958 if (audit_freelist_count > AUDIT_MAXFREE)
959 kfree(ab);
960 else {
961 audit_freelist_count++;
962 list_add(&ab->list, &audit_freelist);
963 }
964 spin_unlock_irqrestore(&audit_freelist_lock, flags);
965}
966
967static struct audit_buffer * audit_buffer_alloc(struct audit_context *ctx,
968 gfp_t gfp_mask, int type)
969{
970 unsigned long flags;
971 struct audit_buffer *ab = NULL;
972 struct nlmsghdr *nlh;
973
974 spin_lock_irqsave(&audit_freelist_lock, flags);
975 if (!list_empty(&audit_freelist)) {
976 ab = list_entry(audit_freelist.next,
977 struct audit_buffer, list);
978 list_del(&ab->list);
979 --audit_freelist_count;
980 }
981 spin_unlock_irqrestore(&audit_freelist_lock, flags);
982
983 if (!ab) {
984 ab = kmalloc(sizeof(*ab), gfp_mask);
985 if (!ab)
986 goto err;
987 }
988
989 ab->ctx = ctx;
990 ab->gfp_mask = gfp_mask;
991
992 ab->skb = nlmsg_new(AUDIT_BUFSIZ, gfp_mask);
993 if (!ab->skb)
994 goto err;
995
996 nlh = nlmsg_put(ab->skb, 0, 0, type, 0, 0);
997 if (!nlh)
998 goto out_kfree_skb;
999
1000 return ab;
1001
1002out_kfree_skb:
1003 kfree_skb(ab->skb);
1004 ab->skb = NULL;
1005err:
1006 audit_buffer_free(ab);
1007 return NULL;
1008}
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027unsigned int audit_serial(void)
1028{
1029 static DEFINE_SPINLOCK(serial_lock);
1030 static unsigned int serial = 0;
1031
1032 unsigned long flags;
1033 unsigned int ret;
1034
1035 spin_lock_irqsave(&serial_lock, flags);
1036 do {
1037 ret = ++serial;
1038 } while (unlikely(!ret));
1039 spin_unlock_irqrestore(&serial_lock, flags);
1040
1041 return ret;
1042}
1043
1044static inline void audit_get_stamp(struct audit_context *ctx,
1045 struct timespec *t, unsigned int *serial)
1046{
1047 if (!ctx || !auditsc_get_stamp(ctx, t, serial)) {
1048 *t = CURRENT_TIME;
1049 *serial = audit_serial();
1050 }
1051}
1052
1053
1054
1055
1056static void wait_for_auditd(unsigned long sleep_time)
1057{
1058 DECLARE_WAITQUEUE(wait, current);
1059 set_current_state(TASK_UNINTERRUPTIBLE);
1060 add_wait_queue(&audit_backlog_wait, &wait);
1061
1062 if (audit_backlog_limit &&
1063 skb_queue_len(&audit_skb_queue) > audit_backlog_limit)
1064 schedule_timeout(sleep_time);
1065
1066 __set_current_state(TASK_RUNNING);
1067 remove_wait_queue(&audit_backlog_wait, &wait);
1068}
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask,
1093 int type)
1094{
1095 struct audit_buffer *ab = NULL;
1096 struct timespec t;
1097 unsigned int uninitialized_var(serial);
1098 int reserve;
1099 unsigned long timeout_start = jiffies;
1100
1101 if (audit_initialized != AUDIT_INITIALIZED)
1102 return NULL;
1103
1104 if (unlikely(audit_filter_type(type)))
1105 return NULL;
1106
1107 if (gfp_mask & __GFP_WAIT)
1108 reserve = 0;
1109 else
1110 reserve = 5;
1111
1112
1113 while (audit_backlog_limit
1114 && skb_queue_len(&audit_skb_queue) > audit_backlog_limit + reserve) {
1115 if (gfp_mask & __GFP_WAIT && audit_backlog_wait_time) {
1116 unsigned long sleep_time;
1117
1118 sleep_time = timeout_start + audit_backlog_wait_time -
1119 jiffies;
1120 if ((long)sleep_time > 0)
1121 wait_for_auditd(sleep_time);
1122 continue;
1123 }
1124 if (audit_rate_check() && printk_ratelimit())
1125 printk(KERN_WARNING
1126 "audit: audit_backlog=%d > "
1127 "audit_backlog_limit=%d\n",
1128 skb_queue_len(&audit_skb_queue),
1129 audit_backlog_limit);
1130 audit_log_lost("backlog limit exceeded");
1131 audit_backlog_wait_time = audit_backlog_wait_overflow;
1132 wake_up(&audit_backlog_wait);
1133 return NULL;
1134 }
1135
1136 ab = audit_buffer_alloc(ctx, gfp_mask, type);
1137 if (!ab) {
1138 audit_log_lost("out of memory in audit_log_start");
1139 return NULL;
1140 }
1141
1142 audit_get_stamp(ab->ctx, &t, &serial);
1143
1144 audit_log_format(ab, "audit(%lu.%03lu:%u): ",
1145 t.tv_sec, t.tv_nsec/1000000, serial);
1146 return ab;
1147}
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157static inline int audit_expand(struct audit_buffer *ab, int extra)
1158{
1159 struct sk_buff *skb = ab->skb;
1160 int oldtail = skb_tailroom(skb);
1161 int ret = pskb_expand_head(skb, 0, extra, ab->gfp_mask);
1162 int newtail = skb_tailroom(skb);
1163
1164 if (ret < 0) {
1165 audit_log_lost("out of memory in audit_expand");
1166 return 0;
1167 }
1168
1169 skb->truesize += newtail - oldtail;
1170 return newtail;
1171}
1172
1173
1174
1175
1176
1177
1178
1179static void audit_log_vformat(struct audit_buffer *ab, const char *fmt,
1180 va_list args)
1181{
1182 int len, avail;
1183 struct sk_buff *skb;
1184 va_list args2;
1185
1186 if (!ab)
1187 return;
1188
1189 BUG_ON(!ab->skb);
1190 skb = ab->skb;
1191 avail = skb_tailroom(skb);
1192 if (avail == 0) {
1193 avail = audit_expand(ab, AUDIT_BUFSIZ);
1194 if (!avail)
1195 goto out;
1196 }
1197 va_copy(args2, args);
1198 len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args);
1199 if (len >= avail) {
1200
1201
1202
1203 avail = audit_expand(ab,
1204 max_t(unsigned, AUDIT_BUFSIZ, 1+len-avail));
1205 if (!avail)
1206 goto out_va_end;
1207 len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args2);
1208 }
1209 if (len > 0)
1210 skb_put(skb, len);
1211out_va_end:
1212 va_end(args2);
1213out:
1214 return;
1215}
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225void audit_log_format(struct audit_buffer *ab, const char *fmt, ...)
1226{
1227 va_list args;
1228
1229 if (!ab)
1230 return;
1231 va_start(args, fmt);
1232 audit_log_vformat(ab, fmt, args);
1233 va_end(args);
1234}
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247void audit_log_n_hex(struct audit_buffer *ab, const unsigned char *buf,
1248 size_t len)
1249{
1250 int i, avail, new_len;
1251 unsigned char *ptr;
1252 struct sk_buff *skb;
1253 static const unsigned char *hex = "0123456789ABCDEF";
1254
1255 if (!ab)
1256 return;
1257
1258 BUG_ON(!ab->skb);
1259 skb = ab->skb;
1260 avail = skb_tailroom(skb);
1261 new_len = len<<1;
1262 if (new_len >= avail) {
1263
1264 new_len = AUDIT_BUFSIZ*(((new_len-avail)/AUDIT_BUFSIZ) + 1);
1265 avail = audit_expand(ab, new_len);
1266 if (!avail)
1267 return;
1268 }
1269
1270 ptr = skb_tail_pointer(skb);
1271 for (i=0; i<len; i++) {
1272 *ptr++ = hex[(buf[i] & 0xF0)>>4];
1273 *ptr++ = hex[buf[i] & 0x0F];
1274 }
1275 *ptr = 0;
1276 skb_put(skb, len << 1);
1277}
1278
1279
1280
1281
1282
1283void audit_log_n_string(struct audit_buffer *ab, const char *string,
1284 size_t slen)
1285{
1286 int avail, new_len;
1287 unsigned char *ptr;
1288 struct sk_buff *skb;
1289
1290 if (!ab)
1291 return;
1292
1293 BUG_ON(!ab->skb);
1294 skb = ab->skb;
1295 avail = skb_tailroom(skb);
1296 new_len = slen + 3;
1297 if (new_len > avail) {
1298 avail = audit_expand(ab, new_len);
1299 if (!avail)
1300 return;
1301 }
1302 ptr = skb_tail_pointer(skb);
1303 *ptr++ = '"';
1304 memcpy(ptr, string, slen);
1305 ptr += slen;
1306 *ptr++ = '"';
1307 *ptr = 0;
1308 skb_put(skb, slen + 2);
1309}
1310
1311
1312
1313
1314
1315
1316int audit_string_contains_control(const char *string, size_t len)
1317{
1318 const unsigned char *p;
1319 for (p = string; p < (const unsigned char *)string + len; p++) {
1320 if (*p == '"' || *p < 0x21 || *p > 0x7e)
1321 return 1;
1322 }
1323 return 0;
1324}
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340void audit_log_n_untrustedstring(struct audit_buffer *ab, const char *string,
1341 size_t len)
1342{
1343 if (audit_string_contains_control(string, len))
1344 audit_log_n_hex(ab, string, len);
1345 else
1346 audit_log_n_string(ab, string, len);
1347}
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357void audit_log_untrustedstring(struct audit_buffer *ab, const char *string)
1358{
1359 audit_log_n_untrustedstring(ab, string, strlen(string));
1360}
1361
1362
1363void audit_log_d_path(struct audit_buffer *ab, const char *prefix,
1364 const struct path *path)
1365{
1366 char *p, *pathname;
1367
1368 if (prefix)
1369 audit_log_format(ab, "%s", prefix);
1370
1371
1372 pathname = kmalloc(PATH_MAX+11, ab->gfp_mask);
1373 if (!pathname) {
1374 audit_log_string(ab, "<no_memory>");
1375 return;
1376 }
1377 p = d_path(path, pathname, PATH_MAX+11);
1378 if (IS_ERR(p)) {
1379
1380 audit_log_string(ab, "<too_long>");
1381 } else
1382 audit_log_untrustedstring(ab, p);
1383 kfree(pathname);
1384}
1385
1386void audit_log_session_info(struct audit_buffer *ab)
1387{
1388 u32 sessionid = audit_get_sessionid(current);
1389 uid_t auid = from_kuid(&init_user_ns, audit_get_loginuid(current));
1390
1391 audit_log_format(ab, " auid=%u ses=%u\n", auid, sessionid);
1392}
1393
1394void audit_log_key(struct audit_buffer *ab, char *key)
1395{
1396 audit_log_format(ab, " key=");
1397 if (key)
1398 audit_log_untrustedstring(ab, key);
1399 else
1400 audit_log_format(ab, "(null)");
1401}
1402
1403void audit_log_cap(struct audit_buffer *ab, char *prefix, kernel_cap_t *cap)
1404{
1405 int i;
1406
1407 audit_log_format(ab, " %s=", prefix);
1408 CAP_FOR_EACH_U32(i) {
1409 audit_log_format(ab, "%08x",
1410 cap->cap[(_KERNEL_CAPABILITY_U32S-1) - i]);
1411 }
1412}
1413
1414void audit_log_fcaps(struct audit_buffer *ab, struct audit_names *name)
1415{
1416 kernel_cap_t *perm = &name->fcap.permitted;
1417 kernel_cap_t *inh = &name->fcap.inheritable;
1418 int log = 0;
1419
1420 if (!cap_isclear(*perm)) {
1421 audit_log_cap(ab, "cap_fp", perm);
1422 log = 1;
1423 }
1424 if (!cap_isclear(*inh)) {
1425 audit_log_cap(ab, "cap_fi", inh);
1426 log = 1;
1427 }
1428
1429 if (log)
1430 audit_log_format(ab, " cap_fe=%d cap_fver=%x",
1431 name->fcap.fE, name->fcap_ver);
1432}
1433
1434static inline int audit_copy_fcaps(struct audit_names *name,
1435 const struct dentry *dentry)
1436{
1437 struct cpu_vfs_cap_data caps;
1438 int rc;
1439
1440 if (!dentry)
1441 return 0;
1442
1443 rc = get_vfs_caps_from_disk(dentry, &caps);
1444 if (rc)
1445 return rc;
1446
1447 name->fcap.permitted = caps.permitted;
1448 name->fcap.inheritable = caps.inheritable;
1449 name->fcap.fE = !!(caps.magic_etc & VFS_CAP_FLAGS_EFFECTIVE);
1450 name->fcap_ver = (caps.magic_etc & VFS_CAP_REVISION_MASK) >>
1451 VFS_CAP_REVISION_SHIFT;
1452
1453 return 0;
1454}
1455
1456
1457void audit_copy_inode(struct audit_names *name, const struct dentry *dentry,
1458 const struct inode *inode)
1459{
1460 name->ino = inode->i_ino;
1461 name->dev = inode->i_sb->s_dev;
1462 name->mode = inode->i_mode;
1463 name->uid = inode->i_uid;
1464 name->gid = inode->i_gid;
1465 name->rdev = inode->i_rdev;
1466 security_inode_getsecid(inode, &name->osid);
1467 audit_copy_fcaps(name, dentry);
1468}
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478void audit_log_name(struct audit_context *context, struct audit_names *n,
1479 struct path *path, int record_num, int *call_panic)
1480{
1481 struct audit_buffer *ab;
1482 ab = audit_log_start(context, GFP_KERNEL, AUDIT_PATH);
1483 if (!ab)
1484 return;
1485
1486 audit_log_format(ab, "item=%d", record_num);
1487
1488 if (path)
1489 audit_log_d_path(ab, " name=", path);
1490 else if (n->name) {
1491 switch (n->name_len) {
1492 case AUDIT_NAME_FULL:
1493
1494 audit_log_format(ab, " name=");
1495 audit_log_untrustedstring(ab, n->name->name);
1496 break;
1497 case 0:
1498
1499
1500 audit_log_d_path(ab, " name=", &context->pwd);
1501 break;
1502 default:
1503
1504 audit_log_format(ab, " name=");
1505 audit_log_n_untrustedstring(ab, n->name->name,
1506 n->name_len);
1507 }
1508 } else
1509 audit_log_format(ab, " name=(null)");
1510
1511 if (n->ino != (unsigned long)-1) {
1512 audit_log_format(ab, " inode=%lu"
1513 " dev=%02x:%02x mode=%#ho"
1514 " ouid=%u ogid=%u rdev=%02x:%02x",
1515 n->ino,
1516 MAJOR(n->dev),
1517 MINOR(n->dev),
1518 n->mode,
1519 from_kuid(&init_user_ns, n->uid),
1520 from_kgid(&init_user_ns, n->gid),
1521 MAJOR(n->rdev),
1522 MINOR(n->rdev));
1523 }
1524 if (n->osid != 0) {
1525 char *ctx = NULL;
1526 u32 len;
1527 if (security_secid_to_secctx(
1528 n->osid, &ctx, &len)) {
1529 audit_log_format(ab, " osid=%u", n->osid);
1530 if (call_panic)
1531 *call_panic = 2;
1532 } else {
1533 audit_log_format(ab, " obj=%s", ctx);
1534 security_release_secctx(ctx, len);
1535 }
1536 }
1537
1538 audit_log_fcaps(ab, n);
1539 audit_log_end(ab);
1540}
1541
1542int audit_log_task_context(struct audit_buffer *ab)
1543{
1544 char *ctx = NULL;
1545 unsigned len;
1546 int error;
1547 u32 sid;
1548
1549 security_task_getsecid(current, &sid);
1550 if (!sid)
1551 return 0;
1552
1553 error = security_secid_to_secctx(sid, &ctx, &len);
1554 if (error) {
1555 if (error != -EINVAL)
1556 goto error_path;
1557 return 0;
1558 }
1559
1560 audit_log_format(ab, " subj=%s", ctx);
1561 security_release_secctx(ctx, len);
1562 return 0;
1563
1564error_path:
1565 audit_panic("error in audit_log_task_context");
1566 return error;
1567}
1568EXPORT_SYMBOL(audit_log_task_context);
1569
1570void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk)
1571{
1572 const struct cred *cred;
1573 char name[sizeof(tsk->comm)];
1574 struct mm_struct *mm = tsk->mm;
1575 char *tty;
1576
1577 if (!ab)
1578 return;
1579
1580
1581 cred = current_cred();
1582
1583 spin_lock_irq(&tsk->sighand->siglock);
1584 if (tsk->signal && tsk->signal->tty && tsk->signal->tty->name)
1585 tty = tsk->signal->tty->name;
1586 else
1587 tty = "(none)";
1588 spin_unlock_irq(&tsk->sighand->siglock);
1589
1590 audit_log_format(ab,
1591 " ppid=%ld pid=%d auid=%u uid=%u gid=%u"
1592 " euid=%u suid=%u fsuid=%u"
1593 " egid=%u sgid=%u fsgid=%u ses=%u tty=%s",
1594 sys_getppid(),
1595 tsk->pid,
1596 from_kuid(&init_user_ns, audit_get_loginuid(tsk)),
1597 from_kuid(&init_user_ns, cred->uid),
1598 from_kgid(&init_user_ns, cred->gid),
1599 from_kuid(&init_user_ns, cred->euid),
1600 from_kuid(&init_user_ns, cred->suid),
1601 from_kuid(&init_user_ns, cred->fsuid),
1602 from_kgid(&init_user_ns, cred->egid),
1603 from_kgid(&init_user_ns, cred->sgid),
1604 from_kgid(&init_user_ns, cred->fsgid),
1605 audit_get_sessionid(tsk), tty);
1606
1607 get_task_comm(name, tsk);
1608 audit_log_format(ab, " comm=");
1609 audit_log_untrustedstring(ab, name);
1610
1611 if (mm) {
1612 down_read(&mm->mmap_sem);
1613 if (mm->exe_file)
1614 audit_log_d_path(ab, " exe=", &mm->exe_file->f_path);
1615 up_read(&mm->mmap_sem);
1616 }
1617 audit_log_task_context(ab);
1618}
1619EXPORT_SYMBOL(audit_log_task_info);
1620
1621
1622
1623
1624
1625
1626void audit_log_link_denied(const char *operation, struct path *link)
1627{
1628 struct audit_buffer *ab;
1629 struct audit_names *name;
1630
1631 name = kzalloc(sizeof(*name), GFP_NOFS);
1632 if (!name)
1633 return;
1634
1635
1636 ab = audit_log_start(current->audit_context, GFP_KERNEL,
1637 AUDIT_ANOM_LINK);
1638 if (!ab)
1639 goto out;
1640 audit_log_format(ab, "op=%s", operation);
1641 audit_log_task_info(ab, current);
1642 audit_log_format(ab, " res=0");
1643 audit_log_end(ab);
1644
1645
1646 name->type = AUDIT_TYPE_NORMAL;
1647 audit_copy_inode(name, link->dentry, link->dentry->d_inode);
1648 audit_log_name(current->audit_context, name, link, 0, NULL);
1649out:
1650 kfree(name);
1651}
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662void audit_log_end(struct audit_buffer *ab)
1663{
1664 if (!ab)
1665 return;
1666 if (!audit_rate_check()) {
1667 audit_log_lost("rate limit exceeded");
1668 } else {
1669 struct nlmsghdr *nlh = nlmsg_hdr(ab->skb);
1670 nlh->nlmsg_len = ab->skb->len - NLMSG_HDRLEN;
1671
1672 if (audit_pid) {
1673 skb_queue_tail(&audit_skb_queue, ab->skb);
1674 wake_up_interruptible(&kauditd_wait);
1675 } else {
1676 audit_printk_skb(ab->skb);
1677 }
1678 ab->skb = NULL;
1679 }
1680 audit_buffer_free(ab);
1681}
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695void audit_log(struct audit_context *ctx, gfp_t gfp_mask, int type,
1696 const char *fmt, ...)
1697{
1698 struct audit_buffer *ab;
1699 va_list args;
1700
1701 ab = audit_log_start(ctx, gfp_mask, type);
1702 if (ab) {
1703 va_start(args, fmt);
1704 audit_log_vformat(ab, fmt, args);
1705 va_end(args);
1706 audit_log_end(ab);
1707 }
1708}
1709
1710#ifdef CONFIG_SECURITY
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721void audit_log_secctx(struct audit_buffer *ab, u32 secid)
1722{
1723 u32 len;
1724 char *secctx;
1725
1726 if (security_secid_to_secctx(secid, &secctx, &len)) {
1727 audit_panic("Cannot convert secid to context");
1728 } else {
1729 audit_log_format(ab, " obj=%s", secctx);
1730 security_release_secctx(secctx, len);
1731 }
1732}
1733EXPORT_SYMBOL(audit_log_secctx);
1734#endif
1735
1736EXPORT_SYMBOL(audit_log_start);
1737EXPORT_SYMBOL(audit_log_end);
1738EXPORT_SYMBOL(audit_log_format);
1739EXPORT_SYMBOL(audit_log);
1740