Commit | Line | Data |
---|---|---|
85c8721f | 1 | /* audit.c -- Auditing support |
1da177e4 LT |
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 | * | |
6a01b07f | 5 | * Copyright 2003-2007 Red Hat Inc., Durham, North Carolina. |
1da177e4 LT |
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 | * | |
d7a96f3a | 24 | * Goals: 1) Integrate fully with Security Modules. |
1da177e4 LT |
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 | * | |
85c8721f | 41 | * Example user-space utilities: http://people.redhat.com/sgrubb/audit/ |
1da177e4 LT |
42 | */ |
43 | ||
44 | #include <linux/init.h> | |
1da177e4 | 45 | #include <asm/types.h> |
60063497 | 46 | #include <linux/atomic.h> |
1da177e4 | 47 | #include <linux/mm.h> |
9984de1a | 48 | #include <linux/export.h> |
5a0e3ad6 | 49 | #include <linux/slab.h> |
b7d11258 DW |
50 | #include <linux/err.h> |
51 | #include <linux/kthread.h> | |
46e959ea | 52 | #include <linux/kernel.h> |
b24a30a7 | 53 | #include <linux/syscalls.h> |
1da177e4 LT |
54 | |
55 | #include <linux/audit.h> | |
56 | ||
57 | #include <net/sock.h> | |
93315ed6 | 58 | #include <net/netlink.h> |
1da177e4 | 59 | #include <linux/skbuff.h> |
131ad62d MDF |
60 | #ifdef CONFIG_SECURITY |
61 | #include <linux/security.h> | |
62 | #endif | |
7dfb7103 | 63 | #include <linux/freezer.h> |
522ed776 | 64 | #include <linux/tty.h> |
34e36d8e | 65 | #include <linux/pid_namespace.h> |
3dc7e315 DG |
66 | |
67 | #include "audit.h" | |
1da177e4 | 68 | |
a3f07114 | 69 | /* No auditing will take place until audit_initialized == AUDIT_INITIALIZED. |
1da177e4 | 70 | * (Initialization happens after skb_init is called.) */ |
a3f07114 EP |
71 | #define AUDIT_DISABLED -1 |
72 | #define AUDIT_UNINITIALIZED 0 | |
73 | #define AUDIT_INITIALIZED 1 | |
1da177e4 LT |
74 | static int audit_initialized; |
75 | ||
1a6b9f23 EP |
76 | #define AUDIT_OFF 0 |
77 | #define AUDIT_ON 1 | |
78 | #define AUDIT_LOCKED 2 | |
1da177e4 | 79 | int audit_enabled; |
b593d384 | 80 | int audit_ever_enabled; |
1da177e4 | 81 | |
ae9d67af JE |
82 | EXPORT_SYMBOL_GPL(audit_enabled); |
83 | ||
1da177e4 LT |
84 | /* Default state when kernel boots without any parameters. */ |
85 | static int audit_default; | |
86 | ||
87 | /* If auditing cannot proceed, audit_failure selects what happens. */ | |
88 | static int audit_failure = AUDIT_FAIL_PRINTK; | |
89 | ||
75c0371a PE |
90 | /* |
91 | * If audit records are to be written to the netlink socket, audit_pid | |
15e47304 EB |
92 | * contains the pid of the auditd process and audit_nlk_portid contains |
93 | * the portid to use to send netlink messages to that process. | |
75c0371a | 94 | */ |
c2f0c7c3 | 95 | int audit_pid; |
15e47304 | 96 | static int audit_nlk_portid; |
1da177e4 | 97 | |
b0dd25a8 | 98 | /* If audit_rate_limit is non-zero, limit the rate of sending audit records |
1da177e4 LT |
99 | * to that number per second. This prevents DoS attacks, but results in |
100 | * audit records being dropped. */ | |
101 | static int audit_rate_limit; | |
102 | ||
103 | /* Number of outstanding audit_buffers allowed. */ | |
104 | static int audit_backlog_limit = 64; | |
ac4cec44 DW |
105 | static int audit_backlog_wait_time = 60 * HZ; |
106 | static int audit_backlog_wait_overflow = 0; | |
1da177e4 | 107 | |
c2f0c7c3 | 108 | /* The identity of the user shutting down the audit system. */ |
cca080d9 | 109 | kuid_t audit_sig_uid = INVALID_UID; |
c2f0c7c3 | 110 | pid_t audit_sig_pid = -1; |
e1396065 | 111 | u32 audit_sig_sid = 0; |
c2f0c7c3 | 112 | |
1da177e4 LT |
113 | /* Records can be lost in several ways: |
114 | 0) [suppressed in audit_alloc] | |
115 | 1) out of memory in audit_log_start [kmalloc of struct audit_buffer] | |
116 | 2) out of memory in audit_log_move [alloc_skb] | |
117 | 3) suppressed due to audit_rate_limit | |
118 | 4) suppressed due to audit_backlog_limit | |
119 | */ | |
120 | static atomic_t audit_lost = ATOMIC_INIT(0); | |
121 | ||
122 | /* The netlink socket. */ | |
123 | static struct sock *audit_sock; | |
124 | ||
f368c07d AG |
125 | /* Hash for inode-based rules */ |
126 | struct list_head audit_inode_hash[AUDIT_INODE_BUCKETS]; | |
127 | ||
b7d11258 | 128 | /* The audit_freelist is a list of pre-allocated audit buffers (if more |
1da177e4 LT |
129 | * than AUDIT_MAXFREE are in use, the audit buffer is freed instead of |
130 | * being placed on the freelist). */ | |
1da177e4 | 131 | static DEFINE_SPINLOCK(audit_freelist_lock); |
b0dd25a8 | 132 | static int audit_freelist_count; |
1da177e4 LT |
133 | static LIST_HEAD(audit_freelist); |
134 | ||
b7d11258 | 135 | static struct sk_buff_head audit_skb_queue; |
f3d357b0 EP |
136 | /* queue of skbs to send to auditd when/if it comes back */ |
137 | static struct sk_buff_head audit_skb_hold_queue; | |
b7d11258 DW |
138 | static struct task_struct *kauditd_task; |
139 | static DECLARE_WAIT_QUEUE_HEAD(kauditd_wait); | |
9ad9ad38 | 140 | static DECLARE_WAIT_QUEUE_HEAD(audit_backlog_wait); |
1da177e4 | 141 | |
b0fed402 EP |
142 | static struct audit_features af = {.vers = AUDIT_FEATURE_VERSION, |
143 | .mask = -1, | |
144 | .features = 0, | |
145 | .lock = 0,}; | |
146 | ||
147 | static char *audit_feature_names[0] = { | |
148 | }; | |
149 | ||
150 | ||
f368c07d | 151 | /* Serialize requests from userspace. */ |
916d7576 | 152 | DEFINE_MUTEX(audit_cmd_mutex); |
1da177e4 LT |
153 | |
154 | /* AUDIT_BUFSIZ is the size of the temporary buffer used for formatting | |
155 | * audit records. Since printk uses a 1024 byte buffer, this buffer | |
156 | * should be at least that large. */ | |
157 | #define AUDIT_BUFSIZ 1024 | |
158 | ||
159 | /* AUDIT_MAXFREE is the number of empty audit_buffers we keep on the | |
160 | * audit_freelist. Doing so eliminates many kmalloc/kfree calls. */ | |
161 | #define AUDIT_MAXFREE (2*NR_CPUS) | |
162 | ||
163 | /* The audit_buffer is used when formatting an audit record. The caller | |
164 | * locks briefly to get the record off the freelist or to allocate the | |
165 | * buffer, and locks briefly to send the buffer to the netlink layer or | |
166 | * to place it on a transmit queue. Multiple audit_buffers can be in | |
167 | * use simultaneously. */ | |
168 | struct audit_buffer { | |
169 | struct list_head list; | |
8fc6115c | 170 | struct sk_buff *skb; /* formatted skb ready to send */ |
1da177e4 | 171 | struct audit_context *ctx; /* NULL or associated context */ |
9796fdd8 | 172 | gfp_t gfp_mask; |
1da177e4 LT |
173 | }; |
174 | ||
f09ac9db EP |
175 | struct audit_reply { |
176 | int pid; | |
177 | struct sk_buff *skb; | |
178 | }; | |
179 | ||
c0404993 SG |
180 | static void audit_set_pid(struct audit_buffer *ab, pid_t pid) |
181 | { | |
50397bd1 EP |
182 | if (ab) { |
183 | struct nlmsghdr *nlh = nlmsg_hdr(ab->skb); | |
184 | nlh->nlmsg_pid = pid; | |
185 | } | |
c0404993 SG |
186 | } |
187 | ||
8c8570fb | 188 | void audit_panic(const char *message) |
1da177e4 LT |
189 | { |
190 | switch (audit_failure) | |
191 | { | |
192 | case AUDIT_FAIL_SILENT: | |
193 | break; | |
194 | case AUDIT_FAIL_PRINTK: | |
320f1b1e EP |
195 | if (printk_ratelimit()) |
196 | printk(KERN_ERR "audit: %s\n", message); | |
1da177e4 LT |
197 | break; |
198 | case AUDIT_FAIL_PANIC: | |
b29ee87e EP |
199 | /* test audit_pid since printk is always losey, why bother? */ |
200 | if (audit_pid) | |
201 | panic("audit: %s\n", message); | |
1da177e4 LT |
202 | break; |
203 | } | |
204 | } | |
205 | ||
206 | static inline int audit_rate_check(void) | |
207 | { | |
208 | static unsigned long last_check = 0; | |
209 | static int messages = 0; | |
210 | static DEFINE_SPINLOCK(lock); | |
211 | unsigned long flags; | |
212 | unsigned long now; | |
213 | unsigned long elapsed; | |
214 | int retval = 0; | |
215 | ||
216 | if (!audit_rate_limit) return 1; | |
217 | ||
218 | spin_lock_irqsave(&lock, flags); | |
219 | if (++messages < audit_rate_limit) { | |
220 | retval = 1; | |
221 | } else { | |
222 | now = jiffies; | |
223 | elapsed = now - last_check; | |
224 | if (elapsed > HZ) { | |
225 | last_check = now; | |
226 | messages = 0; | |
227 | retval = 1; | |
228 | } | |
229 | } | |
230 | spin_unlock_irqrestore(&lock, flags); | |
231 | ||
232 | return retval; | |
233 | } | |
234 | ||
b0dd25a8 RD |
235 | /** |
236 | * audit_log_lost - conditionally log lost audit message event | |
237 | * @message: the message stating reason for lost audit message | |
238 | * | |
239 | * Emit at least 1 message per second, even if audit_rate_check is | |
240 | * throttling. | |
241 | * Always increment the lost messages counter. | |
242 | */ | |
1da177e4 LT |
243 | void audit_log_lost(const char *message) |
244 | { | |
245 | static unsigned long last_msg = 0; | |
246 | static DEFINE_SPINLOCK(lock); | |
247 | unsigned long flags; | |
248 | unsigned long now; | |
249 | int print; | |
250 | ||
251 | atomic_inc(&audit_lost); | |
252 | ||
253 | print = (audit_failure == AUDIT_FAIL_PANIC || !audit_rate_limit); | |
254 | ||
255 | if (!print) { | |
256 | spin_lock_irqsave(&lock, flags); | |
257 | now = jiffies; | |
258 | if (now - last_msg > HZ) { | |
259 | print = 1; | |
260 | last_msg = now; | |
261 | } | |
262 | spin_unlock_irqrestore(&lock, flags); | |
263 | } | |
264 | ||
265 | if (print) { | |
320f1b1e EP |
266 | if (printk_ratelimit()) |
267 | printk(KERN_WARNING | |
268 | "audit: audit_lost=%d audit_rate_limit=%d " | |
269 | "audit_backlog_limit=%d\n", | |
270 | atomic_read(&audit_lost), | |
271 | audit_rate_limit, | |
272 | audit_backlog_limit); | |
1da177e4 LT |
273 | audit_panic(message); |
274 | } | |
1da177e4 LT |
275 | } |
276 | ||
1a6b9f23 | 277 | static int audit_log_config_change(char *function_name, int new, int old, |
2532386f | 278 | int allow_changes) |
1da177e4 | 279 | { |
1a6b9f23 EP |
280 | struct audit_buffer *ab; |
281 | int rc = 0; | |
ce29b682 | 282 | |
1a6b9f23 | 283 | ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE); |
0644ec0c KC |
284 | if (unlikely(!ab)) |
285 | return rc; | |
4d3fb709 EP |
286 | audit_log_format(ab, "%s=%d old=%d", function_name, new, old); |
287 | audit_log_session_info(ab); | |
b122c376 EP |
288 | rc = audit_log_task_context(ab); |
289 | if (rc) | |
290 | allow_changes = 0; /* Something weird, deny request */ | |
1a6b9f23 EP |
291 | audit_log_format(ab, " res=%d", allow_changes); |
292 | audit_log_end(ab); | |
6a01b07f | 293 | return rc; |
1da177e4 LT |
294 | } |
295 | ||
dc9eb698 | 296 | static int audit_do_config_change(char *function_name, int *to_change, int new) |
1da177e4 | 297 | { |
1a6b9f23 | 298 | int allow_changes, rc = 0, old = *to_change; |
6a01b07f SG |
299 | |
300 | /* check if we are locked */ | |
1a6b9f23 EP |
301 | if (audit_enabled == AUDIT_LOCKED) |
302 | allow_changes = 0; | |
6a01b07f | 303 | else |
1a6b9f23 | 304 | allow_changes = 1; |
ce29b682 | 305 | |
1a6b9f23 | 306 | if (audit_enabled != AUDIT_OFF) { |
dc9eb698 | 307 | rc = audit_log_config_change(function_name, new, old, allow_changes); |
1a6b9f23 EP |
308 | if (rc) |
309 | allow_changes = 0; | |
6a01b07f | 310 | } |
6a01b07f SG |
311 | |
312 | /* If we are allowed, make the change */ | |
1a6b9f23 EP |
313 | if (allow_changes == 1) |
314 | *to_change = new; | |
6a01b07f SG |
315 | /* Not allowed, update reason */ |
316 | else if (rc == 0) | |
317 | rc = -EPERM; | |
318 | return rc; | |
1da177e4 LT |
319 | } |
320 | ||
dc9eb698 | 321 | static int audit_set_rate_limit(int limit) |
1da177e4 | 322 | { |
dc9eb698 | 323 | return audit_do_config_change("audit_rate_limit", &audit_rate_limit, limit); |
1a6b9f23 | 324 | } |
ce29b682 | 325 | |
dc9eb698 | 326 | static int audit_set_backlog_limit(int limit) |
1a6b9f23 | 327 | { |
dc9eb698 | 328 | return audit_do_config_change("audit_backlog_limit", &audit_backlog_limit, limit); |
1a6b9f23 | 329 | } |
6a01b07f | 330 | |
dc9eb698 | 331 | static int audit_set_enabled(int state) |
1a6b9f23 | 332 | { |
b593d384 | 333 | int rc; |
1a6b9f23 EP |
334 | if (state < AUDIT_OFF || state > AUDIT_LOCKED) |
335 | return -EINVAL; | |
6a01b07f | 336 | |
dc9eb698 | 337 | rc = audit_do_config_change("audit_enabled", &audit_enabled, state); |
b593d384 EP |
338 | if (!rc) |
339 | audit_ever_enabled |= !!state; | |
340 | ||
341 | return rc; | |
1da177e4 LT |
342 | } |
343 | ||
dc9eb698 | 344 | static int audit_set_failure(int state) |
1da177e4 | 345 | { |
1da177e4 LT |
346 | if (state != AUDIT_FAIL_SILENT |
347 | && state != AUDIT_FAIL_PRINTK | |
348 | && state != AUDIT_FAIL_PANIC) | |
349 | return -EINVAL; | |
ce29b682 | 350 | |
dc9eb698 | 351 | return audit_do_config_change("audit_failure", &audit_failure, state); |
1da177e4 LT |
352 | } |
353 | ||
f3d357b0 EP |
354 | /* |
355 | * Queue skbs to be sent to auditd when/if it comes back. These skbs should | |
356 | * already have been sent via prink/syslog and so if these messages are dropped | |
357 | * it is not a huge concern since we already passed the audit_log_lost() | |
358 | * notification and stuff. This is just nice to get audit messages during | |
359 | * boot before auditd is running or messages generated while auditd is stopped. | |
360 | * This only holds messages is audit_default is set, aka booting with audit=1 | |
361 | * or building your kernel that way. | |
362 | */ | |
363 | static void audit_hold_skb(struct sk_buff *skb) | |
364 | { | |
365 | if (audit_default && | |
366 | skb_queue_len(&audit_skb_hold_queue) < audit_backlog_limit) | |
367 | skb_queue_tail(&audit_skb_hold_queue, skb); | |
368 | else | |
369 | kfree_skb(skb); | |
370 | } | |
371 | ||
038cbcf6 EP |
372 | /* |
373 | * For one reason or another this nlh isn't getting delivered to the userspace | |
374 | * audit daemon, just send it to printk. | |
375 | */ | |
376 | static void audit_printk_skb(struct sk_buff *skb) | |
377 | { | |
378 | struct nlmsghdr *nlh = nlmsg_hdr(skb); | |
c64e66c6 | 379 | char *data = nlmsg_data(nlh); |
038cbcf6 EP |
380 | |
381 | if (nlh->nlmsg_type != AUDIT_EOE) { | |
382 | if (printk_ratelimit()) | |
383 | printk(KERN_NOTICE "type=%d %s\n", nlh->nlmsg_type, data); | |
384 | else | |
385 | audit_log_lost("printk limit exceeded\n"); | |
386 | } | |
387 | ||
388 | audit_hold_skb(skb); | |
389 | } | |
390 | ||
f3d357b0 EP |
391 | static void kauditd_send_skb(struct sk_buff *skb) |
392 | { | |
393 | int err; | |
394 | /* take a reference in case we can't send it and we want to hold it */ | |
395 | skb_get(skb); | |
15e47304 | 396 | err = netlink_unicast(audit_sock, skb, audit_nlk_portid, 0); |
f3d357b0 | 397 | if (err < 0) { |
c9404c9c | 398 | BUG_ON(err != -ECONNREFUSED); /* Shouldn't happen */ |
f3d357b0 | 399 | printk(KERN_ERR "audit: *NO* daemon at audit_pid=%d\n", audit_pid); |
9db3b9bc | 400 | audit_log_lost("auditd disappeared\n"); |
f3d357b0 EP |
401 | audit_pid = 0; |
402 | /* we might get lucky and get this in the next auditd */ | |
403 | audit_hold_skb(skb); | |
404 | } else | |
405 | /* drop the extra reference if sent ok */ | |
70d4bf6d | 406 | consume_skb(skb); |
f3d357b0 EP |
407 | } |
408 | ||
b551d1d9 RGB |
409 | /* |
410 | * flush_hold_queue - empty the hold queue if auditd appears | |
411 | * | |
412 | * If auditd just started, drain the queue of messages already | |
413 | * sent to syslog/printk. Remember loss here is ok. We already | |
414 | * called audit_log_lost() if it didn't go out normally. so the | |
415 | * race between the skb_dequeue and the next check for audit_pid | |
416 | * doesn't matter. | |
417 | * | |
418 | * If you ever find kauditd to be too slow we can get a perf win | |
419 | * by doing our own locking and keeping better track if there | |
420 | * are messages in this queue. I don't see the need now, but | |
421 | * in 5 years when I want to play with this again I'll see this | |
422 | * note and still have no friggin idea what i'm thinking today. | |
423 | */ | |
424 | static void flush_hold_queue(void) | |
b7d11258 DW |
425 | { |
426 | struct sk_buff *skb; | |
427 | ||
b551d1d9 RGB |
428 | if (!audit_default || !audit_pid) |
429 | return; | |
430 | ||
431 | skb = skb_dequeue(&audit_skb_hold_queue); | |
432 | if (likely(!skb)) | |
433 | return; | |
434 | ||
435 | while (skb && audit_pid) { | |
436 | kauditd_send_skb(skb); | |
437 | skb = skb_dequeue(&audit_skb_hold_queue); | |
438 | } | |
439 | ||
440 | /* | |
441 | * if auditd just disappeared but we | |
442 | * dequeued an skb we need to drop ref | |
443 | */ | |
444 | if (skb) | |
445 | consume_skb(skb); | |
446 | } | |
447 | ||
97a41e26 | 448 | static int kauditd_thread(void *dummy) |
b7d11258 | 449 | { |
83144186 | 450 | set_freezable(); |
4899b8b1 | 451 | while (!kthread_should_stop()) { |
3320c513 RGB |
452 | struct sk_buff *skb; |
453 | DECLARE_WAITQUEUE(wait, current); | |
454 | ||
b551d1d9 | 455 | flush_hold_queue(); |
f3d357b0 | 456 | |
b7d11258 | 457 | skb = skb_dequeue(&audit_skb_queue); |
9ad9ad38 | 458 | wake_up(&audit_backlog_wait); |
b7d11258 | 459 | if (skb) { |
f3d357b0 EP |
460 | if (audit_pid) |
461 | kauditd_send_skb(skb); | |
038cbcf6 EP |
462 | else |
463 | audit_printk_skb(skb); | |
3320c513 RGB |
464 | continue; |
465 | } | |
466 | set_current_state(TASK_INTERRUPTIBLE); | |
467 | add_wait_queue(&kauditd_wait, &wait); | |
b7d11258 | 468 | |
3320c513 RGB |
469 | if (!skb_queue_len(&audit_skb_queue)) { |
470 | try_to_freeze(); | |
471 | schedule(); | |
b7d11258 | 472 | } |
3320c513 RGB |
473 | |
474 | __set_current_state(TASK_RUNNING); | |
475 | remove_wait_queue(&kauditd_wait, &wait); | |
b7d11258 | 476 | } |
4899b8b1 | 477 | return 0; |
b7d11258 DW |
478 | } |
479 | ||
9044e6bc AV |
480 | int audit_send_list(void *_dest) |
481 | { | |
482 | struct audit_netlink_list *dest = _dest; | |
483 | int pid = dest->pid; | |
484 | struct sk_buff *skb; | |
485 | ||
486 | /* wait for parent to finish and send an ACK */ | |
f368c07d AG |
487 | mutex_lock(&audit_cmd_mutex); |
488 | mutex_unlock(&audit_cmd_mutex); | |
9044e6bc AV |
489 | |
490 | while ((skb = __skb_dequeue(&dest->q)) != NULL) | |
491 | netlink_unicast(audit_sock, skb, pid, 0); | |
492 | ||
493 | kfree(dest); | |
494 | ||
495 | return 0; | |
496 | } | |
497 | ||
498 | struct sk_buff *audit_make_reply(int pid, int seq, int type, int done, | |
b8800aa5 | 499 | int multi, const void *payload, int size) |
9044e6bc AV |
500 | { |
501 | struct sk_buff *skb; | |
502 | struct nlmsghdr *nlh; | |
9044e6bc AV |
503 | void *data; |
504 | int flags = multi ? NLM_F_MULTI : 0; | |
505 | int t = done ? NLMSG_DONE : type; | |
506 | ||
ee080e6c | 507 | skb = nlmsg_new(size, GFP_KERNEL); |
9044e6bc AV |
508 | if (!skb) |
509 | return NULL; | |
510 | ||
c64e66c6 DM |
511 | nlh = nlmsg_put(skb, pid, seq, t, size, flags); |
512 | if (!nlh) | |
513 | goto out_kfree_skb; | |
514 | data = nlmsg_data(nlh); | |
9044e6bc AV |
515 | memcpy(data, payload, size); |
516 | return skb; | |
517 | ||
c64e66c6 DM |
518 | out_kfree_skb: |
519 | kfree_skb(skb); | |
9044e6bc AV |
520 | return NULL; |
521 | } | |
522 | ||
f09ac9db EP |
523 | static int audit_send_reply_thread(void *arg) |
524 | { | |
525 | struct audit_reply *reply = (struct audit_reply *)arg; | |
526 | ||
527 | mutex_lock(&audit_cmd_mutex); | |
528 | mutex_unlock(&audit_cmd_mutex); | |
529 | ||
530 | /* Ignore failure. It'll only happen if the sender goes away, | |
531 | because our timeout is set to infinite. */ | |
532 | netlink_unicast(audit_sock, reply->skb, reply->pid, 0); | |
533 | kfree(reply); | |
534 | return 0; | |
535 | } | |
b0dd25a8 RD |
536 | /** |
537 | * audit_send_reply - send an audit reply message via netlink | |
538 | * @pid: process id to send reply to | |
539 | * @seq: sequence number | |
540 | * @type: audit message type | |
541 | * @done: done (last) flag | |
542 | * @multi: multi-part message flag | |
543 | * @payload: payload data | |
544 | * @size: payload size | |
545 | * | |
546 | * Allocates an skb, builds the netlink message, and sends it to the pid. | |
547 | * No failure notifications. | |
548 | */ | |
b8800aa5 SH |
549 | static void audit_send_reply(int pid, int seq, int type, int done, int multi, |
550 | const void *payload, int size) | |
1da177e4 | 551 | { |
f09ac9db EP |
552 | struct sk_buff *skb; |
553 | struct task_struct *tsk; | |
554 | struct audit_reply *reply = kmalloc(sizeof(struct audit_reply), | |
555 | GFP_KERNEL); | |
556 | ||
557 | if (!reply) | |
558 | return; | |
559 | ||
9044e6bc | 560 | skb = audit_make_reply(pid, seq, type, done, multi, payload, size); |
1da177e4 | 561 | if (!skb) |
fcaf1eb8 | 562 | goto out; |
f09ac9db EP |
563 | |
564 | reply->pid = pid; | |
565 | reply->skb = skb; | |
566 | ||
567 | tsk = kthread_run(audit_send_reply_thread, reply, "audit_send_reply"); | |
fcaf1eb8 AM |
568 | if (!IS_ERR(tsk)) |
569 | return; | |
570 | kfree_skb(skb); | |
571 | out: | |
572 | kfree(reply); | |
1da177e4 LT |
573 | } |
574 | ||
575 | /* | |
576 | * Check for appropriate CAP_AUDIT_ capabilities on incoming audit | |
577 | * control messages. | |
578 | */ | |
c7bdb545 | 579 | static int audit_netlink_ok(struct sk_buff *skb, u16 msg_type) |
1da177e4 LT |
580 | { |
581 | int err = 0; | |
582 | ||
34e36d8e EB |
583 | /* Only support the initial namespaces for now. */ |
584 | if ((current_user_ns() != &init_user_ns) || | |
585 | (task_active_pid_ns(current) != &init_pid_ns)) | |
586 | return -EPERM; | |
587 | ||
1da177e4 | 588 | switch (msg_type) { |
1da177e4 | 589 | case AUDIT_LIST: |
1da177e4 LT |
590 | case AUDIT_ADD: |
591 | case AUDIT_DEL: | |
18900909 EP |
592 | return -EOPNOTSUPP; |
593 | case AUDIT_GET: | |
594 | case AUDIT_SET: | |
b0fed402 EP |
595 | case AUDIT_GET_FEATURE: |
596 | case AUDIT_SET_FEATURE: | |
18900909 EP |
597 | case AUDIT_LIST_RULES: |
598 | case AUDIT_ADD_RULE: | |
93315ed6 | 599 | case AUDIT_DEL_RULE: |
c2f0c7c3 | 600 | case AUDIT_SIGNAL_INFO: |
522ed776 MT |
601 | case AUDIT_TTY_GET: |
602 | case AUDIT_TTY_SET: | |
74c3cbe3 AV |
603 | case AUDIT_TRIM: |
604 | case AUDIT_MAKE_EQUIV: | |
fd778461 | 605 | if (!capable(CAP_AUDIT_CONTROL)) |
1da177e4 LT |
606 | err = -EPERM; |
607 | break; | |
05474106 | 608 | case AUDIT_USER: |
039b6b3e RD |
609 | case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG: |
610 | case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2: | |
fd778461 | 611 | if (!capable(CAP_AUDIT_WRITE)) |
1da177e4 LT |
612 | err = -EPERM; |
613 | break; | |
614 | default: /* bad msg */ | |
615 | err = -EINVAL; | |
616 | } | |
617 | ||
618 | return err; | |
619 | } | |
620 | ||
dc9eb698 | 621 | static int audit_log_common_recv_msg(struct audit_buffer **ab, u16 msg_type) |
50397bd1 EP |
622 | { |
623 | int rc = 0; | |
dc9eb698 | 624 | uid_t uid = from_kuid(&init_user_ns, current_uid()); |
50397bd1 | 625 | |
0868a5e1 | 626 | if (!audit_enabled && msg_type != AUDIT_USER_AVC) { |
50397bd1 EP |
627 | *ab = NULL; |
628 | return rc; | |
629 | } | |
630 | ||
631 | *ab = audit_log_start(NULL, GFP_KERNEL, msg_type); | |
0644ec0c KC |
632 | if (unlikely(!*ab)) |
633 | return rc; | |
4d3fb709 EP |
634 | audit_log_format(*ab, "pid=%d uid=%u", task_tgid_vnr(current), uid); |
635 | audit_log_session_info(*ab); | |
b122c376 | 636 | audit_log_task_context(*ab); |
50397bd1 EP |
637 | |
638 | return rc; | |
639 | } | |
640 | ||
b0fed402 EP |
641 | int is_audit_feature_set(int i) |
642 | { | |
643 | return af.features & AUDIT_FEATURE_TO_MASK(i); | |
644 | } | |
645 | ||
646 | ||
647 | static int audit_get_feature(struct sk_buff *skb) | |
648 | { | |
649 | u32 seq; | |
650 | ||
651 | seq = nlmsg_hdr(skb)->nlmsg_seq; | |
652 | ||
653 | audit_send_reply(NETLINK_CB(skb).portid, seq, AUDIT_GET, 0, 0, | |
654 | &af, sizeof(af)); | |
655 | ||
656 | return 0; | |
657 | } | |
658 | ||
659 | static void audit_log_feature_change(int which, u32 old_feature, u32 new_feature, | |
660 | u32 old_lock, u32 new_lock, int res) | |
661 | { | |
662 | struct audit_buffer *ab; | |
663 | ||
664 | ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_FEATURE_CHANGE); | |
665 | audit_log_format(ab, "feature=%s new=%d old=%d old_lock=%d new_lock=%d res=%d", | |
666 | audit_feature_names[which], !!old_feature, !!new_feature, | |
667 | !!old_lock, !!new_lock, res); | |
668 | audit_log_end(ab); | |
669 | } | |
670 | ||
671 | static int audit_set_feature(struct sk_buff *skb) | |
672 | { | |
673 | struct audit_features *uaf; | |
674 | int i; | |
675 | ||
676 | BUILD_BUG_ON(AUDIT_LAST_FEATURE + 1 > sizeof(audit_feature_names)/sizeof(audit_feature_names[0])); | |
677 | uaf = nlmsg_data(nlmsg_hdr(skb)); | |
678 | ||
679 | /* if there is ever a version 2 we should handle that here */ | |
680 | ||
681 | for (i = 0; i <= AUDIT_LAST_FEATURE; i++) { | |
682 | u32 feature = AUDIT_FEATURE_TO_MASK(i); | |
683 | u32 old_feature, new_feature, old_lock, new_lock; | |
684 | ||
685 | /* if we are not changing this feature, move along */ | |
686 | if (!(feature & uaf->mask)) | |
687 | continue; | |
688 | ||
689 | old_feature = af.features & feature; | |
690 | new_feature = uaf->features & feature; | |
691 | new_lock = (uaf->lock | af.lock) & feature; | |
692 | old_lock = af.lock & feature; | |
693 | ||
694 | /* are we changing a locked feature? */ | |
695 | if ((af.lock & feature) && (new_feature != old_feature)) { | |
696 | audit_log_feature_change(i, old_feature, new_feature, | |
697 | old_lock, new_lock, 0); | |
698 | return -EPERM; | |
699 | } | |
700 | } | |
701 | /* nothing invalid, do the changes */ | |
702 | for (i = 0; i <= AUDIT_LAST_FEATURE; i++) { | |
703 | u32 feature = AUDIT_FEATURE_TO_MASK(i); | |
704 | u32 old_feature, new_feature, old_lock, new_lock; | |
705 | ||
706 | /* if we are not changing this feature, move along */ | |
707 | if (!(feature & uaf->mask)) | |
708 | continue; | |
709 | ||
710 | old_feature = af.features & feature; | |
711 | new_feature = uaf->features & feature; | |
712 | old_lock = af.lock & feature; | |
713 | new_lock = (uaf->lock | af.lock) & feature; | |
714 | ||
715 | if (new_feature != old_feature) | |
716 | audit_log_feature_change(i, old_feature, new_feature, | |
717 | old_lock, new_lock, 1); | |
718 | ||
719 | if (new_feature) | |
720 | af.features |= feature; | |
721 | else | |
722 | af.features &= ~feature; | |
723 | af.lock |= new_lock; | |
724 | } | |
725 | ||
726 | return 0; | |
727 | } | |
728 | ||
1da177e4 LT |
729 | static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) |
730 | { | |
dc9eb698 | 731 | u32 seq; |
1da177e4 LT |
732 | void *data; |
733 | struct audit_status *status_get, status_set; | |
734 | int err; | |
c0404993 | 735 | struct audit_buffer *ab; |
1da177e4 | 736 | u16 msg_type = nlh->nlmsg_type; |
e1396065 | 737 | struct audit_sig_info *sig_data; |
50397bd1 | 738 | char *ctx = NULL; |
e1396065 | 739 | u32 len; |
1da177e4 | 740 | |
c7bdb545 | 741 | err = audit_netlink_ok(skb, msg_type); |
1da177e4 LT |
742 | if (err) |
743 | return err; | |
744 | ||
b0dd25a8 RD |
745 | /* As soon as there's any sign of userspace auditd, |
746 | * start kauditd to talk to it */ | |
13f51e1c | 747 | if (!kauditd_task) { |
b7d11258 | 748 | kauditd_task = kthread_run(kauditd_thread, NULL, "kauditd"); |
13f51e1c G |
749 | if (IS_ERR(kauditd_task)) { |
750 | err = PTR_ERR(kauditd_task); | |
751 | kauditd_task = NULL; | |
752 | return err; | |
753 | } | |
b7d11258 | 754 | } |
1da177e4 | 755 | seq = nlh->nlmsg_seq; |
c64e66c6 | 756 | data = nlmsg_data(nlh); |
1da177e4 LT |
757 | |
758 | switch (msg_type) { | |
759 | case AUDIT_GET: | |
760 | status_set.enabled = audit_enabled; | |
761 | status_set.failure = audit_failure; | |
762 | status_set.pid = audit_pid; | |
763 | status_set.rate_limit = audit_rate_limit; | |
764 | status_set.backlog_limit = audit_backlog_limit; | |
765 | status_set.lost = atomic_read(&audit_lost); | |
b7d11258 | 766 | status_set.backlog = skb_queue_len(&audit_skb_queue); |
15e47304 | 767 | audit_send_reply(NETLINK_CB(skb).portid, seq, AUDIT_GET, 0, 0, |
1da177e4 LT |
768 | &status_set, sizeof(status_set)); |
769 | break; | |
770 | case AUDIT_SET: | |
771 | if (nlh->nlmsg_len < sizeof(struct audit_status)) | |
772 | return -EINVAL; | |
773 | status_get = (struct audit_status *)data; | |
774 | if (status_get->mask & AUDIT_STATUS_ENABLED) { | |
dc9eb698 | 775 | err = audit_set_enabled(status_get->enabled); |
20c6aaa3 | 776 | if (err < 0) |
777 | return err; | |
1da177e4 LT |
778 | } |
779 | if (status_get->mask & AUDIT_STATUS_FAILURE) { | |
dc9eb698 | 780 | err = audit_set_failure(status_get->failure); |
20c6aaa3 | 781 | if (err < 0) |
782 | return err; | |
1da177e4 LT |
783 | } |
784 | if (status_get->mask & AUDIT_STATUS_PID) { | |
1a6b9f23 EP |
785 | int new_pid = status_get->pid; |
786 | ||
787 | if (audit_enabled != AUDIT_OFF) | |
dc9eb698 | 788 | audit_log_config_change("audit_pid", new_pid, audit_pid, 1); |
1a6b9f23 | 789 | audit_pid = new_pid; |
15e47304 | 790 | audit_nlk_portid = NETLINK_CB(skb).portid; |
1da177e4 | 791 | } |
20c6aaa3 | 792 | if (status_get->mask & AUDIT_STATUS_RATE_LIMIT) { |
dc9eb698 | 793 | err = audit_set_rate_limit(status_get->rate_limit); |
20c6aaa3 | 794 | if (err < 0) |
795 | return err; | |
796 | } | |
1da177e4 | 797 | if (status_get->mask & AUDIT_STATUS_BACKLOG_LIMIT) |
dc9eb698 | 798 | err = audit_set_backlog_limit(status_get->backlog_limit); |
1da177e4 | 799 | break; |
b0fed402 EP |
800 | case AUDIT_GET_FEATURE: |
801 | err = audit_get_feature(skb); | |
802 | if (err) | |
803 | return err; | |
804 | break; | |
805 | case AUDIT_SET_FEATURE: | |
806 | err = audit_set_feature(skb); | |
807 | if (err) | |
808 | return err; | |
809 | break; | |
05474106 | 810 | case AUDIT_USER: |
039b6b3e RD |
811 | case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG: |
812 | case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2: | |
4a4cd633 DW |
813 | if (!audit_enabled && msg_type != AUDIT_USER_AVC) |
814 | return 0; | |
815 | ||
62062cf8 | 816 | err = audit_filter_user(msg_type); |
4a4cd633 DW |
817 | if (err == 1) { |
818 | err = 0; | |
522ed776 | 819 | if (msg_type == AUDIT_USER_TTY) { |
152f497b | 820 | err = tty_audit_push_current(); |
522ed776 MT |
821 | if (err) |
822 | break; | |
823 | } | |
dc9eb698 | 824 | audit_log_common_recv_msg(&ab, msg_type); |
50397bd1 | 825 | if (msg_type != AUDIT_USER_TTY) |
b50eba7e RGB |
826 | audit_log_format(ab, " msg='%.*s'", |
827 | AUDIT_MESSAGE_TEXT_MAX, | |
50397bd1 EP |
828 | (char *)data); |
829 | else { | |
830 | int size; | |
831 | ||
f7616102 | 832 | audit_log_format(ab, " data="); |
50397bd1 | 833 | size = nlmsg_len(nlh); |
55ad2f8d MT |
834 | if (size > 0 && |
835 | ((unsigned char *)data)[size - 1] == '\0') | |
836 | size--; | |
b556f8ad | 837 | audit_log_n_untrustedstring(ab, data, size); |
4a4cd633 | 838 | } |
aecdc33e | 839 | audit_set_pid(ab, NETLINK_CB(skb).portid); |
50397bd1 | 840 | audit_log_end(ab); |
0f45aa18 | 841 | } |
1da177e4 | 842 | break; |
93315ed6 AG |
843 | case AUDIT_ADD_RULE: |
844 | case AUDIT_DEL_RULE: | |
845 | if (nlmsg_len(nlh) < sizeof(struct audit_rule_data)) | |
846 | return -EINVAL; | |
1a6b9f23 | 847 | if (audit_enabled == AUDIT_LOCKED) { |
dc9eb698 EP |
848 | audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE); |
849 | audit_log_format(ab, " audit_enabled=%d res=0", audit_enabled); | |
50397bd1 | 850 | audit_log_end(ab); |
6a01b07f SG |
851 | return -EPERM; |
852 | } | |
93315ed6 AG |
853 | /* fallthrough */ |
854 | case AUDIT_LIST_RULES: | |
15e47304 | 855 | err = audit_receive_filter(msg_type, NETLINK_CB(skb).portid, |
dc9eb698 | 856 | seq, data, nlmsg_len(nlh)); |
1da177e4 | 857 | break; |
74c3cbe3 AV |
858 | case AUDIT_TRIM: |
859 | audit_trim_trees(); | |
dc9eb698 | 860 | audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE); |
74c3cbe3 AV |
861 | audit_log_format(ab, " op=trim res=1"); |
862 | audit_log_end(ab); | |
863 | break; | |
864 | case AUDIT_MAKE_EQUIV: { | |
865 | void *bufp = data; | |
866 | u32 sizes[2]; | |
7719e437 | 867 | size_t msglen = nlmsg_len(nlh); |
74c3cbe3 AV |
868 | char *old, *new; |
869 | ||
870 | err = -EINVAL; | |
7719e437 | 871 | if (msglen < 2 * sizeof(u32)) |
74c3cbe3 AV |
872 | break; |
873 | memcpy(sizes, bufp, 2 * sizeof(u32)); | |
874 | bufp += 2 * sizeof(u32); | |
7719e437 HH |
875 | msglen -= 2 * sizeof(u32); |
876 | old = audit_unpack_string(&bufp, &msglen, sizes[0]); | |
74c3cbe3 AV |
877 | if (IS_ERR(old)) { |
878 | err = PTR_ERR(old); | |
879 | break; | |
880 | } | |
7719e437 | 881 | new = audit_unpack_string(&bufp, &msglen, sizes[1]); |
74c3cbe3 AV |
882 | if (IS_ERR(new)) { |
883 | err = PTR_ERR(new); | |
884 | kfree(old); | |
885 | break; | |
886 | } | |
887 | /* OK, here comes... */ | |
888 | err = audit_tag_tree(old, new); | |
889 | ||
dc9eb698 | 890 | audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE); |
50397bd1 | 891 | |
74c3cbe3 AV |
892 | audit_log_format(ab, " op=make_equiv old="); |
893 | audit_log_untrustedstring(ab, old); | |
894 | audit_log_format(ab, " new="); | |
895 | audit_log_untrustedstring(ab, new); | |
896 | audit_log_format(ab, " res=%d", !err); | |
897 | audit_log_end(ab); | |
898 | kfree(old); | |
899 | kfree(new); | |
900 | break; | |
901 | } | |
c2f0c7c3 | 902 | case AUDIT_SIGNAL_INFO: |
939cbf26 EP |
903 | len = 0; |
904 | if (audit_sig_sid) { | |
905 | err = security_secid_to_secctx(audit_sig_sid, &ctx, &len); | |
906 | if (err) | |
907 | return err; | |
908 | } | |
e1396065 AV |
909 | sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL); |
910 | if (!sig_data) { | |
939cbf26 EP |
911 | if (audit_sig_sid) |
912 | security_release_secctx(ctx, len); | |
e1396065 AV |
913 | return -ENOMEM; |
914 | } | |
cca080d9 | 915 | sig_data->uid = from_kuid(&init_user_ns, audit_sig_uid); |
e1396065 | 916 | sig_data->pid = audit_sig_pid; |
939cbf26 EP |
917 | if (audit_sig_sid) { |
918 | memcpy(sig_data->ctx, ctx, len); | |
919 | security_release_secctx(ctx, len); | |
920 | } | |
15e47304 | 921 | audit_send_reply(NETLINK_CB(skb).portid, seq, AUDIT_SIGNAL_INFO, |
e1396065 AV |
922 | 0, 0, sig_data, sizeof(*sig_data) + len); |
923 | kfree(sig_data); | |
c2f0c7c3 | 924 | break; |
522ed776 MT |
925 | case AUDIT_TTY_GET: { |
926 | struct audit_tty_status s; | |
8aa14b64 EB |
927 | struct task_struct *tsk = current; |
928 | ||
7173c54e | 929 | spin_lock(&tsk->sighand->siglock); |
8aa14b64 | 930 | s.enabled = tsk->signal->audit_tty != 0; |
46e959ea | 931 | s.log_passwd = tsk->signal->audit_tty_log_passwd; |
7173c54e | 932 | spin_unlock(&tsk->sighand->siglock); |
8aa14b64 | 933 | |
aecdc33e | 934 | audit_send_reply(NETLINK_CB(skb).portid, seq, |
8aa14b64 | 935 | AUDIT_TTY_GET, 0, 0, &s, sizeof(s)); |
522ed776 MT |
936 | break; |
937 | } | |
938 | case AUDIT_TTY_SET: { | |
46e959ea | 939 | struct audit_tty_status s; |
8aa14b64 | 940 | struct task_struct *tsk = current; |
522ed776 | 941 | |
46e959ea RGB |
942 | memset(&s, 0, sizeof(s)); |
943 | /* guard against past and future API changes */ | |
944 | memcpy(&s, data, min(sizeof(s), (size_t)nlh->nlmsg_len)); | |
945 | if ((s.enabled != 0 && s.enabled != 1) || | |
946 | (s.log_passwd != 0 && s.log_passwd != 1)) | |
522ed776 | 947 | return -EINVAL; |
8aa14b64 | 948 | |
7173c54e | 949 | spin_lock(&tsk->sighand->siglock); |
46e959ea RGB |
950 | tsk->signal->audit_tty = s.enabled; |
951 | tsk->signal->audit_tty_log_passwd = s.log_passwd; | |
7173c54e | 952 | spin_unlock(&tsk->sighand->siglock); |
522ed776 MT |
953 | break; |
954 | } | |
1da177e4 LT |
955 | default: |
956 | err = -EINVAL; | |
957 | break; | |
958 | } | |
959 | ||
960 | return err < 0 ? err : 0; | |
961 | } | |
962 | ||
b0dd25a8 | 963 | /* |
ea7ae60b EP |
964 | * Get message from skb. Each message is processed by audit_receive_msg. |
965 | * Malformed skbs with wrong length are discarded silently. | |
b0dd25a8 | 966 | */ |
2a0a6ebe | 967 | static void audit_receive_skb(struct sk_buff *skb) |
1da177e4 | 968 | { |
ea7ae60b EP |
969 | struct nlmsghdr *nlh; |
970 | /* | |
94191213 | 971 | * len MUST be signed for nlmsg_next to be able to dec it below 0 |
ea7ae60b EP |
972 | * if the nlmsg_len was not aligned |
973 | */ | |
974 | int len; | |
975 | int err; | |
976 | ||
977 | nlh = nlmsg_hdr(skb); | |
978 | len = skb->len; | |
979 | ||
94191213 | 980 | while (nlmsg_ok(nlh, len)) { |
ea7ae60b EP |
981 | err = audit_receive_msg(skb, nlh); |
982 | /* if err or if this message says it wants a response */ | |
983 | if (err || (nlh->nlmsg_flags & NLM_F_ACK)) | |
1da177e4 | 984 | netlink_ack(skb, nlh, err); |
ea7ae60b | 985 | |
2851da57 | 986 | nlh = nlmsg_next(nlh, &len); |
1da177e4 | 987 | } |
1da177e4 LT |
988 | } |
989 | ||
990 | /* Receive messages from netlink socket. */ | |
cd40b7d3 | 991 | static void audit_receive(struct sk_buff *skb) |
1da177e4 | 992 | { |
f368c07d | 993 | mutex_lock(&audit_cmd_mutex); |
cd40b7d3 | 994 | audit_receive_skb(skb); |
f368c07d | 995 | mutex_unlock(&audit_cmd_mutex); |
1da177e4 LT |
996 | } |
997 | ||
1da177e4 LT |
998 | /* Initialize audit support at boot time. */ |
999 | static int __init audit_init(void) | |
1000 | { | |
f368c07d | 1001 | int i; |
a31f2d17 PNA |
1002 | struct netlink_kernel_cfg cfg = { |
1003 | .input = audit_receive, | |
1004 | }; | |
f368c07d | 1005 | |
a3f07114 EP |
1006 | if (audit_initialized == AUDIT_DISABLED) |
1007 | return 0; | |
1008 | ||
1da177e4 LT |
1009 | printk(KERN_INFO "audit: initializing netlink socket (%s)\n", |
1010 | audit_default ? "enabled" : "disabled"); | |
9f00d977 | 1011 | audit_sock = netlink_kernel_create(&init_net, NETLINK_AUDIT, &cfg); |
1da177e4 LT |
1012 | if (!audit_sock) |
1013 | audit_panic("cannot initialize netlink socket"); | |
71e1c784 AG |
1014 | else |
1015 | audit_sock->sk_sndtimeo = MAX_SCHEDULE_TIMEOUT; | |
1da177e4 | 1016 | |
b7d11258 | 1017 | skb_queue_head_init(&audit_skb_queue); |
f3d357b0 | 1018 | skb_queue_head_init(&audit_skb_hold_queue); |
a3f07114 | 1019 | audit_initialized = AUDIT_INITIALIZED; |
1da177e4 | 1020 | audit_enabled = audit_default; |
b593d384 | 1021 | audit_ever_enabled |= !!audit_default; |
3dc7e315 | 1022 | |
9ad9ad38 | 1023 | audit_log(NULL, GFP_KERNEL, AUDIT_KERNEL, "initialized"); |
f368c07d | 1024 | |
f368c07d AG |
1025 | for (i = 0; i < AUDIT_INODE_BUCKETS; i++) |
1026 | INIT_LIST_HEAD(&audit_inode_hash[i]); | |
f368c07d | 1027 | |
1da177e4 LT |
1028 | return 0; |
1029 | } | |
1da177e4 LT |
1030 | __initcall(audit_init); |
1031 | ||
1032 | /* Process kernel command-line parameter at boot time. audit=0 or audit=1. */ | |
1033 | static int __init audit_enable(char *str) | |
1034 | { | |
1035 | audit_default = !!simple_strtol(str, NULL, 0); | |
a3f07114 EP |
1036 | if (!audit_default) |
1037 | audit_initialized = AUDIT_DISABLED; | |
1038 | ||
1039 | printk(KERN_INFO "audit: %s", audit_default ? "enabled" : "disabled"); | |
1040 | ||
1041 | if (audit_initialized == AUDIT_INITIALIZED) { | |
1da177e4 | 1042 | audit_enabled = audit_default; |
b593d384 | 1043 | audit_ever_enabled |= !!audit_default; |
a3f07114 EP |
1044 | } else if (audit_initialized == AUDIT_UNINITIALIZED) { |
1045 | printk(" (after initialization)"); | |
1046 | } else { | |
1047 | printk(" (until reboot)"); | |
b593d384 | 1048 | } |
a3f07114 EP |
1049 | printk("\n"); |
1050 | ||
9b41046c | 1051 | return 1; |
1da177e4 LT |
1052 | } |
1053 | ||
1054 | __setup("audit=", audit_enable); | |
1055 | ||
16e1904e CW |
1056 | static void audit_buffer_free(struct audit_buffer *ab) |
1057 | { | |
1058 | unsigned long flags; | |
1059 | ||
8fc6115c CW |
1060 | if (!ab) |
1061 | return; | |
1062 | ||
5ac52f33 CW |
1063 | if (ab->skb) |
1064 | kfree_skb(ab->skb); | |
b7d11258 | 1065 | |
16e1904e | 1066 | spin_lock_irqsave(&audit_freelist_lock, flags); |
5d136a01 | 1067 | if (audit_freelist_count > AUDIT_MAXFREE) |
16e1904e | 1068 | kfree(ab); |
5d136a01 SH |
1069 | else { |
1070 | audit_freelist_count++; | |
16e1904e | 1071 | list_add(&ab->list, &audit_freelist); |
5d136a01 | 1072 | } |
16e1904e CW |
1073 | spin_unlock_irqrestore(&audit_freelist_lock, flags); |
1074 | } | |
1075 | ||
c0404993 | 1076 | static struct audit_buffer * audit_buffer_alloc(struct audit_context *ctx, |
dd0fc66f | 1077 | gfp_t gfp_mask, int type) |
16e1904e CW |
1078 | { |
1079 | unsigned long flags; | |
1080 | struct audit_buffer *ab = NULL; | |
c0404993 | 1081 | struct nlmsghdr *nlh; |
16e1904e CW |
1082 | |
1083 | spin_lock_irqsave(&audit_freelist_lock, flags); | |
1084 | if (!list_empty(&audit_freelist)) { | |
1085 | ab = list_entry(audit_freelist.next, | |
1086 | struct audit_buffer, list); | |
1087 | list_del(&ab->list); | |
1088 | --audit_freelist_count; | |
1089 | } | |
1090 | spin_unlock_irqrestore(&audit_freelist_lock, flags); | |
1091 | ||
1092 | if (!ab) { | |
4332bdd3 | 1093 | ab = kmalloc(sizeof(*ab), gfp_mask); |
16e1904e | 1094 | if (!ab) |
8fc6115c | 1095 | goto err; |
16e1904e | 1096 | } |
8fc6115c | 1097 | |
b7d11258 | 1098 | ab->ctx = ctx; |
9ad9ad38 | 1099 | ab->gfp_mask = gfp_mask; |
ee080e6c EP |
1100 | |
1101 | ab->skb = nlmsg_new(AUDIT_BUFSIZ, gfp_mask); | |
1102 | if (!ab->skb) | |
c64e66c6 | 1103 | goto err; |
ee080e6c | 1104 | |
c64e66c6 DM |
1105 | nlh = nlmsg_put(ab->skb, 0, 0, type, 0, 0); |
1106 | if (!nlh) | |
1107 | goto out_kfree_skb; | |
ee080e6c | 1108 | |
16e1904e | 1109 | return ab; |
ee080e6c | 1110 | |
c64e66c6 | 1111 | out_kfree_skb: |
ee080e6c EP |
1112 | kfree_skb(ab->skb); |
1113 | ab->skb = NULL; | |
8fc6115c CW |
1114 | err: |
1115 | audit_buffer_free(ab); | |
1116 | return NULL; | |
16e1904e | 1117 | } |
1da177e4 | 1118 | |
b0dd25a8 RD |
1119 | /** |
1120 | * audit_serial - compute a serial number for the audit record | |
1121 | * | |
1122 | * Compute a serial number for the audit record. Audit records are | |
bfb4496e DW |
1123 | * written to user-space as soon as they are generated, so a complete |
1124 | * audit record may be written in several pieces. The timestamp of the | |
1125 | * record and this serial number are used by the user-space tools to | |
1126 | * determine which pieces belong to the same audit record. The | |
1127 | * (timestamp,serial) tuple is unique for each syscall and is live from | |
1128 | * syscall entry to syscall exit. | |
1129 | * | |
bfb4496e DW |
1130 | * NOTE: Another possibility is to store the formatted records off the |
1131 | * audit context (for those records that have a context), and emit them | |
1132 | * all at syscall exit. However, this could delay the reporting of | |
1133 | * significant errors until syscall exit (or never, if the system | |
b0dd25a8 RD |
1134 | * halts). |
1135 | */ | |
bfb4496e DW |
1136 | unsigned int audit_serial(void) |
1137 | { | |
34af946a | 1138 | static DEFINE_SPINLOCK(serial_lock); |
d5b454f2 DW |
1139 | static unsigned int serial = 0; |
1140 | ||
1141 | unsigned long flags; | |
1142 | unsigned int ret; | |
bfb4496e | 1143 | |
d5b454f2 | 1144 | spin_lock_irqsave(&serial_lock, flags); |
bfb4496e | 1145 | do { |
ce625a80 DW |
1146 | ret = ++serial; |
1147 | } while (unlikely(!ret)); | |
d5b454f2 | 1148 | spin_unlock_irqrestore(&serial_lock, flags); |
bfb4496e | 1149 | |
d5b454f2 | 1150 | return ret; |
bfb4496e DW |
1151 | } |
1152 | ||
5600b892 | 1153 | static inline void audit_get_stamp(struct audit_context *ctx, |
bfb4496e DW |
1154 | struct timespec *t, unsigned int *serial) |
1155 | { | |
48887e63 | 1156 | if (!ctx || !auditsc_get_stamp(ctx, t, serial)) { |
bfb4496e DW |
1157 | *t = CURRENT_TIME; |
1158 | *serial = audit_serial(); | |
1159 | } | |
1160 | } | |
1161 | ||
82919919 AM |
1162 | /* |
1163 | * Wait for auditd to drain the queue a little | |
1164 | */ | |
1165 | static void wait_for_auditd(unsigned long sleep_time) | |
1166 | { | |
1167 | DECLARE_WAITQUEUE(wait, current); | |
f000cfdd | 1168 | set_current_state(TASK_UNINTERRUPTIBLE); |
82919919 AM |
1169 | add_wait_queue(&audit_backlog_wait, &wait); |
1170 | ||
1171 | if (audit_backlog_limit && | |
1172 | skb_queue_len(&audit_skb_queue) > audit_backlog_limit) | |
1173 | schedule_timeout(sleep_time); | |
1174 | ||
1175 | __set_current_state(TASK_RUNNING); | |
1176 | remove_wait_queue(&audit_backlog_wait, &wait); | |
1177 | } | |
1178 | ||
b0dd25a8 RD |
1179 | /** |
1180 | * audit_log_start - obtain an audit buffer | |
1181 | * @ctx: audit_context (may be NULL) | |
1182 | * @gfp_mask: type of allocation | |
1183 | * @type: audit message type | |
1184 | * | |
1185 | * Returns audit_buffer pointer on success or NULL on error. | |
1186 | * | |
1187 | * Obtain an audit buffer. This routine does locking to obtain the | |
1188 | * audit buffer, but then no locking is required for calls to | |
1189 | * audit_log_*format. If the task (ctx) is a task that is currently in a | |
1190 | * syscall, then the syscall is marked as auditable and an audit record | |
1191 | * will be written at syscall exit. If there is no associated task, then | |
1192 | * task context (ctx) should be NULL. | |
1193 | */ | |
9796fdd8 | 1194 | struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask, |
9ad9ad38 | 1195 | int type) |
1da177e4 LT |
1196 | { |
1197 | struct audit_buffer *ab = NULL; | |
1da177e4 | 1198 | struct timespec t; |
ef00be05 | 1199 | unsigned int uninitialized_var(serial); |
9ad9ad38 | 1200 | int reserve; |
ac4cec44 | 1201 | unsigned long timeout_start = jiffies; |
1da177e4 | 1202 | |
a3f07114 | 1203 | if (audit_initialized != AUDIT_INITIALIZED) |
1da177e4 LT |
1204 | return NULL; |
1205 | ||
c8edc80c DK |
1206 | if (unlikely(audit_filter_type(type))) |
1207 | return NULL; | |
1208 | ||
9ad9ad38 DW |
1209 | if (gfp_mask & __GFP_WAIT) |
1210 | reserve = 0; | |
1211 | else | |
5600b892 | 1212 | reserve = 5; /* Allow atomic callers to go up to five |
9ad9ad38 DW |
1213 | entries over the normal backlog limit */ |
1214 | ||
1215 | while (audit_backlog_limit | |
1216 | && skb_queue_len(&audit_skb_queue) > audit_backlog_limit + reserve) { | |
82919919 AM |
1217 | if (gfp_mask & __GFP_WAIT && audit_backlog_wait_time) { |
1218 | unsigned long sleep_time; | |
9ad9ad38 | 1219 | |
82919919 AM |
1220 | sleep_time = timeout_start + audit_backlog_wait_time - |
1221 | jiffies; | |
1222 | if ((long)sleep_time > 0) | |
1223 | wait_for_auditd(sleep_time); | |
ac4cec44 | 1224 | continue; |
9ad9ad38 | 1225 | } |
320f1b1e | 1226 | if (audit_rate_check() && printk_ratelimit()) |
fb19b4c6 DW |
1227 | printk(KERN_WARNING |
1228 | "audit: audit_backlog=%d > " | |
1229 | "audit_backlog_limit=%d\n", | |
1230 | skb_queue_len(&audit_skb_queue), | |
1231 | audit_backlog_limit); | |
1232 | audit_log_lost("backlog limit exceeded"); | |
ac4cec44 DW |
1233 | audit_backlog_wait_time = audit_backlog_wait_overflow; |
1234 | wake_up(&audit_backlog_wait); | |
fb19b4c6 DW |
1235 | return NULL; |
1236 | } | |
1237 | ||
9ad9ad38 | 1238 | ab = audit_buffer_alloc(ctx, gfp_mask, type); |
1da177e4 LT |
1239 | if (!ab) { |
1240 | audit_log_lost("out of memory in audit_log_start"); | |
1241 | return NULL; | |
1242 | } | |
1243 | ||
bfb4496e | 1244 | audit_get_stamp(ab->ctx, &t, &serial); |
197c69c6 | 1245 | |
1da177e4 LT |
1246 | audit_log_format(ab, "audit(%lu.%03lu:%u): ", |
1247 | t.tv_sec, t.tv_nsec/1000000, serial); | |
1248 | return ab; | |
1249 | } | |
1250 | ||
8fc6115c | 1251 | /** |
5ac52f33 | 1252 | * audit_expand - expand skb in the audit buffer |
8fc6115c | 1253 | * @ab: audit_buffer |
b0dd25a8 | 1254 | * @extra: space to add at tail of the skb |
8fc6115c CW |
1255 | * |
1256 | * Returns 0 (no space) on failed expansion, or available space if | |
1257 | * successful. | |
1258 | */ | |
e3b926b4 | 1259 | static inline int audit_expand(struct audit_buffer *ab, int extra) |
8fc6115c | 1260 | { |
5ac52f33 | 1261 | struct sk_buff *skb = ab->skb; |
406a1d86 HX |
1262 | int oldtail = skb_tailroom(skb); |
1263 | int ret = pskb_expand_head(skb, 0, extra, ab->gfp_mask); | |
1264 | int newtail = skb_tailroom(skb); | |
1265 | ||
5ac52f33 CW |
1266 | if (ret < 0) { |
1267 | audit_log_lost("out of memory in audit_expand"); | |
8fc6115c | 1268 | return 0; |
5ac52f33 | 1269 | } |
406a1d86 HX |
1270 | |
1271 | skb->truesize += newtail - oldtail; | |
1272 | return newtail; | |
8fc6115c | 1273 | } |
1da177e4 | 1274 | |
b0dd25a8 RD |
1275 | /* |
1276 | * Format an audit message into the audit buffer. If there isn't enough | |
1da177e4 LT |
1277 | * room in the audit buffer, more room will be allocated and vsnprint |
1278 | * will be called a second time. Currently, we assume that a printk | |
b0dd25a8 RD |
1279 | * can't format message larger than 1024 bytes, so we don't either. |
1280 | */ | |
1da177e4 LT |
1281 | static void audit_log_vformat(struct audit_buffer *ab, const char *fmt, |
1282 | va_list args) | |
1283 | { | |
1284 | int len, avail; | |
5ac52f33 | 1285 | struct sk_buff *skb; |
eecb0a73 | 1286 | va_list args2; |
1da177e4 LT |
1287 | |
1288 | if (!ab) | |
1289 | return; | |
1290 | ||
5ac52f33 CW |
1291 | BUG_ON(!ab->skb); |
1292 | skb = ab->skb; | |
1293 | avail = skb_tailroom(skb); | |
1294 | if (avail == 0) { | |
e3b926b4 | 1295 | avail = audit_expand(ab, AUDIT_BUFSIZ); |
8fc6115c CW |
1296 | if (!avail) |
1297 | goto out; | |
1da177e4 | 1298 | } |
eecb0a73 | 1299 | va_copy(args2, args); |
27a884dc | 1300 | len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args); |
1da177e4 LT |
1301 | if (len >= avail) { |
1302 | /* The printk buffer is 1024 bytes long, so if we get | |
1303 | * here and AUDIT_BUFSIZ is at least 1024, then we can | |
1304 | * log everything that printk could have logged. */ | |
b0dd25a8 RD |
1305 | avail = audit_expand(ab, |
1306 | max_t(unsigned, AUDIT_BUFSIZ, 1+len-avail)); | |
8fc6115c | 1307 | if (!avail) |
a0e86bd4 | 1308 | goto out_va_end; |
27a884dc | 1309 | len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args2); |
1da177e4 | 1310 | } |
168b7173 SG |
1311 | if (len > 0) |
1312 | skb_put(skb, len); | |
a0e86bd4 JJ |
1313 | out_va_end: |
1314 | va_end(args2); | |
8fc6115c CW |
1315 | out: |
1316 | return; | |
1da177e4 LT |
1317 | } |
1318 | ||
b0dd25a8 RD |
1319 | /** |
1320 | * audit_log_format - format a message into the audit buffer. | |
1321 | * @ab: audit_buffer | |
1322 | * @fmt: format string | |
1323 | * @...: optional parameters matching @fmt string | |
1324 | * | |
1325 | * All the work is done in audit_log_vformat. | |
1326 | */ | |
1da177e4 LT |
1327 | void audit_log_format(struct audit_buffer *ab, const char *fmt, ...) |
1328 | { | |
1329 | va_list args; | |
1330 | ||
1331 | if (!ab) | |
1332 | return; | |
1333 | va_start(args, fmt); | |
1334 | audit_log_vformat(ab, fmt, args); | |
1335 | va_end(args); | |
1336 | } | |
1337 | ||
b0dd25a8 RD |
1338 | /** |
1339 | * audit_log_hex - convert a buffer to hex and append it to the audit skb | |
1340 | * @ab: the audit_buffer | |
1341 | * @buf: buffer to convert to hex | |
1342 | * @len: length of @buf to be converted | |
1343 | * | |
1344 | * No return value; failure to expand is silently ignored. | |
1345 | * | |
1346 | * This function will take the passed buf and convert it into a string of | |
1347 | * ascii hex digits. The new string is placed onto the skb. | |
1348 | */ | |
b556f8ad | 1349 | void audit_log_n_hex(struct audit_buffer *ab, const unsigned char *buf, |
168b7173 | 1350 | size_t len) |
83c7d091 | 1351 | { |
168b7173 SG |
1352 | int i, avail, new_len; |
1353 | unsigned char *ptr; | |
1354 | struct sk_buff *skb; | |
1355 | static const unsigned char *hex = "0123456789ABCDEF"; | |
1356 | ||
8ef2d304 AG |
1357 | if (!ab) |
1358 | return; | |
1359 | ||
168b7173 SG |
1360 | BUG_ON(!ab->skb); |
1361 | skb = ab->skb; | |
1362 | avail = skb_tailroom(skb); | |
1363 | new_len = len<<1; | |
1364 | if (new_len >= avail) { | |
1365 | /* Round the buffer request up to the next multiple */ | |
1366 | new_len = AUDIT_BUFSIZ*(((new_len-avail)/AUDIT_BUFSIZ) + 1); | |
1367 | avail = audit_expand(ab, new_len); | |
1368 | if (!avail) | |
1369 | return; | |
1370 | } | |
83c7d091 | 1371 | |
27a884dc | 1372 | ptr = skb_tail_pointer(skb); |
168b7173 SG |
1373 | for (i=0; i<len; i++) { |
1374 | *ptr++ = hex[(buf[i] & 0xF0)>>4]; /* Upper nibble */ | |
1375 | *ptr++ = hex[buf[i] & 0x0F]; /* Lower nibble */ | |
1376 | } | |
1377 | *ptr = 0; | |
1378 | skb_put(skb, len << 1); /* new string is twice the old string */ | |
83c7d091 | 1379 | } |
1380 | ||
9c937dcc AG |
1381 | /* |
1382 | * Format a string of no more than slen characters into the audit buffer, | |
1383 | * enclosed in quote marks. | |
1384 | */ | |
b556f8ad EP |
1385 | void audit_log_n_string(struct audit_buffer *ab, const char *string, |
1386 | size_t slen) | |
9c937dcc AG |
1387 | { |
1388 | int avail, new_len; | |
1389 | unsigned char *ptr; | |
1390 | struct sk_buff *skb; | |
1391 | ||
8ef2d304 AG |
1392 | if (!ab) |
1393 | return; | |
1394 | ||
9c937dcc AG |
1395 | BUG_ON(!ab->skb); |
1396 | skb = ab->skb; | |
1397 | avail = skb_tailroom(skb); | |
1398 | new_len = slen + 3; /* enclosing quotes + null terminator */ | |
1399 | if (new_len > avail) { | |
1400 | avail = audit_expand(ab, new_len); | |
1401 | if (!avail) | |
1402 | return; | |
1403 | } | |
27a884dc | 1404 | ptr = skb_tail_pointer(skb); |
9c937dcc AG |
1405 | *ptr++ = '"'; |
1406 | memcpy(ptr, string, slen); | |
1407 | ptr += slen; | |
1408 | *ptr++ = '"'; | |
1409 | *ptr = 0; | |
1410 | skb_put(skb, slen + 2); /* don't include null terminator */ | |
1411 | } | |
1412 | ||
de6bbd1d EP |
1413 | /** |
1414 | * audit_string_contains_control - does a string need to be logged in hex | |
f706d5d2 DJ |
1415 | * @string: string to be checked |
1416 | * @len: max length of the string to check | |
de6bbd1d EP |
1417 | */ |
1418 | int audit_string_contains_control(const char *string, size_t len) | |
1419 | { | |
1420 | const unsigned char *p; | |
b3897f56 | 1421 | for (p = string; p < (const unsigned char *)string + len; p++) { |
1d6c9649 | 1422 | if (*p == '"' || *p < 0x21 || *p > 0x7e) |
de6bbd1d EP |
1423 | return 1; |
1424 | } | |
1425 | return 0; | |
1426 | } | |
1427 | ||
b0dd25a8 | 1428 | /** |
522ed776 | 1429 | * audit_log_n_untrustedstring - log a string that may contain random characters |
b0dd25a8 | 1430 | * @ab: audit_buffer |
f706d5d2 | 1431 | * @len: length of string (not including trailing null) |
b0dd25a8 RD |
1432 | * @string: string to be logged |
1433 | * | |
1434 | * This code will escape a string that is passed to it if the string | |
1435 | * contains a control character, unprintable character, double quote mark, | |
168b7173 | 1436 | * or a space. Unescaped strings will start and end with a double quote mark. |
b0dd25a8 | 1437 | * Strings that are escaped are printed in hex (2 digits per char). |
9c937dcc AG |
1438 | * |
1439 | * The caller specifies the number of characters in the string to log, which may | |
1440 | * or may not be the entire string. | |
b0dd25a8 | 1441 | */ |
b556f8ad EP |
1442 | void audit_log_n_untrustedstring(struct audit_buffer *ab, const char *string, |
1443 | size_t len) | |
83c7d091 | 1444 | { |
de6bbd1d | 1445 | if (audit_string_contains_control(string, len)) |
b556f8ad | 1446 | audit_log_n_hex(ab, string, len); |
de6bbd1d | 1447 | else |
b556f8ad | 1448 | audit_log_n_string(ab, string, len); |
83c7d091 | 1449 | } |
1450 | ||
9c937dcc | 1451 | /** |
522ed776 | 1452 | * audit_log_untrustedstring - log a string that may contain random characters |
9c937dcc AG |
1453 | * @ab: audit_buffer |
1454 | * @string: string to be logged | |
1455 | * | |
522ed776 | 1456 | * Same as audit_log_n_untrustedstring(), except that strlen is used to |
9c937dcc AG |
1457 | * determine string length. |
1458 | */ | |
de6bbd1d | 1459 | void audit_log_untrustedstring(struct audit_buffer *ab, const char *string) |
9c937dcc | 1460 | { |
b556f8ad | 1461 | audit_log_n_untrustedstring(ab, string, strlen(string)); |
9c937dcc AG |
1462 | } |
1463 | ||
168b7173 | 1464 | /* This is a helper-function to print the escaped d_path */ |
1da177e4 | 1465 | void audit_log_d_path(struct audit_buffer *ab, const char *prefix, |
66b3fad3 | 1466 | const struct path *path) |
1da177e4 | 1467 | { |
44707fdf | 1468 | char *p, *pathname; |
1da177e4 | 1469 | |
8fc6115c | 1470 | if (prefix) |
c158a35c | 1471 | audit_log_format(ab, "%s", prefix); |
1da177e4 | 1472 | |
168b7173 | 1473 | /* We will allow 11 spaces for ' (deleted)' to be appended */ |
44707fdf JB |
1474 | pathname = kmalloc(PATH_MAX+11, ab->gfp_mask); |
1475 | if (!pathname) { | |
def57543 | 1476 | audit_log_string(ab, "<no_memory>"); |
168b7173 | 1477 | return; |
1da177e4 | 1478 | } |
cf28b486 | 1479 | p = d_path(path, pathname, PATH_MAX+11); |
168b7173 SG |
1480 | if (IS_ERR(p)) { /* Should never happen since we send PATH_MAX */ |
1481 | /* FIXME: can we save some information here? */ | |
def57543 | 1482 | audit_log_string(ab, "<too_long>"); |
5600b892 | 1483 | } else |
168b7173 | 1484 | audit_log_untrustedstring(ab, p); |
44707fdf | 1485 | kfree(pathname); |
1da177e4 LT |
1486 | } |
1487 | ||
4d3fb709 EP |
1488 | void audit_log_session_info(struct audit_buffer *ab) |
1489 | { | |
1490 | u32 sessionid = audit_get_sessionid(current); | |
1491 | uid_t auid = from_kuid(&init_user_ns, audit_get_loginuid(current)); | |
1492 | ||
b8f89caa | 1493 | audit_log_format(ab, " auid=%u ses=%u", auid, sessionid); |
4d3fb709 EP |
1494 | } |
1495 | ||
9d960985 EP |
1496 | void audit_log_key(struct audit_buffer *ab, char *key) |
1497 | { | |
1498 | audit_log_format(ab, " key="); | |
1499 | if (key) | |
1500 | audit_log_untrustedstring(ab, key); | |
1501 | else | |
1502 | audit_log_format(ab, "(null)"); | |
1503 | } | |
1504 | ||
b24a30a7 EP |
1505 | void audit_log_cap(struct audit_buffer *ab, char *prefix, kernel_cap_t *cap) |
1506 | { | |
1507 | int i; | |
1508 | ||
1509 | audit_log_format(ab, " %s=", prefix); | |
1510 | CAP_FOR_EACH_U32(i) { | |
1511 | audit_log_format(ab, "%08x", | |
1512 | cap->cap[(_KERNEL_CAPABILITY_U32S-1) - i]); | |
1513 | } | |
1514 | } | |
1515 | ||
1516 | void audit_log_fcaps(struct audit_buffer *ab, struct audit_names *name) | |
1517 | { | |
1518 | kernel_cap_t *perm = &name->fcap.permitted; | |
1519 | kernel_cap_t *inh = &name->fcap.inheritable; | |
1520 | int log = 0; | |
1521 | ||
1522 | if (!cap_isclear(*perm)) { | |
1523 | audit_log_cap(ab, "cap_fp", perm); | |
1524 | log = 1; | |
1525 | } | |
1526 | if (!cap_isclear(*inh)) { | |
1527 | audit_log_cap(ab, "cap_fi", inh); | |
1528 | log = 1; | |
1529 | } | |
1530 | ||
1531 | if (log) | |
1532 | audit_log_format(ab, " cap_fe=%d cap_fver=%x", | |
1533 | name->fcap.fE, name->fcap_ver); | |
1534 | } | |
1535 | ||
1536 | static inline int audit_copy_fcaps(struct audit_names *name, | |
1537 | const struct dentry *dentry) | |
1538 | { | |
1539 | struct cpu_vfs_cap_data caps; | |
1540 | int rc; | |
1541 | ||
1542 | if (!dentry) | |
1543 | return 0; | |
1544 | ||
1545 | rc = get_vfs_caps_from_disk(dentry, &caps); | |
1546 | if (rc) | |
1547 | return rc; | |
1548 | ||
1549 | name->fcap.permitted = caps.permitted; | |
1550 | name->fcap.inheritable = caps.inheritable; | |
1551 | name->fcap.fE = !!(caps.magic_etc & VFS_CAP_FLAGS_EFFECTIVE); | |
1552 | name->fcap_ver = (caps.magic_etc & VFS_CAP_REVISION_MASK) >> | |
1553 | VFS_CAP_REVISION_SHIFT; | |
1554 | ||
1555 | return 0; | |
1556 | } | |
1557 | ||
1558 | /* Copy inode data into an audit_names. */ | |
1559 | void audit_copy_inode(struct audit_names *name, const struct dentry *dentry, | |
1560 | const struct inode *inode) | |
1561 | { | |
1562 | name->ino = inode->i_ino; | |
1563 | name->dev = inode->i_sb->s_dev; | |
1564 | name->mode = inode->i_mode; | |
1565 | name->uid = inode->i_uid; | |
1566 | name->gid = inode->i_gid; | |
1567 | name->rdev = inode->i_rdev; | |
1568 | security_inode_getsecid(inode, &name->osid); | |
1569 | audit_copy_fcaps(name, dentry); | |
1570 | } | |
1571 | ||
1572 | /** | |
1573 | * audit_log_name - produce AUDIT_PATH record from struct audit_names | |
1574 | * @context: audit_context for the task | |
1575 | * @n: audit_names structure with reportable details | |
1576 | * @path: optional path to report instead of audit_names->name | |
1577 | * @record_num: record number to report when handling a list of names | |
1578 | * @call_panic: optional pointer to int that will be updated if secid fails | |
1579 | */ | |
1580 | void audit_log_name(struct audit_context *context, struct audit_names *n, | |
1581 | struct path *path, int record_num, int *call_panic) | |
1582 | { | |
1583 | struct audit_buffer *ab; | |
1584 | ab = audit_log_start(context, GFP_KERNEL, AUDIT_PATH); | |
1585 | if (!ab) | |
1586 | return; | |
1587 | ||
1588 | audit_log_format(ab, "item=%d", record_num); | |
1589 | ||
1590 | if (path) | |
1591 | audit_log_d_path(ab, " name=", path); | |
1592 | else if (n->name) { | |
1593 | switch (n->name_len) { | |
1594 | case AUDIT_NAME_FULL: | |
1595 | /* log the full path */ | |
1596 | audit_log_format(ab, " name="); | |
1597 | audit_log_untrustedstring(ab, n->name->name); | |
1598 | break; | |
1599 | case 0: | |
1600 | /* name was specified as a relative path and the | |
1601 | * directory component is the cwd */ | |
1602 | audit_log_d_path(ab, " name=", &context->pwd); | |
1603 | break; | |
1604 | default: | |
1605 | /* log the name's directory component */ | |
1606 | audit_log_format(ab, " name="); | |
1607 | audit_log_n_untrustedstring(ab, n->name->name, | |
1608 | n->name_len); | |
1609 | } | |
1610 | } else | |
1611 | audit_log_format(ab, " name=(null)"); | |
1612 | ||
1613 | if (n->ino != (unsigned long)-1) { | |
1614 | audit_log_format(ab, " inode=%lu" | |
1615 | " dev=%02x:%02x mode=%#ho" | |
1616 | " ouid=%u ogid=%u rdev=%02x:%02x", | |
1617 | n->ino, | |
1618 | MAJOR(n->dev), | |
1619 | MINOR(n->dev), | |
1620 | n->mode, | |
1621 | from_kuid(&init_user_ns, n->uid), | |
1622 | from_kgid(&init_user_ns, n->gid), | |
1623 | MAJOR(n->rdev), | |
1624 | MINOR(n->rdev)); | |
1625 | } | |
1626 | if (n->osid != 0) { | |
1627 | char *ctx = NULL; | |
1628 | u32 len; | |
1629 | if (security_secid_to_secctx( | |
1630 | n->osid, &ctx, &len)) { | |
1631 | audit_log_format(ab, " osid=%u", n->osid); | |
1632 | if (call_panic) | |
1633 | *call_panic = 2; | |
1634 | } else { | |
1635 | audit_log_format(ab, " obj=%s", ctx); | |
1636 | security_release_secctx(ctx, len); | |
1637 | } | |
1638 | } | |
1639 | ||
1640 | audit_log_fcaps(ab, n); | |
1641 | audit_log_end(ab); | |
1642 | } | |
1643 | ||
1644 | int audit_log_task_context(struct audit_buffer *ab) | |
1645 | { | |
1646 | char *ctx = NULL; | |
1647 | unsigned len; | |
1648 | int error; | |
1649 | u32 sid; | |
1650 | ||
1651 | security_task_getsecid(current, &sid); | |
1652 | if (!sid) | |
1653 | return 0; | |
1654 | ||
1655 | error = security_secid_to_secctx(sid, &ctx, &len); | |
1656 | if (error) { | |
1657 | if (error != -EINVAL) | |
1658 | goto error_path; | |
1659 | return 0; | |
1660 | } | |
1661 | ||
1662 | audit_log_format(ab, " subj=%s", ctx); | |
1663 | security_release_secctx(ctx, len); | |
1664 | return 0; | |
1665 | ||
1666 | error_path: | |
1667 | audit_panic("error in audit_log_task_context"); | |
1668 | return error; | |
1669 | } | |
1670 | EXPORT_SYMBOL(audit_log_task_context); | |
1671 | ||
1672 | void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk) | |
1673 | { | |
1674 | const struct cred *cred; | |
1675 | char name[sizeof(tsk->comm)]; | |
1676 | struct mm_struct *mm = tsk->mm; | |
1677 | char *tty; | |
1678 | ||
1679 | if (!ab) | |
1680 | return; | |
1681 | ||
1682 | /* tsk == current */ | |
1683 | cred = current_cred(); | |
1684 | ||
1685 | spin_lock_irq(&tsk->sighand->siglock); | |
1686 | if (tsk->signal && tsk->signal->tty && tsk->signal->tty->name) | |
1687 | tty = tsk->signal->tty->name; | |
1688 | else | |
1689 | tty = "(none)"; | |
1690 | spin_unlock_irq(&tsk->sighand->siglock); | |
1691 | ||
1692 | audit_log_format(ab, | |
1693 | " ppid=%ld pid=%d auid=%u uid=%u gid=%u" | |
1694 | " euid=%u suid=%u fsuid=%u" | |
1695 | " egid=%u sgid=%u fsgid=%u ses=%u tty=%s", | |
1696 | sys_getppid(), | |
1697 | tsk->pid, | |
1698 | from_kuid(&init_user_ns, audit_get_loginuid(tsk)), | |
1699 | from_kuid(&init_user_ns, cred->uid), | |
1700 | from_kgid(&init_user_ns, cred->gid), | |
1701 | from_kuid(&init_user_ns, cred->euid), | |
1702 | from_kuid(&init_user_ns, cred->suid), | |
1703 | from_kuid(&init_user_ns, cred->fsuid), | |
1704 | from_kgid(&init_user_ns, cred->egid), | |
1705 | from_kgid(&init_user_ns, cred->sgid), | |
1706 | from_kgid(&init_user_ns, cred->fsgid), | |
1707 | audit_get_sessionid(tsk), tty); | |
1708 | ||
1709 | get_task_comm(name, tsk); | |
1710 | audit_log_format(ab, " comm="); | |
1711 | audit_log_untrustedstring(ab, name); | |
1712 | ||
1713 | if (mm) { | |
1714 | down_read(&mm->mmap_sem); | |
1715 | if (mm->exe_file) | |
1716 | audit_log_d_path(ab, " exe=", &mm->exe_file->f_path); | |
1717 | up_read(&mm->mmap_sem); | |
1718 | } | |
1719 | audit_log_task_context(ab); | |
1720 | } | |
1721 | EXPORT_SYMBOL(audit_log_task_info); | |
1722 | ||
a51d9eaa KC |
1723 | /** |
1724 | * audit_log_link_denied - report a link restriction denial | |
1725 | * @operation: specific link opreation | |
1726 | * @link: the path that triggered the restriction | |
1727 | */ | |
1728 | void audit_log_link_denied(const char *operation, struct path *link) | |
1729 | { | |
1730 | struct audit_buffer *ab; | |
b24a30a7 EP |
1731 | struct audit_names *name; |
1732 | ||
1733 | name = kzalloc(sizeof(*name), GFP_NOFS); | |
1734 | if (!name) | |
1735 | return; | |
a51d9eaa | 1736 | |
b24a30a7 | 1737 | /* Generate AUDIT_ANOM_LINK with subject, operation, outcome. */ |
a51d9eaa KC |
1738 | ab = audit_log_start(current->audit_context, GFP_KERNEL, |
1739 | AUDIT_ANOM_LINK); | |
d1c7d97a | 1740 | if (!ab) |
b24a30a7 EP |
1741 | goto out; |
1742 | audit_log_format(ab, "op=%s", operation); | |
1743 | audit_log_task_info(ab, current); | |
1744 | audit_log_format(ab, " res=0"); | |
a51d9eaa | 1745 | audit_log_end(ab); |
b24a30a7 EP |
1746 | |
1747 | /* Generate AUDIT_PATH record with object. */ | |
1748 | name->type = AUDIT_TYPE_NORMAL; | |
1749 | audit_copy_inode(name, link->dentry, link->dentry->d_inode); | |
1750 | audit_log_name(current->audit_context, name, link, 0, NULL); | |
1751 | out: | |
1752 | kfree(name); | |
a51d9eaa KC |
1753 | } |
1754 | ||
b0dd25a8 RD |
1755 | /** |
1756 | * audit_log_end - end one audit record | |
1757 | * @ab: the audit_buffer | |
1758 | * | |
1759 | * The netlink_* functions cannot be called inside an irq context, so | |
1760 | * the audit buffer is placed on a queue and a tasklet is scheduled to | |
1da177e4 | 1761 | * remove them from the queue outside the irq context. May be called in |
b0dd25a8 RD |
1762 | * any context. |
1763 | */ | |
b7d11258 | 1764 | void audit_log_end(struct audit_buffer *ab) |
1da177e4 | 1765 | { |
1da177e4 LT |
1766 | if (!ab) |
1767 | return; | |
1768 | if (!audit_rate_check()) { | |
1769 | audit_log_lost("rate limit exceeded"); | |
1770 | } else { | |
8d07a67c | 1771 | struct nlmsghdr *nlh = nlmsg_hdr(ab->skb); |
94191213 | 1772 | nlh->nlmsg_len = ab->skb->len - NLMSG_HDRLEN; |
f3d357b0 | 1773 | |
b7d11258 | 1774 | if (audit_pid) { |
b7d11258 | 1775 | skb_queue_tail(&audit_skb_queue, ab->skb); |
b7d11258 | 1776 | wake_up_interruptible(&kauditd_wait); |
f3d357b0 | 1777 | } else { |
038cbcf6 | 1778 | audit_printk_skb(ab->skb); |
b7d11258 | 1779 | } |
f3d357b0 | 1780 | ab->skb = NULL; |
1da177e4 | 1781 | } |
16e1904e | 1782 | audit_buffer_free(ab); |
1da177e4 LT |
1783 | } |
1784 | ||
b0dd25a8 RD |
1785 | /** |
1786 | * audit_log - Log an audit record | |
1787 | * @ctx: audit context | |
1788 | * @gfp_mask: type of allocation | |
1789 | * @type: audit message type | |
1790 | * @fmt: format string to use | |
1791 | * @...: variable parameters matching the format string | |
1792 | * | |
1793 | * This is a convenience function that calls audit_log_start, | |
1794 | * audit_log_vformat, and audit_log_end. It may be called | |
1795 | * in any context. | |
1796 | */ | |
5600b892 | 1797 | void audit_log(struct audit_context *ctx, gfp_t gfp_mask, int type, |
9ad9ad38 | 1798 | const char *fmt, ...) |
1da177e4 LT |
1799 | { |
1800 | struct audit_buffer *ab; | |
1801 | va_list args; | |
1802 | ||
9ad9ad38 | 1803 | ab = audit_log_start(ctx, gfp_mask, type); |
1da177e4 LT |
1804 | if (ab) { |
1805 | va_start(args, fmt); | |
1806 | audit_log_vformat(ab, fmt, args); | |
1807 | va_end(args); | |
1808 | audit_log_end(ab); | |
1809 | } | |
1810 | } | |
bf45da97 | 1811 | |
131ad62d MDF |
1812 | #ifdef CONFIG_SECURITY |
1813 | /** | |
1814 | * audit_log_secctx - Converts and logs SELinux context | |
1815 | * @ab: audit_buffer | |
1816 | * @secid: security number | |
1817 | * | |
1818 | * This is a helper function that calls security_secid_to_secctx to convert | |
1819 | * secid to secctx and then adds the (converted) SELinux context to the audit | |
1820 | * log by calling audit_log_format, thus also preventing leak of internal secid | |
1821 | * to userspace. If secid cannot be converted audit_panic is called. | |
1822 | */ | |
1823 | void audit_log_secctx(struct audit_buffer *ab, u32 secid) | |
1824 | { | |
1825 | u32 len; | |
1826 | char *secctx; | |
1827 | ||
1828 | if (security_secid_to_secctx(secid, &secctx, &len)) { | |
1829 | audit_panic("Cannot convert secid to context"); | |
1830 | } else { | |
1831 | audit_log_format(ab, " obj=%s", secctx); | |
1832 | security_release_secctx(secctx, len); | |
1833 | } | |
1834 | } | |
1835 | EXPORT_SYMBOL(audit_log_secctx); | |
1836 | #endif | |
1837 | ||
bf45da97 | 1838 | EXPORT_SYMBOL(audit_log_start); |
1839 | EXPORT_SYMBOL(audit_log_end); | |
1840 | EXPORT_SYMBOL(audit_log_format); | |
1841 | EXPORT_SYMBOL(audit_log); |