Commit | Line | Data |
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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> | |
1da177e4 LT |
52 | |
53 | #include <linux/audit.h> | |
54 | ||
55 | #include <net/sock.h> | |
93315ed6 | 56 | #include <net/netlink.h> |
1da177e4 | 57 | #include <linux/skbuff.h> |
131ad62d MDF |
58 | #ifdef CONFIG_SECURITY |
59 | #include <linux/security.h> | |
60 | #endif | |
1da177e4 | 61 | #include <linux/netlink.h> |
7dfb7103 | 62 | #include <linux/freezer.h> |
522ed776 | 63 | #include <linux/tty.h> |
34e36d8e | 64 | #include <linux/pid_namespace.h> |
3dc7e315 DG |
65 | |
66 | #include "audit.h" | |
1da177e4 | 67 | |
a3f07114 | 68 | /* No auditing will take place until audit_initialized == AUDIT_INITIALIZED. |
1da177e4 | 69 | * (Initialization happens after skb_init is called.) */ |
a3f07114 EP |
70 | #define AUDIT_DISABLED -1 |
71 | #define AUDIT_UNINITIALIZED 0 | |
72 | #define AUDIT_INITIALIZED 1 | |
1da177e4 LT |
73 | static int audit_initialized; |
74 | ||
1a6b9f23 EP |
75 | #define AUDIT_OFF 0 |
76 | #define AUDIT_ON 1 | |
77 | #define AUDIT_LOCKED 2 | |
1da177e4 | 78 | int audit_enabled; |
b593d384 | 79 | int audit_ever_enabled; |
1da177e4 | 80 | |
ae9d67af JE |
81 | EXPORT_SYMBOL_GPL(audit_enabled); |
82 | ||
1da177e4 LT |
83 | /* Default state when kernel boots without any parameters. */ |
84 | static int audit_default; | |
85 | ||
86 | /* If auditing cannot proceed, audit_failure selects what happens. */ | |
87 | static int audit_failure = AUDIT_FAIL_PRINTK; | |
88 | ||
75c0371a PE |
89 | /* |
90 | * If audit records are to be written to the netlink socket, audit_pid | |
15e47304 EB |
91 | * contains the pid of the auditd process and audit_nlk_portid contains |
92 | * the portid to use to send netlink messages to that process. | |
75c0371a | 93 | */ |
c2f0c7c3 | 94 | int audit_pid; |
15e47304 | 95 | static int audit_nlk_portid; |
1da177e4 | 96 | |
b0dd25a8 | 97 | /* If audit_rate_limit is non-zero, limit the rate of sending audit records |
1da177e4 LT |
98 | * to that number per second. This prevents DoS attacks, but results in |
99 | * audit records being dropped. */ | |
100 | static int audit_rate_limit; | |
101 | ||
102 | /* Number of outstanding audit_buffers allowed. */ | |
103 | static int audit_backlog_limit = 64; | |
ac4cec44 DW |
104 | static int audit_backlog_wait_time = 60 * HZ; |
105 | static int audit_backlog_wait_overflow = 0; | |
1da177e4 | 106 | |
c2f0c7c3 | 107 | /* The identity of the user shutting down the audit system. */ |
cca080d9 | 108 | kuid_t audit_sig_uid = INVALID_UID; |
c2f0c7c3 | 109 | pid_t audit_sig_pid = -1; |
e1396065 | 110 | u32 audit_sig_sid = 0; |
c2f0c7c3 | 111 | |
1da177e4 LT |
112 | /* Records can be lost in several ways: |
113 | 0) [suppressed in audit_alloc] | |
114 | 1) out of memory in audit_log_start [kmalloc of struct audit_buffer] | |
115 | 2) out of memory in audit_log_move [alloc_skb] | |
116 | 3) suppressed due to audit_rate_limit | |
117 | 4) suppressed due to audit_backlog_limit | |
118 | */ | |
119 | static atomic_t audit_lost = ATOMIC_INIT(0); | |
120 | ||
121 | /* The netlink socket. */ | |
122 | static struct sock *audit_sock; | |
123 | ||
f368c07d AG |
124 | /* Hash for inode-based rules */ |
125 | struct list_head audit_inode_hash[AUDIT_INODE_BUCKETS]; | |
126 | ||
b7d11258 | 127 | /* The audit_freelist is a list of pre-allocated audit buffers (if more |
1da177e4 LT |
128 | * than AUDIT_MAXFREE are in use, the audit buffer is freed instead of |
129 | * being placed on the freelist). */ | |
1da177e4 | 130 | static DEFINE_SPINLOCK(audit_freelist_lock); |
b0dd25a8 | 131 | static int audit_freelist_count; |
1da177e4 LT |
132 | static LIST_HEAD(audit_freelist); |
133 | ||
b7d11258 | 134 | static struct sk_buff_head audit_skb_queue; |
f3d357b0 EP |
135 | /* queue of skbs to send to auditd when/if it comes back */ |
136 | static struct sk_buff_head audit_skb_hold_queue; | |
b7d11258 DW |
137 | static struct task_struct *kauditd_task; |
138 | static DECLARE_WAIT_QUEUE_HEAD(kauditd_wait); | |
9ad9ad38 | 139 | static DECLARE_WAIT_QUEUE_HEAD(audit_backlog_wait); |
1da177e4 | 140 | |
f368c07d | 141 | /* Serialize requests from userspace. */ |
916d7576 | 142 | DEFINE_MUTEX(audit_cmd_mutex); |
1da177e4 LT |
143 | |
144 | /* AUDIT_BUFSIZ is the size of the temporary buffer used for formatting | |
145 | * audit records. Since printk uses a 1024 byte buffer, this buffer | |
146 | * should be at least that large. */ | |
147 | #define AUDIT_BUFSIZ 1024 | |
148 | ||
149 | /* AUDIT_MAXFREE is the number of empty audit_buffers we keep on the | |
150 | * audit_freelist. Doing so eliminates many kmalloc/kfree calls. */ | |
151 | #define AUDIT_MAXFREE (2*NR_CPUS) | |
152 | ||
153 | /* The audit_buffer is used when formatting an audit record. The caller | |
154 | * locks briefly to get the record off the freelist or to allocate the | |
155 | * buffer, and locks briefly to send the buffer to the netlink layer or | |
156 | * to place it on a transmit queue. Multiple audit_buffers can be in | |
157 | * use simultaneously. */ | |
158 | struct audit_buffer { | |
159 | struct list_head list; | |
8fc6115c | 160 | struct sk_buff *skb; /* formatted skb ready to send */ |
1da177e4 | 161 | struct audit_context *ctx; /* NULL or associated context */ |
9796fdd8 | 162 | gfp_t gfp_mask; |
1da177e4 LT |
163 | }; |
164 | ||
f09ac9db EP |
165 | struct audit_reply { |
166 | int pid; | |
167 | struct sk_buff *skb; | |
168 | }; | |
169 | ||
c0404993 SG |
170 | static void audit_set_pid(struct audit_buffer *ab, pid_t pid) |
171 | { | |
50397bd1 EP |
172 | if (ab) { |
173 | struct nlmsghdr *nlh = nlmsg_hdr(ab->skb); | |
174 | nlh->nlmsg_pid = pid; | |
175 | } | |
c0404993 SG |
176 | } |
177 | ||
8c8570fb | 178 | void audit_panic(const char *message) |
1da177e4 LT |
179 | { |
180 | switch (audit_failure) | |
181 | { | |
182 | case AUDIT_FAIL_SILENT: | |
183 | break; | |
184 | case AUDIT_FAIL_PRINTK: | |
320f1b1e EP |
185 | if (printk_ratelimit()) |
186 | printk(KERN_ERR "audit: %s\n", message); | |
1da177e4 LT |
187 | break; |
188 | case AUDIT_FAIL_PANIC: | |
b29ee87e EP |
189 | /* test audit_pid since printk is always losey, why bother? */ |
190 | if (audit_pid) | |
191 | panic("audit: %s\n", message); | |
1da177e4 LT |
192 | break; |
193 | } | |
194 | } | |
195 | ||
196 | static inline int audit_rate_check(void) | |
197 | { | |
198 | static unsigned long last_check = 0; | |
199 | static int messages = 0; | |
200 | static DEFINE_SPINLOCK(lock); | |
201 | unsigned long flags; | |
202 | unsigned long now; | |
203 | unsigned long elapsed; | |
204 | int retval = 0; | |
205 | ||
206 | if (!audit_rate_limit) return 1; | |
207 | ||
208 | spin_lock_irqsave(&lock, flags); | |
209 | if (++messages < audit_rate_limit) { | |
210 | retval = 1; | |
211 | } else { | |
212 | now = jiffies; | |
213 | elapsed = now - last_check; | |
214 | if (elapsed > HZ) { | |
215 | last_check = now; | |
216 | messages = 0; | |
217 | retval = 1; | |
218 | } | |
219 | } | |
220 | spin_unlock_irqrestore(&lock, flags); | |
221 | ||
222 | return retval; | |
223 | } | |
224 | ||
b0dd25a8 RD |
225 | /** |
226 | * audit_log_lost - conditionally log lost audit message event | |
227 | * @message: the message stating reason for lost audit message | |
228 | * | |
229 | * Emit at least 1 message per second, even if audit_rate_check is | |
230 | * throttling. | |
231 | * Always increment the lost messages counter. | |
232 | */ | |
1da177e4 LT |
233 | void audit_log_lost(const char *message) |
234 | { | |
235 | static unsigned long last_msg = 0; | |
236 | static DEFINE_SPINLOCK(lock); | |
237 | unsigned long flags; | |
238 | unsigned long now; | |
239 | int print; | |
240 | ||
241 | atomic_inc(&audit_lost); | |
242 | ||
243 | print = (audit_failure == AUDIT_FAIL_PANIC || !audit_rate_limit); | |
244 | ||
245 | if (!print) { | |
246 | spin_lock_irqsave(&lock, flags); | |
247 | now = jiffies; | |
248 | if (now - last_msg > HZ) { | |
249 | print = 1; | |
250 | last_msg = now; | |
251 | } | |
252 | spin_unlock_irqrestore(&lock, flags); | |
253 | } | |
254 | ||
255 | if (print) { | |
320f1b1e EP |
256 | if (printk_ratelimit()) |
257 | printk(KERN_WARNING | |
258 | "audit: audit_lost=%d audit_rate_limit=%d " | |
259 | "audit_backlog_limit=%d\n", | |
260 | atomic_read(&audit_lost), | |
261 | audit_rate_limit, | |
262 | audit_backlog_limit); | |
1da177e4 LT |
263 | audit_panic(message); |
264 | } | |
1da177e4 LT |
265 | } |
266 | ||
1a6b9f23 | 267 | static int audit_log_config_change(char *function_name, int new, int old, |
2532386f | 268 | int allow_changes) |
1da177e4 | 269 | { |
1a6b9f23 EP |
270 | struct audit_buffer *ab; |
271 | int rc = 0; | |
dc9eb698 EP |
272 | u32 sessionid = audit_get_sessionid(current); |
273 | uid_t auid = from_kuid(&init_user_ns, audit_get_loginuid(current)); | |
274 | u32 sid; | |
275 | ||
ce29b682 | 276 | |
1a6b9f23 | 277 | ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE); |
0644ec0c KC |
278 | if (unlikely(!ab)) |
279 | return rc; | |
2532386f | 280 | audit_log_format(ab, "%s=%d old=%d auid=%u ses=%u", function_name, new, |
dc9eb698 EP |
281 | old, auid, sessionid); |
282 | ||
283 | security_task_getsecid(current, &sid); | |
ce29b682 SG |
284 | if (sid) { |
285 | char *ctx = NULL; | |
286 | u32 len; | |
1a6b9f23 | 287 | |
2a862b32 | 288 | rc = security_secid_to_secctx(sid, &ctx, &len); |
1a6b9f23 EP |
289 | if (rc) { |
290 | audit_log_format(ab, " sid=%u", sid); | |
291 | allow_changes = 0; /* Something weird, deny request */ | |
292 | } else { | |
293 | audit_log_format(ab, " subj=%s", ctx); | |
2a862b32 | 294 | security_release_secctx(ctx, len); |
1a6b9f23 | 295 | } |
6a01b07f | 296 | } |
1a6b9f23 EP |
297 | audit_log_format(ab, " res=%d", allow_changes); |
298 | audit_log_end(ab); | |
6a01b07f | 299 | return rc; |
1da177e4 LT |
300 | } |
301 | ||
dc9eb698 | 302 | static int audit_do_config_change(char *function_name, int *to_change, int new) |
1da177e4 | 303 | { |
1a6b9f23 | 304 | int allow_changes, rc = 0, old = *to_change; |
6a01b07f SG |
305 | |
306 | /* check if we are locked */ | |
1a6b9f23 EP |
307 | if (audit_enabled == AUDIT_LOCKED) |
308 | allow_changes = 0; | |
6a01b07f | 309 | else |
1a6b9f23 | 310 | allow_changes = 1; |
ce29b682 | 311 | |
1a6b9f23 | 312 | if (audit_enabled != AUDIT_OFF) { |
dc9eb698 | 313 | rc = audit_log_config_change(function_name, new, old, allow_changes); |
1a6b9f23 EP |
314 | if (rc) |
315 | allow_changes = 0; | |
6a01b07f | 316 | } |
6a01b07f SG |
317 | |
318 | /* If we are allowed, make the change */ | |
1a6b9f23 EP |
319 | if (allow_changes == 1) |
320 | *to_change = new; | |
6a01b07f SG |
321 | /* Not allowed, update reason */ |
322 | else if (rc == 0) | |
323 | rc = -EPERM; | |
324 | return rc; | |
1da177e4 LT |
325 | } |
326 | ||
dc9eb698 | 327 | static int audit_set_rate_limit(int limit) |
1da177e4 | 328 | { |
dc9eb698 | 329 | return audit_do_config_change("audit_rate_limit", &audit_rate_limit, limit); |
1a6b9f23 | 330 | } |
ce29b682 | 331 | |
dc9eb698 | 332 | static int audit_set_backlog_limit(int limit) |
1a6b9f23 | 333 | { |
dc9eb698 | 334 | return audit_do_config_change("audit_backlog_limit", &audit_backlog_limit, limit); |
1a6b9f23 | 335 | } |
6a01b07f | 336 | |
dc9eb698 | 337 | static int audit_set_enabled(int state) |
1a6b9f23 | 338 | { |
b593d384 | 339 | int rc; |
1a6b9f23 EP |
340 | if (state < AUDIT_OFF || state > AUDIT_LOCKED) |
341 | return -EINVAL; | |
6a01b07f | 342 | |
dc9eb698 | 343 | rc = audit_do_config_change("audit_enabled", &audit_enabled, state); |
b593d384 EP |
344 | if (!rc) |
345 | audit_ever_enabled |= !!state; | |
346 | ||
347 | return rc; | |
1da177e4 LT |
348 | } |
349 | ||
dc9eb698 | 350 | static int audit_set_failure(int state) |
1da177e4 | 351 | { |
1da177e4 LT |
352 | if (state != AUDIT_FAIL_SILENT |
353 | && state != AUDIT_FAIL_PRINTK | |
354 | && state != AUDIT_FAIL_PANIC) | |
355 | return -EINVAL; | |
ce29b682 | 356 | |
dc9eb698 | 357 | return audit_do_config_change("audit_failure", &audit_failure, state); |
1da177e4 LT |
358 | } |
359 | ||
f3d357b0 EP |
360 | /* |
361 | * Queue skbs to be sent to auditd when/if it comes back. These skbs should | |
362 | * already have been sent via prink/syslog and so if these messages are dropped | |
363 | * it is not a huge concern since we already passed the audit_log_lost() | |
364 | * notification and stuff. This is just nice to get audit messages during | |
365 | * boot before auditd is running or messages generated while auditd is stopped. | |
366 | * This only holds messages is audit_default is set, aka booting with audit=1 | |
367 | * or building your kernel that way. | |
368 | */ | |
369 | static void audit_hold_skb(struct sk_buff *skb) | |
370 | { | |
371 | if (audit_default && | |
372 | skb_queue_len(&audit_skb_hold_queue) < audit_backlog_limit) | |
373 | skb_queue_tail(&audit_skb_hold_queue, skb); | |
374 | else | |
375 | kfree_skb(skb); | |
376 | } | |
377 | ||
038cbcf6 EP |
378 | /* |
379 | * For one reason or another this nlh isn't getting delivered to the userspace | |
380 | * audit daemon, just send it to printk. | |
381 | */ | |
382 | static void audit_printk_skb(struct sk_buff *skb) | |
383 | { | |
384 | struct nlmsghdr *nlh = nlmsg_hdr(skb); | |
c64e66c6 | 385 | char *data = nlmsg_data(nlh); |
038cbcf6 EP |
386 | |
387 | if (nlh->nlmsg_type != AUDIT_EOE) { | |
388 | if (printk_ratelimit()) | |
389 | printk(KERN_NOTICE "type=%d %s\n", nlh->nlmsg_type, data); | |
390 | else | |
391 | audit_log_lost("printk limit exceeded\n"); | |
392 | } | |
393 | ||
394 | audit_hold_skb(skb); | |
395 | } | |
396 | ||
f3d357b0 EP |
397 | static void kauditd_send_skb(struct sk_buff *skb) |
398 | { | |
399 | int err; | |
400 | /* take a reference in case we can't send it and we want to hold it */ | |
401 | skb_get(skb); | |
15e47304 | 402 | err = netlink_unicast(audit_sock, skb, audit_nlk_portid, 0); |
f3d357b0 | 403 | if (err < 0) { |
c9404c9c | 404 | BUG_ON(err != -ECONNREFUSED); /* Shouldn't happen */ |
f3d357b0 | 405 | printk(KERN_ERR "audit: *NO* daemon at audit_pid=%d\n", audit_pid); |
9db3b9bc | 406 | audit_log_lost("auditd disappeared\n"); |
f3d357b0 EP |
407 | audit_pid = 0; |
408 | /* we might get lucky and get this in the next auditd */ | |
409 | audit_hold_skb(skb); | |
410 | } else | |
411 | /* drop the extra reference if sent ok */ | |
70d4bf6d | 412 | consume_skb(skb); |
f3d357b0 EP |
413 | } |
414 | ||
b551d1d9 RGB |
415 | /* |
416 | * flush_hold_queue - empty the hold queue if auditd appears | |
417 | * | |
418 | * If auditd just started, drain the queue of messages already | |
419 | * sent to syslog/printk. Remember loss here is ok. We already | |
420 | * called audit_log_lost() if it didn't go out normally. so the | |
421 | * race between the skb_dequeue and the next check for audit_pid | |
422 | * doesn't matter. | |
423 | * | |
424 | * If you ever find kauditd to be too slow we can get a perf win | |
425 | * by doing our own locking and keeping better track if there | |
426 | * are messages in this queue. I don't see the need now, but | |
427 | * in 5 years when I want to play with this again I'll see this | |
428 | * note and still have no friggin idea what i'm thinking today. | |
429 | */ | |
430 | static void flush_hold_queue(void) | |
431 | { | |
432 | struct sk_buff *skb; | |
433 | ||
434 | if (!audit_default || !audit_pid) | |
435 | return; | |
436 | ||
437 | skb = skb_dequeue(&audit_skb_hold_queue); | |
438 | if (likely(!skb)) | |
439 | return; | |
440 | ||
441 | while (skb && audit_pid) { | |
442 | kauditd_send_skb(skb); | |
443 | skb = skb_dequeue(&audit_skb_hold_queue); | |
444 | } | |
445 | ||
446 | /* | |
447 | * if auditd just disappeared but we | |
448 | * dequeued an skb we need to drop ref | |
449 | */ | |
450 | if (skb) | |
451 | consume_skb(skb); | |
452 | } | |
453 | ||
97a41e26 | 454 | static int kauditd_thread(void *dummy) |
b7d11258 | 455 | { |
83144186 | 456 | set_freezable(); |
4899b8b1 | 457 | while (!kthread_should_stop()) { |
3320c513 RGB |
458 | struct sk_buff *skb; |
459 | DECLARE_WAITQUEUE(wait, current); | |
460 | ||
b551d1d9 | 461 | flush_hold_queue(); |
f3d357b0 | 462 | |
b7d11258 | 463 | skb = skb_dequeue(&audit_skb_queue); |
9ad9ad38 | 464 | wake_up(&audit_backlog_wait); |
b7d11258 | 465 | if (skb) { |
f3d357b0 EP |
466 | if (audit_pid) |
467 | kauditd_send_skb(skb); | |
038cbcf6 EP |
468 | else |
469 | audit_printk_skb(skb); | |
3320c513 RGB |
470 | continue; |
471 | } | |
472 | set_current_state(TASK_INTERRUPTIBLE); | |
473 | add_wait_queue(&kauditd_wait, &wait); | |
b7d11258 | 474 | |
3320c513 RGB |
475 | if (!skb_queue_len(&audit_skb_queue)) { |
476 | try_to_freeze(); | |
477 | schedule(); | |
b7d11258 | 478 | } |
3320c513 RGB |
479 | |
480 | __set_current_state(TASK_RUNNING); | |
481 | remove_wait_queue(&kauditd_wait, &wait); | |
b7d11258 | 482 | } |
4899b8b1 | 483 | return 0; |
b7d11258 DW |
484 | } |
485 | ||
9044e6bc AV |
486 | int audit_send_list(void *_dest) |
487 | { | |
488 | struct audit_netlink_list *dest = _dest; | |
489 | int pid = dest->pid; | |
490 | struct sk_buff *skb; | |
491 | ||
492 | /* wait for parent to finish and send an ACK */ | |
f368c07d AG |
493 | mutex_lock(&audit_cmd_mutex); |
494 | mutex_unlock(&audit_cmd_mutex); | |
9044e6bc AV |
495 | |
496 | while ((skb = __skb_dequeue(&dest->q)) != NULL) | |
497 | netlink_unicast(audit_sock, skb, pid, 0); | |
498 | ||
499 | kfree(dest); | |
500 | ||
501 | return 0; | |
502 | } | |
503 | ||
504 | struct sk_buff *audit_make_reply(int pid, int seq, int type, int done, | |
b8800aa5 | 505 | int multi, const void *payload, int size) |
9044e6bc AV |
506 | { |
507 | struct sk_buff *skb; | |
508 | struct nlmsghdr *nlh; | |
9044e6bc AV |
509 | void *data; |
510 | int flags = multi ? NLM_F_MULTI : 0; | |
511 | int t = done ? NLMSG_DONE : type; | |
512 | ||
ee080e6c | 513 | skb = nlmsg_new(size, GFP_KERNEL); |
9044e6bc AV |
514 | if (!skb) |
515 | return NULL; | |
516 | ||
c64e66c6 DM |
517 | nlh = nlmsg_put(skb, pid, seq, t, size, flags); |
518 | if (!nlh) | |
519 | goto out_kfree_skb; | |
520 | data = nlmsg_data(nlh); | |
9044e6bc AV |
521 | memcpy(data, payload, size); |
522 | return skb; | |
523 | ||
c64e66c6 DM |
524 | out_kfree_skb: |
525 | kfree_skb(skb); | |
9044e6bc AV |
526 | return NULL; |
527 | } | |
528 | ||
f09ac9db EP |
529 | static int audit_send_reply_thread(void *arg) |
530 | { | |
531 | struct audit_reply *reply = (struct audit_reply *)arg; | |
532 | ||
533 | mutex_lock(&audit_cmd_mutex); | |
534 | mutex_unlock(&audit_cmd_mutex); | |
535 | ||
536 | /* Ignore failure. It'll only happen if the sender goes away, | |
537 | because our timeout is set to infinite. */ | |
538 | netlink_unicast(audit_sock, reply->skb, reply->pid, 0); | |
539 | kfree(reply); | |
540 | return 0; | |
541 | } | |
b0dd25a8 RD |
542 | /** |
543 | * audit_send_reply - send an audit reply message via netlink | |
544 | * @pid: process id to send reply to | |
545 | * @seq: sequence number | |
546 | * @type: audit message type | |
547 | * @done: done (last) flag | |
548 | * @multi: multi-part message flag | |
549 | * @payload: payload data | |
550 | * @size: payload size | |
551 | * | |
552 | * Allocates an skb, builds the netlink message, and sends it to the pid. | |
553 | * No failure notifications. | |
554 | */ | |
b8800aa5 SH |
555 | static void audit_send_reply(int pid, int seq, int type, int done, int multi, |
556 | const void *payload, int size) | |
1da177e4 | 557 | { |
f09ac9db EP |
558 | struct sk_buff *skb; |
559 | struct task_struct *tsk; | |
560 | struct audit_reply *reply = kmalloc(sizeof(struct audit_reply), | |
561 | GFP_KERNEL); | |
562 | ||
563 | if (!reply) | |
564 | return; | |
565 | ||
9044e6bc | 566 | skb = audit_make_reply(pid, seq, type, done, multi, payload, size); |
1da177e4 | 567 | if (!skb) |
fcaf1eb8 | 568 | goto out; |
f09ac9db EP |
569 | |
570 | reply->pid = pid; | |
571 | reply->skb = skb; | |
572 | ||
573 | tsk = kthread_run(audit_send_reply_thread, reply, "audit_send_reply"); | |
fcaf1eb8 AM |
574 | if (!IS_ERR(tsk)) |
575 | return; | |
576 | kfree_skb(skb); | |
577 | out: | |
578 | kfree(reply); | |
1da177e4 LT |
579 | } |
580 | ||
581 | /* | |
582 | * Check for appropriate CAP_AUDIT_ capabilities on incoming audit | |
583 | * control messages. | |
584 | */ | |
c7bdb545 | 585 | static int audit_netlink_ok(struct sk_buff *skb, u16 msg_type) |
1da177e4 LT |
586 | { |
587 | int err = 0; | |
588 | ||
34e36d8e EB |
589 | /* Only support the initial namespaces for now. */ |
590 | if ((current_user_ns() != &init_user_ns) || | |
591 | (task_active_pid_ns(current) != &init_pid_ns)) | |
592 | return -EPERM; | |
593 | ||
1da177e4 | 594 | switch (msg_type) { |
1da177e4 | 595 | case AUDIT_LIST: |
1da177e4 LT |
596 | case AUDIT_ADD: |
597 | case AUDIT_DEL: | |
18900909 EP |
598 | return -EOPNOTSUPP; |
599 | case AUDIT_GET: | |
600 | case AUDIT_SET: | |
601 | case AUDIT_LIST_RULES: | |
602 | case AUDIT_ADD_RULE: | |
93315ed6 | 603 | case AUDIT_DEL_RULE: |
c2f0c7c3 | 604 | case AUDIT_SIGNAL_INFO: |
522ed776 MT |
605 | case AUDIT_TTY_GET: |
606 | case AUDIT_TTY_SET: | |
74c3cbe3 AV |
607 | case AUDIT_TRIM: |
608 | case AUDIT_MAKE_EQUIV: | |
fd778461 | 609 | if (!capable(CAP_AUDIT_CONTROL)) |
1da177e4 LT |
610 | err = -EPERM; |
611 | break; | |
05474106 | 612 | case AUDIT_USER: |
039b6b3e RD |
613 | case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG: |
614 | case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2: | |
fd778461 | 615 | if (!capable(CAP_AUDIT_WRITE)) |
1da177e4 LT |
616 | err = -EPERM; |
617 | break; | |
618 | default: /* bad msg */ | |
619 | err = -EINVAL; | |
620 | } | |
621 | ||
622 | return err; | |
623 | } | |
624 | ||
dc9eb698 | 625 | static int audit_log_common_recv_msg(struct audit_buffer **ab, u16 msg_type) |
50397bd1 EP |
626 | { |
627 | int rc = 0; | |
628 | char *ctx = NULL; | |
629 | u32 len; | |
dc9eb698 EP |
630 | u32 sessionid = audit_get_sessionid(current); |
631 | uid_t uid = from_kuid(&init_user_ns, current_uid()); | |
632 | uid_t auid = from_kuid(&init_user_ns, audit_get_loginuid(current)); | |
633 | u32 sid; | |
50397bd1 EP |
634 | |
635 | if (!audit_enabled) { | |
636 | *ab = NULL; | |
637 | return rc; | |
638 | } | |
639 | ||
640 | *ab = audit_log_start(NULL, GFP_KERNEL, msg_type); | |
0644ec0c KC |
641 | if (unlikely(!*ab)) |
642 | return rc; | |
3035c51e | 643 | audit_log_format(*ab, "pid=%d uid=%u auid=%u ses=%u", |
dc9eb698 EP |
644 | task_tgid_vnr(current), uid, auid, sessionid); |
645 | security_task_getsecid(current, &sid); | |
50397bd1 | 646 | if (sid) { |
2a862b32 | 647 | rc = security_secid_to_secctx(sid, &ctx, &len); |
50397bd1 EP |
648 | if (rc) |
649 | audit_log_format(*ab, " ssid=%u", sid); | |
2a862b32 | 650 | else { |
50397bd1 | 651 | audit_log_format(*ab, " subj=%s", ctx); |
2a862b32 AD |
652 | security_release_secctx(ctx, len); |
653 | } | |
50397bd1 EP |
654 | } |
655 | ||
656 | return rc; | |
657 | } | |
658 | ||
1da177e4 LT |
659 | static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) |
660 | { | |
dc9eb698 | 661 | u32 seq; |
1da177e4 LT |
662 | void *data; |
663 | struct audit_status *status_get, status_set; | |
664 | int err; | |
c0404993 | 665 | struct audit_buffer *ab; |
1da177e4 | 666 | u16 msg_type = nlh->nlmsg_type; |
e1396065 | 667 | struct audit_sig_info *sig_data; |
50397bd1 | 668 | char *ctx = NULL; |
e1396065 | 669 | u32 len; |
1da177e4 | 670 | |
c7bdb545 | 671 | err = audit_netlink_ok(skb, msg_type); |
1da177e4 LT |
672 | if (err) |
673 | return err; | |
674 | ||
1da177e4 | 675 | seq = nlh->nlmsg_seq; |
c64e66c6 | 676 | data = nlmsg_data(nlh); |
1da177e4 LT |
677 | |
678 | switch (msg_type) { | |
679 | case AUDIT_GET: | |
680 | status_set.enabled = audit_enabled; | |
681 | status_set.failure = audit_failure; | |
682 | status_set.pid = audit_pid; | |
683 | status_set.rate_limit = audit_rate_limit; | |
684 | status_set.backlog_limit = audit_backlog_limit; | |
685 | status_set.lost = atomic_read(&audit_lost); | |
b7d11258 | 686 | status_set.backlog = skb_queue_len(&audit_skb_queue); |
15e47304 | 687 | audit_send_reply(NETLINK_CB(skb).portid, seq, AUDIT_GET, 0, 0, |
1da177e4 LT |
688 | &status_set, sizeof(status_set)); |
689 | break; | |
690 | case AUDIT_SET: | |
691 | if (nlh->nlmsg_len < sizeof(struct audit_status)) | |
692 | return -EINVAL; | |
693 | status_get = (struct audit_status *)data; | |
694 | if (status_get->mask & AUDIT_STATUS_ENABLED) { | |
dc9eb698 | 695 | err = audit_set_enabled(status_get->enabled); |
20c6aaa3 | 696 | if (err < 0) |
697 | return err; | |
1da177e4 LT |
698 | } |
699 | if (status_get->mask & AUDIT_STATUS_FAILURE) { | |
dc9eb698 | 700 | err = audit_set_failure(status_get->failure); |
20c6aaa3 | 701 | if (err < 0) |
702 | return err; | |
1da177e4 LT |
703 | } |
704 | if (status_get->mask & AUDIT_STATUS_PID) { | |
1a6b9f23 EP |
705 | int new_pid = status_get->pid; |
706 | ||
707 | if (audit_enabled != AUDIT_OFF) | |
dc9eb698 | 708 | audit_log_config_change("audit_pid", new_pid, audit_pid, 1); |
1a6b9f23 | 709 | audit_pid = new_pid; |
15e47304 | 710 | audit_nlk_portid = NETLINK_CB(skb).portid; |
1da177e4 | 711 | } |
20c6aaa3 | 712 | if (status_get->mask & AUDIT_STATUS_RATE_LIMIT) { |
dc9eb698 | 713 | err = audit_set_rate_limit(status_get->rate_limit); |
20c6aaa3 | 714 | if (err < 0) |
715 | return err; | |
716 | } | |
1da177e4 | 717 | if (status_get->mask & AUDIT_STATUS_BACKLOG_LIMIT) |
dc9eb698 | 718 | err = audit_set_backlog_limit(status_get->backlog_limit); |
1da177e4 | 719 | break; |
05474106 | 720 | case AUDIT_USER: |
039b6b3e RD |
721 | case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG: |
722 | case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2: | |
4a4cd633 DW |
723 | if (!audit_enabled && msg_type != AUDIT_USER_AVC) |
724 | return 0; | |
725 | ||
62062cf8 | 726 | err = audit_filter_user(msg_type); |
4a4cd633 DW |
727 | if (err == 1) { |
728 | err = 0; | |
522ed776 | 729 | if (msg_type == AUDIT_USER_TTY) { |
dc9eb698 | 730 | err = tty_audit_push_task(current); |
522ed776 MT |
731 | if (err) |
732 | break; | |
733 | } | |
dc9eb698 | 734 | audit_log_common_recv_msg(&ab, msg_type); |
50397bd1 EP |
735 | if (msg_type != AUDIT_USER_TTY) |
736 | audit_log_format(ab, " msg='%.1024s'", | |
737 | (char *)data); | |
738 | else { | |
739 | int size; | |
740 | ||
f7616102 | 741 | audit_log_format(ab, " data="); |
50397bd1 | 742 | size = nlmsg_len(nlh); |
55ad2f8d MT |
743 | if (size > 0 && |
744 | ((unsigned char *)data)[size - 1] == '\0') | |
745 | size--; | |
b556f8ad | 746 | audit_log_n_untrustedstring(ab, data, size); |
4a4cd633 | 747 | } |
aecdc33e | 748 | audit_set_pid(ab, NETLINK_CB(skb).portid); |
50397bd1 | 749 | audit_log_end(ab); |
0f45aa18 | 750 | } |
1da177e4 | 751 | break; |
93315ed6 AG |
752 | case AUDIT_ADD_RULE: |
753 | case AUDIT_DEL_RULE: | |
754 | if (nlmsg_len(nlh) < sizeof(struct audit_rule_data)) | |
755 | return -EINVAL; | |
1a6b9f23 | 756 | if (audit_enabled == AUDIT_LOCKED) { |
dc9eb698 EP |
757 | audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE); |
758 | audit_log_format(ab, " audit_enabled=%d res=0", audit_enabled); | |
50397bd1 | 759 | audit_log_end(ab); |
6a01b07f SG |
760 | return -EPERM; |
761 | } | |
93315ed6 AG |
762 | /* fallthrough */ |
763 | case AUDIT_LIST_RULES: | |
15e47304 | 764 | err = audit_receive_filter(msg_type, NETLINK_CB(skb).portid, |
dc9eb698 | 765 | seq, data, nlmsg_len(nlh)); |
1da177e4 | 766 | break; |
74c3cbe3 AV |
767 | case AUDIT_TRIM: |
768 | audit_trim_trees(); | |
dc9eb698 | 769 | audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE); |
74c3cbe3 AV |
770 | audit_log_format(ab, " op=trim res=1"); |
771 | audit_log_end(ab); | |
772 | break; | |
773 | case AUDIT_MAKE_EQUIV: { | |
774 | void *bufp = data; | |
775 | u32 sizes[2]; | |
7719e437 | 776 | size_t msglen = nlmsg_len(nlh); |
74c3cbe3 AV |
777 | char *old, *new; |
778 | ||
779 | err = -EINVAL; | |
7719e437 | 780 | if (msglen < 2 * sizeof(u32)) |
74c3cbe3 AV |
781 | break; |
782 | memcpy(sizes, bufp, 2 * sizeof(u32)); | |
783 | bufp += 2 * sizeof(u32); | |
7719e437 HH |
784 | msglen -= 2 * sizeof(u32); |
785 | old = audit_unpack_string(&bufp, &msglen, sizes[0]); | |
74c3cbe3 AV |
786 | if (IS_ERR(old)) { |
787 | err = PTR_ERR(old); | |
788 | break; | |
789 | } | |
7719e437 | 790 | new = audit_unpack_string(&bufp, &msglen, sizes[1]); |
74c3cbe3 AV |
791 | if (IS_ERR(new)) { |
792 | err = PTR_ERR(new); | |
793 | kfree(old); | |
794 | break; | |
795 | } | |
796 | /* OK, here comes... */ | |
797 | err = audit_tag_tree(old, new); | |
798 | ||
dc9eb698 | 799 | audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE); |
50397bd1 | 800 | |
74c3cbe3 AV |
801 | audit_log_format(ab, " op=make_equiv old="); |
802 | audit_log_untrustedstring(ab, old); | |
803 | audit_log_format(ab, " new="); | |
804 | audit_log_untrustedstring(ab, new); | |
805 | audit_log_format(ab, " res=%d", !err); | |
806 | audit_log_end(ab); | |
807 | kfree(old); | |
808 | kfree(new); | |
809 | break; | |
810 | } | |
c2f0c7c3 | 811 | case AUDIT_SIGNAL_INFO: |
939cbf26 EP |
812 | len = 0; |
813 | if (audit_sig_sid) { | |
814 | err = security_secid_to_secctx(audit_sig_sid, &ctx, &len); | |
815 | if (err) | |
816 | return err; | |
817 | } | |
e1396065 AV |
818 | sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL); |
819 | if (!sig_data) { | |
939cbf26 EP |
820 | if (audit_sig_sid) |
821 | security_release_secctx(ctx, len); | |
e1396065 AV |
822 | return -ENOMEM; |
823 | } | |
cca080d9 | 824 | sig_data->uid = from_kuid(&init_user_ns, audit_sig_uid); |
e1396065 | 825 | sig_data->pid = audit_sig_pid; |
939cbf26 EP |
826 | if (audit_sig_sid) { |
827 | memcpy(sig_data->ctx, ctx, len); | |
828 | security_release_secctx(ctx, len); | |
829 | } | |
15e47304 | 830 | audit_send_reply(NETLINK_CB(skb).portid, seq, AUDIT_SIGNAL_INFO, |
e1396065 AV |
831 | 0, 0, sig_data, sizeof(*sig_data) + len); |
832 | kfree(sig_data); | |
c2f0c7c3 | 833 | break; |
522ed776 MT |
834 | case AUDIT_TTY_GET: { |
835 | struct audit_tty_status s; | |
8aa14b64 EB |
836 | struct task_struct *tsk = current; |
837 | ||
838 | spin_lock_irq(&tsk->sighand->siglock); | |
839 | s.enabled = tsk->signal->audit_tty != 0; | |
840 | spin_unlock_irq(&tsk->sighand->siglock); | |
841 | ||
aecdc33e | 842 | audit_send_reply(NETLINK_CB(skb).portid, seq, |
8aa14b64 | 843 | AUDIT_TTY_GET, 0, 0, &s, sizeof(s)); |
522ed776 MT |
844 | break; |
845 | } | |
846 | case AUDIT_TTY_SET: { | |
847 | struct audit_tty_status *s; | |
8aa14b64 | 848 | struct task_struct *tsk = current; |
522ed776 MT |
849 | |
850 | if (nlh->nlmsg_len < sizeof(struct audit_tty_status)) | |
851 | return -EINVAL; | |
852 | s = data; | |
853 | if (s->enabled != 0 && s->enabled != 1) | |
854 | return -EINVAL; | |
8aa14b64 EB |
855 | |
856 | spin_lock_irq(&tsk->sighand->siglock); | |
857 | tsk->signal->audit_tty = s->enabled != 0; | |
858 | spin_unlock_irq(&tsk->sighand->siglock); | |
522ed776 MT |
859 | break; |
860 | } | |
1da177e4 LT |
861 | default: |
862 | err = -EINVAL; | |
863 | break; | |
864 | } | |
865 | ||
866 | return err < 0 ? err : 0; | |
867 | } | |
868 | ||
b0dd25a8 | 869 | /* |
ea7ae60b EP |
870 | * Get message from skb. Each message is processed by audit_receive_msg. |
871 | * Malformed skbs with wrong length are discarded silently. | |
b0dd25a8 | 872 | */ |
2a0a6ebe | 873 | static void audit_receive_skb(struct sk_buff *skb) |
1da177e4 | 874 | { |
ea7ae60b EP |
875 | struct nlmsghdr *nlh; |
876 | /* | |
877 | * len MUST be signed for NLMSG_NEXT to be able to dec it below 0 | |
878 | * if the nlmsg_len was not aligned | |
879 | */ | |
880 | int len; | |
881 | int err; | |
882 | ||
883 | nlh = nlmsg_hdr(skb); | |
884 | len = skb->len; | |
885 | ||
886 | while (NLMSG_OK(nlh, len)) { | |
887 | err = audit_receive_msg(skb, nlh); | |
888 | /* if err or if this message says it wants a response */ | |
889 | if (err || (nlh->nlmsg_flags & NLM_F_ACK)) | |
1da177e4 | 890 | netlink_ack(skb, nlh, err); |
ea7ae60b EP |
891 | |
892 | nlh = NLMSG_NEXT(nlh, len); | |
1da177e4 | 893 | } |
1da177e4 LT |
894 | } |
895 | ||
896 | /* Receive messages from netlink socket. */ | |
cd40b7d3 | 897 | static void audit_receive(struct sk_buff *skb) |
1da177e4 | 898 | { |
f368c07d | 899 | mutex_lock(&audit_cmd_mutex); |
cd40b7d3 | 900 | audit_receive_skb(skb); |
f368c07d | 901 | mutex_unlock(&audit_cmd_mutex); |
1da177e4 LT |
902 | } |
903 | ||
1da177e4 LT |
904 | /* Initialize audit support at boot time. */ |
905 | static int __init audit_init(void) | |
906 | { | |
f368c07d | 907 | int i; |
a31f2d17 PNA |
908 | struct netlink_kernel_cfg cfg = { |
909 | .input = audit_receive, | |
910 | }; | |
f368c07d | 911 | |
a3f07114 EP |
912 | if (audit_initialized == AUDIT_DISABLED) |
913 | return 0; | |
914 | ||
1da177e4 LT |
915 | printk(KERN_INFO "audit: initializing netlink socket (%s)\n", |
916 | audit_default ? "enabled" : "disabled"); | |
9f00d977 | 917 | audit_sock = netlink_kernel_create(&init_net, NETLINK_AUDIT, &cfg); |
1da177e4 LT |
918 | if (!audit_sock) |
919 | audit_panic("cannot initialize netlink socket"); | |
71e1c784 AG |
920 | else |
921 | audit_sock->sk_sndtimeo = MAX_SCHEDULE_TIMEOUT; | |
1da177e4 | 922 | |
6ff5e459 RGB |
923 | kauditd_task = kthread_run(kauditd_thread, NULL, "kauditd"); |
924 | if (IS_ERR(kauditd_task)) | |
925 | return PTR_ERR(kauditd_task); | |
926 | ||
b7d11258 | 927 | skb_queue_head_init(&audit_skb_queue); |
f3d357b0 | 928 | skb_queue_head_init(&audit_skb_hold_queue); |
a3f07114 | 929 | audit_initialized = AUDIT_INITIALIZED; |
1da177e4 | 930 | audit_enabled = audit_default; |
b593d384 | 931 | audit_ever_enabled |= !!audit_default; |
3dc7e315 | 932 | |
9ad9ad38 | 933 | audit_log(NULL, GFP_KERNEL, AUDIT_KERNEL, "initialized"); |
f368c07d | 934 | |
f368c07d AG |
935 | for (i = 0; i < AUDIT_INODE_BUCKETS; i++) |
936 | INIT_LIST_HEAD(&audit_inode_hash[i]); | |
f368c07d | 937 | |
1da177e4 LT |
938 | return 0; |
939 | } | |
1da177e4 LT |
940 | __initcall(audit_init); |
941 | ||
942 | /* Process kernel command-line parameter at boot time. audit=0 or audit=1. */ | |
943 | static int __init audit_enable(char *str) | |
944 | { | |
945 | audit_default = !!simple_strtol(str, NULL, 0); | |
a3f07114 EP |
946 | if (!audit_default) |
947 | audit_initialized = AUDIT_DISABLED; | |
948 | ||
949 | printk(KERN_INFO "audit: %s", audit_default ? "enabled" : "disabled"); | |
950 | ||
951 | if (audit_initialized == AUDIT_INITIALIZED) { | |
1da177e4 | 952 | audit_enabled = audit_default; |
b593d384 | 953 | audit_ever_enabled |= !!audit_default; |
a3f07114 EP |
954 | } else if (audit_initialized == AUDIT_UNINITIALIZED) { |
955 | printk(" (after initialization)"); | |
956 | } else { | |
957 | printk(" (until reboot)"); | |
b593d384 | 958 | } |
a3f07114 EP |
959 | printk("\n"); |
960 | ||
9b41046c | 961 | return 1; |
1da177e4 LT |
962 | } |
963 | ||
964 | __setup("audit=", audit_enable); | |
965 | ||
16e1904e CW |
966 | static void audit_buffer_free(struct audit_buffer *ab) |
967 | { | |
968 | unsigned long flags; | |
969 | ||
8fc6115c CW |
970 | if (!ab) |
971 | return; | |
972 | ||
5ac52f33 CW |
973 | if (ab->skb) |
974 | kfree_skb(ab->skb); | |
b7d11258 | 975 | |
16e1904e | 976 | spin_lock_irqsave(&audit_freelist_lock, flags); |
5d136a01 | 977 | if (audit_freelist_count > AUDIT_MAXFREE) |
16e1904e | 978 | kfree(ab); |
5d136a01 SH |
979 | else { |
980 | audit_freelist_count++; | |
16e1904e | 981 | list_add(&ab->list, &audit_freelist); |
5d136a01 | 982 | } |
16e1904e CW |
983 | spin_unlock_irqrestore(&audit_freelist_lock, flags); |
984 | } | |
985 | ||
c0404993 | 986 | static struct audit_buffer * audit_buffer_alloc(struct audit_context *ctx, |
dd0fc66f | 987 | gfp_t gfp_mask, int type) |
16e1904e CW |
988 | { |
989 | unsigned long flags; | |
990 | struct audit_buffer *ab = NULL; | |
c0404993 | 991 | struct nlmsghdr *nlh; |
16e1904e CW |
992 | |
993 | spin_lock_irqsave(&audit_freelist_lock, flags); | |
994 | if (!list_empty(&audit_freelist)) { | |
995 | ab = list_entry(audit_freelist.next, | |
996 | struct audit_buffer, list); | |
997 | list_del(&ab->list); | |
998 | --audit_freelist_count; | |
999 | } | |
1000 | spin_unlock_irqrestore(&audit_freelist_lock, flags); | |
1001 | ||
1002 | if (!ab) { | |
4332bdd3 | 1003 | ab = kmalloc(sizeof(*ab), gfp_mask); |
16e1904e | 1004 | if (!ab) |
8fc6115c | 1005 | goto err; |
16e1904e | 1006 | } |
8fc6115c | 1007 | |
b7d11258 | 1008 | ab->ctx = ctx; |
9ad9ad38 | 1009 | ab->gfp_mask = gfp_mask; |
ee080e6c EP |
1010 | |
1011 | ab->skb = nlmsg_new(AUDIT_BUFSIZ, gfp_mask); | |
1012 | if (!ab->skb) | |
c64e66c6 | 1013 | goto err; |
ee080e6c | 1014 | |
c64e66c6 DM |
1015 | nlh = nlmsg_put(ab->skb, 0, 0, type, 0, 0); |
1016 | if (!nlh) | |
1017 | goto out_kfree_skb; | |
ee080e6c | 1018 | |
16e1904e | 1019 | return ab; |
ee080e6c | 1020 | |
c64e66c6 | 1021 | out_kfree_skb: |
ee080e6c EP |
1022 | kfree_skb(ab->skb); |
1023 | ab->skb = NULL; | |
8fc6115c CW |
1024 | err: |
1025 | audit_buffer_free(ab); | |
1026 | return NULL; | |
16e1904e | 1027 | } |
1da177e4 | 1028 | |
b0dd25a8 RD |
1029 | /** |
1030 | * audit_serial - compute a serial number for the audit record | |
1031 | * | |
1032 | * Compute a serial number for the audit record. Audit records are | |
bfb4496e DW |
1033 | * written to user-space as soon as they are generated, so a complete |
1034 | * audit record may be written in several pieces. The timestamp of the | |
1035 | * record and this serial number are used by the user-space tools to | |
1036 | * determine which pieces belong to the same audit record. The | |
1037 | * (timestamp,serial) tuple is unique for each syscall and is live from | |
1038 | * syscall entry to syscall exit. | |
1039 | * | |
bfb4496e DW |
1040 | * NOTE: Another possibility is to store the formatted records off the |
1041 | * audit context (for those records that have a context), and emit them | |
1042 | * all at syscall exit. However, this could delay the reporting of | |
1043 | * significant errors until syscall exit (or never, if the system | |
b0dd25a8 RD |
1044 | * halts). |
1045 | */ | |
bfb4496e DW |
1046 | unsigned int audit_serial(void) |
1047 | { | |
34af946a | 1048 | static DEFINE_SPINLOCK(serial_lock); |
d5b454f2 DW |
1049 | static unsigned int serial = 0; |
1050 | ||
1051 | unsigned long flags; | |
1052 | unsigned int ret; | |
bfb4496e | 1053 | |
d5b454f2 | 1054 | spin_lock_irqsave(&serial_lock, flags); |
bfb4496e | 1055 | do { |
ce625a80 DW |
1056 | ret = ++serial; |
1057 | } while (unlikely(!ret)); | |
d5b454f2 | 1058 | spin_unlock_irqrestore(&serial_lock, flags); |
bfb4496e | 1059 | |
d5b454f2 | 1060 | return ret; |
bfb4496e DW |
1061 | } |
1062 | ||
5600b892 | 1063 | static inline void audit_get_stamp(struct audit_context *ctx, |
bfb4496e DW |
1064 | struct timespec *t, unsigned int *serial) |
1065 | { | |
48887e63 | 1066 | if (!ctx || !auditsc_get_stamp(ctx, t, serial)) { |
bfb4496e DW |
1067 | *t = CURRENT_TIME; |
1068 | *serial = audit_serial(); | |
1069 | } | |
1070 | } | |
1071 | ||
82919919 AM |
1072 | /* |
1073 | * Wait for auditd to drain the queue a little | |
1074 | */ | |
1075 | static void wait_for_auditd(unsigned long sleep_time) | |
1076 | { | |
1077 | DECLARE_WAITQUEUE(wait, current); | |
1078 | set_current_state(TASK_INTERRUPTIBLE); | |
1079 | add_wait_queue(&audit_backlog_wait, &wait); | |
1080 | ||
1081 | if (audit_backlog_limit && | |
1082 | skb_queue_len(&audit_skb_queue) > audit_backlog_limit) | |
1083 | schedule_timeout(sleep_time); | |
1084 | ||
1085 | __set_current_state(TASK_RUNNING); | |
1086 | remove_wait_queue(&audit_backlog_wait, &wait); | |
1087 | } | |
1088 | ||
1da177e4 LT |
1089 | /* Obtain an audit buffer. This routine does locking to obtain the |
1090 | * audit buffer, but then no locking is required for calls to | |
1091 | * audit_log_*format. If the tsk is a task that is currently in a | |
1092 | * syscall, then the syscall is marked as auditable and an audit record | |
1093 | * will be written at syscall exit. If there is no associated task, tsk | |
1094 | * should be NULL. */ | |
9ad9ad38 | 1095 | |
b0dd25a8 RD |
1096 | /** |
1097 | * audit_log_start - obtain an audit buffer | |
1098 | * @ctx: audit_context (may be NULL) | |
1099 | * @gfp_mask: type of allocation | |
1100 | * @type: audit message type | |
1101 | * | |
1102 | * Returns audit_buffer pointer on success or NULL on error. | |
1103 | * | |
1104 | * Obtain an audit buffer. This routine does locking to obtain the | |
1105 | * audit buffer, but then no locking is required for calls to | |
1106 | * audit_log_*format. If the task (ctx) is a task that is currently in a | |
1107 | * syscall, then the syscall is marked as auditable and an audit record | |
1108 | * will be written at syscall exit. If there is no associated task, then | |
1109 | * task context (ctx) should be NULL. | |
1110 | */ | |
9796fdd8 | 1111 | struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask, |
9ad9ad38 | 1112 | int type) |
1da177e4 LT |
1113 | { |
1114 | struct audit_buffer *ab = NULL; | |
1da177e4 | 1115 | struct timespec t; |
ef00be05 | 1116 | unsigned int uninitialized_var(serial); |
9ad9ad38 | 1117 | int reserve; |
ac4cec44 | 1118 | unsigned long timeout_start = jiffies; |
1da177e4 | 1119 | |
a3f07114 | 1120 | if (audit_initialized != AUDIT_INITIALIZED) |
1da177e4 LT |
1121 | return NULL; |
1122 | ||
c8edc80c DK |
1123 | if (unlikely(audit_filter_type(type))) |
1124 | return NULL; | |
1125 | ||
9ad9ad38 DW |
1126 | if (gfp_mask & __GFP_WAIT) |
1127 | reserve = 0; | |
1128 | else | |
5600b892 | 1129 | reserve = 5; /* Allow atomic callers to go up to five |
9ad9ad38 DW |
1130 | entries over the normal backlog limit */ |
1131 | ||
1132 | while (audit_backlog_limit | |
1133 | && skb_queue_len(&audit_skb_queue) > audit_backlog_limit + reserve) { | |
82919919 AM |
1134 | if (gfp_mask & __GFP_WAIT && audit_backlog_wait_time) { |
1135 | unsigned long sleep_time; | |
9ad9ad38 | 1136 | |
82919919 AM |
1137 | sleep_time = timeout_start + audit_backlog_wait_time - |
1138 | jiffies; | |
1139 | if ((long)sleep_time > 0) | |
1140 | wait_for_auditd(sleep_time); | |
ac4cec44 | 1141 | continue; |
9ad9ad38 | 1142 | } |
320f1b1e | 1143 | if (audit_rate_check() && printk_ratelimit()) |
fb19b4c6 DW |
1144 | printk(KERN_WARNING |
1145 | "audit: audit_backlog=%d > " | |
1146 | "audit_backlog_limit=%d\n", | |
1147 | skb_queue_len(&audit_skb_queue), | |
1148 | audit_backlog_limit); | |
1149 | audit_log_lost("backlog limit exceeded"); | |
ac4cec44 DW |
1150 | audit_backlog_wait_time = audit_backlog_wait_overflow; |
1151 | wake_up(&audit_backlog_wait); | |
fb19b4c6 DW |
1152 | return NULL; |
1153 | } | |
1154 | ||
9ad9ad38 | 1155 | ab = audit_buffer_alloc(ctx, gfp_mask, type); |
1da177e4 LT |
1156 | if (!ab) { |
1157 | audit_log_lost("out of memory in audit_log_start"); | |
1158 | return NULL; | |
1159 | } | |
1160 | ||
bfb4496e | 1161 | audit_get_stamp(ab->ctx, &t, &serial); |
197c69c6 | 1162 | |
1da177e4 LT |
1163 | audit_log_format(ab, "audit(%lu.%03lu:%u): ", |
1164 | t.tv_sec, t.tv_nsec/1000000, serial); | |
1165 | return ab; | |
1166 | } | |
1167 | ||
8fc6115c | 1168 | /** |
5ac52f33 | 1169 | * audit_expand - expand skb in the audit buffer |
8fc6115c | 1170 | * @ab: audit_buffer |
b0dd25a8 | 1171 | * @extra: space to add at tail of the skb |
8fc6115c CW |
1172 | * |
1173 | * Returns 0 (no space) on failed expansion, or available space if | |
1174 | * successful. | |
1175 | */ | |
e3b926b4 | 1176 | static inline int audit_expand(struct audit_buffer *ab, int extra) |
8fc6115c | 1177 | { |
5ac52f33 | 1178 | struct sk_buff *skb = ab->skb; |
406a1d86 HX |
1179 | int oldtail = skb_tailroom(skb); |
1180 | int ret = pskb_expand_head(skb, 0, extra, ab->gfp_mask); | |
1181 | int newtail = skb_tailroom(skb); | |
1182 | ||
5ac52f33 CW |
1183 | if (ret < 0) { |
1184 | audit_log_lost("out of memory in audit_expand"); | |
8fc6115c | 1185 | return 0; |
5ac52f33 | 1186 | } |
406a1d86 HX |
1187 | |
1188 | skb->truesize += newtail - oldtail; | |
1189 | return newtail; | |
8fc6115c | 1190 | } |
1da177e4 | 1191 | |
b0dd25a8 RD |
1192 | /* |
1193 | * Format an audit message into the audit buffer. If there isn't enough | |
1da177e4 LT |
1194 | * room in the audit buffer, more room will be allocated and vsnprint |
1195 | * will be called a second time. Currently, we assume that a printk | |
b0dd25a8 RD |
1196 | * can't format message larger than 1024 bytes, so we don't either. |
1197 | */ | |
1da177e4 LT |
1198 | static void audit_log_vformat(struct audit_buffer *ab, const char *fmt, |
1199 | va_list args) | |
1200 | { | |
1201 | int len, avail; | |
5ac52f33 | 1202 | struct sk_buff *skb; |
eecb0a73 | 1203 | va_list args2; |
1da177e4 LT |
1204 | |
1205 | if (!ab) | |
1206 | return; | |
1207 | ||
5ac52f33 CW |
1208 | BUG_ON(!ab->skb); |
1209 | skb = ab->skb; | |
1210 | avail = skb_tailroom(skb); | |
1211 | if (avail == 0) { | |
e3b926b4 | 1212 | avail = audit_expand(ab, AUDIT_BUFSIZ); |
8fc6115c CW |
1213 | if (!avail) |
1214 | goto out; | |
1da177e4 | 1215 | } |
eecb0a73 | 1216 | va_copy(args2, args); |
27a884dc | 1217 | len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args); |
1da177e4 LT |
1218 | if (len >= avail) { |
1219 | /* The printk buffer is 1024 bytes long, so if we get | |
1220 | * here and AUDIT_BUFSIZ is at least 1024, then we can | |
1221 | * log everything that printk could have logged. */ | |
b0dd25a8 RD |
1222 | avail = audit_expand(ab, |
1223 | max_t(unsigned, AUDIT_BUFSIZ, 1+len-avail)); | |
8fc6115c | 1224 | if (!avail) |
a0e86bd4 | 1225 | goto out_va_end; |
27a884dc | 1226 | len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args2); |
1da177e4 | 1227 | } |
168b7173 SG |
1228 | if (len > 0) |
1229 | skb_put(skb, len); | |
a0e86bd4 JJ |
1230 | out_va_end: |
1231 | va_end(args2); | |
8fc6115c CW |
1232 | out: |
1233 | return; | |
1da177e4 LT |
1234 | } |
1235 | ||
b0dd25a8 RD |
1236 | /** |
1237 | * audit_log_format - format a message into the audit buffer. | |
1238 | * @ab: audit_buffer | |
1239 | * @fmt: format string | |
1240 | * @...: optional parameters matching @fmt string | |
1241 | * | |
1242 | * All the work is done in audit_log_vformat. | |
1243 | */ | |
1da177e4 LT |
1244 | void audit_log_format(struct audit_buffer *ab, const char *fmt, ...) |
1245 | { | |
1246 | va_list args; | |
1247 | ||
1248 | if (!ab) | |
1249 | return; | |
1250 | va_start(args, fmt); | |
1251 | audit_log_vformat(ab, fmt, args); | |
1252 | va_end(args); | |
1253 | } | |
1254 | ||
b0dd25a8 RD |
1255 | /** |
1256 | * audit_log_hex - convert a buffer to hex and append it to the audit skb | |
1257 | * @ab: the audit_buffer | |
1258 | * @buf: buffer to convert to hex | |
1259 | * @len: length of @buf to be converted | |
1260 | * | |
1261 | * No return value; failure to expand is silently ignored. | |
1262 | * | |
1263 | * This function will take the passed buf and convert it into a string of | |
1264 | * ascii hex digits. The new string is placed onto the skb. | |
1265 | */ | |
b556f8ad | 1266 | void audit_log_n_hex(struct audit_buffer *ab, const unsigned char *buf, |
168b7173 | 1267 | size_t len) |
83c7d091 | 1268 | { |
168b7173 SG |
1269 | int i, avail, new_len; |
1270 | unsigned char *ptr; | |
1271 | struct sk_buff *skb; | |
1272 | static const unsigned char *hex = "0123456789ABCDEF"; | |
1273 | ||
8ef2d304 AG |
1274 | if (!ab) |
1275 | return; | |
1276 | ||
168b7173 SG |
1277 | BUG_ON(!ab->skb); |
1278 | skb = ab->skb; | |
1279 | avail = skb_tailroom(skb); | |
1280 | new_len = len<<1; | |
1281 | if (new_len >= avail) { | |
1282 | /* Round the buffer request up to the next multiple */ | |
1283 | new_len = AUDIT_BUFSIZ*(((new_len-avail)/AUDIT_BUFSIZ) + 1); | |
1284 | avail = audit_expand(ab, new_len); | |
1285 | if (!avail) | |
1286 | return; | |
1287 | } | |
83c7d091 | 1288 | |
27a884dc | 1289 | ptr = skb_tail_pointer(skb); |
168b7173 SG |
1290 | for (i=0; i<len; i++) { |
1291 | *ptr++ = hex[(buf[i] & 0xF0)>>4]; /* Upper nibble */ | |
1292 | *ptr++ = hex[buf[i] & 0x0F]; /* Lower nibble */ | |
1293 | } | |
1294 | *ptr = 0; | |
1295 | skb_put(skb, len << 1); /* new string is twice the old string */ | |
83c7d091 | 1296 | } |
1297 | ||
9c937dcc AG |
1298 | /* |
1299 | * Format a string of no more than slen characters into the audit buffer, | |
1300 | * enclosed in quote marks. | |
1301 | */ | |
b556f8ad EP |
1302 | void audit_log_n_string(struct audit_buffer *ab, const char *string, |
1303 | size_t slen) | |
9c937dcc AG |
1304 | { |
1305 | int avail, new_len; | |
1306 | unsigned char *ptr; | |
1307 | struct sk_buff *skb; | |
1308 | ||
8ef2d304 AG |
1309 | if (!ab) |
1310 | return; | |
1311 | ||
9c937dcc AG |
1312 | BUG_ON(!ab->skb); |
1313 | skb = ab->skb; | |
1314 | avail = skb_tailroom(skb); | |
1315 | new_len = slen + 3; /* enclosing quotes + null terminator */ | |
1316 | if (new_len > avail) { | |
1317 | avail = audit_expand(ab, new_len); | |
1318 | if (!avail) | |
1319 | return; | |
1320 | } | |
27a884dc | 1321 | ptr = skb_tail_pointer(skb); |
9c937dcc AG |
1322 | *ptr++ = '"'; |
1323 | memcpy(ptr, string, slen); | |
1324 | ptr += slen; | |
1325 | *ptr++ = '"'; | |
1326 | *ptr = 0; | |
1327 | skb_put(skb, slen + 2); /* don't include null terminator */ | |
1328 | } | |
1329 | ||
de6bbd1d EP |
1330 | /** |
1331 | * audit_string_contains_control - does a string need to be logged in hex | |
f706d5d2 DJ |
1332 | * @string: string to be checked |
1333 | * @len: max length of the string to check | |
de6bbd1d EP |
1334 | */ |
1335 | int audit_string_contains_control(const char *string, size_t len) | |
1336 | { | |
1337 | const unsigned char *p; | |
b3897f56 | 1338 | for (p = string; p < (const unsigned char *)string + len; p++) { |
1d6c9649 | 1339 | if (*p == '"' || *p < 0x21 || *p > 0x7e) |
de6bbd1d EP |
1340 | return 1; |
1341 | } | |
1342 | return 0; | |
1343 | } | |
1344 | ||
b0dd25a8 | 1345 | /** |
522ed776 | 1346 | * audit_log_n_untrustedstring - log a string that may contain random characters |
b0dd25a8 | 1347 | * @ab: audit_buffer |
f706d5d2 | 1348 | * @len: length of string (not including trailing null) |
b0dd25a8 RD |
1349 | * @string: string to be logged |
1350 | * | |
1351 | * This code will escape a string that is passed to it if the string | |
1352 | * contains a control character, unprintable character, double quote mark, | |
168b7173 | 1353 | * or a space. Unescaped strings will start and end with a double quote mark. |
b0dd25a8 | 1354 | * Strings that are escaped are printed in hex (2 digits per char). |
9c937dcc AG |
1355 | * |
1356 | * The caller specifies the number of characters in the string to log, which may | |
1357 | * or may not be the entire string. | |
b0dd25a8 | 1358 | */ |
b556f8ad EP |
1359 | void audit_log_n_untrustedstring(struct audit_buffer *ab, const char *string, |
1360 | size_t len) | |
83c7d091 | 1361 | { |
de6bbd1d | 1362 | if (audit_string_contains_control(string, len)) |
b556f8ad | 1363 | audit_log_n_hex(ab, string, len); |
de6bbd1d | 1364 | else |
b556f8ad | 1365 | audit_log_n_string(ab, string, len); |
83c7d091 | 1366 | } |
1367 | ||
9c937dcc | 1368 | /** |
522ed776 | 1369 | * audit_log_untrustedstring - log a string that may contain random characters |
9c937dcc AG |
1370 | * @ab: audit_buffer |
1371 | * @string: string to be logged | |
1372 | * | |
522ed776 | 1373 | * Same as audit_log_n_untrustedstring(), except that strlen is used to |
9c937dcc AG |
1374 | * determine string length. |
1375 | */ | |
de6bbd1d | 1376 | void audit_log_untrustedstring(struct audit_buffer *ab, const char *string) |
9c937dcc | 1377 | { |
b556f8ad | 1378 | audit_log_n_untrustedstring(ab, string, strlen(string)); |
9c937dcc AG |
1379 | } |
1380 | ||
168b7173 | 1381 | /* This is a helper-function to print the escaped d_path */ |
1da177e4 | 1382 | void audit_log_d_path(struct audit_buffer *ab, const char *prefix, |
66b3fad3 | 1383 | const struct path *path) |
1da177e4 | 1384 | { |
44707fdf | 1385 | char *p, *pathname; |
1da177e4 | 1386 | |
8fc6115c | 1387 | if (prefix) |
c158a35c | 1388 | audit_log_format(ab, "%s", prefix); |
1da177e4 | 1389 | |
168b7173 | 1390 | /* We will allow 11 spaces for ' (deleted)' to be appended */ |
44707fdf JB |
1391 | pathname = kmalloc(PATH_MAX+11, ab->gfp_mask); |
1392 | if (!pathname) { | |
def57543 | 1393 | audit_log_string(ab, "<no_memory>"); |
168b7173 | 1394 | return; |
1da177e4 | 1395 | } |
cf28b486 | 1396 | p = d_path(path, pathname, PATH_MAX+11); |
168b7173 SG |
1397 | if (IS_ERR(p)) { /* Should never happen since we send PATH_MAX */ |
1398 | /* FIXME: can we save some information here? */ | |
def57543 | 1399 | audit_log_string(ab, "<too_long>"); |
5600b892 | 1400 | } else |
168b7173 | 1401 | audit_log_untrustedstring(ab, p); |
44707fdf | 1402 | kfree(pathname); |
1da177e4 LT |
1403 | } |
1404 | ||
9d960985 EP |
1405 | void audit_log_key(struct audit_buffer *ab, char *key) |
1406 | { | |
1407 | audit_log_format(ab, " key="); | |
1408 | if (key) | |
1409 | audit_log_untrustedstring(ab, key); | |
1410 | else | |
1411 | audit_log_format(ab, "(null)"); | |
1412 | } | |
1413 | ||
a51d9eaa KC |
1414 | /** |
1415 | * audit_log_link_denied - report a link restriction denial | |
1416 | * @operation: specific link opreation | |
1417 | * @link: the path that triggered the restriction | |
1418 | */ | |
1419 | void audit_log_link_denied(const char *operation, struct path *link) | |
1420 | { | |
1421 | struct audit_buffer *ab; | |
1422 | ||
1423 | ab = audit_log_start(current->audit_context, GFP_KERNEL, | |
1424 | AUDIT_ANOM_LINK); | |
d1c7d97a SL |
1425 | if (!ab) |
1426 | return; | |
a51d9eaa KC |
1427 | audit_log_format(ab, "op=%s action=denied", operation); |
1428 | audit_log_format(ab, " pid=%d comm=", current->pid); | |
1429 | audit_log_untrustedstring(ab, current->comm); | |
1430 | audit_log_d_path(ab, " path=", link); | |
1431 | audit_log_format(ab, " dev="); | |
1432 | audit_log_untrustedstring(ab, link->dentry->d_inode->i_sb->s_id); | |
1433 | audit_log_format(ab, " ino=%lu", link->dentry->d_inode->i_ino); | |
1434 | audit_log_end(ab); | |
1435 | } | |
1436 | ||
b0dd25a8 RD |
1437 | /** |
1438 | * audit_log_end - end one audit record | |
1439 | * @ab: the audit_buffer | |
1440 | * | |
1441 | * The netlink_* functions cannot be called inside an irq context, so | |
1442 | * the audit buffer is placed on a queue and a tasklet is scheduled to | |
1da177e4 | 1443 | * remove them from the queue outside the irq context. May be called in |
b0dd25a8 RD |
1444 | * any context. |
1445 | */ | |
b7d11258 | 1446 | void audit_log_end(struct audit_buffer *ab) |
1da177e4 | 1447 | { |
1da177e4 LT |
1448 | if (!ab) |
1449 | return; | |
1450 | if (!audit_rate_check()) { | |
1451 | audit_log_lost("rate limit exceeded"); | |
1452 | } else { | |
8d07a67c | 1453 | struct nlmsghdr *nlh = nlmsg_hdr(ab->skb); |
f3d357b0 EP |
1454 | nlh->nlmsg_len = ab->skb->len - NLMSG_SPACE(0); |
1455 | ||
b7d11258 | 1456 | if (audit_pid) { |
b7d11258 | 1457 | skb_queue_tail(&audit_skb_queue, ab->skb); |
b7d11258 | 1458 | wake_up_interruptible(&kauditd_wait); |
f3d357b0 | 1459 | } else { |
038cbcf6 | 1460 | audit_printk_skb(ab->skb); |
b7d11258 | 1461 | } |
f3d357b0 | 1462 | ab->skb = NULL; |
1da177e4 | 1463 | } |
16e1904e | 1464 | audit_buffer_free(ab); |
1da177e4 LT |
1465 | } |
1466 | ||
b0dd25a8 RD |
1467 | /** |
1468 | * audit_log - Log an audit record | |
1469 | * @ctx: audit context | |
1470 | * @gfp_mask: type of allocation | |
1471 | * @type: audit message type | |
1472 | * @fmt: format string to use | |
1473 | * @...: variable parameters matching the format string | |
1474 | * | |
1475 | * This is a convenience function that calls audit_log_start, | |
1476 | * audit_log_vformat, and audit_log_end. It may be called | |
1477 | * in any context. | |
1478 | */ | |
5600b892 | 1479 | void audit_log(struct audit_context *ctx, gfp_t gfp_mask, int type, |
9ad9ad38 | 1480 | const char *fmt, ...) |
1da177e4 LT |
1481 | { |
1482 | struct audit_buffer *ab; | |
1483 | va_list args; | |
1484 | ||
9ad9ad38 | 1485 | ab = audit_log_start(ctx, gfp_mask, type); |
1da177e4 LT |
1486 | if (ab) { |
1487 | va_start(args, fmt); | |
1488 | audit_log_vformat(ab, fmt, args); | |
1489 | va_end(args); | |
1490 | audit_log_end(ab); | |
1491 | } | |
1492 | } | |
bf45da97 | 1493 | |
131ad62d MDF |
1494 | #ifdef CONFIG_SECURITY |
1495 | /** | |
1496 | * audit_log_secctx - Converts and logs SELinux context | |
1497 | * @ab: audit_buffer | |
1498 | * @secid: security number | |
1499 | * | |
1500 | * This is a helper function that calls security_secid_to_secctx to convert | |
1501 | * secid to secctx and then adds the (converted) SELinux context to the audit | |
1502 | * log by calling audit_log_format, thus also preventing leak of internal secid | |
1503 | * to userspace. If secid cannot be converted audit_panic is called. | |
1504 | */ | |
1505 | void audit_log_secctx(struct audit_buffer *ab, u32 secid) | |
1506 | { | |
1507 | u32 len; | |
1508 | char *secctx; | |
1509 | ||
1510 | if (security_secid_to_secctx(secid, &secctx, &len)) { | |
1511 | audit_panic("Cannot convert secid to context"); | |
1512 | } else { | |
1513 | audit_log_format(ab, " obj=%s", secctx); | |
1514 | security_release_secctx(secctx, len); | |
1515 | } | |
1516 | } | |
1517 | EXPORT_SYMBOL(audit_log_secctx); | |
1518 | #endif | |
1519 | ||
bf45da97 | 1520 | EXPORT_SYMBOL(audit_log_start); |
1521 | EXPORT_SYMBOL(audit_log_end); | |
1522 | EXPORT_SYMBOL(audit_log_format); | |
1523 | EXPORT_SYMBOL(audit_log); |