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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 <[email protected]> | |
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> |
3dc7e315 DG |
64 | |
65 | #include "audit.h" | |
1da177e4 | 66 | |
a3f07114 | 67 | /* No auditing will take place until audit_initialized == AUDIT_INITIALIZED. |
1da177e4 | 68 | * (Initialization happens after skb_init is called.) */ |
a3f07114 EP |
69 | #define AUDIT_DISABLED -1 |
70 | #define AUDIT_UNINITIALIZED 0 | |
71 | #define AUDIT_INITIALIZED 1 | |
1da177e4 LT |
72 | static int audit_initialized; |
73 | ||
1a6b9f23 EP |
74 | #define AUDIT_OFF 0 |
75 | #define AUDIT_ON 1 | |
76 | #define AUDIT_LOCKED 2 | |
1da177e4 | 77 | int audit_enabled; |
b593d384 | 78 | int audit_ever_enabled; |
1da177e4 | 79 | |
ae9d67af JE |
80 | EXPORT_SYMBOL_GPL(audit_enabled); |
81 | ||
1da177e4 LT |
82 | /* Default state when kernel boots without any parameters. */ |
83 | static int audit_default; | |
84 | ||
85 | /* If auditing cannot proceed, audit_failure selects what happens. */ | |
86 | static int audit_failure = AUDIT_FAIL_PRINTK; | |
87 | ||
75c0371a PE |
88 | /* |
89 | * If audit records are to be written to the netlink socket, audit_pid | |
90 | * contains the pid of the auditd process and audit_nlk_pid contains | |
91 | * the pid to use to send netlink messages to that process. | |
92 | */ | |
c2f0c7c3 | 93 | int audit_pid; |
75c0371a | 94 | static int audit_nlk_pid; |
1da177e4 | 95 | |
b0dd25a8 | 96 | /* If audit_rate_limit is non-zero, limit the rate of sending audit records |
1da177e4 LT |
97 | * to that number per second. This prevents DoS attacks, but results in |
98 | * audit records being dropped. */ | |
99 | static int audit_rate_limit; | |
100 | ||
101 | /* Number of outstanding audit_buffers allowed. */ | |
102 | static int audit_backlog_limit = 64; | |
ac4cec44 DW |
103 | static int audit_backlog_wait_time = 60 * HZ; |
104 | static int audit_backlog_wait_overflow = 0; | |
1da177e4 | 105 | |
c2f0c7c3 SG |
106 | /* The identity of the user shutting down the audit system. */ |
107 | uid_t audit_sig_uid = -1; | |
108 | pid_t audit_sig_pid = -1; | |
e1396065 | 109 | u32 audit_sig_sid = 0; |
c2f0c7c3 | 110 | |
1da177e4 LT |
111 | /* Records can be lost in several ways: |
112 | 0) [suppressed in audit_alloc] | |
113 | 1) out of memory in audit_log_start [kmalloc of struct audit_buffer] | |
114 | 2) out of memory in audit_log_move [alloc_skb] | |
115 | 3) suppressed due to audit_rate_limit | |
116 | 4) suppressed due to audit_backlog_limit | |
117 | */ | |
118 | static atomic_t audit_lost = ATOMIC_INIT(0); | |
119 | ||
120 | /* The netlink socket. */ | |
121 | static struct sock *audit_sock; | |
122 | ||
f368c07d AG |
123 | /* Hash for inode-based rules */ |
124 | struct list_head audit_inode_hash[AUDIT_INODE_BUCKETS]; | |
125 | ||
b7d11258 | 126 | /* The audit_freelist is a list of pre-allocated audit buffers (if more |
1da177e4 LT |
127 | * than AUDIT_MAXFREE are in use, the audit buffer is freed instead of |
128 | * being placed on the freelist). */ | |
1da177e4 | 129 | static DEFINE_SPINLOCK(audit_freelist_lock); |
b0dd25a8 | 130 | static int audit_freelist_count; |
1da177e4 LT |
131 | static LIST_HEAD(audit_freelist); |
132 | ||
b7d11258 | 133 | static struct sk_buff_head audit_skb_queue; |
f3d357b0 EP |
134 | /* queue of skbs to send to auditd when/if it comes back */ |
135 | static struct sk_buff_head audit_skb_hold_queue; | |
b7d11258 DW |
136 | static struct task_struct *kauditd_task; |
137 | static DECLARE_WAIT_QUEUE_HEAD(kauditd_wait); | |
9ad9ad38 | 138 | static DECLARE_WAIT_QUEUE_HEAD(audit_backlog_wait); |
1da177e4 | 139 | |
f368c07d | 140 | /* Serialize requests from userspace. */ |
916d7576 | 141 | DEFINE_MUTEX(audit_cmd_mutex); |
1da177e4 LT |
142 | |
143 | /* AUDIT_BUFSIZ is the size of the temporary buffer used for formatting | |
144 | * audit records. Since printk uses a 1024 byte buffer, this buffer | |
145 | * should be at least that large. */ | |
146 | #define AUDIT_BUFSIZ 1024 | |
147 | ||
148 | /* AUDIT_MAXFREE is the number of empty audit_buffers we keep on the | |
149 | * audit_freelist. Doing so eliminates many kmalloc/kfree calls. */ | |
150 | #define AUDIT_MAXFREE (2*NR_CPUS) | |
151 | ||
152 | /* The audit_buffer is used when formatting an audit record. The caller | |
153 | * locks briefly to get the record off the freelist or to allocate the | |
154 | * buffer, and locks briefly to send the buffer to the netlink layer or | |
155 | * to place it on a transmit queue. Multiple audit_buffers can be in | |
156 | * use simultaneously. */ | |
157 | struct audit_buffer { | |
158 | struct list_head list; | |
8fc6115c | 159 | struct sk_buff *skb; /* formatted skb ready to send */ |
1da177e4 | 160 | struct audit_context *ctx; /* NULL or associated context */ |
9796fdd8 | 161 | gfp_t gfp_mask; |
1da177e4 LT |
162 | }; |
163 | ||
f09ac9db EP |
164 | struct audit_reply { |
165 | int pid; | |
166 | struct sk_buff *skb; | |
167 | }; | |
168 | ||
c0404993 SG |
169 | static void audit_set_pid(struct audit_buffer *ab, pid_t pid) |
170 | { | |
50397bd1 EP |
171 | if (ab) { |
172 | struct nlmsghdr *nlh = nlmsg_hdr(ab->skb); | |
173 | nlh->nlmsg_pid = pid; | |
174 | } | |
c0404993 SG |
175 | } |
176 | ||
8c8570fb | 177 | void audit_panic(const char *message) |
1da177e4 LT |
178 | { |
179 | switch (audit_failure) | |
180 | { | |
181 | case AUDIT_FAIL_SILENT: | |
182 | break; | |
183 | case AUDIT_FAIL_PRINTK: | |
320f1b1e EP |
184 | if (printk_ratelimit()) |
185 | printk(KERN_ERR "audit: %s\n", message); | |
1da177e4 LT |
186 | break; |
187 | case AUDIT_FAIL_PANIC: | |
b29ee87e EP |
188 | /* test audit_pid since printk is always losey, why bother? */ |
189 | if (audit_pid) | |
190 | panic("audit: %s\n", message); | |
1da177e4 LT |
191 | break; |
192 | } | |
193 | } | |
194 | ||
195 | static inline int audit_rate_check(void) | |
196 | { | |
197 | static unsigned long last_check = 0; | |
198 | static int messages = 0; | |
199 | static DEFINE_SPINLOCK(lock); | |
200 | unsigned long flags; | |
201 | unsigned long now; | |
202 | unsigned long elapsed; | |
203 | int retval = 0; | |
204 | ||
205 | if (!audit_rate_limit) return 1; | |
206 | ||
207 | spin_lock_irqsave(&lock, flags); | |
208 | if (++messages < audit_rate_limit) { | |
209 | retval = 1; | |
210 | } else { | |
211 | now = jiffies; | |
212 | elapsed = now - last_check; | |
213 | if (elapsed > HZ) { | |
214 | last_check = now; | |
215 | messages = 0; | |
216 | retval = 1; | |
217 | } | |
218 | } | |
219 | spin_unlock_irqrestore(&lock, flags); | |
220 | ||
221 | return retval; | |
222 | } | |
223 | ||
b0dd25a8 RD |
224 | /** |
225 | * audit_log_lost - conditionally log lost audit message event | |
226 | * @message: the message stating reason for lost audit message | |
227 | * | |
228 | * Emit at least 1 message per second, even if audit_rate_check is | |
229 | * throttling. | |
230 | * Always increment the lost messages counter. | |
231 | */ | |
1da177e4 LT |
232 | void audit_log_lost(const char *message) |
233 | { | |
234 | static unsigned long last_msg = 0; | |
235 | static DEFINE_SPINLOCK(lock); | |
236 | unsigned long flags; | |
237 | unsigned long now; | |
238 | int print; | |
239 | ||
240 | atomic_inc(&audit_lost); | |
241 | ||
242 | print = (audit_failure == AUDIT_FAIL_PANIC || !audit_rate_limit); | |
243 | ||
244 | if (!print) { | |
245 | spin_lock_irqsave(&lock, flags); | |
246 | now = jiffies; | |
247 | if (now - last_msg > HZ) { | |
248 | print = 1; | |
249 | last_msg = now; | |
250 | } | |
251 | spin_unlock_irqrestore(&lock, flags); | |
252 | } | |
253 | ||
254 | if (print) { | |
320f1b1e EP |
255 | if (printk_ratelimit()) |
256 | printk(KERN_WARNING | |
257 | "audit: audit_lost=%d audit_rate_limit=%d " | |
258 | "audit_backlog_limit=%d\n", | |
259 | atomic_read(&audit_lost), | |
260 | audit_rate_limit, | |
261 | audit_backlog_limit); | |
1da177e4 LT |
262 | audit_panic(message); |
263 | } | |
1da177e4 LT |
264 | } |
265 | ||
1a6b9f23 | 266 | static int audit_log_config_change(char *function_name, int new, int old, |
2532386f EP |
267 | uid_t loginuid, u32 sessionid, u32 sid, |
268 | int allow_changes) | |
1da177e4 | 269 | { |
1a6b9f23 EP |
270 | struct audit_buffer *ab; |
271 | int rc = 0; | |
ce29b682 | 272 | |
1a6b9f23 | 273 | ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE); |
2532386f EP |
274 | audit_log_format(ab, "%s=%d old=%d auid=%u ses=%u", function_name, new, |
275 | old, loginuid, sessionid); | |
ce29b682 SG |
276 | if (sid) { |
277 | char *ctx = NULL; | |
278 | u32 len; | |
1a6b9f23 | 279 | |
2a862b32 | 280 | rc = security_secid_to_secctx(sid, &ctx, &len); |
1a6b9f23 EP |
281 | if (rc) { |
282 | audit_log_format(ab, " sid=%u", sid); | |
283 | allow_changes = 0; /* Something weird, deny request */ | |
284 | } else { | |
285 | audit_log_format(ab, " subj=%s", ctx); | |
2a862b32 | 286 | security_release_secctx(ctx, len); |
1a6b9f23 | 287 | } |
6a01b07f | 288 | } |
1a6b9f23 EP |
289 | audit_log_format(ab, " res=%d", allow_changes); |
290 | audit_log_end(ab); | |
6a01b07f | 291 | return rc; |
1da177e4 LT |
292 | } |
293 | ||
1a6b9f23 | 294 | static int audit_do_config_change(char *function_name, int *to_change, |
2532386f EP |
295 | int new, uid_t loginuid, u32 sessionid, |
296 | u32 sid) | |
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) { |
2532386f EP |
307 | rc = audit_log_config_change(function_name, new, old, loginuid, |
308 | sessionid, sid, allow_changes); | |
1a6b9f23 EP |
309 | if (rc) |
310 | allow_changes = 0; | |
6a01b07f | 311 | } |
6a01b07f SG |
312 | |
313 | /* If we are allowed, make the change */ | |
1a6b9f23 EP |
314 | if (allow_changes == 1) |
315 | *to_change = new; | |
6a01b07f SG |
316 | /* Not allowed, update reason */ |
317 | else if (rc == 0) | |
318 | rc = -EPERM; | |
319 | return rc; | |
1da177e4 LT |
320 | } |
321 | ||
2532386f EP |
322 | static int audit_set_rate_limit(int limit, uid_t loginuid, u32 sessionid, |
323 | u32 sid) | |
1da177e4 | 324 | { |
1a6b9f23 | 325 | return audit_do_config_change("audit_rate_limit", &audit_rate_limit, |
2532386f | 326 | limit, loginuid, sessionid, sid); |
1a6b9f23 | 327 | } |
ce29b682 | 328 | |
2532386f EP |
329 | static int audit_set_backlog_limit(int limit, uid_t loginuid, u32 sessionid, |
330 | u32 sid) | |
1a6b9f23 EP |
331 | { |
332 | return audit_do_config_change("audit_backlog_limit", &audit_backlog_limit, | |
2532386f | 333 | limit, loginuid, sessionid, sid); |
1a6b9f23 | 334 | } |
6a01b07f | 335 | |
2532386f | 336 | static int audit_set_enabled(int state, uid_t loginuid, u32 sessionid, u32 sid) |
1a6b9f23 | 337 | { |
b593d384 | 338 | int rc; |
1a6b9f23 EP |
339 | if (state < AUDIT_OFF || state > AUDIT_LOCKED) |
340 | return -EINVAL; | |
6a01b07f | 341 | |
b593d384 | 342 | rc = audit_do_config_change("audit_enabled", &audit_enabled, state, |
2532386f | 343 | loginuid, sessionid, sid); |
b593d384 EP |
344 | |
345 | if (!rc) | |
346 | audit_ever_enabled |= !!state; | |
347 | ||
348 | return rc; | |
1da177e4 LT |
349 | } |
350 | ||
2532386f | 351 | static int audit_set_failure(int state, uid_t loginuid, u32 sessionid, u32 sid) |
1da177e4 | 352 | { |
1da177e4 LT |
353 | if (state != AUDIT_FAIL_SILENT |
354 | && state != AUDIT_FAIL_PRINTK | |
355 | && state != AUDIT_FAIL_PANIC) | |
356 | return -EINVAL; | |
ce29b682 | 357 | |
1a6b9f23 | 358 | return audit_do_config_change("audit_failure", &audit_failure, state, |
2532386f | 359 | loginuid, sessionid, sid); |
1da177e4 LT |
360 | } |
361 | ||
f3d357b0 EP |
362 | /* |
363 | * Queue skbs to be sent to auditd when/if it comes back. These skbs should | |
364 | * already have been sent via prink/syslog and so if these messages are dropped | |
365 | * it is not a huge concern since we already passed the audit_log_lost() | |
366 | * notification and stuff. This is just nice to get audit messages during | |
367 | * boot before auditd is running or messages generated while auditd is stopped. | |
368 | * This only holds messages is audit_default is set, aka booting with audit=1 | |
369 | * or building your kernel that way. | |
370 | */ | |
371 | static void audit_hold_skb(struct sk_buff *skb) | |
372 | { | |
373 | if (audit_default && | |
374 | skb_queue_len(&audit_skb_hold_queue) < audit_backlog_limit) | |
375 | skb_queue_tail(&audit_skb_hold_queue, skb); | |
376 | else | |
377 | kfree_skb(skb); | |
378 | } | |
379 | ||
038cbcf6 EP |
380 | /* |
381 | * For one reason or another this nlh isn't getting delivered to the userspace | |
382 | * audit daemon, just send it to printk. | |
383 | */ | |
384 | static void audit_printk_skb(struct sk_buff *skb) | |
385 | { | |
386 | struct nlmsghdr *nlh = nlmsg_hdr(skb); | |
c64e66c6 | 387 | char *data = nlmsg_data(nlh); |
038cbcf6 EP |
388 | |
389 | if (nlh->nlmsg_type != AUDIT_EOE) { | |
390 | if (printk_ratelimit()) | |
391 | printk(KERN_NOTICE "type=%d %s\n", nlh->nlmsg_type, data); | |
392 | else | |
393 | audit_log_lost("printk limit exceeded\n"); | |
394 | } | |
395 | ||
396 | audit_hold_skb(skb); | |
397 | } | |
398 | ||
f3d357b0 EP |
399 | static void kauditd_send_skb(struct sk_buff *skb) |
400 | { | |
401 | int err; | |
402 | /* take a reference in case we can't send it and we want to hold it */ | |
403 | skb_get(skb); | |
404 | err = netlink_unicast(audit_sock, skb, audit_nlk_pid, 0); | |
405 | if (err < 0) { | |
c9404c9c | 406 | BUG_ON(err != -ECONNREFUSED); /* Shouldn't happen */ |
f3d357b0 | 407 | printk(KERN_ERR "audit: *NO* daemon at audit_pid=%d\n", audit_pid); |
9db3b9bc | 408 | audit_log_lost("auditd disappeared\n"); |
f3d357b0 EP |
409 | audit_pid = 0; |
410 | /* we might get lucky and get this in the next auditd */ | |
411 | audit_hold_skb(skb); | |
412 | } else | |
413 | /* drop the extra reference if sent ok */ | |
70d4bf6d | 414 | consume_skb(skb); |
f3d357b0 EP |
415 | } |
416 | ||
97a41e26 | 417 | static int kauditd_thread(void *dummy) |
b7d11258 DW |
418 | { |
419 | struct sk_buff *skb; | |
420 | ||
83144186 | 421 | set_freezable(); |
4899b8b1 | 422 | while (!kthread_should_stop()) { |
f3d357b0 EP |
423 | /* |
424 | * if auditd just started drain the queue of messages already | |
425 | * sent to syslog/printk. remember loss here is ok. we already | |
426 | * called audit_log_lost() if it didn't go out normally. so the | |
427 | * race between the skb_dequeue and the next check for audit_pid | |
428 | * doesn't matter. | |
429 | * | |
430 | * if you ever find kauditd to be too slow we can get a perf win | |
431 | * by doing our own locking and keeping better track if there | |
432 | * are messages in this queue. I don't see the need now, but | |
433 | * in 5 years when I want to play with this again I'll see this | |
434 | * note and still have no friggin idea what i'm thinking today. | |
435 | */ | |
436 | if (audit_default && audit_pid) { | |
437 | skb = skb_dequeue(&audit_skb_hold_queue); | |
438 | if (unlikely(skb)) { | |
439 | while (skb && audit_pid) { | |
440 | kauditd_send_skb(skb); | |
441 | skb = skb_dequeue(&audit_skb_hold_queue); | |
442 | } | |
443 | } | |
444 | } | |
445 | ||
b7d11258 | 446 | skb = skb_dequeue(&audit_skb_queue); |
9ad9ad38 | 447 | wake_up(&audit_backlog_wait); |
b7d11258 | 448 | if (skb) { |
f3d357b0 EP |
449 | if (audit_pid) |
450 | kauditd_send_skb(skb); | |
038cbcf6 EP |
451 | else |
452 | audit_printk_skb(skb); | |
b7d11258 DW |
453 | } else { |
454 | DECLARE_WAITQUEUE(wait, current); | |
455 | set_current_state(TASK_INTERRUPTIBLE); | |
456 | add_wait_queue(&kauditd_wait, &wait); | |
457 | ||
7a4ae749 PO |
458 | if (!skb_queue_len(&audit_skb_queue)) { |
459 | try_to_freeze(); | |
b7d11258 | 460 | schedule(); |
7a4ae749 | 461 | } |
b7d11258 DW |
462 | |
463 | __set_current_state(TASK_RUNNING); | |
464 | remove_wait_queue(&kauditd_wait, &wait); | |
465 | } | |
466 | } | |
4899b8b1 | 467 | return 0; |
b7d11258 DW |
468 | } |
469 | ||
2532386f | 470 | static int audit_prepare_user_tty(pid_t pid, uid_t loginuid, u32 sessionid) |
522ed776 MT |
471 | { |
472 | struct task_struct *tsk; | |
473 | int err; | |
474 | ||
3c80fe4a | 475 | rcu_read_lock(); |
4a761b8c | 476 | tsk = find_task_by_vpid(pid); |
3c80fe4a TG |
477 | if (!tsk) { |
478 | rcu_read_unlock(); | |
479 | return -ESRCH; | |
480 | } | |
481 | get_task_struct(tsk); | |
482 | rcu_read_unlock(); | |
483 | err = tty_audit_push_task(tsk, loginuid, sessionid); | |
484 | put_task_struct(tsk); | |
522ed776 MT |
485 | return err; |
486 | } | |
487 | ||
9044e6bc AV |
488 | int audit_send_list(void *_dest) |
489 | { | |
490 | struct audit_netlink_list *dest = _dest; | |
491 | int pid = dest->pid; | |
492 | struct sk_buff *skb; | |
493 | ||
494 | /* wait for parent to finish and send an ACK */ | |
f368c07d AG |
495 | mutex_lock(&audit_cmd_mutex); |
496 | mutex_unlock(&audit_cmd_mutex); | |
9044e6bc AV |
497 | |
498 | while ((skb = __skb_dequeue(&dest->q)) != NULL) | |
499 | netlink_unicast(audit_sock, skb, pid, 0); | |
500 | ||
501 | kfree(dest); | |
502 | ||
503 | return 0; | |
504 | } | |
505 | ||
506 | struct sk_buff *audit_make_reply(int pid, int seq, int type, int done, | |
b8800aa5 | 507 | int multi, const void *payload, int size) |
9044e6bc AV |
508 | { |
509 | struct sk_buff *skb; | |
510 | struct nlmsghdr *nlh; | |
9044e6bc AV |
511 | void *data; |
512 | int flags = multi ? NLM_F_MULTI : 0; | |
513 | int t = done ? NLMSG_DONE : type; | |
514 | ||
ee080e6c | 515 | skb = nlmsg_new(size, GFP_KERNEL); |
9044e6bc AV |
516 | if (!skb) |
517 | return NULL; | |
518 | ||
c64e66c6 DM |
519 | nlh = nlmsg_put(skb, pid, seq, t, size, flags); |
520 | if (!nlh) | |
521 | goto out_kfree_skb; | |
522 | data = nlmsg_data(nlh); | |
9044e6bc AV |
523 | memcpy(data, payload, size); |
524 | return skb; | |
525 | ||
c64e66c6 DM |
526 | out_kfree_skb: |
527 | kfree_skb(skb); | |
9044e6bc AV |
528 | return NULL; |
529 | } | |
530 | ||
f09ac9db EP |
531 | static int audit_send_reply_thread(void *arg) |
532 | { | |
533 | struct audit_reply *reply = (struct audit_reply *)arg; | |
534 | ||
535 | mutex_lock(&audit_cmd_mutex); | |
536 | mutex_unlock(&audit_cmd_mutex); | |
537 | ||
538 | /* Ignore failure. It'll only happen if the sender goes away, | |
539 | because our timeout is set to infinite. */ | |
540 | netlink_unicast(audit_sock, reply->skb, reply->pid, 0); | |
541 | kfree(reply); | |
542 | return 0; | |
543 | } | |
b0dd25a8 RD |
544 | /** |
545 | * audit_send_reply - send an audit reply message via netlink | |
546 | * @pid: process id to send reply to | |
547 | * @seq: sequence number | |
548 | * @type: audit message type | |
549 | * @done: done (last) flag | |
550 | * @multi: multi-part message flag | |
551 | * @payload: payload data | |
552 | * @size: payload size | |
553 | * | |
554 | * Allocates an skb, builds the netlink message, and sends it to the pid. | |
555 | * No failure notifications. | |
556 | */ | |
b8800aa5 SH |
557 | static void audit_send_reply(int pid, int seq, int type, int done, int multi, |
558 | const void *payload, int size) | |
1da177e4 | 559 | { |
f09ac9db EP |
560 | struct sk_buff *skb; |
561 | struct task_struct *tsk; | |
562 | struct audit_reply *reply = kmalloc(sizeof(struct audit_reply), | |
563 | GFP_KERNEL); | |
564 | ||
565 | if (!reply) | |
566 | return; | |
567 | ||
9044e6bc | 568 | skb = audit_make_reply(pid, seq, type, done, multi, payload, size); |
1da177e4 | 569 | if (!skb) |
fcaf1eb8 | 570 | goto out; |
f09ac9db EP |
571 | |
572 | reply->pid = pid; | |
573 | reply->skb = skb; | |
574 | ||
575 | tsk = kthread_run(audit_send_reply_thread, reply, "audit_send_reply"); | |
fcaf1eb8 AM |
576 | if (!IS_ERR(tsk)) |
577 | return; | |
578 | kfree_skb(skb); | |
579 | out: | |
580 | kfree(reply); | |
1da177e4 LT |
581 | } |
582 | ||
583 | /* | |
584 | * Check for appropriate CAP_AUDIT_ capabilities on incoming audit | |
585 | * control messages. | |
586 | */ | |
c7bdb545 | 587 | static int audit_netlink_ok(struct sk_buff *skb, u16 msg_type) |
1da177e4 LT |
588 | { |
589 | int err = 0; | |
590 | ||
591 | switch (msg_type) { | |
592 | case AUDIT_GET: | |
593 | case AUDIT_LIST: | |
93315ed6 | 594 | case AUDIT_LIST_RULES: |
1da177e4 LT |
595 | case AUDIT_SET: |
596 | case AUDIT_ADD: | |
93315ed6 | 597 | case AUDIT_ADD_RULE: |
1da177e4 | 598 | case AUDIT_DEL: |
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 | ||
50397bd1 | 621 | static int audit_log_common_recv_msg(struct audit_buffer **ab, u16 msg_type, |
2532386f EP |
622 | u32 pid, u32 uid, uid_t auid, u32 ses, |
623 | u32 sid) | |
50397bd1 EP |
624 | { |
625 | int rc = 0; | |
626 | char *ctx = NULL; | |
627 | u32 len; | |
628 | ||
629 | if (!audit_enabled) { | |
630 | *ab = NULL; | |
631 | return rc; | |
632 | } | |
633 | ||
634 | *ab = audit_log_start(NULL, GFP_KERNEL, msg_type); | |
3035c51e | 635 | audit_log_format(*ab, "pid=%d uid=%u auid=%u ses=%u", |
2532386f | 636 | pid, uid, auid, ses); |
50397bd1 | 637 | if (sid) { |
2a862b32 | 638 | rc = security_secid_to_secctx(sid, &ctx, &len); |
50397bd1 EP |
639 | if (rc) |
640 | audit_log_format(*ab, " ssid=%u", sid); | |
2a862b32 | 641 | else { |
50397bd1 | 642 | audit_log_format(*ab, " subj=%s", ctx); |
2a862b32 AD |
643 | security_release_secctx(ctx, len); |
644 | } | |
50397bd1 EP |
645 | } |
646 | ||
647 | return rc; | |
648 | } | |
649 | ||
1da177e4 LT |
650 | static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) |
651 | { | |
e7c34970 | 652 | u32 uid, pid, seq, sid; |
1da177e4 LT |
653 | void *data; |
654 | struct audit_status *status_get, status_set; | |
655 | int err; | |
c0404993 | 656 | struct audit_buffer *ab; |
1da177e4 | 657 | u16 msg_type = nlh->nlmsg_type; |
c94c257c | 658 | uid_t loginuid; /* loginuid of sender */ |
2532386f | 659 | u32 sessionid; |
e1396065 | 660 | struct audit_sig_info *sig_data; |
50397bd1 | 661 | char *ctx = NULL; |
e1396065 | 662 | u32 len; |
1da177e4 | 663 | |
c7bdb545 | 664 | err = audit_netlink_ok(skb, msg_type); |
1da177e4 LT |
665 | if (err) |
666 | return err; | |
667 | ||
b0dd25a8 RD |
668 | /* As soon as there's any sign of userspace auditd, |
669 | * start kauditd to talk to it */ | |
b7d11258 DW |
670 | if (!kauditd_task) |
671 | kauditd_task = kthread_run(kauditd_thread, NULL, "kauditd"); | |
672 | if (IS_ERR(kauditd_task)) { | |
673 | err = PTR_ERR(kauditd_task); | |
674 | kauditd_task = NULL; | |
675 | return err; | |
676 | } | |
677 | ||
1da177e4 LT |
678 | pid = NETLINK_CREDS(skb)->pid; |
679 | uid = NETLINK_CREDS(skb)->uid; | |
c53fa1ed PM |
680 | loginuid = audit_get_loginuid(current); |
681 | sessionid = audit_get_sessionid(current); | |
682 | security_task_getsecid(current, &sid); | |
1da177e4 | 683 | seq = nlh->nlmsg_seq; |
c64e66c6 | 684 | data = nlmsg_data(nlh); |
1da177e4 LT |
685 | |
686 | switch (msg_type) { | |
687 | case AUDIT_GET: | |
688 | status_set.enabled = audit_enabled; | |
689 | status_set.failure = audit_failure; | |
690 | status_set.pid = audit_pid; | |
691 | status_set.rate_limit = audit_rate_limit; | |
692 | status_set.backlog_limit = audit_backlog_limit; | |
693 | status_set.lost = atomic_read(&audit_lost); | |
b7d11258 | 694 | status_set.backlog = skb_queue_len(&audit_skb_queue); |
1da177e4 LT |
695 | audit_send_reply(NETLINK_CB(skb).pid, seq, AUDIT_GET, 0, 0, |
696 | &status_set, sizeof(status_set)); | |
697 | break; | |
698 | case AUDIT_SET: | |
699 | if (nlh->nlmsg_len < sizeof(struct audit_status)) | |
700 | return -EINVAL; | |
701 | status_get = (struct audit_status *)data; | |
702 | if (status_get->mask & AUDIT_STATUS_ENABLED) { | |
ce29b682 | 703 | err = audit_set_enabled(status_get->enabled, |
2532386f | 704 | loginuid, sessionid, sid); |
20c6aaa3 | 705 | if (err < 0) |
706 | return err; | |
1da177e4 LT |
707 | } |
708 | if (status_get->mask & AUDIT_STATUS_FAILURE) { | |
ce29b682 | 709 | err = audit_set_failure(status_get->failure, |
2532386f | 710 | loginuid, sessionid, sid); |
20c6aaa3 | 711 | if (err < 0) |
712 | return err; | |
1da177e4 LT |
713 | } |
714 | if (status_get->mask & AUDIT_STATUS_PID) { | |
1a6b9f23 EP |
715 | int new_pid = status_get->pid; |
716 | ||
717 | if (audit_enabled != AUDIT_OFF) | |
718 | audit_log_config_change("audit_pid", new_pid, | |
719 | audit_pid, loginuid, | |
2532386f | 720 | sessionid, sid, 1); |
1a6b9f23 EP |
721 | |
722 | audit_pid = new_pid; | |
75c0371a | 723 | audit_nlk_pid = NETLINK_CB(skb).pid; |
1da177e4 | 724 | } |
20c6aaa3 | 725 | if (status_get->mask & AUDIT_STATUS_RATE_LIMIT) { |
5d136a01 | 726 | err = audit_set_rate_limit(status_get->rate_limit, |
2532386f | 727 | loginuid, sessionid, sid); |
20c6aaa3 | 728 | if (err < 0) |
729 | return err; | |
730 | } | |
1da177e4 | 731 | if (status_get->mask & AUDIT_STATUS_BACKLOG_LIMIT) |
5d136a01 | 732 | err = audit_set_backlog_limit(status_get->backlog_limit, |
2532386f | 733 | loginuid, sessionid, sid); |
1da177e4 | 734 | break; |
05474106 | 735 | case AUDIT_USER: |
039b6b3e RD |
736 | case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG: |
737 | case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2: | |
4a4cd633 DW |
738 | if (!audit_enabled && msg_type != AUDIT_USER_AVC) |
739 | return 0; | |
740 | ||
d8de7247 | 741 | err = audit_filter_user(&NETLINK_CB(skb)); |
4a4cd633 DW |
742 | if (err == 1) { |
743 | err = 0; | |
522ed776 | 744 | if (msg_type == AUDIT_USER_TTY) { |
2532386f EP |
745 | err = audit_prepare_user_tty(pid, loginuid, |
746 | sessionid); | |
522ed776 MT |
747 | if (err) |
748 | break; | |
749 | } | |
50397bd1 | 750 | audit_log_common_recv_msg(&ab, msg_type, pid, uid, |
2532386f | 751 | loginuid, sessionid, sid); |
50397bd1 EP |
752 | |
753 | if (msg_type != AUDIT_USER_TTY) | |
754 | audit_log_format(ab, " msg='%.1024s'", | |
755 | (char *)data); | |
756 | else { | |
757 | int size; | |
758 | ||
759 | audit_log_format(ab, " msg="); | |
760 | size = nlmsg_len(nlh); | |
55ad2f8d MT |
761 | if (size > 0 && |
762 | ((unsigned char *)data)[size - 1] == '\0') | |
763 | size--; | |
b556f8ad | 764 | audit_log_n_untrustedstring(ab, data, size); |
4a4cd633 | 765 | } |
50397bd1 EP |
766 | audit_set_pid(ab, pid); |
767 | audit_log_end(ab); | |
0f45aa18 | 768 | } |
1da177e4 LT |
769 | break; |
770 | case AUDIT_ADD: | |
771 | case AUDIT_DEL: | |
93315ed6 | 772 | if (nlmsg_len(nlh) < sizeof(struct audit_rule)) |
1da177e4 | 773 | return -EINVAL; |
1a6b9f23 | 774 | if (audit_enabled == AUDIT_LOCKED) { |
50397bd1 | 775 | audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid, |
2532386f | 776 | uid, loginuid, sessionid, sid); |
50397bd1 EP |
777 | |
778 | audit_log_format(ab, " audit_enabled=%d res=0", | |
779 | audit_enabled); | |
780 | audit_log_end(ab); | |
6a01b07f SG |
781 | return -EPERM; |
782 | } | |
1da177e4 LT |
783 | /* fallthrough */ |
784 | case AUDIT_LIST: | |
13d5ef97 | 785 | err = audit_receive_filter(msg_type, NETLINK_CB(skb).pid, |
93315ed6 | 786 | uid, seq, data, nlmsg_len(nlh), |
2532386f | 787 | loginuid, sessionid, sid); |
93315ed6 AG |
788 | break; |
789 | case AUDIT_ADD_RULE: | |
790 | case AUDIT_DEL_RULE: | |
791 | if (nlmsg_len(nlh) < sizeof(struct audit_rule_data)) | |
792 | return -EINVAL; | |
1a6b9f23 | 793 | if (audit_enabled == AUDIT_LOCKED) { |
50397bd1 | 794 | audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid, |
2532386f | 795 | uid, loginuid, sessionid, sid); |
50397bd1 EP |
796 | |
797 | audit_log_format(ab, " audit_enabled=%d res=0", | |
798 | audit_enabled); | |
799 | audit_log_end(ab); | |
6a01b07f SG |
800 | return -EPERM; |
801 | } | |
93315ed6 AG |
802 | /* fallthrough */ |
803 | case AUDIT_LIST_RULES: | |
13d5ef97 | 804 | err = audit_receive_filter(msg_type, NETLINK_CB(skb).pid, |
93315ed6 | 805 | uid, seq, data, nlmsg_len(nlh), |
2532386f | 806 | loginuid, sessionid, sid); |
1da177e4 | 807 | break; |
74c3cbe3 AV |
808 | case AUDIT_TRIM: |
809 | audit_trim_trees(); | |
50397bd1 EP |
810 | |
811 | audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid, | |
2532386f | 812 | uid, loginuid, sessionid, sid); |
50397bd1 | 813 | |
74c3cbe3 AV |
814 | audit_log_format(ab, " op=trim res=1"); |
815 | audit_log_end(ab); | |
816 | break; | |
817 | case AUDIT_MAKE_EQUIV: { | |
818 | void *bufp = data; | |
819 | u32 sizes[2]; | |
7719e437 | 820 | size_t msglen = nlmsg_len(nlh); |
74c3cbe3 AV |
821 | char *old, *new; |
822 | ||
823 | err = -EINVAL; | |
7719e437 | 824 | if (msglen < 2 * sizeof(u32)) |
74c3cbe3 AV |
825 | break; |
826 | memcpy(sizes, bufp, 2 * sizeof(u32)); | |
827 | bufp += 2 * sizeof(u32); | |
7719e437 HH |
828 | msglen -= 2 * sizeof(u32); |
829 | old = audit_unpack_string(&bufp, &msglen, sizes[0]); | |
74c3cbe3 AV |
830 | if (IS_ERR(old)) { |
831 | err = PTR_ERR(old); | |
832 | break; | |
833 | } | |
7719e437 | 834 | new = audit_unpack_string(&bufp, &msglen, sizes[1]); |
74c3cbe3 AV |
835 | if (IS_ERR(new)) { |
836 | err = PTR_ERR(new); | |
837 | kfree(old); | |
838 | break; | |
839 | } | |
840 | /* OK, here comes... */ | |
841 | err = audit_tag_tree(old, new); | |
842 | ||
50397bd1 | 843 | audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid, |
2532386f | 844 | uid, loginuid, sessionid, sid); |
50397bd1 | 845 | |
74c3cbe3 AV |
846 | audit_log_format(ab, " op=make_equiv old="); |
847 | audit_log_untrustedstring(ab, old); | |
848 | audit_log_format(ab, " new="); | |
849 | audit_log_untrustedstring(ab, new); | |
850 | audit_log_format(ab, " res=%d", !err); | |
851 | audit_log_end(ab); | |
852 | kfree(old); | |
853 | kfree(new); | |
854 | break; | |
855 | } | |
c2f0c7c3 | 856 | case AUDIT_SIGNAL_INFO: |
939cbf26 EP |
857 | len = 0; |
858 | if (audit_sig_sid) { | |
859 | err = security_secid_to_secctx(audit_sig_sid, &ctx, &len); | |
860 | if (err) | |
861 | return err; | |
862 | } | |
e1396065 AV |
863 | sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL); |
864 | if (!sig_data) { | |
939cbf26 EP |
865 | if (audit_sig_sid) |
866 | security_release_secctx(ctx, len); | |
e1396065 AV |
867 | return -ENOMEM; |
868 | } | |
869 | sig_data->uid = audit_sig_uid; | |
870 | sig_data->pid = audit_sig_pid; | |
939cbf26 EP |
871 | if (audit_sig_sid) { |
872 | memcpy(sig_data->ctx, ctx, len); | |
873 | security_release_secctx(ctx, len); | |
874 | } | |
5600b892 | 875 | audit_send_reply(NETLINK_CB(skb).pid, seq, AUDIT_SIGNAL_INFO, |
e1396065 AV |
876 | 0, 0, sig_data, sizeof(*sig_data) + len); |
877 | kfree(sig_data); | |
c2f0c7c3 | 878 | break; |
522ed776 MT |
879 | case AUDIT_TTY_GET: { |
880 | struct audit_tty_status s; | |
881 | struct task_struct *tsk; | |
ab263f47 | 882 | unsigned long flags; |
522ed776 | 883 | |
ab263f47 | 884 | rcu_read_lock(); |
4a761b8c | 885 | tsk = find_task_by_vpid(pid); |
ab263f47 | 886 | if (tsk && lock_task_sighand(tsk, &flags)) { |
522ed776 | 887 | s.enabled = tsk->signal->audit_tty != 0; |
ab263f47 TG |
888 | unlock_task_sighand(tsk, &flags); |
889 | } else | |
890 | err = -ESRCH; | |
891 | rcu_read_unlock(); | |
20703205 TG |
892 | |
893 | if (!err) | |
894 | audit_send_reply(NETLINK_CB(skb).pid, seq, | |
895 | AUDIT_TTY_GET, 0, 0, &s, sizeof(s)); | |
522ed776 MT |
896 | break; |
897 | } | |
898 | case AUDIT_TTY_SET: { | |
899 | struct audit_tty_status *s; | |
900 | struct task_struct *tsk; | |
ab263f47 | 901 | unsigned long flags; |
522ed776 MT |
902 | |
903 | if (nlh->nlmsg_len < sizeof(struct audit_tty_status)) | |
904 | return -EINVAL; | |
905 | s = data; | |
906 | if (s->enabled != 0 && s->enabled != 1) | |
907 | return -EINVAL; | |
ab263f47 | 908 | rcu_read_lock(); |
4a761b8c | 909 | tsk = find_task_by_vpid(pid); |
ab263f47 | 910 | if (tsk && lock_task_sighand(tsk, &flags)) { |
522ed776 | 911 | tsk->signal->audit_tty = s->enabled != 0; |
ab263f47 TG |
912 | unlock_task_sighand(tsk, &flags); |
913 | } else | |
914 | err = -ESRCH; | |
915 | rcu_read_unlock(); | |
522ed776 MT |
916 | break; |
917 | } | |
1da177e4 LT |
918 | default: |
919 | err = -EINVAL; | |
920 | break; | |
921 | } | |
922 | ||
923 | return err < 0 ? err : 0; | |
924 | } | |
925 | ||
b0dd25a8 | 926 | /* |
ea7ae60b EP |
927 | * Get message from skb. Each message is processed by audit_receive_msg. |
928 | * Malformed skbs with wrong length are discarded silently. | |
b0dd25a8 | 929 | */ |
2a0a6ebe | 930 | static void audit_receive_skb(struct sk_buff *skb) |
1da177e4 | 931 | { |
ea7ae60b EP |
932 | struct nlmsghdr *nlh; |
933 | /* | |
934 | * len MUST be signed for NLMSG_NEXT to be able to dec it below 0 | |
935 | * if the nlmsg_len was not aligned | |
936 | */ | |
937 | int len; | |
938 | int err; | |
939 | ||
940 | nlh = nlmsg_hdr(skb); | |
941 | len = skb->len; | |
942 | ||
943 | while (NLMSG_OK(nlh, len)) { | |
944 | err = audit_receive_msg(skb, nlh); | |
945 | /* if err or if this message says it wants a response */ | |
946 | if (err || (nlh->nlmsg_flags & NLM_F_ACK)) | |
1da177e4 | 947 | netlink_ack(skb, nlh, err); |
ea7ae60b EP |
948 | |
949 | nlh = NLMSG_NEXT(nlh, len); | |
1da177e4 | 950 | } |
1da177e4 LT |
951 | } |
952 | ||
953 | /* Receive messages from netlink socket. */ | |
cd40b7d3 | 954 | static void audit_receive(struct sk_buff *skb) |
1da177e4 | 955 | { |
f368c07d | 956 | mutex_lock(&audit_cmd_mutex); |
cd40b7d3 | 957 | audit_receive_skb(skb); |
f368c07d | 958 | mutex_unlock(&audit_cmd_mutex); |
1da177e4 LT |
959 | } |
960 | ||
1da177e4 LT |
961 | /* Initialize audit support at boot time. */ |
962 | static int __init audit_init(void) | |
963 | { | |
f368c07d | 964 | int i; |
a31f2d17 PNA |
965 | struct netlink_kernel_cfg cfg = { |
966 | .input = audit_receive, | |
967 | }; | |
f368c07d | 968 | |
a3f07114 EP |
969 | if (audit_initialized == AUDIT_DISABLED) |
970 | return 0; | |
971 | ||
1da177e4 LT |
972 | printk(KERN_INFO "audit: initializing netlink socket (%s)\n", |
973 | audit_default ? "enabled" : "disabled"); | |
a31f2d17 PNA |
974 | audit_sock = netlink_kernel_create(&init_net, NETLINK_AUDIT, |
975 | THIS_MODULE, &cfg); | |
1da177e4 LT |
976 | if (!audit_sock) |
977 | audit_panic("cannot initialize netlink socket"); | |
71e1c784 AG |
978 | else |
979 | audit_sock->sk_sndtimeo = MAX_SCHEDULE_TIMEOUT; | |
1da177e4 | 980 | |
b7d11258 | 981 | skb_queue_head_init(&audit_skb_queue); |
f3d357b0 | 982 | skb_queue_head_init(&audit_skb_hold_queue); |
a3f07114 | 983 | audit_initialized = AUDIT_INITIALIZED; |
1da177e4 | 984 | audit_enabled = audit_default; |
b593d384 | 985 | audit_ever_enabled |= !!audit_default; |
3dc7e315 | 986 | |
9ad9ad38 | 987 | audit_log(NULL, GFP_KERNEL, AUDIT_KERNEL, "initialized"); |
f368c07d | 988 | |
f368c07d AG |
989 | for (i = 0; i < AUDIT_INODE_BUCKETS; i++) |
990 | INIT_LIST_HEAD(&audit_inode_hash[i]); | |
f368c07d | 991 | |
1da177e4 LT |
992 | return 0; |
993 | } | |
1da177e4 LT |
994 | __initcall(audit_init); |
995 | ||
996 | /* Process kernel command-line parameter at boot time. audit=0 or audit=1. */ | |
997 | static int __init audit_enable(char *str) | |
998 | { | |
999 | audit_default = !!simple_strtol(str, NULL, 0); | |
a3f07114 EP |
1000 | if (!audit_default) |
1001 | audit_initialized = AUDIT_DISABLED; | |
1002 | ||
1003 | printk(KERN_INFO "audit: %s", audit_default ? "enabled" : "disabled"); | |
1004 | ||
1005 | if (audit_initialized == AUDIT_INITIALIZED) { | |
1da177e4 | 1006 | audit_enabled = audit_default; |
b593d384 | 1007 | audit_ever_enabled |= !!audit_default; |
a3f07114 EP |
1008 | } else if (audit_initialized == AUDIT_UNINITIALIZED) { |
1009 | printk(" (after initialization)"); | |
1010 | } else { | |
1011 | printk(" (until reboot)"); | |
b593d384 | 1012 | } |
a3f07114 EP |
1013 | printk("\n"); |
1014 | ||
9b41046c | 1015 | return 1; |
1da177e4 LT |
1016 | } |
1017 | ||
1018 | __setup("audit=", audit_enable); | |
1019 | ||
16e1904e CW |
1020 | static void audit_buffer_free(struct audit_buffer *ab) |
1021 | { | |
1022 | unsigned long flags; | |
1023 | ||
8fc6115c CW |
1024 | if (!ab) |
1025 | return; | |
1026 | ||
5ac52f33 CW |
1027 | if (ab->skb) |
1028 | kfree_skb(ab->skb); | |
b7d11258 | 1029 | |
16e1904e | 1030 | spin_lock_irqsave(&audit_freelist_lock, flags); |
5d136a01 | 1031 | if (audit_freelist_count > AUDIT_MAXFREE) |
16e1904e | 1032 | kfree(ab); |
5d136a01 SH |
1033 | else { |
1034 | audit_freelist_count++; | |
16e1904e | 1035 | list_add(&ab->list, &audit_freelist); |
5d136a01 | 1036 | } |
16e1904e CW |
1037 | spin_unlock_irqrestore(&audit_freelist_lock, flags); |
1038 | } | |
1039 | ||
c0404993 | 1040 | static struct audit_buffer * audit_buffer_alloc(struct audit_context *ctx, |
dd0fc66f | 1041 | gfp_t gfp_mask, int type) |
16e1904e CW |
1042 | { |
1043 | unsigned long flags; | |
1044 | struct audit_buffer *ab = NULL; | |
c0404993 | 1045 | struct nlmsghdr *nlh; |
16e1904e CW |
1046 | |
1047 | spin_lock_irqsave(&audit_freelist_lock, flags); | |
1048 | if (!list_empty(&audit_freelist)) { | |
1049 | ab = list_entry(audit_freelist.next, | |
1050 | struct audit_buffer, list); | |
1051 | list_del(&ab->list); | |
1052 | --audit_freelist_count; | |
1053 | } | |
1054 | spin_unlock_irqrestore(&audit_freelist_lock, flags); | |
1055 | ||
1056 | if (!ab) { | |
4332bdd3 | 1057 | ab = kmalloc(sizeof(*ab), gfp_mask); |
16e1904e | 1058 | if (!ab) |
8fc6115c | 1059 | goto err; |
16e1904e | 1060 | } |
8fc6115c | 1061 | |
b7d11258 | 1062 | ab->ctx = ctx; |
9ad9ad38 | 1063 | ab->gfp_mask = gfp_mask; |
ee080e6c EP |
1064 | |
1065 | ab->skb = nlmsg_new(AUDIT_BUFSIZ, gfp_mask); | |
1066 | if (!ab->skb) | |
c64e66c6 | 1067 | goto err; |
ee080e6c | 1068 | |
c64e66c6 DM |
1069 | nlh = nlmsg_put(ab->skb, 0, 0, type, 0, 0); |
1070 | if (!nlh) | |
1071 | goto out_kfree_skb; | |
ee080e6c | 1072 | |
16e1904e | 1073 | return ab; |
ee080e6c | 1074 | |
c64e66c6 | 1075 | out_kfree_skb: |
ee080e6c EP |
1076 | kfree_skb(ab->skb); |
1077 | ab->skb = NULL; | |
8fc6115c CW |
1078 | err: |
1079 | audit_buffer_free(ab); | |
1080 | return NULL; | |
16e1904e | 1081 | } |
1da177e4 | 1082 | |
b0dd25a8 RD |
1083 | /** |
1084 | * audit_serial - compute a serial number for the audit record | |
1085 | * | |
1086 | * Compute a serial number for the audit record. Audit records are | |
bfb4496e DW |
1087 | * written to user-space as soon as they are generated, so a complete |
1088 | * audit record may be written in several pieces. The timestamp of the | |
1089 | * record and this serial number are used by the user-space tools to | |
1090 | * determine which pieces belong to the same audit record. The | |
1091 | * (timestamp,serial) tuple is unique for each syscall and is live from | |
1092 | * syscall entry to syscall exit. | |
1093 | * | |
bfb4496e DW |
1094 | * NOTE: Another possibility is to store the formatted records off the |
1095 | * audit context (for those records that have a context), and emit them | |
1096 | * all at syscall exit. However, this could delay the reporting of | |
1097 | * significant errors until syscall exit (or never, if the system | |
b0dd25a8 RD |
1098 | * halts). |
1099 | */ | |
bfb4496e DW |
1100 | unsigned int audit_serial(void) |
1101 | { | |
34af946a | 1102 | static DEFINE_SPINLOCK(serial_lock); |
d5b454f2 DW |
1103 | static unsigned int serial = 0; |
1104 | ||
1105 | unsigned long flags; | |
1106 | unsigned int ret; | |
bfb4496e | 1107 | |
d5b454f2 | 1108 | spin_lock_irqsave(&serial_lock, flags); |
bfb4496e | 1109 | do { |
ce625a80 DW |
1110 | ret = ++serial; |
1111 | } while (unlikely(!ret)); | |
d5b454f2 | 1112 | spin_unlock_irqrestore(&serial_lock, flags); |
bfb4496e | 1113 | |
d5b454f2 | 1114 | return ret; |
bfb4496e DW |
1115 | } |
1116 | ||
5600b892 | 1117 | static inline void audit_get_stamp(struct audit_context *ctx, |
bfb4496e DW |
1118 | struct timespec *t, unsigned int *serial) |
1119 | { | |
48887e63 | 1120 | if (!ctx || !auditsc_get_stamp(ctx, t, serial)) { |
bfb4496e DW |
1121 | *t = CURRENT_TIME; |
1122 | *serial = audit_serial(); | |
1123 | } | |
1124 | } | |
1125 | ||
1da177e4 LT |
1126 | /* Obtain an audit buffer. This routine does locking to obtain the |
1127 | * audit buffer, but then no locking is required for calls to | |
1128 | * audit_log_*format. If the tsk is a task that is currently in a | |
1129 | * syscall, then the syscall is marked as auditable and an audit record | |
1130 | * will be written at syscall exit. If there is no associated task, tsk | |
1131 | * should be NULL. */ | |
9ad9ad38 | 1132 | |
b0dd25a8 RD |
1133 | /** |
1134 | * audit_log_start - obtain an audit buffer | |
1135 | * @ctx: audit_context (may be NULL) | |
1136 | * @gfp_mask: type of allocation | |
1137 | * @type: audit message type | |
1138 | * | |
1139 | * Returns audit_buffer pointer on success or NULL on error. | |
1140 | * | |
1141 | * Obtain an audit buffer. This routine does locking to obtain the | |
1142 | * audit buffer, but then no locking is required for calls to | |
1143 | * audit_log_*format. If the task (ctx) is a task that is currently in a | |
1144 | * syscall, then the syscall is marked as auditable and an audit record | |
1145 | * will be written at syscall exit. If there is no associated task, then | |
1146 | * task context (ctx) should be NULL. | |
1147 | */ | |
9796fdd8 | 1148 | struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask, |
9ad9ad38 | 1149 | int type) |
1da177e4 LT |
1150 | { |
1151 | struct audit_buffer *ab = NULL; | |
1da177e4 | 1152 | struct timespec t; |
ef00be05 | 1153 | unsigned int uninitialized_var(serial); |
9ad9ad38 | 1154 | int reserve; |
ac4cec44 | 1155 | unsigned long timeout_start = jiffies; |
1da177e4 | 1156 | |
a3f07114 | 1157 | if (audit_initialized != AUDIT_INITIALIZED) |
1da177e4 LT |
1158 | return NULL; |
1159 | ||
c8edc80c DK |
1160 | if (unlikely(audit_filter_type(type))) |
1161 | return NULL; | |
1162 | ||
9ad9ad38 DW |
1163 | if (gfp_mask & __GFP_WAIT) |
1164 | reserve = 0; | |
1165 | else | |
5600b892 | 1166 | reserve = 5; /* Allow atomic callers to go up to five |
9ad9ad38 DW |
1167 | entries over the normal backlog limit */ |
1168 | ||
1169 | while (audit_backlog_limit | |
1170 | && skb_queue_len(&audit_skb_queue) > audit_backlog_limit + reserve) { | |
ac4cec44 DW |
1171 | if (gfp_mask & __GFP_WAIT && audit_backlog_wait_time |
1172 | && time_before(jiffies, timeout_start + audit_backlog_wait_time)) { | |
1173 | ||
9ad9ad38 DW |
1174 | /* Wait for auditd to drain the queue a little */ |
1175 | DECLARE_WAITQUEUE(wait, current); | |
1176 | set_current_state(TASK_INTERRUPTIBLE); | |
1177 | add_wait_queue(&audit_backlog_wait, &wait); | |
1178 | ||
1179 | if (audit_backlog_limit && | |
1180 | skb_queue_len(&audit_skb_queue) > audit_backlog_limit) | |
ac4cec44 | 1181 | schedule_timeout(timeout_start + audit_backlog_wait_time - jiffies); |
9ad9ad38 DW |
1182 | |
1183 | __set_current_state(TASK_RUNNING); | |
1184 | remove_wait_queue(&audit_backlog_wait, &wait); | |
ac4cec44 | 1185 | continue; |
9ad9ad38 | 1186 | } |
320f1b1e | 1187 | if (audit_rate_check() && printk_ratelimit()) |
fb19b4c6 DW |
1188 | printk(KERN_WARNING |
1189 | "audit: audit_backlog=%d > " | |
1190 | "audit_backlog_limit=%d\n", | |
1191 | skb_queue_len(&audit_skb_queue), | |
1192 | audit_backlog_limit); | |
1193 | audit_log_lost("backlog limit exceeded"); | |
ac4cec44 DW |
1194 | audit_backlog_wait_time = audit_backlog_wait_overflow; |
1195 | wake_up(&audit_backlog_wait); | |
fb19b4c6 DW |
1196 | return NULL; |
1197 | } | |
1198 | ||
9ad9ad38 | 1199 | ab = audit_buffer_alloc(ctx, gfp_mask, type); |
1da177e4 LT |
1200 | if (!ab) { |
1201 | audit_log_lost("out of memory in audit_log_start"); | |
1202 | return NULL; | |
1203 | } | |
1204 | ||
bfb4496e | 1205 | audit_get_stamp(ab->ctx, &t, &serial); |
197c69c6 | 1206 | |
1da177e4 LT |
1207 | audit_log_format(ab, "audit(%lu.%03lu:%u): ", |
1208 | t.tv_sec, t.tv_nsec/1000000, serial); | |
1209 | return ab; | |
1210 | } | |
1211 | ||
8fc6115c | 1212 | /** |
5ac52f33 | 1213 | * audit_expand - expand skb in the audit buffer |
8fc6115c | 1214 | * @ab: audit_buffer |
b0dd25a8 | 1215 | * @extra: space to add at tail of the skb |
8fc6115c CW |
1216 | * |
1217 | * Returns 0 (no space) on failed expansion, or available space if | |
1218 | * successful. | |
1219 | */ | |
e3b926b4 | 1220 | static inline int audit_expand(struct audit_buffer *ab, int extra) |
8fc6115c | 1221 | { |
5ac52f33 | 1222 | struct sk_buff *skb = ab->skb; |
406a1d86 HX |
1223 | int oldtail = skb_tailroom(skb); |
1224 | int ret = pskb_expand_head(skb, 0, extra, ab->gfp_mask); | |
1225 | int newtail = skb_tailroom(skb); | |
1226 | ||
5ac52f33 CW |
1227 | if (ret < 0) { |
1228 | audit_log_lost("out of memory in audit_expand"); | |
8fc6115c | 1229 | return 0; |
5ac52f33 | 1230 | } |
406a1d86 HX |
1231 | |
1232 | skb->truesize += newtail - oldtail; | |
1233 | return newtail; | |
8fc6115c | 1234 | } |
1da177e4 | 1235 | |
b0dd25a8 RD |
1236 | /* |
1237 | * Format an audit message into the audit buffer. If there isn't enough | |
1da177e4 LT |
1238 | * room in the audit buffer, more room will be allocated and vsnprint |
1239 | * will be called a second time. Currently, we assume that a printk | |
b0dd25a8 RD |
1240 | * can't format message larger than 1024 bytes, so we don't either. |
1241 | */ | |
1da177e4 LT |
1242 | static void audit_log_vformat(struct audit_buffer *ab, const char *fmt, |
1243 | va_list args) | |
1244 | { | |
1245 | int len, avail; | |
5ac52f33 | 1246 | struct sk_buff *skb; |
eecb0a73 | 1247 | va_list args2; |
1da177e4 LT |
1248 | |
1249 | if (!ab) | |
1250 | return; | |
1251 | ||
5ac52f33 CW |
1252 | BUG_ON(!ab->skb); |
1253 | skb = ab->skb; | |
1254 | avail = skb_tailroom(skb); | |
1255 | if (avail == 0) { | |
e3b926b4 | 1256 | avail = audit_expand(ab, AUDIT_BUFSIZ); |
8fc6115c CW |
1257 | if (!avail) |
1258 | goto out; | |
1da177e4 | 1259 | } |
eecb0a73 | 1260 | va_copy(args2, args); |
27a884dc | 1261 | len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args); |
1da177e4 LT |
1262 | if (len >= avail) { |
1263 | /* The printk buffer is 1024 bytes long, so if we get | |
1264 | * here and AUDIT_BUFSIZ is at least 1024, then we can | |
1265 | * log everything that printk could have logged. */ | |
b0dd25a8 RD |
1266 | avail = audit_expand(ab, |
1267 | max_t(unsigned, AUDIT_BUFSIZ, 1+len-avail)); | |
8fc6115c | 1268 | if (!avail) |
a0e86bd4 | 1269 | goto out_va_end; |
27a884dc | 1270 | len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args2); |
1da177e4 | 1271 | } |
168b7173 SG |
1272 | if (len > 0) |
1273 | skb_put(skb, len); | |
a0e86bd4 JJ |
1274 | out_va_end: |
1275 | va_end(args2); | |
8fc6115c CW |
1276 | out: |
1277 | return; | |
1da177e4 LT |
1278 | } |
1279 | ||
b0dd25a8 RD |
1280 | /** |
1281 | * audit_log_format - format a message into the audit buffer. | |
1282 | * @ab: audit_buffer | |
1283 | * @fmt: format string | |
1284 | * @...: optional parameters matching @fmt string | |
1285 | * | |
1286 | * All the work is done in audit_log_vformat. | |
1287 | */ | |
1da177e4 LT |
1288 | void audit_log_format(struct audit_buffer *ab, const char *fmt, ...) |
1289 | { | |
1290 | va_list args; | |
1291 | ||
1292 | if (!ab) | |
1293 | return; | |
1294 | va_start(args, fmt); | |
1295 | audit_log_vformat(ab, fmt, args); | |
1296 | va_end(args); | |
1297 | } | |
1298 | ||
b0dd25a8 RD |
1299 | /** |
1300 | * audit_log_hex - convert a buffer to hex and append it to the audit skb | |
1301 | * @ab: the audit_buffer | |
1302 | * @buf: buffer to convert to hex | |
1303 | * @len: length of @buf to be converted | |
1304 | * | |
1305 | * No return value; failure to expand is silently ignored. | |
1306 | * | |
1307 | * This function will take the passed buf and convert it into a string of | |
1308 | * ascii hex digits. The new string is placed onto the skb. | |
1309 | */ | |
b556f8ad | 1310 | void audit_log_n_hex(struct audit_buffer *ab, const unsigned char *buf, |
168b7173 | 1311 | size_t len) |
83c7d091 | 1312 | { |
168b7173 SG |
1313 | int i, avail, new_len; |
1314 | unsigned char *ptr; | |
1315 | struct sk_buff *skb; | |
1316 | static const unsigned char *hex = "0123456789ABCDEF"; | |
1317 | ||
8ef2d304 AG |
1318 | if (!ab) |
1319 | return; | |
1320 | ||
168b7173 SG |
1321 | BUG_ON(!ab->skb); |
1322 | skb = ab->skb; | |
1323 | avail = skb_tailroom(skb); | |
1324 | new_len = len<<1; | |
1325 | if (new_len >= avail) { | |
1326 | /* Round the buffer request up to the next multiple */ | |
1327 | new_len = AUDIT_BUFSIZ*(((new_len-avail)/AUDIT_BUFSIZ) + 1); | |
1328 | avail = audit_expand(ab, new_len); | |
1329 | if (!avail) | |
1330 | return; | |
1331 | } | |
83c7d091 | 1332 | |
27a884dc | 1333 | ptr = skb_tail_pointer(skb); |
168b7173 SG |
1334 | for (i=0; i<len; i++) { |
1335 | *ptr++ = hex[(buf[i] & 0xF0)>>4]; /* Upper nibble */ | |
1336 | *ptr++ = hex[buf[i] & 0x0F]; /* Lower nibble */ | |
1337 | } | |
1338 | *ptr = 0; | |
1339 | skb_put(skb, len << 1); /* new string is twice the old string */ | |
83c7d091 DW |
1340 | } |
1341 | ||
9c937dcc AG |
1342 | /* |
1343 | * Format a string of no more than slen characters into the audit buffer, | |
1344 | * enclosed in quote marks. | |
1345 | */ | |
b556f8ad EP |
1346 | void audit_log_n_string(struct audit_buffer *ab, const char *string, |
1347 | size_t slen) | |
9c937dcc AG |
1348 | { |
1349 | int avail, new_len; | |
1350 | unsigned char *ptr; | |
1351 | struct sk_buff *skb; | |
1352 | ||
8ef2d304 AG |
1353 | if (!ab) |
1354 | return; | |
1355 | ||
9c937dcc AG |
1356 | BUG_ON(!ab->skb); |
1357 | skb = ab->skb; | |
1358 | avail = skb_tailroom(skb); | |
1359 | new_len = slen + 3; /* enclosing quotes + null terminator */ | |
1360 | if (new_len > avail) { | |
1361 | avail = audit_expand(ab, new_len); | |
1362 | if (!avail) | |
1363 | return; | |
1364 | } | |
27a884dc | 1365 | ptr = skb_tail_pointer(skb); |
9c937dcc AG |
1366 | *ptr++ = '"'; |
1367 | memcpy(ptr, string, slen); | |
1368 | ptr += slen; | |
1369 | *ptr++ = '"'; | |
1370 | *ptr = 0; | |
1371 | skb_put(skb, slen + 2); /* don't include null terminator */ | |
1372 | } | |
1373 | ||
de6bbd1d EP |
1374 | /** |
1375 | * audit_string_contains_control - does a string need to be logged in hex | |
f706d5d2 DJ |
1376 | * @string: string to be checked |
1377 | * @len: max length of the string to check | |
de6bbd1d EP |
1378 | */ |
1379 | int audit_string_contains_control(const char *string, size_t len) | |
1380 | { | |
1381 | const unsigned char *p; | |
b3897f56 | 1382 | for (p = string; p < (const unsigned char *)string + len; p++) { |
1d6c9649 | 1383 | if (*p == '"' || *p < 0x21 || *p > 0x7e) |
de6bbd1d EP |
1384 | return 1; |
1385 | } | |
1386 | return 0; | |
1387 | } | |
1388 | ||
b0dd25a8 | 1389 | /** |
522ed776 | 1390 | * audit_log_n_untrustedstring - log a string that may contain random characters |
b0dd25a8 | 1391 | * @ab: audit_buffer |
f706d5d2 | 1392 | * @len: length of string (not including trailing null) |
b0dd25a8 RD |
1393 | * @string: string to be logged |
1394 | * | |
1395 | * This code will escape a string that is passed to it if the string | |
1396 | * contains a control character, unprintable character, double quote mark, | |
168b7173 | 1397 | * or a space. Unescaped strings will start and end with a double quote mark. |
b0dd25a8 | 1398 | * Strings that are escaped are printed in hex (2 digits per char). |
9c937dcc AG |
1399 | * |
1400 | * The caller specifies the number of characters in the string to log, which may | |
1401 | * or may not be the entire string. | |
b0dd25a8 | 1402 | */ |
b556f8ad EP |
1403 | void audit_log_n_untrustedstring(struct audit_buffer *ab, const char *string, |
1404 | size_t len) | |
83c7d091 | 1405 | { |
de6bbd1d | 1406 | if (audit_string_contains_control(string, len)) |
b556f8ad | 1407 | audit_log_n_hex(ab, string, len); |
de6bbd1d | 1408 | else |
b556f8ad | 1409 | audit_log_n_string(ab, string, len); |
83c7d091 DW |
1410 | } |
1411 | ||
9c937dcc | 1412 | /** |
522ed776 | 1413 | * audit_log_untrustedstring - log a string that may contain random characters |
9c937dcc AG |
1414 | * @ab: audit_buffer |
1415 | * @string: string to be logged | |
1416 | * | |
522ed776 | 1417 | * Same as audit_log_n_untrustedstring(), except that strlen is used to |
9c937dcc AG |
1418 | * determine string length. |
1419 | */ | |
de6bbd1d | 1420 | void audit_log_untrustedstring(struct audit_buffer *ab, const char *string) |
9c937dcc | 1421 | { |
b556f8ad | 1422 | audit_log_n_untrustedstring(ab, string, strlen(string)); |
9c937dcc AG |
1423 | } |
1424 | ||
168b7173 | 1425 | /* This is a helper-function to print the escaped d_path */ |
1da177e4 | 1426 | void audit_log_d_path(struct audit_buffer *ab, const char *prefix, |
66b3fad3 | 1427 | const struct path *path) |
1da177e4 | 1428 | { |
44707fdf | 1429 | char *p, *pathname; |
1da177e4 | 1430 | |
8fc6115c | 1431 | if (prefix) |
c158a35c | 1432 | audit_log_format(ab, "%s", prefix); |
1da177e4 | 1433 | |
168b7173 | 1434 | /* We will allow 11 spaces for ' (deleted)' to be appended */ |
44707fdf JB |
1435 | pathname = kmalloc(PATH_MAX+11, ab->gfp_mask); |
1436 | if (!pathname) { | |
def57543 | 1437 | audit_log_string(ab, "<no_memory>"); |
168b7173 | 1438 | return; |
1da177e4 | 1439 | } |
cf28b486 | 1440 | p = d_path(path, pathname, PATH_MAX+11); |
168b7173 SG |
1441 | if (IS_ERR(p)) { /* Should never happen since we send PATH_MAX */ |
1442 | /* FIXME: can we save some information here? */ | |
def57543 | 1443 | audit_log_string(ab, "<too_long>"); |
5600b892 | 1444 | } else |
168b7173 | 1445 | audit_log_untrustedstring(ab, p); |
44707fdf | 1446 | kfree(pathname); |
1da177e4 LT |
1447 | } |
1448 | ||
9d960985 EP |
1449 | void audit_log_key(struct audit_buffer *ab, char *key) |
1450 | { | |
1451 | audit_log_format(ab, " key="); | |
1452 | if (key) | |
1453 | audit_log_untrustedstring(ab, key); | |
1454 | else | |
1455 | audit_log_format(ab, "(null)"); | |
1456 | } | |
1457 | ||
a51d9eaa KC |
1458 | /** |
1459 | * audit_log_link_denied - report a link restriction denial | |
1460 | * @operation: specific link opreation | |
1461 | * @link: the path that triggered the restriction | |
1462 | */ | |
1463 | void audit_log_link_denied(const char *operation, struct path *link) | |
1464 | { | |
1465 | struct audit_buffer *ab; | |
1466 | ||
1467 | ab = audit_log_start(current->audit_context, GFP_KERNEL, | |
1468 | AUDIT_ANOM_LINK); | |
1469 | audit_log_format(ab, "op=%s action=denied", operation); | |
1470 | audit_log_format(ab, " pid=%d comm=", current->pid); | |
1471 | audit_log_untrustedstring(ab, current->comm); | |
1472 | audit_log_d_path(ab, " path=", link); | |
1473 | audit_log_format(ab, " dev="); | |
1474 | audit_log_untrustedstring(ab, link->dentry->d_inode->i_sb->s_id); | |
1475 | audit_log_format(ab, " ino=%lu", link->dentry->d_inode->i_ino); | |
1476 | audit_log_end(ab); | |
1477 | } | |
1478 | ||
b0dd25a8 RD |
1479 | /** |
1480 | * audit_log_end - end one audit record | |
1481 | * @ab: the audit_buffer | |
1482 | * | |
1483 | * The netlink_* functions cannot be called inside an irq context, so | |
1484 | * the audit buffer is placed on a queue and a tasklet is scheduled to | |
1da177e4 | 1485 | * remove them from the queue outside the irq context. May be called in |
b0dd25a8 RD |
1486 | * any context. |
1487 | */ | |
b7d11258 | 1488 | void audit_log_end(struct audit_buffer *ab) |
1da177e4 | 1489 | { |
1da177e4 LT |
1490 | if (!ab) |
1491 | return; | |
1492 | if (!audit_rate_check()) { | |
1493 | audit_log_lost("rate limit exceeded"); | |
1494 | } else { | |
8d07a67c | 1495 | struct nlmsghdr *nlh = nlmsg_hdr(ab->skb); |
f3d357b0 EP |
1496 | nlh->nlmsg_len = ab->skb->len - NLMSG_SPACE(0); |
1497 | ||
b7d11258 | 1498 | if (audit_pid) { |
b7d11258 | 1499 | skb_queue_tail(&audit_skb_queue, ab->skb); |
b7d11258 | 1500 | wake_up_interruptible(&kauditd_wait); |
f3d357b0 | 1501 | } else { |
038cbcf6 | 1502 | audit_printk_skb(ab->skb); |
b7d11258 | 1503 | } |
f3d357b0 | 1504 | ab->skb = NULL; |
1da177e4 | 1505 | } |
16e1904e | 1506 | audit_buffer_free(ab); |
1da177e4 LT |
1507 | } |
1508 | ||
b0dd25a8 RD |
1509 | /** |
1510 | * audit_log - Log an audit record | |
1511 | * @ctx: audit context | |
1512 | * @gfp_mask: type of allocation | |
1513 | * @type: audit message type | |
1514 | * @fmt: format string to use | |
1515 | * @...: variable parameters matching the format string | |
1516 | * | |
1517 | * This is a convenience function that calls audit_log_start, | |
1518 | * audit_log_vformat, and audit_log_end. It may be called | |
1519 | * in any context. | |
1520 | */ | |
5600b892 | 1521 | void audit_log(struct audit_context *ctx, gfp_t gfp_mask, int type, |
9ad9ad38 | 1522 | const char *fmt, ...) |
1da177e4 LT |
1523 | { |
1524 | struct audit_buffer *ab; | |
1525 | va_list args; | |
1526 | ||
9ad9ad38 | 1527 | ab = audit_log_start(ctx, gfp_mask, type); |
1da177e4 LT |
1528 | if (ab) { |
1529 | va_start(args, fmt); | |
1530 | audit_log_vformat(ab, fmt, args); | |
1531 | va_end(args); | |
1532 | audit_log_end(ab); | |
1533 | } | |
1534 | } | |
bf45da97 | 1535 | |
131ad62d MDF |
1536 | #ifdef CONFIG_SECURITY |
1537 | /** | |
1538 | * audit_log_secctx - Converts and logs SELinux context | |
1539 | * @ab: audit_buffer | |
1540 | * @secid: security number | |
1541 | * | |
1542 | * This is a helper function that calls security_secid_to_secctx to convert | |
1543 | * secid to secctx and then adds the (converted) SELinux context to the audit | |
1544 | * log by calling audit_log_format, thus also preventing leak of internal secid | |
1545 | * to userspace. If secid cannot be converted audit_panic is called. | |
1546 | */ | |
1547 | void audit_log_secctx(struct audit_buffer *ab, u32 secid) | |
1548 | { | |
1549 | u32 len; | |
1550 | char *secctx; | |
1551 | ||
1552 | if (security_secid_to_secctx(secid, &secctx, &len)) { | |
1553 | audit_panic("Cannot convert secid to context"); | |
1554 | } else { | |
1555 | audit_log_format(ab, " obj=%s", secctx); | |
1556 | security_release_secctx(secctx, len); | |
1557 | } | |
1558 | } | |
1559 | EXPORT_SYMBOL(audit_log_secctx); | |
1560 | #endif | |
1561 | ||
bf45da97 | 1562 | EXPORT_SYMBOL(audit_log_start); |
1563 | EXPORT_SYMBOL(audit_log_end); | |
1564 | EXPORT_SYMBOL(audit_log_format); | |
1565 | EXPORT_SYMBOL(audit_log); |