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> | |
46e959ea | 52 | #include <linux/kernel.h> |
b24a30a7 | 53 | #include <linux/syscalls.h> |
1da177e4 LT |
54 | |
55 | #include <linux/audit.h> | |
56 | ||
57 | #include <net/sock.h> | |
93315ed6 | 58 | #include <net/netlink.h> |
1da177e4 | 59 | #include <linux/skbuff.h> |
131ad62d MDF |
60 | #ifdef CONFIG_SECURITY |
61 | #include <linux/security.h> | |
62 | #endif | |
7dfb7103 | 63 | #include <linux/freezer.h> |
522ed776 | 64 | #include <linux/tty.h> |
34e36d8e | 65 | #include <linux/pid_namespace.h> |
3dc7e315 DG |
66 | |
67 | #include "audit.h" | |
1da177e4 | 68 | |
a3f07114 | 69 | /* No auditing will take place until audit_initialized == AUDIT_INITIALIZED. |
1da177e4 | 70 | * (Initialization happens after skb_init is called.) */ |
a3f07114 EP |
71 | #define AUDIT_DISABLED -1 |
72 | #define AUDIT_UNINITIALIZED 0 | |
73 | #define AUDIT_INITIALIZED 1 | |
1da177e4 LT |
74 | static int audit_initialized; |
75 | ||
1a6b9f23 EP |
76 | #define AUDIT_OFF 0 |
77 | #define AUDIT_ON 1 | |
78 | #define AUDIT_LOCKED 2 | |
1da177e4 | 79 | int audit_enabled; |
b593d384 | 80 | int audit_ever_enabled; |
1da177e4 | 81 | |
ae9d67af JE |
82 | EXPORT_SYMBOL_GPL(audit_enabled); |
83 | ||
1da177e4 LT |
84 | /* Default state when kernel boots without any parameters. */ |
85 | static int audit_default; | |
86 | ||
87 | /* If auditing cannot proceed, audit_failure selects what happens. */ | |
88 | static int audit_failure = AUDIT_FAIL_PRINTK; | |
89 | ||
75c0371a PE |
90 | /* |
91 | * If audit records are to be written to the netlink socket, audit_pid | |
15e47304 EB |
92 | * contains the pid of the auditd process and audit_nlk_portid contains |
93 | * the portid to use to send netlink messages to that process. | |
75c0371a | 94 | */ |
c2f0c7c3 | 95 | int audit_pid; |
15e47304 | 96 | static int audit_nlk_portid; |
1da177e4 | 97 | |
b0dd25a8 | 98 | /* If audit_rate_limit is non-zero, limit the rate of sending audit records |
1da177e4 LT |
99 | * to that number per second. This prevents DoS attacks, but results in |
100 | * audit records being dropped. */ | |
101 | static int audit_rate_limit; | |
102 | ||
103 | /* Number of outstanding audit_buffers allowed. */ | |
104 | static int audit_backlog_limit = 64; | |
ac4cec44 DW |
105 | static int audit_backlog_wait_time = 60 * HZ; |
106 | static int audit_backlog_wait_overflow = 0; | |
1da177e4 | 107 | |
c2f0c7c3 | 108 | /* The identity of the user shutting down the audit system. */ |
cca080d9 | 109 | kuid_t audit_sig_uid = INVALID_UID; |
c2f0c7c3 | 110 | pid_t audit_sig_pid = -1; |
e1396065 | 111 | u32 audit_sig_sid = 0; |
c2f0c7c3 | 112 | |
1da177e4 LT |
113 | /* Records can be lost in several ways: |
114 | 0) [suppressed in audit_alloc] | |
115 | 1) out of memory in audit_log_start [kmalloc of struct audit_buffer] | |
116 | 2) out of memory in audit_log_move [alloc_skb] | |
117 | 3) suppressed due to audit_rate_limit | |
118 | 4) suppressed due to audit_backlog_limit | |
119 | */ | |
120 | static atomic_t audit_lost = ATOMIC_INIT(0); | |
121 | ||
122 | /* The netlink socket. */ | |
123 | static struct sock *audit_sock; | |
124 | ||
f368c07d AG |
125 | /* Hash for inode-based rules */ |
126 | struct list_head audit_inode_hash[AUDIT_INODE_BUCKETS]; | |
127 | ||
b7d11258 | 128 | /* The audit_freelist is a list of pre-allocated audit buffers (if more |
1da177e4 LT |
129 | * than AUDIT_MAXFREE are in use, the audit buffer is freed instead of |
130 | * being placed on the freelist). */ | |
1da177e4 | 131 | static DEFINE_SPINLOCK(audit_freelist_lock); |
b0dd25a8 | 132 | static int audit_freelist_count; |
1da177e4 LT |
133 | static LIST_HEAD(audit_freelist); |
134 | ||
b7d11258 | 135 | static struct sk_buff_head audit_skb_queue; |
f3d357b0 EP |
136 | /* queue of skbs to send to auditd when/if it comes back */ |
137 | static struct sk_buff_head audit_skb_hold_queue; | |
b7d11258 DW |
138 | static struct task_struct *kauditd_task; |
139 | static DECLARE_WAIT_QUEUE_HEAD(kauditd_wait); | |
9ad9ad38 | 140 | static DECLARE_WAIT_QUEUE_HEAD(audit_backlog_wait); |
1da177e4 | 141 | |
b0fed402 EP |
142 | static struct audit_features af = {.vers = AUDIT_FEATURE_VERSION, |
143 | .mask = -1, | |
144 | .features = 0, | |
145 | .lock = 0,}; | |
146 | ||
21b85c31 | 147 | static char *audit_feature_names[2] = { |
d040e5af | 148 | "only_unset_loginuid", |
21b85c31 | 149 | "loginuid_immutable", |
b0fed402 EP |
150 | }; |
151 | ||
152 | ||
f368c07d | 153 | /* Serialize requests from userspace. */ |
916d7576 | 154 | DEFINE_MUTEX(audit_cmd_mutex); |
1da177e4 LT |
155 | |
156 | /* AUDIT_BUFSIZ is the size of the temporary buffer used for formatting | |
157 | * audit records. Since printk uses a 1024 byte buffer, this buffer | |
158 | * should be at least that large. */ | |
159 | #define AUDIT_BUFSIZ 1024 | |
160 | ||
161 | /* AUDIT_MAXFREE is the number of empty audit_buffers we keep on the | |
162 | * audit_freelist. Doing so eliminates many kmalloc/kfree calls. */ | |
163 | #define AUDIT_MAXFREE (2*NR_CPUS) | |
164 | ||
165 | /* The audit_buffer is used when formatting an audit record. The caller | |
166 | * locks briefly to get the record off the freelist or to allocate the | |
167 | * buffer, and locks briefly to send the buffer to the netlink layer or | |
168 | * to place it on a transmit queue. Multiple audit_buffers can be in | |
169 | * use simultaneously. */ | |
170 | struct audit_buffer { | |
171 | struct list_head list; | |
8fc6115c | 172 | struct sk_buff *skb; /* formatted skb ready to send */ |
1da177e4 | 173 | struct audit_context *ctx; /* NULL or associated context */ |
9796fdd8 | 174 | gfp_t gfp_mask; |
1da177e4 LT |
175 | }; |
176 | ||
f09ac9db EP |
177 | struct audit_reply { |
178 | int pid; | |
179 | struct sk_buff *skb; | |
180 | }; | |
181 | ||
c0404993 SG |
182 | static void audit_set_pid(struct audit_buffer *ab, pid_t pid) |
183 | { | |
50397bd1 EP |
184 | if (ab) { |
185 | struct nlmsghdr *nlh = nlmsg_hdr(ab->skb); | |
186 | nlh->nlmsg_pid = pid; | |
187 | } | |
c0404993 SG |
188 | } |
189 | ||
8c8570fb | 190 | void audit_panic(const char *message) |
1da177e4 LT |
191 | { |
192 | switch (audit_failure) | |
193 | { | |
194 | case AUDIT_FAIL_SILENT: | |
195 | break; | |
196 | case AUDIT_FAIL_PRINTK: | |
320f1b1e EP |
197 | if (printk_ratelimit()) |
198 | printk(KERN_ERR "audit: %s\n", message); | |
1da177e4 LT |
199 | break; |
200 | case AUDIT_FAIL_PANIC: | |
b29ee87e EP |
201 | /* test audit_pid since printk is always losey, why bother? */ |
202 | if (audit_pid) | |
203 | panic("audit: %s\n", message); | |
1da177e4 LT |
204 | break; |
205 | } | |
206 | } | |
207 | ||
208 | static inline int audit_rate_check(void) | |
209 | { | |
210 | static unsigned long last_check = 0; | |
211 | static int messages = 0; | |
212 | static DEFINE_SPINLOCK(lock); | |
213 | unsigned long flags; | |
214 | unsigned long now; | |
215 | unsigned long elapsed; | |
216 | int retval = 0; | |
217 | ||
218 | if (!audit_rate_limit) return 1; | |
219 | ||
220 | spin_lock_irqsave(&lock, flags); | |
221 | if (++messages < audit_rate_limit) { | |
222 | retval = 1; | |
223 | } else { | |
224 | now = jiffies; | |
225 | elapsed = now - last_check; | |
226 | if (elapsed > HZ) { | |
227 | last_check = now; | |
228 | messages = 0; | |
229 | retval = 1; | |
230 | } | |
231 | } | |
232 | spin_unlock_irqrestore(&lock, flags); | |
233 | ||
234 | return retval; | |
235 | } | |
236 | ||
b0dd25a8 RD |
237 | /** |
238 | * audit_log_lost - conditionally log lost audit message event | |
239 | * @message: the message stating reason for lost audit message | |
240 | * | |
241 | * Emit at least 1 message per second, even if audit_rate_check is | |
242 | * throttling. | |
243 | * Always increment the lost messages counter. | |
244 | */ | |
1da177e4 LT |
245 | void audit_log_lost(const char *message) |
246 | { | |
247 | static unsigned long last_msg = 0; | |
248 | static DEFINE_SPINLOCK(lock); | |
249 | unsigned long flags; | |
250 | unsigned long now; | |
251 | int print; | |
252 | ||
253 | atomic_inc(&audit_lost); | |
254 | ||
255 | print = (audit_failure == AUDIT_FAIL_PANIC || !audit_rate_limit); | |
256 | ||
257 | if (!print) { | |
258 | spin_lock_irqsave(&lock, flags); | |
259 | now = jiffies; | |
260 | if (now - last_msg > HZ) { | |
261 | print = 1; | |
262 | last_msg = now; | |
263 | } | |
264 | spin_unlock_irqrestore(&lock, flags); | |
265 | } | |
266 | ||
267 | if (print) { | |
320f1b1e EP |
268 | if (printk_ratelimit()) |
269 | printk(KERN_WARNING | |
270 | "audit: audit_lost=%d audit_rate_limit=%d " | |
271 | "audit_backlog_limit=%d\n", | |
272 | atomic_read(&audit_lost), | |
273 | audit_rate_limit, | |
274 | audit_backlog_limit); | |
1da177e4 LT |
275 | audit_panic(message); |
276 | } | |
1da177e4 LT |
277 | } |
278 | ||
1a6b9f23 | 279 | static int audit_log_config_change(char *function_name, int new, int old, |
2532386f | 280 | int allow_changes) |
1da177e4 | 281 | { |
1a6b9f23 EP |
282 | struct audit_buffer *ab; |
283 | int rc = 0; | |
ce29b682 | 284 | |
1a6b9f23 | 285 | ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE); |
0644ec0c KC |
286 | if (unlikely(!ab)) |
287 | return rc; | |
4d3fb709 EP |
288 | audit_log_format(ab, "%s=%d old=%d", function_name, new, old); |
289 | audit_log_session_info(ab); | |
b122c376 EP |
290 | rc = audit_log_task_context(ab); |
291 | if (rc) | |
292 | allow_changes = 0; /* Something weird, deny request */ | |
1a6b9f23 EP |
293 | audit_log_format(ab, " res=%d", allow_changes); |
294 | audit_log_end(ab); | |
6a01b07f | 295 | return rc; |
1da177e4 LT |
296 | } |
297 | ||
dc9eb698 | 298 | static int audit_do_config_change(char *function_name, int *to_change, int new) |
1da177e4 | 299 | { |
1a6b9f23 | 300 | int allow_changes, rc = 0, old = *to_change; |
6a01b07f SG |
301 | |
302 | /* check if we are locked */ | |
1a6b9f23 EP |
303 | if (audit_enabled == AUDIT_LOCKED) |
304 | allow_changes = 0; | |
6a01b07f | 305 | else |
1a6b9f23 | 306 | allow_changes = 1; |
ce29b682 | 307 | |
1a6b9f23 | 308 | if (audit_enabled != AUDIT_OFF) { |
dc9eb698 | 309 | rc = audit_log_config_change(function_name, new, old, allow_changes); |
1a6b9f23 EP |
310 | if (rc) |
311 | allow_changes = 0; | |
6a01b07f | 312 | } |
6a01b07f SG |
313 | |
314 | /* If we are allowed, make the change */ | |
1a6b9f23 EP |
315 | if (allow_changes == 1) |
316 | *to_change = new; | |
6a01b07f SG |
317 | /* Not allowed, update reason */ |
318 | else if (rc == 0) | |
319 | rc = -EPERM; | |
320 | return rc; | |
1da177e4 LT |
321 | } |
322 | ||
dc9eb698 | 323 | static int audit_set_rate_limit(int limit) |
1da177e4 | 324 | { |
dc9eb698 | 325 | return audit_do_config_change("audit_rate_limit", &audit_rate_limit, limit); |
1a6b9f23 | 326 | } |
ce29b682 | 327 | |
dc9eb698 | 328 | static int audit_set_backlog_limit(int limit) |
1a6b9f23 | 329 | { |
dc9eb698 | 330 | return audit_do_config_change("audit_backlog_limit", &audit_backlog_limit, limit); |
1a6b9f23 | 331 | } |
6a01b07f | 332 | |
dc9eb698 | 333 | static int audit_set_enabled(int state) |
1a6b9f23 | 334 | { |
b593d384 | 335 | int rc; |
1a6b9f23 EP |
336 | if (state < AUDIT_OFF || state > AUDIT_LOCKED) |
337 | return -EINVAL; | |
6a01b07f | 338 | |
dc9eb698 | 339 | rc = audit_do_config_change("audit_enabled", &audit_enabled, state); |
b593d384 EP |
340 | if (!rc) |
341 | audit_ever_enabled |= !!state; | |
342 | ||
343 | return rc; | |
1da177e4 LT |
344 | } |
345 | ||
dc9eb698 | 346 | static int audit_set_failure(int state) |
1da177e4 | 347 | { |
1da177e4 LT |
348 | if (state != AUDIT_FAIL_SILENT |
349 | && state != AUDIT_FAIL_PRINTK | |
350 | && state != AUDIT_FAIL_PANIC) | |
351 | return -EINVAL; | |
ce29b682 | 352 | |
dc9eb698 | 353 | return audit_do_config_change("audit_failure", &audit_failure, state); |
1da177e4 LT |
354 | } |
355 | ||
f3d357b0 EP |
356 | /* |
357 | * Queue skbs to be sent to auditd when/if it comes back. These skbs should | |
358 | * already have been sent via prink/syslog and so if these messages are dropped | |
359 | * it is not a huge concern since we already passed the audit_log_lost() | |
360 | * notification and stuff. This is just nice to get audit messages during | |
361 | * boot before auditd is running or messages generated while auditd is stopped. | |
362 | * This only holds messages is audit_default is set, aka booting with audit=1 | |
363 | * or building your kernel that way. | |
364 | */ | |
365 | static void audit_hold_skb(struct sk_buff *skb) | |
366 | { | |
367 | if (audit_default && | |
368 | skb_queue_len(&audit_skb_hold_queue) < audit_backlog_limit) | |
369 | skb_queue_tail(&audit_skb_hold_queue, skb); | |
370 | else | |
371 | kfree_skb(skb); | |
372 | } | |
373 | ||
038cbcf6 EP |
374 | /* |
375 | * For one reason or another this nlh isn't getting delivered to the userspace | |
376 | * audit daemon, just send it to printk. | |
377 | */ | |
378 | static void audit_printk_skb(struct sk_buff *skb) | |
379 | { | |
380 | struct nlmsghdr *nlh = nlmsg_hdr(skb); | |
c64e66c6 | 381 | char *data = nlmsg_data(nlh); |
038cbcf6 EP |
382 | |
383 | if (nlh->nlmsg_type != AUDIT_EOE) { | |
384 | if (printk_ratelimit()) | |
385 | printk(KERN_NOTICE "type=%d %s\n", nlh->nlmsg_type, data); | |
386 | else | |
387 | audit_log_lost("printk limit exceeded\n"); | |
388 | } | |
389 | ||
390 | audit_hold_skb(skb); | |
391 | } | |
392 | ||
f3d357b0 EP |
393 | static void kauditd_send_skb(struct sk_buff *skb) |
394 | { | |
395 | int err; | |
396 | /* take a reference in case we can't send it and we want to hold it */ | |
397 | skb_get(skb); | |
15e47304 | 398 | err = netlink_unicast(audit_sock, skb, audit_nlk_portid, 0); |
f3d357b0 | 399 | if (err < 0) { |
c9404c9c | 400 | BUG_ON(err != -ECONNREFUSED); /* Shouldn't happen */ |
f3d357b0 | 401 | printk(KERN_ERR "audit: *NO* daemon at audit_pid=%d\n", audit_pid); |
9db3b9bc | 402 | audit_log_lost("auditd disappeared\n"); |
f3d357b0 EP |
403 | audit_pid = 0; |
404 | /* we might get lucky and get this in the next auditd */ | |
405 | audit_hold_skb(skb); | |
406 | } else | |
407 | /* drop the extra reference if sent ok */ | |
70d4bf6d | 408 | consume_skb(skb); |
f3d357b0 EP |
409 | } |
410 | ||
b551d1d9 RGB |
411 | /* |
412 | * flush_hold_queue - empty the hold queue if auditd appears | |
413 | * | |
414 | * If auditd just started, drain the queue of messages already | |
415 | * sent to syslog/printk. Remember loss here is ok. We already | |
416 | * called audit_log_lost() if it didn't go out normally. so the | |
417 | * race between the skb_dequeue and the next check for audit_pid | |
418 | * doesn't matter. | |
419 | * | |
420 | * If you ever find kauditd to be too slow we can get a perf win | |
421 | * by doing our own locking and keeping better track if there | |
422 | * are messages in this queue. I don't see the need now, but | |
423 | * in 5 years when I want to play with this again I'll see this | |
424 | * note and still have no friggin idea what i'm thinking today. | |
425 | */ | |
426 | static void flush_hold_queue(void) | |
b7d11258 DW |
427 | { |
428 | struct sk_buff *skb; | |
429 | ||
b551d1d9 RGB |
430 | if (!audit_default || !audit_pid) |
431 | return; | |
432 | ||
433 | skb = skb_dequeue(&audit_skb_hold_queue); | |
434 | if (likely(!skb)) | |
435 | return; | |
436 | ||
437 | while (skb && audit_pid) { | |
438 | kauditd_send_skb(skb); | |
439 | skb = skb_dequeue(&audit_skb_hold_queue); | |
440 | } | |
441 | ||
442 | /* | |
443 | * if auditd just disappeared but we | |
444 | * dequeued an skb we need to drop ref | |
445 | */ | |
446 | if (skb) | |
447 | consume_skb(skb); | |
448 | } | |
449 | ||
97a41e26 | 450 | static int kauditd_thread(void *dummy) |
b7d11258 | 451 | { |
83144186 | 452 | set_freezable(); |
4899b8b1 | 453 | while (!kthread_should_stop()) { |
3320c513 RGB |
454 | struct sk_buff *skb; |
455 | DECLARE_WAITQUEUE(wait, current); | |
456 | ||
b551d1d9 | 457 | flush_hold_queue(); |
f3d357b0 | 458 | |
b7d11258 | 459 | skb = skb_dequeue(&audit_skb_queue); |
9ad9ad38 | 460 | wake_up(&audit_backlog_wait); |
b7d11258 | 461 | if (skb) { |
f3d357b0 EP |
462 | if (audit_pid) |
463 | kauditd_send_skb(skb); | |
038cbcf6 EP |
464 | else |
465 | audit_printk_skb(skb); | |
3320c513 RGB |
466 | continue; |
467 | } | |
468 | set_current_state(TASK_INTERRUPTIBLE); | |
469 | add_wait_queue(&kauditd_wait, &wait); | |
b7d11258 | 470 | |
3320c513 RGB |
471 | if (!skb_queue_len(&audit_skb_queue)) { |
472 | try_to_freeze(); | |
473 | schedule(); | |
b7d11258 | 474 | } |
3320c513 RGB |
475 | |
476 | __set_current_state(TASK_RUNNING); | |
477 | remove_wait_queue(&kauditd_wait, &wait); | |
b7d11258 | 478 | } |
4899b8b1 | 479 | return 0; |
b7d11258 DW |
480 | } |
481 | ||
9044e6bc AV |
482 | int audit_send_list(void *_dest) |
483 | { | |
484 | struct audit_netlink_list *dest = _dest; | |
485 | int pid = dest->pid; | |
486 | struct sk_buff *skb; | |
487 | ||
488 | /* wait for parent to finish and send an ACK */ | |
f368c07d AG |
489 | mutex_lock(&audit_cmd_mutex); |
490 | mutex_unlock(&audit_cmd_mutex); | |
9044e6bc AV |
491 | |
492 | while ((skb = __skb_dequeue(&dest->q)) != NULL) | |
493 | netlink_unicast(audit_sock, skb, pid, 0); | |
494 | ||
495 | kfree(dest); | |
496 | ||
497 | return 0; | |
498 | } | |
499 | ||
500 | struct sk_buff *audit_make_reply(int pid, int seq, int type, int done, | |
b8800aa5 | 501 | int multi, const void *payload, int size) |
9044e6bc AV |
502 | { |
503 | struct sk_buff *skb; | |
504 | struct nlmsghdr *nlh; | |
9044e6bc AV |
505 | void *data; |
506 | int flags = multi ? NLM_F_MULTI : 0; | |
507 | int t = done ? NLMSG_DONE : type; | |
508 | ||
ee080e6c | 509 | skb = nlmsg_new(size, GFP_KERNEL); |
9044e6bc AV |
510 | if (!skb) |
511 | return NULL; | |
512 | ||
c64e66c6 DM |
513 | nlh = nlmsg_put(skb, pid, seq, t, size, flags); |
514 | if (!nlh) | |
515 | goto out_kfree_skb; | |
516 | data = nlmsg_data(nlh); | |
9044e6bc AV |
517 | memcpy(data, payload, size); |
518 | return skb; | |
519 | ||
c64e66c6 DM |
520 | out_kfree_skb: |
521 | kfree_skb(skb); | |
9044e6bc AV |
522 | return NULL; |
523 | } | |
524 | ||
f09ac9db EP |
525 | static int audit_send_reply_thread(void *arg) |
526 | { | |
527 | struct audit_reply *reply = (struct audit_reply *)arg; | |
528 | ||
529 | mutex_lock(&audit_cmd_mutex); | |
530 | mutex_unlock(&audit_cmd_mutex); | |
531 | ||
532 | /* Ignore failure. It'll only happen if the sender goes away, | |
533 | because our timeout is set to infinite. */ | |
534 | netlink_unicast(audit_sock, reply->skb, reply->pid, 0); | |
535 | kfree(reply); | |
536 | return 0; | |
537 | } | |
b0dd25a8 RD |
538 | /** |
539 | * audit_send_reply - send an audit reply message via netlink | |
540 | * @pid: process id to send reply to | |
541 | * @seq: sequence number | |
542 | * @type: audit message type | |
543 | * @done: done (last) flag | |
544 | * @multi: multi-part message flag | |
545 | * @payload: payload data | |
546 | * @size: payload size | |
547 | * | |
548 | * Allocates an skb, builds the netlink message, and sends it to the pid. | |
549 | * No failure notifications. | |
550 | */ | |
b8800aa5 SH |
551 | static void audit_send_reply(int pid, int seq, int type, int done, int multi, |
552 | const void *payload, int size) | |
1da177e4 | 553 | { |
f09ac9db EP |
554 | struct sk_buff *skb; |
555 | struct task_struct *tsk; | |
556 | struct audit_reply *reply = kmalloc(sizeof(struct audit_reply), | |
557 | GFP_KERNEL); | |
558 | ||
559 | if (!reply) | |
560 | return; | |
561 | ||
9044e6bc | 562 | skb = audit_make_reply(pid, seq, type, done, multi, payload, size); |
1da177e4 | 563 | if (!skb) |
fcaf1eb8 | 564 | goto out; |
f09ac9db EP |
565 | |
566 | reply->pid = pid; | |
567 | reply->skb = skb; | |
568 | ||
569 | tsk = kthread_run(audit_send_reply_thread, reply, "audit_send_reply"); | |
fcaf1eb8 AM |
570 | if (!IS_ERR(tsk)) |
571 | return; | |
572 | kfree_skb(skb); | |
573 | out: | |
574 | kfree(reply); | |
1da177e4 LT |
575 | } |
576 | ||
577 | /* | |
578 | * Check for appropriate CAP_AUDIT_ capabilities on incoming audit | |
579 | * control messages. | |
580 | */ | |
c7bdb545 | 581 | static int audit_netlink_ok(struct sk_buff *skb, u16 msg_type) |
1da177e4 LT |
582 | { |
583 | int err = 0; | |
584 | ||
34e36d8e EB |
585 | /* Only support the initial namespaces for now. */ |
586 | if ((current_user_ns() != &init_user_ns) || | |
587 | (task_active_pid_ns(current) != &init_pid_ns)) | |
588 | return -EPERM; | |
589 | ||
1da177e4 | 590 | switch (msg_type) { |
1da177e4 | 591 | case AUDIT_LIST: |
1da177e4 LT |
592 | case AUDIT_ADD: |
593 | case AUDIT_DEL: | |
18900909 EP |
594 | return -EOPNOTSUPP; |
595 | case AUDIT_GET: | |
596 | case AUDIT_SET: | |
b0fed402 EP |
597 | case AUDIT_GET_FEATURE: |
598 | case AUDIT_SET_FEATURE: | |
18900909 EP |
599 | case AUDIT_LIST_RULES: |
600 | case AUDIT_ADD_RULE: | |
93315ed6 | 601 | case AUDIT_DEL_RULE: |
c2f0c7c3 | 602 | case AUDIT_SIGNAL_INFO: |
522ed776 MT |
603 | case AUDIT_TTY_GET: |
604 | case AUDIT_TTY_SET: | |
74c3cbe3 AV |
605 | case AUDIT_TRIM: |
606 | case AUDIT_MAKE_EQUIV: | |
fd778461 | 607 | if (!capable(CAP_AUDIT_CONTROL)) |
1da177e4 LT |
608 | err = -EPERM; |
609 | break; | |
05474106 | 610 | case AUDIT_USER: |
039b6b3e RD |
611 | case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG: |
612 | case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2: | |
fd778461 | 613 | if (!capable(CAP_AUDIT_WRITE)) |
1da177e4 LT |
614 | err = -EPERM; |
615 | break; | |
616 | default: /* bad msg */ | |
617 | err = -EINVAL; | |
618 | } | |
619 | ||
620 | return err; | |
621 | } | |
622 | ||
dc9eb698 | 623 | static int audit_log_common_recv_msg(struct audit_buffer **ab, u16 msg_type) |
50397bd1 EP |
624 | { |
625 | int rc = 0; | |
dc9eb698 | 626 | uid_t uid = from_kuid(&init_user_ns, current_uid()); |
50397bd1 | 627 | |
0868a5e1 | 628 | if (!audit_enabled && msg_type != AUDIT_USER_AVC) { |
50397bd1 EP |
629 | *ab = NULL; |
630 | return rc; | |
631 | } | |
632 | ||
633 | *ab = audit_log_start(NULL, GFP_KERNEL, msg_type); | |
0644ec0c KC |
634 | if (unlikely(!*ab)) |
635 | return rc; | |
4d3fb709 EP |
636 | audit_log_format(*ab, "pid=%d uid=%u", task_tgid_vnr(current), uid); |
637 | audit_log_session_info(*ab); | |
b122c376 | 638 | audit_log_task_context(*ab); |
50397bd1 EP |
639 | |
640 | return rc; | |
641 | } | |
642 | ||
b0fed402 EP |
643 | int is_audit_feature_set(int i) |
644 | { | |
645 | return af.features & AUDIT_FEATURE_TO_MASK(i); | |
646 | } | |
647 | ||
648 | ||
649 | static int audit_get_feature(struct sk_buff *skb) | |
650 | { | |
651 | u32 seq; | |
652 | ||
653 | seq = nlmsg_hdr(skb)->nlmsg_seq; | |
654 | ||
655 | audit_send_reply(NETLINK_CB(skb).portid, seq, AUDIT_GET, 0, 0, | |
656 | &af, sizeof(af)); | |
657 | ||
658 | return 0; | |
659 | } | |
660 | ||
661 | static void audit_log_feature_change(int which, u32 old_feature, u32 new_feature, | |
662 | u32 old_lock, u32 new_lock, int res) | |
663 | { | |
664 | struct audit_buffer *ab; | |
665 | ||
666 | ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_FEATURE_CHANGE); | |
667 | audit_log_format(ab, "feature=%s new=%d old=%d old_lock=%d new_lock=%d res=%d", | |
668 | audit_feature_names[which], !!old_feature, !!new_feature, | |
669 | !!old_lock, !!new_lock, res); | |
670 | audit_log_end(ab); | |
671 | } | |
672 | ||
673 | static int audit_set_feature(struct sk_buff *skb) | |
674 | { | |
675 | struct audit_features *uaf; | |
676 | int i; | |
677 | ||
678 | BUILD_BUG_ON(AUDIT_LAST_FEATURE + 1 > sizeof(audit_feature_names)/sizeof(audit_feature_names[0])); | |
679 | uaf = nlmsg_data(nlmsg_hdr(skb)); | |
680 | ||
681 | /* if there is ever a version 2 we should handle that here */ | |
682 | ||
683 | for (i = 0; i <= AUDIT_LAST_FEATURE; i++) { | |
684 | u32 feature = AUDIT_FEATURE_TO_MASK(i); | |
685 | u32 old_feature, new_feature, old_lock, new_lock; | |
686 | ||
687 | /* if we are not changing this feature, move along */ | |
688 | if (!(feature & uaf->mask)) | |
689 | continue; | |
690 | ||
691 | old_feature = af.features & feature; | |
692 | new_feature = uaf->features & feature; | |
693 | new_lock = (uaf->lock | af.lock) & feature; | |
694 | old_lock = af.lock & feature; | |
695 | ||
696 | /* are we changing a locked feature? */ | |
697 | if ((af.lock & feature) && (new_feature != old_feature)) { | |
698 | audit_log_feature_change(i, old_feature, new_feature, | |
699 | old_lock, new_lock, 0); | |
700 | return -EPERM; | |
701 | } | |
702 | } | |
703 | /* nothing invalid, do the changes */ | |
704 | for (i = 0; i <= AUDIT_LAST_FEATURE; i++) { | |
705 | u32 feature = AUDIT_FEATURE_TO_MASK(i); | |
706 | u32 old_feature, new_feature, old_lock, new_lock; | |
707 | ||
708 | /* if we are not changing this feature, move along */ | |
709 | if (!(feature & uaf->mask)) | |
710 | continue; | |
711 | ||
712 | old_feature = af.features & feature; | |
713 | new_feature = uaf->features & feature; | |
714 | old_lock = af.lock & feature; | |
715 | new_lock = (uaf->lock | af.lock) & feature; | |
716 | ||
717 | if (new_feature != old_feature) | |
718 | audit_log_feature_change(i, old_feature, new_feature, | |
719 | old_lock, new_lock, 1); | |
720 | ||
721 | if (new_feature) | |
722 | af.features |= feature; | |
723 | else | |
724 | af.features &= ~feature; | |
725 | af.lock |= new_lock; | |
726 | } | |
727 | ||
728 | return 0; | |
729 | } | |
730 | ||
1da177e4 LT |
731 | static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) |
732 | { | |
dc9eb698 | 733 | u32 seq; |
1da177e4 LT |
734 | void *data; |
735 | struct audit_status *status_get, status_set; | |
736 | int err; | |
c0404993 | 737 | struct audit_buffer *ab; |
1da177e4 | 738 | u16 msg_type = nlh->nlmsg_type; |
e1396065 | 739 | struct audit_sig_info *sig_data; |
50397bd1 | 740 | char *ctx = NULL; |
e1396065 | 741 | u32 len; |
1da177e4 | 742 | |
c7bdb545 | 743 | err = audit_netlink_ok(skb, msg_type); |
1da177e4 LT |
744 | if (err) |
745 | return err; | |
746 | ||
b0dd25a8 RD |
747 | /* As soon as there's any sign of userspace auditd, |
748 | * start kauditd to talk to it */ | |
13f51e1c | 749 | if (!kauditd_task) { |
b7d11258 | 750 | kauditd_task = kthread_run(kauditd_thread, NULL, "kauditd"); |
13f51e1c G |
751 | if (IS_ERR(kauditd_task)) { |
752 | err = PTR_ERR(kauditd_task); | |
753 | kauditd_task = NULL; | |
754 | return err; | |
755 | } | |
b7d11258 | 756 | } |
1da177e4 | 757 | seq = nlh->nlmsg_seq; |
c64e66c6 | 758 | data = nlmsg_data(nlh); |
1da177e4 LT |
759 | |
760 | switch (msg_type) { | |
761 | case AUDIT_GET: | |
e13f91e3 | 762 | memset(&status_set, 0, sizeof(status_set)); |
1da177e4 LT |
763 | status_set.enabled = audit_enabled; |
764 | status_set.failure = audit_failure; | |
765 | status_set.pid = audit_pid; | |
766 | status_set.rate_limit = audit_rate_limit; | |
767 | status_set.backlog_limit = audit_backlog_limit; | |
768 | status_set.lost = atomic_read(&audit_lost); | |
b7d11258 | 769 | status_set.backlog = skb_queue_len(&audit_skb_queue); |
15e47304 | 770 | audit_send_reply(NETLINK_CB(skb).portid, seq, AUDIT_GET, 0, 0, |
1da177e4 LT |
771 | &status_set, sizeof(status_set)); |
772 | break; | |
773 | case AUDIT_SET: | |
4d8fe737 | 774 | if (nlmsg_len(nlh) < sizeof(struct audit_status)) |
1da177e4 LT |
775 | return -EINVAL; |
776 | status_get = (struct audit_status *)data; | |
777 | if (status_get->mask & AUDIT_STATUS_ENABLED) { | |
dc9eb698 | 778 | err = audit_set_enabled(status_get->enabled); |
20c6aaa3 | 779 | if (err < 0) |
780 | return err; | |
1da177e4 LT |
781 | } |
782 | if (status_get->mask & AUDIT_STATUS_FAILURE) { | |
dc9eb698 | 783 | err = audit_set_failure(status_get->failure); |
20c6aaa3 | 784 | if (err < 0) |
785 | return err; | |
1da177e4 LT |
786 | } |
787 | if (status_get->mask & AUDIT_STATUS_PID) { | |
1a6b9f23 EP |
788 | int new_pid = status_get->pid; |
789 | ||
790 | if (audit_enabled != AUDIT_OFF) | |
dc9eb698 | 791 | audit_log_config_change("audit_pid", new_pid, audit_pid, 1); |
1a6b9f23 | 792 | audit_pid = new_pid; |
15e47304 | 793 | audit_nlk_portid = NETLINK_CB(skb).portid; |
1da177e4 | 794 | } |
20c6aaa3 | 795 | if (status_get->mask & AUDIT_STATUS_RATE_LIMIT) { |
dc9eb698 | 796 | err = audit_set_rate_limit(status_get->rate_limit); |
20c6aaa3 | 797 | if (err < 0) |
798 | return err; | |
799 | } | |
1da177e4 | 800 | if (status_get->mask & AUDIT_STATUS_BACKLOG_LIMIT) |
dc9eb698 | 801 | err = audit_set_backlog_limit(status_get->backlog_limit); |
1da177e4 | 802 | break; |
b0fed402 EP |
803 | case AUDIT_GET_FEATURE: |
804 | err = audit_get_feature(skb); | |
805 | if (err) | |
806 | return err; | |
807 | break; | |
808 | case AUDIT_SET_FEATURE: | |
809 | err = audit_set_feature(skb); | |
810 | if (err) | |
811 | return err; | |
812 | break; | |
05474106 | 813 | case AUDIT_USER: |
039b6b3e RD |
814 | case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG: |
815 | case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2: | |
4a4cd633 DW |
816 | if (!audit_enabled && msg_type != AUDIT_USER_AVC) |
817 | return 0; | |
818 | ||
62062cf8 | 819 | err = audit_filter_user(msg_type); |
4a4cd633 DW |
820 | if (err == 1) { |
821 | err = 0; | |
522ed776 | 822 | if (msg_type == AUDIT_USER_TTY) { |
152f497b | 823 | err = tty_audit_push_current(); |
522ed776 MT |
824 | if (err) |
825 | break; | |
826 | } | |
dc9eb698 | 827 | audit_log_common_recv_msg(&ab, msg_type); |
50397bd1 | 828 | if (msg_type != AUDIT_USER_TTY) |
b50eba7e RGB |
829 | audit_log_format(ab, " msg='%.*s'", |
830 | AUDIT_MESSAGE_TEXT_MAX, | |
50397bd1 EP |
831 | (char *)data); |
832 | else { | |
833 | int size; | |
834 | ||
f7616102 | 835 | audit_log_format(ab, " data="); |
50397bd1 | 836 | size = nlmsg_len(nlh); |
55ad2f8d MT |
837 | if (size > 0 && |
838 | ((unsigned char *)data)[size - 1] == '\0') | |
839 | size--; | |
b556f8ad | 840 | audit_log_n_untrustedstring(ab, data, size); |
4a4cd633 | 841 | } |
aecdc33e | 842 | audit_set_pid(ab, NETLINK_CB(skb).portid); |
50397bd1 | 843 | audit_log_end(ab); |
0f45aa18 | 844 | } |
1da177e4 | 845 | break; |
93315ed6 AG |
846 | case AUDIT_ADD_RULE: |
847 | case AUDIT_DEL_RULE: | |
848 | if (nlmsg_len(nlh) < sizeof(struct audit_rule_data)) | |
849 | return -EINVAL; | |
1a6b9f23 | 850 | if (audit_enabled == AUDIT_LOCKED) { |
dc9eb698 EP |
851 | audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE); |
852 | audit_log_format(ab, " audit_enabled=%d res=0", audit_enabled); | |
50397bd1 | 853 | audit_log_end(ab); |
6a01b07f SG |
854 | return -EPERM; |
855 | } | |
93315ed6 AG |
856 | /* fallthrough */ |
857 | case AUDIT_LIST_RULES: | |
15e47304 | 858 | err = audit_receive_filter(msg_type, NETLINK_CB(skb).portid, |
dc9eb698 | 859 | seq, data, nlmsg_len(nlh)); |
1da177e4 | 860 | break; |
74c3cbe3 AV |
861 | case AUDIT_TRIM: |
862 | audit_trim_trees(); | |
dc9eb698 | 863 | audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE); |
74c3cbe3 AV |
864 | audit_log_format(ab, " op=trim res=1"); |
865 | audit_log_end(ab); | |
866 | break; | |
867 | case AUDIT_MAKE_EQUIV: { | |
868 | void *bufp = data; | |
869 | u32 sizes[2]; | |
7719e437 | 870 | size_t msglen = nlmsg_len(nlh); |
74c3cbe3 AV |
871 | char *old, *new; |
872 | ||
873 | err = -EINVAL; | |
7719e437 | 874 | if (msglen < 2 * sizeof(u32)) |
74c3cbe3 AV |
875 | break; |
876 | memcpy(sizes, bufp, 2 * sizeof(u32)); | |
877 | bufp += 2 * sizeof(u32); | |
7719e437 HH |
878 | msglen -= 2 * sizeof(u32); |
879 | old = audit_unpack_string(&bufp, &msglen, sizes[0]); | |
74c3cbe3 AV |
880 | if (IS_ERR(old)) { |
881 | err = PTR_ERR(old); | |
882 | break; | |
883 | } | |
7719e437 | 884 | new = audit_unpack_string(&bufp, &msglen, sizes[1]); |
74c3cbe3 AV |
885 | if (IS_ERR(new)) { |
886 | err = PTR_ERR(new); | |
887 | kfree(old); | |
888 | break; | |
889 | } | |
890 | /* OK, here comes... */ | |
891 | err = audit_tag_tree(old, new); | |
892 | ||
dc9eb698 | 893 | audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE); |
50397bd1 | 894 | |
74c3cbe3 AV |
895 | audit_log_format(ab, " op=make_equiv old="); |
896 | audit_log_untrustedstring(ab, old); | |
897 | audit_log_format(ab, " new="); | |
898 | audit_log_untrustedstring(ab, new); | |
899 | audit_log_format(ab, " res=%d", !err); | |
900 | audit_log_end(ab); | |
901 | kfree(old); | |
902 | kfree(new); | |
903 | break; | |
904 | } | |
c2f0c7c3 | 905 | case AUDIT_SIGNAL_INFO: |
939cbf26 EP |
906 | len = 0; |
907 | if (audit_sig_sid) { | |
908 | err = security_secid_to_secctx(audit_sig_sid, &ctx, &len); | |
909 | if (err) | |
910 | return err; | |
911 | } | |
e1396065 AV |
912 | sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL); |
913 | if (!sig_data) { | |
939cbf26 EP |
914 | if (audit_sig_sid) |
915 | security_release_secctx(ctx, len); | |
e1396065 AV |
916 | return -ENOMEM; |
917 | } | |
cca080d9 | 918 | sig_data->uid = from_kuid(&init_user_ns, audit_sig_uid); |
e1396065 | 919 | sig_data->pid = audit_sig_pid; |
939cbf26 EP |
920 | if (audit_sig_sid) { |
921 | memcpy(sig_data->ctx, ctx, len); | |
922 | security_release_secctx(ctx, len); | |
923 | } | |
15e47304 | 924 | audit_send_reply(NETLINK_CB(skb).portid, seq, AUDIT_SIGNAL_INFO, |
e1396065 AV |
925 | 0, 0, sig_data, sizeof(*sig_data) + len); |
926 | kfree(sig_data); | |
c2f0c7c3 | 927 | break; |
522ed776 MT |
928 | case AUDIT_TTY_GET: { |
929 | struct audit_tty_status s; | |
8aa14b64 EB |
930 | struct task_struct *tsk = current; |
931 | ||
7173c54e | 932 | spin_lock(&tsk->sighand->siglock); |
b95d77fe | 933 | s.enabled = tsk->signal->audit_tty; |
46e959ea | 934 | s.log_passwd = tsk->signal->audit_tty_log_passwd; |
7173c54e | 935 | spin_unlock(&tsk->sighand->siglock); |
8aa14b64 | 936 | |
aecdc33e | 937 | audit_send_reply(NETLINK_CB(skb).portid, seq, |
8aa14b64 | 938 | AUDIT_TTY_GET, 0, 0, &s, sizeof(s)); |
522ed776 MT |
939 | break; |
940 | } | |
941 | case AUDIT_TTY_SET: { | |
46e959ea | 942 | struct audit_tty_status s; |
8aa14b64 | 943 | struct task_struct *tsk = current; |
522ed776 | 944 | |
46e959ea RGB |
945 | memset(&s, 0, sizeof(s)); |
946 | /* guard against past and future API changes */ | |
4d8fe737 | 947 | memcpy(&s, data, min_t(size_t, sizeof(s), nlmsg_len(nlh))); |
46e959ea RGB |
948 | if ((s.enabled != 0 && s.enabled != 1) || |
949 | (s.log_passwd != 0 && s.log_passwd != 1)) | |
522ed776 | 950 | return -EINVAL; |
8aa14b64 | 951 | |
7173c54e | 952 | spin_lock(&tsk->sighand->siglock); |
46e959ea RGB |
953 | tsk->signal->audit_tty = s.enabled; |
954 | tsk->signal->audit_tty_log_passwd = s.log_passwd; | |
7173c54e | 955 | spin_unlock(&tsk->sighand->siglock); |
522ed776 MT |
956 | break; |
957 | } | |
1da177e4 LT |
958 | default: |
959 | err = -EINVAL; | |
960 | break; | |
961 | } | |
962 | ||
963 | return err < 0 ? err : 0; | |
964 | } | |
965 | ||
b0dd25a8 | 966 | /* |
ea7ae60b EP |
967 | * Get message from skb. Each message is processed by audit_receive_msg. |
968 | * Malformed skbs with wrong length are discarded silently. | |
b0dd25a8 | 969 | */ |
2a0a6ebe | 970 | static void audit_receive_skb(struct sk_buff *skb) |
1da177e4 | 971 | { |
ea7ae60b EP |
972 | struct nlmsghdr *nlh; |
973 | /* | |
94191213 | 974 | * len MUST be signed for nlmsg_next to be able to dec it below 0 |
ea7ae60b EP |
975 | * if the nlmsg_len was not aligned |
976 | */ | |
977 | int len; | |
978 | int err; | |
979 | ||
980 | nlh = nlmsg_hdr(skb); | |
981 | len = skb->len; | |
982 | ||
94191213 | 983 | while (nlmsg_ok(nlh, len)) { |
ea7ae60b EP |
984 | err = audit_receive_msg(skb, nlh); |
985 | /* if err or if this message says it wants a response */ | |
986 | if (err || (nlh->nlmsg_flags & NLM_F_ACK)) | |
1da177e4 | 987 | netlink_ack(skb, nlh, err); |
ea7ae60b | 988 | |
2851da57 | 989 | nlh = nlmsg_next(nlh, &len); |
1da177e4 | 990 | } |
1da177e4 LT |
991 | } |
992 | ||
993 | /* Receive messages from netlink socket. */ | |
cd40b7d3 | 994 | static void audit_receive(struct sk_buff *skb) |
1da177e4 | 995 | { |
f368c07d | 996 | mutex_lock(&audit_cmd_mutex); |
cd40b7d3 | 997 | audit_receive_skb(skb); |
f368c07d | 998 | mutex_unlock(&audit_cmd_mutex); |
1da177e4 LT |
999 | } |
1000 | ||
1da177e4 LT |
1001 | /* Initialize audit support at boot time. */ |
1002 | static int __init audit_init(void) | |
1003 | { | |
f368c07d | 1004 | int i; |
a31f2d17 PNA |
1005 | struct netlink_kernel_cfg cfg = { |
1006 | .input = audit_receive, | |
1007 | }; | |
f368c07d | 1008 | |
a3f07114 EP |
1009 | if (audit_initialized == AUDIT_DISABLED) |
1010 | return 0; | |
1011 | ||
1da177e4 LT |
1012 | printk(KERN_INFO "audit: initializing netlink socket (%s)\n", |
1013 | audit_default ? "enabled" : "disabled"); | |
9f00d977 | 1014 | audit_sock = netlink_kernel_create(&init_net, NETLINK_AUDIT, &cfg); |
1da177e4 LT |
1015 | if (!audit_sock) |
1016 | audit_panic("cannot initialize netlink socket"); | |
71e1c784 AG |
1017 | else |
1018 | audit_sock->sk_sndtimeo = MAX_SCHEDULE_TIMEOUT; | |
1da177e4 | 1019 | |
b7d11258 | 1020 | skb_queue_head_init(&audit_skb_queue); |
f3d357b0 | 1021 | skb_queue_head_init(&audit_skb_hold_queue); |
a3f07114 | 1022 | audit_initialized = AUDIT_INITIALIZED; |
1da177e4 | 1023 | audit_enabled = audit_default; |
b593d384 | 1024 | audit_ever_enabled |= !!audit_default; |
3dc7e315 | 1025 | |
9ad9ad38 | 1026 | audit_log(NULL, GFP_KERNEL, AUDIT_KERNEL, "initialized"); |
f368c07d | 1027 | |
f368c07d AG |
1028 | for (i = 0; i < AUDIT_INODE_BUCKETS; i++) |
1029 | INIT_LIST_HEAD(&audit_inode_hash[i]); | |
f368c07d | 1030 | |
1da177e4 LT |
1031 | return 0; |
1032 | } | |
1da177e4 LT |
1033 | __initcall(audit_init); |
1034 | ||
1035 | /* Process kernel command-line parameter at boot time. audit=0 or audit=1. */ | |
1036 | static int __init audit_enable(char *str) | |
1037 | { | |
1038 | audit_default = !!simple_strtol(str, NULL, 0); | |
a3f07114 EP |
1039 | if (!audit_default) |
1040 | audit_initialized = AUDIT_DISABLED; | |
1041 | ||
1042 | printk(KERN_INFO "audit: %s", audit_default ? "enabled" : "disabled"); | |
1043 | ||
1044 | if (audit_initialized == AUDIT_INITIALIZED) { | |
1da177e4 | 1045 | audit_enabled = audit_default; |
b593d384 | 1046 | audit_ever_enabled |= !!audit_default; |
a3f07114 EP |
1047 | } else if (audit_initialized == AUDIT_UNINITIALIZED) { |
1048 | printk(" (after initialization)"); | |
1049 | } else { | |
1050 | printk(" (until reboot)"); | |
b593d384 | 1051 | } |
a3f07114 EP |
1052 | printk("\n"); |
1053 | ||
9b41046c | 1054 | return 1; |
1da177e4 LT |
1055 | } |
1056 | ||
1057 | __setup("audit=", audit_enable); | |
1058 | ||
16e1904e CW |
1059 | static void audit_buffer_free(struct audit_buffer *ab) |
1060 | { | |
1061 | unsigned long flags; | |
1062 | ||
8fc6115c CW |
1063 | if (!ab) |
1064 | return; | |
1065 | ||
5ac52f33 CW |
1066 | if (ab->skb) |
1067 | kfree_skb(ab->skb); | |
b7d11258 | 1068 | |
16e1904e | 1069 | spin_lock_irqsave(&audit_freelist_lock, flags); |
5d136a01 | 1070 | if (audit_freelist_count > AUDIT_MAXFREE) |
16e1904e | 1071 | kfree(ab); |
5d136a01 SH |
1072 | else { |
1073 | audit_freelist_count++; | |
16e1904e | 1074 | list_add(&ab->list, &audit_freelist); |
5d136a01 | 1075 | } |
16e1904e CW |
1076 | spin_unlock_irqrestore(&audit_freelist_lock, flags); |
1077 | } | |
1078 | ||
c0404993 | 1079 | static struct audit_buffer * audit_buffer_alloc(struct audit_context *ctx, |
dd0fc66f | 1080 | gfp_t gfp_mask, int type) |
16e1904e CW |
1081 | { |
1082 | unsigned long flags; | |
1083 | struct audit_buffer *ab = NULL; | |
c0404993 | 1084 | struct nlmsghdr *nlh; |
16e1904e CW |
1085 | |
1086 | spin_lock_irqsave(&audit_freelist_lock, flags); | |
1087 | if (!list_empty(&audit_freelist)) { | |
1088 | ab = list_entry(audit_freelist.next, | |
1089 | struct audit_buffer, list); | |
1090 | list_del(&ab->list); | |
1091 | --audit_freelist_count; | |
1092 | } | |
1093 | spin_unlock_irqrestore(&audit_freelist_lock, flags); | |
1094 | ||
1095 | if (!ab) { | |
4332bdd3 | 1096 | ab = kmalloc(sizeof(*ab), gfp_mask); |
16e1904e | 1097 | if (!ab) |
8fc6115c | 1098 | goto err; |
16e1904e | 1099 | } |
8fc6115c | 1100 | |
b7d11258 | 1101 | ab->ctx = ctx; |
9ad9ad38 | 1102 | ab->gfp_mask = gfp_mask; |
ee080e6c EP |
1103 | |
1104 | ab->skb = nlmsg_new(AUDIT_BUFSIZ, gfp_mask); | |
1105 | if (!ab->skb) | |
c64e66c6 | 1106 | goto err; |
ee080e6c | 1107 | |
c64e66c6 DM |
1108 | nlh = nlmsg_put(ab->skb, 0, 0, type, 0, 0); |
1109 | if (!nlh) | |
1110 | goto out_kfree_skb; | |
ee080e6c | 1111 | |
16e1904e | 1112 | return ab; |
ee080e6c | 1113 | |
c64e66c6 | 1114 | out_kfree_skb: |
ee080e6c EP |
1115 | kfree_skb(ab->skb); |
1116 | ab->skb = NULL; | |
8fc6115c CW |
1117 | err: |
1118 | audit_buffer_free(ab); | |
1119 | return NULL; | |
16e1904e | 1120 | } |
1da177e4 | 1121 | |
b0dd25a8 RD |
1122 | /** |
1123 | * audit_serial - compute a serial number for the audit record | |
1124 | * | |
1125 | * Compute a serial number for the audit record. Audit records are | |
bfb4496e DW |
1126 | * written to user-space as soon as they are generated, so a complete |
1127 | * audit record may be written in several pieces. The timestamp of the | |
1128 | * record and this serial number are used by the user-space tools to | |
1129 | * determine which pieces belong to the same audit record. The | |
1130 | * (timestamp,serial) tuple is unique for each syscall and is live from | |
1131 | * syscall entry to syscall exit. | |
1132 | * | |
bfb4496e DW |
1133 | * NOTE: Another possibility is to store the formatted records off the |
1134 | * audit context (for those records that have a context), and emit them | |
1135 | * all at syscall exit. However, this could delay the reporting of | |
1136 | * significant errors until syscall exit (or never, if the system | |
b0dd25a8 RD |
1137 | * halts). |
1138 | */ | |
bfb4496e DW |
1139 | unsigned int audit_serial(void) |
1140 | { | |
34af946a | 1141 | static DEFINE_SPINLOCK(serial_lock); |
d5b454f2 DW |
1142 | static unsigned int serial = 0; |
1143 | ||
1144 | unsigned long flags; | |
1145 | unsigned int ret; | |
bfb4496e | 1146 | |
d5b454f2 | 1147 | spin_lock_irqsave(&serial_lock, flags); |
bfb4496e | 1148 | do { |
ce625a80 DW |
1149 | ret = ++serial; |
1150 | } while (unlikely(!ret)); | |
d5b454f2 | 1151 | spin_unlock_irqrestore(&serial_lock, flags); |
bfb4496e | 1152 | |
d5b454f2 | 1153 | return ret; |
bfb4496e DW |
1154 | } |
1155 | ||
5600b892 | 1156 | static inline void audit_get_stamp(struct audit_context *ctx, |
bfb4496e DW |
1157 | struct timespec *t, unsigned int *serial) |
1158 | { | |
48887e63 | 1159 | if (!ctx || !auditsc_get_stamp(ctx, t, serial)) { |
bfb4496e DW |
1160 | *t = CURRENT_TIME; |
1161 | *serial = audit_serial(); | |
1162 | } | |
1163 | } | |
1164 | ||
82919919 AM |
1165 | /* |
1166 | * Wait for auditd to drain the queue a little | |
1167 | */ | |
1168 | static void wait_for_auditd(unsigned long sleep_time) | |
1169 | { | |
1170 | DECLARE_WAITQUEUE(wait, current); | |
f000cfdd | 1171 | set_current_state(TASK_UNINTERRUPTIBLE); |
82919919 AM |
1172 | add_wait_queue(&audit_backlog_wait, &wait); |
1173 | ||
1174 | if (audit_backlog_limit && | |
1175 | skb_queue_len(&audit_skb_queue) > audit_backlog_limit) | |
1176 | schedule_timeout(sleep_time); | |
1177 | ||
1178 | __set_current_state(TASK_RUNNING); | |
1179 | remove_wait_queue(&audit_backlog_wait, &wait); | |
1180 | } | |
1181 | ||
b0dd25a8 RD |
1182 | /** |
1183 | * audit_log_start - obtain an audit buffer | |
1184 | * @ctx: audit_context (may be NULL) | |
1185 | * @gfp_mask: type of allocation | |
1186 | * @type: audit message type | |
1187 | * | |
1188 | * Returns audit_buffer pointer on success or NULL on error. | |
1189 | * | |
1190 | * Obtain an audit buffer. This routine does locking to obtain the | |
1191 | * audit buffer, but then no locking is required for calls to | |
1192 | * audit_log_*format. If the task (ctx) is a task that is currently in a | |
1193 | * syscall, then the syscall is marked as auditable and an audit record | |
1194 | * will be written at syscall exit. If there is no associated task, then | |
1195 | * task context (ctx) should be NULL. | |
1196 | */ | |
9796fdd8 | 1197 | struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask, |
9ad9ad38 | 1198 | int type) |
1da177e4 LT |
1199 | { |
1200 | struct audit_buffer *ab = NULL; | |
1da177e4 | 1201 | struct timespec t; |
ef00be05 | 1202 | unsigned int uninitialized_var(serial); |
9ad9ad38 | 1203 | int reserve; |
ac4cec44 | 1204 | unsigned long timeout_start = jiffies; |
1da177e4 | 1205 | |
a3f07114 | 1206 | if (audit_initialized != AUDIT_INITIALIZED) |
1da177e4 LT |
1207 | return NULL; |
1208 | ||
c8edc80c DK |
1209 | if (unlikely(audit_filter_type(type))) |
1210 | return NULL; | |
1211 | ||
9ad9ad38 DW |
1212 | if (gfp_mask & __GFP_WAIT) |
1213 | reserve = 0; | |
1214 | else | |
5600b892 | 1215 | reserve = 5; /* Allow atomic callers to go up to five |
9ad9ad38 DW |
1216 | entries over the normal backlog limit */ |
1217 | ||
1218 | while (audit_backlog_limit | |
1219 | && skb_queue_len(&audit_skb_queue) > audit_backlog_limit + reserve) { | |
82919919 AM |
1220 | if (gfp_mask & __GFP_WAIT && audit_backlog_wait_time) { |
1221 | unsigned long sleep_time; | |
9ad9ad38 | 1222 | |
82919919 AM |
1223 | sleep_time = timeout_start + audit_backlog_wait_time - |
1224 | jiffies; | |
8ac1c8d5 | 1225 | if ((long)sleep_time > 0) { |
82919919 | 1226 | wait_for_auditd(sleep_time); |
8ac1c8d5 KK |
1227 | continue; |
1228 | } | |
9ad9ad38 | 1229 | } |
320f1b1e | 1230 | if (audit_rate_check() && printk_ratelimit()) |
fb19b4c6 DW |
1231 | printk(KERN_WARNING |
1232 | "audit: audit_backlog=%d > " | |
1233 | "audit_backlog_limit=%d\n", | |
1234 | skb_queue_len(&audit_skb_queue), | |
1235 | audit_backlog_limit); | |
1236 | audit_log_lost("backlog limit exceeded"); | |
ac4cec44 DW |
1237 | audit_backlog_wait_time = audit_backlog_wait_overflow; |
1238 | wake_up(&audit_backlog_wait); | |
fb19b4c6 DW |
1239 | return NULL; |
1240 | } | |
1241 | ||
9ad9ad38 | 1242 | ab = audit_buffer_alloc(ctx, gfp_mask, type); |
1da177e4 LT |
1243 | if (!ab) { |
1244 | audit_log_lost("out of memory in audit_log_start"); | |
1245 | return NULL; | |
1246 | } | |
1247 | ||
bfb4496e | 1248 | audit_get_stamp(ab->ctx, &t, &serial); |
197c69c6 | 1249 | |
1da177e4 LT |
1250 | audit_log_format(ab, "audit(%lu.%03lu:%u): ", |
1251 | t.tv_sec, t.tv_nsec/1000000, serial); | |
1252 | return ab; | |
1253 | } | |
1254 | ||
8fc6115c | 1255 | /** |
5ac52f33 | 1256 | * audit_expand - expand skb in the audit buffer |
8fc6115c | 1257 | * @ab: audit_buffer |
b0dd25a8 | 1258 | * @extra: space to add at tail of the skb |
8fc6115c CW |
1259 | * |
1260 | * Returns 0 (no space) on failed expansion, or available space if | |
1261 | * successful. | |
1262 | */ | |
e3b926b4 | 1263 | static inline int audit_expand(struct audit_buffer *ab, int extra) |
8fc6115c | 1264 | { |
5ac52f33 | 1265 | struct sk_buff *skb = ab->skb; |
406a1d86 HX |
1266 | int oldtail = skb_tailroom(skb); |
1267 | int ret = pskb_expand_head(skb, 0, extra, ab->gfp_mask); | |
1268 | int newtail = skb_tailroom(skb); | |
1269 | ||
5ac52f33 CW |
1270 | if (ret < 0) { |
1271 | audit_log_lost("out of memory in audit_expand"); | |
8fc6115c | 1272 | return 0; |
5ac52f33 | 1273 | } |
406a1d86 HX |
1274 | |
1275 | skb->truesize += newtail - oldtail; | |
1276 | return newtail; | |
8fc6115c | 1277 | } |
1da177e4 | 1278 | |
b0dd25a8 RD |
1279 | /* |
1280 | * Format an audit message into the audit buffer. If there isn't enough | |
1da177e4 LT |
1281 | * room in the audit buffer, more room will be allocated and vsnprint |
1282 | * will be called a second time. Currently, we assume that a printk | |
b0dd25a8 RD |
1283 | * can't format message larger than 1024 bytes, so we don't either. |
1284 | */ | |
1da177e4 LT |
1285 | static void audit_log_vformat(struct audit_buffer *ab, const char *fmt, |
1286 | va_list args) | |
1287 | { | |
1288 | int len, avail; | |
5ac52f33 | 1289 | struct sk_buff *skb; |
eecb0a73 | 1290 | va_list args2; |
1da177e4 LT |
1291 | |
1292 | if (!ab) | |
1293 | return; | |
1294 | ||
5ac52f33 CW |
1295 | BUG_ON(!ab->skb); |
1296 | skb = ab->skb; | |
1297 | avail = skb_tailroom(skb); | |
1298 | if (avail == 0) { | |
e3b926b4 | 1299 | avail = audit_expand(ab, AUDIT_BUFSIZ); |
8fc6115c CW |
1300 | if (!avail) |
1301 | goto out; | |
1da177e4 | 1302 | } |
eecb0a73 | 1303 | va_copy(args2, args); |
27a884dc | 1304 | len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args); |
1da177e4 LT |
1305 | if (len >= avail) { |
1306 | /* The printk buffer is 1024 bytes long, so if we get | |
1307 | * here and AUDIT_BUFSIZ is at least 1024, then we can | |
1308 | * log everything that printk could have logged. */ | |
b0dd25a8 RD |
1309 | avail = audit_expand(ab, |
1310 | max_t(unsigned, AUDIT_BUFSIZ, 1+len-avail)); | |
8fc6115c | 1311 | if (!avail) |
a0e86bd4 | 1312 | goto out_va_end; |
27a884dc | 1313 | len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args2); |
1da177e4 | 1314 | } |
168b7173 SG |
1315 | if (len > 0) |
1316 | skb_put(skb, len); | |
a0e86bd4 JJ |
1317 | out_va_end: |
1318 | va_end(args2); | |
8fc6115c CW |
1319 | out: |
1320 | return; | |
1da177e4 LT |
1321 | } |
1322 | ||
b0dd25a8 RD |
1323 | /** |
1324 | * audit_log_format - format a message into the audit buffer. | |
1325 | * @ab: audit_buffer | |
1326 | * @fmt: format string | |
1327 | * @...: optional parameters matching @fmt string | |
1328 | * | |
1329 | * All the work is done in audit_log_vformat. | |
1330 | */ | |
1da177e4 LT |
1331 | void audit_log_format(struct audit_buffer *ab, const char *fmt, ...) |
1332 | { | |
1333 | va_list args; | |
1334 | ||
1335 | if (!ab) | |
1336 | return; | |
1337 | va_start(args, fmt); | |
1338 | audit_log_vformat(ab, fmt, args); | |
1339 | va_end(args); | |
1340 | } | |
1341 | ||
b0dd25a8 RD |
1342 | /** |
1343 | * audit_log_hex - convert a buffer to hex and append it to the audit skb | |
1344 | * @ab: the audit_buffer | |
1345 | * @buf: buffer to convert to hex | |
1346 | * @len: length of @buf to be converted | |
1347 | * | |
1348 | * No return value; failure to expand is silently ignored. | |
1349 | * | |
1350 | * This function will take the passed buf and convert it into a string of | |
1351 | * ascii hex digits. The new string is placed onto the skb. | |
1352 | */ | |
b556f8ad | 1353 | void audit_log_n_hex(struct audit_buffer *ab, const unsigned char *buf, |
168b7173 | 1354 | size_t len) |
83c7d091 | 1355 | { |
168b7173 SG |
1356 | int i, avail, new_len; |
1357 | unsigned char *ptr; | |
1358 | struct sk_buff *skb; | |
1359 | static const unsigned char *hex = "0123456789ABCDEF"; | |
1360 | ||
8ef2d304 AG |
1361 | if (!ab) |
1362 | return; | |
1363 | ||
168b7173 SG |
1364 | BUG_ON(!ab->skb); |
1365 | skb = ab->skb; | |
1366 | avail = skb_tailroom(skb); | |
1367 | new_len = len<<1; | |
1368 | if (new_len >= avail) { | |
1369 | /* Round the buffer request up to the next multiple */ | |
1370 | new_len = AUDIT_BUFSIZ*(((new_len-avail)/AUDIT_BUFSIZ) + 1); | |
1371 | avail = audit_expand(ab, new_len); | |
1372 | if (!avail) | |
1373 | return; | |
1374 | } | |
83c7d091 | 1375 | |
27a884dc | 1376 | ptr = skb_tail_pointer(skb); |
168b7173 SG |
1377 | for (i=0; i<len; i++) { |
1378 | *ptr++ = hex[(buf[i] & 0xF0)>>4]; /* Upper nibble */ | |
1379 | *ptr++ = hex[buf[i] & 0x0F]; /* Lower nibble */ | |
1380 | } | |
1381 | *ptr = 0; | |
1382 | skb_put(skb, len << 1); /* new string is twice the old string */ | |
83c7d091 | 1383 | } |
1384 | ||
9c937dcc AG |
1385 | /* |
1386 | * Format a string of no more than slen characters into the audit buffer, | |
1387 | * enclosed in quote marks. | |
1388 | */ | |
b556f8ad EP |
1389 | void audit_log_n_string(struct audit_buffer *ab, const char *string, |
1390 | size_t slen) | |
9c937dcc AG |
1391 | { |
1392 | int avail, new_len; | |
1393 | unsigned char *ptr; | |
1394 | struct sk_buff *skb; | |
1395 | ||
8ef2d304 AG |
1396 | if (!ab) |
1397 | return; | |
1398 | ||
9c937dcc AG |
1399 | BUG_ON(!ab->skb); |
1400 | skb = ab->skb; | |
1401 | avail = skb_tailroom(skb); | |
1402 | new_len = slen + 3; /* enclosing quotes + null terminator */ | |
1403 | if (new_len > avail) { | |
1404 | avail = audit_expand(ab, new_len); | |
1405 | if (!avail) | |
1406 | return; | |
1407 | } | |
27a884dc | 1408 | ptr = skb_tail_pointer(skb); |
9c937dcc AG |
1409 | *ptr++ = '"'; |
1410 | memcpy(ptr, string, slen); | |
1411 | ptr += slen; | |
1412 | *ptr++ = '"'; | |
1413 | *ptr = 0; | |
1414 | skb_put(skb, slen + 2); /* don't include null terminator */ | |
1415 | } | |
1416 | ||
de6bbd1d EP |
1417 | /** |
1418 | * audit_string_contains_control - does a string need to be logged in hex | |
f706d5d2 DJ |
1419 | * @string: string to be checked |
1420 | * @len: max length of the string to check | |
de6bbd1d EP |
1421 | */ |
1422 | int audit_string_contains_control(const char *string, size_t len) | |
1423 | { | |
1424 | const unsigned char *p; | |
b3897f56 | 1425 | for (p = string; p < (const unsigned char *)string + len; p++) { |
1d6c9649 | 1426 | if (*p == '"' || *p < 0x21 || *p > 0x7e) |
de6bbd1d EP |
1427 | return 1; |
1428 | } | |
1429 | return 0; | |
1430 | } | |
1431 | ||
b0dd25a8 | 1432 | /** |
522ed776 | 1433 | * audit_log_n_untrustedstring - log a string that may contain random characters |
b0dd25a8 | 1434 | * @ab: audit_buffer |
f706d5d2 | 1435 | * @len: length of string (not including trailing null) |
b0dd25a8 RD |
1436 | * @string: string to be logged |
1437 | * | |
1438 | * This code will escape a string that is passed to it if the string | |
1439 | * contains a control character, unprintable character, double quote mark, | |
168b7173 | 1440 | * or a space. Unescaped strings will start and end with a double quote mark. |
b0dd25a8 | 1441 | * Strings that are escaped are printed in hex (2 digits per char). |
9c937dcc AG |
1442 | * |
1443 | * The caller specifies the number of characters in the string to log, which may | |
1444 | * or may not be the entire string. | |
b0dd25a8 | 1445 | */ |
b556f8ad EP |
1446 | void audit_log_n_untrustedstring(struct audit_buffer *ab, const char *string, |
1447 | size_t len) | |
83c7d091 | 1448 | { |
de6bbd1d | 1449 | if (audit_string_contains_control(string, len)) |
b556f8ad | 1450 | audit_log_n_hex(ab, string, len); |
de6bbd1d | 1451 | else |
b556f8ad | 1452 | audit_log_n_string(ab, string, len); |
83c7d091 | 1453 | } |
1454 | ||
9c937dcc | 1455 | /** |
522ed776 | 1456 | * audit_log_untrustedstring - log a string that may contain random characters |
9c937dcc AG |
1457 | * @ab: audit_buffer |
1458 | * @string: string to be logged | |
1459 | * | |
522ed776 | 1460 | * Same as audit_log_n_untrustedstring(), except that strlen is used to |
9c937dcc AG |
1461 | * determine string length. |
1462 | */ | |
de6bbd1d | 1463 | void audit_log_untrustedstring(struct audit_buffer *ab, const char *string) |
9c937dcc | 1464 | { |
b556f8ad | 1465 | audit_log_n_untrustedstring(ab, string, strlen(string)); |
9c937dcc AG |
1466 | } |
1467 | ||
168b7173 | 1468 | /* This is a helper-function to print the escaped d_path */ |
1da177e4 | 1469 | void audit_log_d_path(struct audit_buffer *ab, const char *prefix, |
66b3fad3 | 1470 | const struct path *path) |
1da177e4 | 1471 | { |
44707fdf | 1472 | char *p, *pathname; |
1da177e4 | 1473 | |
8fc6115c | 1474 | if (prefix) |
c158a35c | 1475 | audit_log_format(ab, "%s", prefix); |
1da177e4 | 1476 | |
168b7173 | 1477 | /* We will allow 11 spaces for ' (deleted)' to be appended */ |
44707fdf JB |
1478 | pathname = kmalloc(PATH_MAX+11, ab->gfp_mask); |
1479 | if (!pathname) { | |
def57543 | 1480 | audit_log_string(ab, "<no_memory>"); |
168b7173 | 1481 | return; |
1da177e4 | 1482 | } |
cf28b486 | 1483 | p = d_path(path, pathname, PATH_MAX+11); |
168b7173 SG |
1484 | if (IS_ERR(p)) { /* Should never happen since we send PATH_MAX */ |
1485 | /* FIXME: can we save some information here? */ | |
def57543 | 1486 | audit_log_string(ab, "<too_long>"); |
5600b892 | 1487 | } else |
168b7173 | 1488 | audit_log_untrustedstring(ab, p); |
44707fdf | 1489 | kfree(pathname); |
1da177e4 LT |
1490 | } |
1491 | ||
4d3fb709 EP |
1492 | void audit_log_session_info(struct audit_buffer *ab) |
1493 | { | |
1494 | u32 sessionid = audit_get_sessionid(current); | |
1495 | uid_t auid = from_kuid(&init_user_ns, audit_get_loginuid(current)); | |
1496 | ||
b8f89caa | 1497 | audit_log_format(ab, " auid=%u ses=%u", auid, sessionid); |
4d3fb709 EP |
1498 | } |
1499 | ||
9d960985 EP |
1500 | void audit_log_key(struct audit_buffer *ab, char *key) |
1501 | { | |
1502 | audit_log_format(ab, " key="); | |
1503 | if (key) | |
1504 | audit_log_untrustedstring(ab, key); | |
1505 | else | |
1506 | audit_log_format(ab, "(null)"); | |
1507 | } | |
1508 | ||
b24a30a7 EP |
1509 | void audit_log_cap(struct audit_buffer *ab, char *prefix, kernel_cap_t *cap) |
1510 | { | |
1511 | int i; | |
1512 | ||
1513 | audit_log_format(ab, " %s=", prefix); | |
1514 | CAP_FOR_EACH_U32(i) { | |
1515 | audit_log_format(ab, "%08x", | |
1516 | cap->cap[(_KERNEL_CAPABILITY_U32S-1) - i]); | |
1517 | } | |
1518 | } | |
1519 | ||
1520 | void audit_log_fcaps(struct audit_buffer *ab, struct audit_names *name) | |
1521 | { | |
1522 | kernel_cap_t *perm = &name->fcap.permitted; | |
1523 | kernel_cap_t *inh = &name->fcap.inheritable; | |
1524 | int log = 0; | |
1525 | ||
1526 | if (!cap_isclear(*perm)) { | |
1527 | audit_log_cap(ab, "cap_fp", perm); | |
1528 | log = 1; | |
1529 | } | |
1530 | if (!cap_isclear(*inh)) { | |
1531 | audit_log_cap(ab, "cap_fi", inh); | |
1532 | log = 1; | |
1533 | } | |
1534 | ||
1535 | if (log) | |
1536 | audit_log_format(ab, " cap_fe=%d cap_fver=%x", | |
1537 | name->fcap.fE, name->fcap_ver); | |
1538 | } | |
1539 | ||
1540 | static inline int audit_copy_fcaps(struct audit_names *name, | |
1541 | const struct dentry *dentry) | |
1542 | { | |
1543 | struct cpu_vfs_cap_data caps; | |
1544 | int rc; | |
1545 | ||
1546 | if (!dentry) | |
1547 | return 0; | |
1548 | ||
1549 | rc = get_vfs_caps_from_disk(dentry, &caps); | |
1550 | if (rc) | |
1551 | return rc; | |
1552 | ||
1553 | name->fcap.permitted = caps.permitted; | |
1554 | name->fcap.inheritable = caps.inheritable; | |
1555 | name->fcap.fE = !!(caps.magic_etc & VFS_CAP_FLAGS_EFFECTIVE); | |
1556 | name->fcap_ver = (caps.magic_etc & VFS_CAP_REVISION_MASK) >> | |
1557 | VFS_CAP_REVISION_SHIFT; | |
1558 | ||
1559 | return 0; | |
1560 | } | |
1561 | ||
1562 | /* Copy inode data into an audit_names. */ | |
1563 | void audit_copy_inode(struct audit_names *name, const struct dentry *dentry, | |
1564 | const struct inode *inode) | |
1565 | { | |
1566 | name->ino = inode->i_ino; | |
1567 | name->dev = inode->i_sb->s_dev; | |
1568 | name->mode = inode->i_mode; | |
1569 | name->uid = inode->i_uid; | |
1570 | name->gid = inode->i_gid; | |
1571 | name->rdev = inode->i_rdev; | |
1572 | security_inode_getsecid(inode, &name->osid); | |
1573 | audit_copy_fcaps(name, dentry); | |
1574 | } | |
1575 | ||
1576 | /** | |
1577 | * audit_log_name - produce AUDIT_PATH record from struct audit_names | |
1578 | * @context: audit_context for the task | |
1579 | * @n: audit_names structure with reportable details | |
1580 | * @path: optional path to report instead of audit_names->name | |
1581 | * @record_num: record number to report when handling a list of names | |
1582 | * @call_panic: optional pointer to int that will be updated if secid fails | |
1583 | */ | |
1584 | void audit_log_name(struct audit_context *context, struct audit_names *n, | |
1585 | struct path *path, int record_num, int *call_panic) | |
1586 | { | |
1587 | struct audit_buffer *ab; | |
1588 | ab = audit_log_start(context, GFP_KERNEL, AUDIT_PATH); | |
1589 | if (!ab) | |
1590 | return; | |
1591 | ||
1592 | audit_log_format(ab, "item=%d", record_num); | |
1593 | ||
1594 | if (path) | |
1595 | audit_log_d_path(ab, " name=", path); | |
1596 | else if (n->name) { | |
1597 | switch (n->name_len) { | |
1598 | case AUDIT_NAME_FULL: | |
1599 | /* log the full path */ | |
1600 | audit_log_format(ab, " name="); | |
1601 | audit_log_untrustedstring(ab, n->name->name); | |
1602 | break; | |
1603 | case 0: | |
1604 | /* name was specified as a relative path and the | |
1605 | * directory component is the cwd */ | |
1606 | audit_log_d_path(ab, " name=", &context->pwd); | |
1607 | break; | |
1608 | default: | |
1609 | /* log the name's directory component */ | |
1610 | audit_log_format(ab, " name="); | |
1611 | audit_log_n_untrustedstring(ab, n->name->name, | |
1612 | n->name_len); | |
1613 | } | |
1614 | } else | |
1615 | audit_log_format(ab, " name=(null)"); | |
1616 | ||
1617 | if (n->ino != (unsigned long)-1) { | |
1618 | audit_log_format(ab, " inode=%lu" | |
1619 | " dev=%02x:%02x mode=%#ho" | |
1620 | " ouid=%u ogid=%u rdev=%02x:%02x", | |
1621 | n->ino, | |
1622 | MAJOR(n->dev), | |
1623 | MINOR(n->dev), | |
1624 | n->mode, | |
1625 | from_kuid(&init_user_ns, n->uid), | |
1626 | from_kgid(&init_user_ns, n->gid), | |
1627 | MAJOR(n->rdev), | |
1628 | MINOR(n->rdev)); | |
1629 | } | |
1630 | if (n->osid != 0) { | |
1631 | char *ctx = NULL; | |
1632 | u32 len; | |
1633 | if (security_secid_to_secctx( | |
1634 | n->osid, &ctx, &len)) { | |
1635 | audit_log_format(ab, " osid=%u", n->osid); | |
1636 | if (call_panic) | |
1637 | *call_panic = 2; | |
1638 | } else { | |
1639 | audit_log_format(ab, " obj=%s", ctx); | |
1640 | security_release_secctx(ctx, len); | |
1641 | } | |
1642 | } | |
1643 | ||
d3aea84a JL |
1644 | /* log the audit_names record type */ |
1645 | audit_log_format(ab, " nametype="); | |
1646 | switch(n->type) { | |
1647 | case AUDIT_TYPE_NORMAL: | |
1648 | audit_log_format(ab, "NORMAL"); | |
1649 | break; | |
1650 | case AUDIT_TYPE_PARENT: | |
1651 | audit_log_format(ab, "PARENT"); | |
1652 | break; | |
1653 | case AUDIT_TYPE_CHILD_DELETE: | |
1654 | audit_log_format(ab, "DELETE"); | |
1655 | break; | |
1656 | case AUDIT_TYPE_CHILD_CREATE: | |
1657 | audit_log_format(ab, "CREATE"); | |
1658 | break; | |
1659 | default: | |
1660 | audit_log_format(ab, "UNKNOWN"); | |
1661 | break; | |
1662 | } | |
1663 | ||
b24a30a7 EP |
1664 | audit_log_fcaps(ab, n); |
1665 | audit_log_end(ab); | |
1666 | } | |
1667 | ||
1668 | int audit_log_task_context(struct audit_buffer *ab) | |
1669 | { | |
1670 | char *ctx = NULL; | |
1671 | unsigned len; | |
1672 | int error; | |
1673 | u32 sid; | |
1674 | ||
1675 | security_task_getsecid(current, &sid); | |
1676 | if (!sid) | |
1677 | return 0; | |
1678 | ||
1679 | error = security_secid_to_secctx(sid, &ctx, &len); | |
1680 | if (error) { | |
1681 | if (error != -EINVAL) | |
1682 | goto error_path; | |
1683 | return 0; | |
1684 | } | |
1685 | ||
1686 | audit_log_format(ab, " subj=%s", ctx); | |
1687 | security_release_secctx(ctx, len); | |
1688 | return 0; | |
1689 | ||
1690 | error_path: | |
1691 | audit_panic("error in audit_log_task_context"); | |
1692 | return error; | |
1693 | } | |
1694 | EXPORT_SYMBOL(audit_log_task_context); | |
1695 | ||
1696 | void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk) | |
1697 | { | |
1698 | const struct cred *cred; | |
1699 | char name[sizeof(tsk->comm)]; | |
1700 | struct mm_struct *mm = tsk->mm; | |
1701 | char *tty; | |
1702 | ||
1703 | if (!ab) | |
1704 | return; | |
1705 | ||
1706 | /* tsk == current */ | |
1707 | cred = current_cred(); | |
1708 | ||
1709 | spin_lock_irq(&tsk->sighand->siglock); | |
1710 | if (tsk->signal && tsk->signal->tty && tsk->signal->tty->name) | |
1711 | tty = tsk->signal->tty->name; | |
1712 | else | |
1713 | tty = "(none)"; | |
1714 | spin_unlock_irq(&tsk->sighand->siglock); | |
1715 | ||
1716 | audit_log_format(ab, | |
1717 | " ppid=%ld pid=%d auid=%u uid=%u gid=%u" | |
1718 | " euid=%u suid=%u fsuid=%u" | |
1719 | " egid=%u sgid=%u fsgid=%u ses=%u tty=%s", | |
1720 | sys_getppid(), | |
1721 | tsk->pid, | |
1722 | from_kuid(&init_user_ns, audit_get_loginuid(tsk)), | |
1723 | from_kuid(&init_user_ns, cred->uid), | |
1724 | from_kgid(&init_user_ns, cred->gid), | |
1725 | from_kuid(&init_user_ns, cred->euid), | |
1726 | from_kuid(&init_user_ns, cred->suid), | |
1727 | from_kuid(&init_user_ns, cred->fsuid), | |
1728 | from_kgid(&init_user_ns, cred->egid), | |
1729 | from_kgid(&init_user_ns, cred->sgid), | |
1730 | from_kgid(&init_user_ns, cred->fsgid), | |
1731 | audit_get_sessionid(tsk), tty); | |
1732 | ||
1733 | get_task_comm(name, tsk); | |
1734 | audit_log_format(ab, " comm="); | |
1735 | audit_log_untrustedstring(ab, name); | |
1736 | ||
1737 | if (mm) { | |
1738 | down_read(&mm->mmap_sem); | |
1739 | if (mm->exe_file) | |
1740 | audit_log_d_path(ab, " exe=", &mm->exe_file->f_path); | |
1741 | up_read(&mm->mmap_sem); | |
1742 | } | |
1743 | audit_log_task_context(ab); | |
1744 | } | |
1745 | EXPORT_SYMBOL(audit_log_task_info); | |
1746 | ||
a51d9eaa KC |
1747 | /** |
1748 | * audit_log_link_denied - report a link restriction denial | |
1749 | * @operation: specific link opreation | |
1750 | * @link: the path that triggered the restriction | |
1751 | */ | |
1752 | void audit_log_link_denied(const char *operation, struct path *link) | |
1753 | { | |
1754 | struct audit_buffer *ab; | |
b24a30a7 EP |
1755 | struct audit_names *name; |
1756 | ||
1757 | name = kzalloc(sizeof(*name), GFP_NOFS); | |
1758 | if (!name) | |
1759 | return; | |
a51d9eaa | 1760 | |
b24a30a7 | 1761 | /* Generate AUDIT_ANOM_LINK with subject, operation, outcome. */ |
a51d9eaa KC |
1762 | ab = audit_log_start(current->audit_context, GFP_KERNEL, |
1763 | AUDIT_ANOM_LINK); | |
d1c7d97a | 1764 | if (!ab) |
b24a30a7 EP |
1765 | goto out; |
1766 | audit_log_format(ab, "op=%s", operation); | |
1767 | audit_log_task_info(ab, current); | |
1768 | audit_log_format(ab, " res=0"); | |
a51d9eaa | 1769 | audit_log_end(ab); |
b24a30a7 EP |
1770 | |
1771 | /* Generate AUDIT_PATH record with object. */ | |
1772 | name->type = AUDIT_TYPE_NORMAL; | |
1773 | audit_copy_inode(name, link->dentry, link->dentry->d_inode); | |
1774 | audit_log_name(current->audit_context, name, link, 0, NULL); | |
1775 | out: | |
1776 | kfree(name); | |
a51d9eaa KC |
1777 | } |
1778 | ||
b0dd25a8 RD |
1779 | /** |
1780 | * audit_log_end - end one audit record | |
1781 | * @ab: the audit_buffer | |
1782 | * | |
1783 | * The netlink_* functions cannot be called inside an irq context, so | |
1784 | * the audit buffer is placed on a queue and a tasklet is scheduled to | |
1da177e4 | 1785 | * remove them from the queue outside the irq context. May be called in |
b0dd25a8 RD |
1786 | * any context. |
1787 | */ | |
b7d11258 | 1788 | void audit_log_end(struct audit_buffer *ab) |
1da177e4 | 1789 | { |
1da177e4 LT |
1790 | if (!ab) |
1791 | return; | |
1792 | if (!audit_rate_check()) { | |
1793 | audit_log_lost("rate limit exceeded"); | |
1794 | } else { | |
8d07a67c | 1795 | struct nlmsghdr *nlh = nlmsg_hdr(ab->skb); |
94191213 | 1796 | nlh->nlmsg_len = ab->skb->len - NLMSG_HDRLEN; |
f3d357b0 | 1797 | |
b7d11258 | 1798 | if (audit_pid) { |
b7d11258 | 1799 | skb_queue_tail(&audit_skb_queue, ab->skb); |
b7d11258 | 1800 | wake_up_interruptible(&kauditd_wait); |
f3d357b0 | 1801 | } else { |
038cbcf6 | 1802 | audit_printk_skb(ab->skb); |
b7d11258 | 1803 | } |
f3d357b0 | 1804 | ab->skb = NULL; |
1da177e4 | 1805 | } |
16e1904e | 1806 | audit_buffer_free(ab); |
1da177e4 LT |
1807 | } |
1808 | ||
b0dd25a8 RD |
1809 | /** |
1810 | * audit_log - Log an audit record | |
1811 | * @ctx: audit context | |
1812 | * @gfp_mask: type of allocation | |
1813 | * @type: audit message type | |
1814 | * @fmt: format string to use | |
1815 | * @...: variable parameters matching the format string | |
1816 | * | |
1817 | * This is a convenience function that calls audit_log_start, | |
1818 | * audit_log_vformat, and audit_log_end. It may be called | |
1819 | * in any context. | |
1820 | */ | |
5600b892 | 1821 | void audit_log(struct audit_context *ctx, gfp_t gfp_mask, int type, |
9ad9ad38 | 1822 | const char *fmt, ...) |
1da177e4 LT |
1823 | { |
1824 | struct audit_buffer *ab; | |
1825 | va_list args; | |
1826 | ||
9ad9ad38 | 1827 | ab = audit_log_start(ctx, gfp_mask, type); |
1da177e4 LT |
1828 | if (ab) { |
1829 | va_start(args, fmt); | |
1830 | audit_log_vformat(ab, fmt, args); | |
1831 | va_end(args); | |
1832 | audit_log_end(ab); | |
1833 | } | |
1834 | } | |
bf45da97 | 1835 | |
131ad62d MDF |
1836 | #ifdef CONFIG_SECURITY |
1837 | /** | |
1838 | * audit_log_secctx - Converts and logs SELinux context | |
1839 | * @ab: audit_buffer | |
1840 | * @secid: security number | |
1841 | * | |
1842 | * This is a helper function that calls security_secid_to_secctx to convert | |
1843 | * secid to secctx and then adds the (converted) SELinux context to the audit | |
1844 | * log by calling audit_log_format, thus also preventing leak of internal secid | |
1845 | * to userspace. If secid cannot be converted audit_panic is called. | |
1846 | */ | |
1847 | void audit_log_secctx(struct audit_buffer *ab, u32 secid) | |
1848 | { | |
1849 | u32 len; | |
1850 | char *secctx; | |
1851 | ||
1852 | if (security_secid_to_secctx(secid, &secctx, &len)) { | |
1853 | audit_panic("Cannot convert secid to context"); | |
1854 | } else { | |
1855 | audit_log_format(ab, " obj=%s", secctx); | |
1856 | security_release_secctx(secctx, len); | |
1857 | } | |
1858 | } | |
1859 | EXPORT_SYMBOL(audit_log_secctx); | |
1860 | #endif | |
1861 | ||
bf45da97 | 1862 | EXPORT_SYMBOL(audit_log_start); |
1863 | EXPORT_SYMBOL(audit_log_end); | |
1864 | EXPORT_SYMBOL(audit_log_format); | |
1865 | EXPORT_SYMBOL(audit_log); |