]>
Commit | Line | Data |
---|---|---|
85c8721f | 1 | /* audit.c -- Auditing support |
1da177e4 LT |
2 | * Gateway between the kernel (e.g., selinux) and the user-space audit daemon. |
3 | * System-call specific features have moved to auditsc.c | |
4 | * | |
6a01b07f | 5 | * Copyright 2003-2007 Red Hat Inc., Durham, North Carolina. |
1da177e4 LT |
6 | * All Rights Reserved. |
7 | * | |
8 | * This program is free software; you can redistribute it and/or modify | |
9 | * it under the terms of the GNU General Public License as published by | |
10 | * the Free Software Foundation; either version 2 of the License, or | |
11 | * (at your option) any later version. | |
12 | * | |
13 | * This program is distributed in the hope that it will be useful, | |
14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
16 | * GNU General Public License for more details. | |
17 | * | |
18 | * You should have received a copy of the GNU General Public License | |
19 | * along with this program; if not, write to the Free Software | |
20 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA | |
21 | * | |
22 | * Written by Rickard E. (Rik) Faith <faith@redhat.com> | |
23 | * | |
d7a96f3a | 24 | * Goals: 1) Integrate fully with Security Modules. |
1da177e4 LT |
25 | * 2) Minimal run-time overhead: |
26 | * a) Minimal when syscall auditing is disabled (audit_enable=0). | |
27 | * b) Small when syscall auditing is enabled and no audit record | |
28 | * is generated (defer as much work as possible to record | |
29 | * generation time): | |
30 | * i) context is allocated, | |
31 | * ii) names from getname are stored without a copy, and | |
32 | * iii) inode information stored from path_lookup. | |
33 | * 3) Ability to disable syscall auditing at boot time (audit=0). | |
34 | * 4) Usable by other parts of the kernel (if audit_log* is called, | |
35 | * then a syscall record will be generated automatically for the | |
36 | * current syscall). | |
37 | * 5) Netlink interface to user-space. | |
38 | * 6) Support low-overhead kernel-based filtering to minimize the | |
39 | * information that must be passed to user-space. | |
40 | * | |
85c8721f | 41 | * Example user-space utilities: http://people.redhat.com/sgrubb/audit/ |
1da177e4 LT |
42 | */ |
43 | ||
44 | #include <linux/init.h> | |
1da177e4 | 45 | #include <asm/types.h> |
60063497 | 46 | #include <linux/atomic.h> |
1da177e4 | 47 | #include <linux/mm.h> |
9984de1a | 48 | #include <linux/export.h> |
5a0e3ad6 | 49 | #include <linux/slab.h> |
b7d11258 DW |
50 | #include <linux/err.h> |
51 | #include <linux/kthread.h> | |
46e959ea | 52 | #include <linux/kernel.h> |
b24a30a7 | 53 | #include <linux/syscalls.h> |
1da177e4 LT |
54 | |
55 | #include <linux/audit.h> | |
56 | ||
57 | #include <net/sock.h> | |
93315ed6 | 58 | #include <net/netlink.h> |
1da177e4 | 59 | #include <linux/skbuff.h> |
131ad62d MDF |
60 | #ifdef CONFIG_SECURITY |
61 | #include <linux/security.h> | |
62 | #endif | |
7dfb7103 | 63 | #include <linux/freezer.h> |
522ed776 | 64 | #include <linux/tty.h> |
34e36d8e | 65 | #include <linux/pid_namespace.h> |
33faba7f | 66 | #include <net/netns/generic.h> |
3dc7e315 DG |
67 | |
68 | #include "audit.h" | |
1da177e4 | 69 | |
a3f07114 | 70 | /* No auditing will take place until audit_initialized == AUDIT_INITIALIZED. |
1da177e4 | 71 | * (Initialization happens after skb_init is called.) */ |
a3f07114 EP |
72 | #define AUDIT_DISABLED -1 |
73 | #define AUDIT_UNINITIALIZED 0 | |
74 | #define AUDIT_INITIALIZED 1 | |
1da177e4 LT |
75 | static int audit_initialized; |
76 | ||
1a6b9f23 EP |
77 | #define AUDIT_OFF 0 |
78 | #define AUDIT_ON 1 | |
79 | #define AUDIT_LOCKED 2 | |
1da177e4 | 80 | int audit_enabled; |
b593d384 | 81 | int audit_ever_enabled; |
1da177e4 | 82 | |
ae9d67af JE |
83 | EXPORT_SYMBOL_GPL(audit_enabled); |
84 | ||
1da177e4 LT |
85 | /* Default state when kernel boots without any parameters. */ |
86 | static int audit_default; | |
87 | ||
88 | /* If auditing cannot proceed, audit_failure selects what happens. */ | |
89 | static int audit_failure = AUDIT_FAIL_PRINTK; | |
90 | ||
75c0371a PE |
91 | /* |
92 | * If audit records are to be written to the netlink socket, audit_pid | |
15e47304 EB |
93 | * contains the pid of the auditd process and audit_nlk_portid contains |
94 | * the portid to use to send netlink messages to that process. | |
75c0371a | 95 | */ |
c2f0c7c3 | 96 | int audit_pid; |
f9441639 | 97 | static __u32 audit_nlk_portid; |
1da177e4 | 98 | |
b0dd25a8 | 99 | /* If audit_rate_limit is non-zero, limit the rate of sending audit records |
1da177e4 LT |
100 | * to that number per second. This prevents DoS attacks, but results in |
101 | * audit records being dropped. */ | |
102 | static int audit_rate_limit; | |
103 | ||
40c0775e RGB |
104 | /* Number of outstanding audit_buffers allowed. |
105 | * When set to zero, this means unlimited. */ | |
1da177e4 | 106 | static int audit_backlog_limit = 64; |
e789e561 RGB |
107 | #define AUDIT_BACKLOG_WAIT_TIME (60 * HZ) |
108 | static int audit_backlog_wait_time = AUDIT_BACKLOG_WAIT_TIME; | |
ac4cec44 | 109 | static int audit_backlog_wait_overflow = 0; |
1da177e4 | 110 | |
c2f0c7c3 | 111 | /* The identity of the user shutting down the audit system. */ |
cca080d9 | 112 | kuid_t audit_sig_uid = INVALID_UID; |
c2f0c7c3 | 113 | pid_t audit_sig_pid = -1; |
e1396065 | 114 | u32 audit_sig_sid = 0; |
c2f0c7c3 | 115 | |
1da177e4 LT |
116 | /* Records can be lost in several ways: |
117 | 0) [suppressed in audit_alloc] | |
118 | 1) out of memory in audit_log_start [kmalloc of struct audit_buffer] | |
119 | 2) out of memory in audit_log_move [alloc_skb] | |
120 | 3) suppressed due to audit_rate_limit | |
121 | 4) suppressed due to audit_backlog_limit | |
122 | */ | |
123 | static atomic_t audit_lost = ATOMIC_INIT(0); | |
124 | ||
125 | /* The netlink socket. */ | |
126 | static struct sock *audit_sock; | |
33faba7f | 127 | int audit_net_id; |
1da177e4 | 128 | |
f368c07d AG |
129 | /* Hash for inode-based rules */ |
130 | struct list_head audit_inode_hash[AUDIT_INODE_BUCKETS]; | |
131 | ||
b7d11258 | 132 | /* The audit_freelist is a list of pre-allocated audit buffers (if more |
1da177e4 LT |
133 | * than AUDIT_MAXFREE are in use, the audit buffer is freed instead of |
134 | * being placed on the freelist). */ | |
1da177e4 | 135 | static DEFINE_SPINLOCK(audit_freelist_lock); |
b0dd25a8 | 136 | static int audit_freelist_count; |
1da177e4 LT |
137 | static LIST_HEAD(audit_freelist); |
138 | ||
b7d11258 | 139 | static struct sk_buff_head audit_skb_queue; |
f3d357b0 EP |
140 | /* queue of skbs to send to auditd when/if it comes back */ |
141 | static struct sk_buff_head audit_skb_hold_queue; | |
b7d11258 DW |
142 | static struct task_struct *kauditd_task; |
143 | static DECLARE_WAIT_QUEUE_HEAD(kauditd_wait); | |
9ad9ad38 | 144 | static DECLARE_WAIT_QUEUE_HEAD(audit_backlog_wait); |
1da177e4 | 145 | |
b0fed402 EP |
146 | static struct audit_features af = {.vers = AUDIT_FEATURE_VERSION, |
147 | .mask = -1, | |
148 | .features = 0, | |
149 | .lock = 0,}; | |
150 | ||
21b85c31 | 151 | static char *audit_feature_names[2] = { |
d040e5af | 152 | "only_unset_loginuid", |
21b85c31 | 153 | "loginuid_immutable", |
b0fed402 EP |
154 | }; |
155 | ||
156 | ||
f368c07d | 157 | /* Serialize requests from userspace. */ |
916d7576 | 158 | DEFINE_MUTEX(audit_cmd_mutex); |
1da177e4 LT |
159 | |
160 | /* AUDIT_BUFSIZ is the size of the temporary buffer used for formatting | |
161 | * audit records. Since printk uses a 1024 byte buffer, this buffer | |
162 | * should be at least that large. */ | |
163 | #define AUDIT_BUFSIZ 1024 | |
164 | ||
165 | /* AUDIT_MAXFREE is the number of empty audit_buffers we keep on the | |
166 | * audit_freelist. Doing so eliminates many kmalloc/kfree calls. */ | |
167 | #define AUDIT_MAXFREE (2*NR_CPUS) | |
168 | ||
169 | /* The audit_buffer is used when formatting an audit record. The caller | |
170 | * locks briefly to get the record off the freelist or to allocate the | |
171 | * buffer, and locks briefly to send the buffer to the netlink layer or | |
172 | * to place it on a transmit queue. Multiple audit_buffers can be in | |
173 | * use simultaneously. */ | |
174 | struct audit_buffer { | |
175 | struct list_head list; | |
8fc6115c | 176 | struct sk_buff *skb; /* formatted skb ready to send */ |
1da177e4 | 177 | struct audit_context *ctx; /* NULL or associated context */ |
9796fdd8 | 178 | gfp_t gfp_mask; |
1da177e4 LT |
179 | }; |
180 | ||
f09ac9db | 181 | struct audit_reply { |
f9441639 | 182 | __u32 portid; |
33faba7f | 183 | pid_t pid; |
f09ac9db EP |
184 | struct sk_buff *skb; |
185 | }; | |
186 | ||
f9441639 | 187 | static void audit_set_portid(struct audit_buffer *ab, __u32 portid) |
c0404993 | 188 | { |
50397bd1 EP |
189 | if (ab) { |
190 | struct nlmsghdr *nlh = nlmsg_hdr(ab->skb); | |
f9441639 | 191 | nlh->nlmsg_pid = portid; |
50397bd1 | 192 | } |
c0404993 SG |
193 | } |
194 | ||
8c8570fb | 195 | void audit_panic(const char *message) |
1da177e4 LT |
196 | { |
197 | switch (audit_failure) | |
198 | { | |
199 | case AUDIT_FAIL_SILENT: | |
200 | break; | |
201 | case AUDIT_FAIL_PRINTK: | |
320f1b1e EP |
202 | if (printk_ratelimit()) |
203 | printk(KERN_ERR "audit: %s\n", message); | |
1da177e4 LT |
204 | break; |
205 | case AUDIT_FAIL_PANIC: | |
b29ee87e EP |
206 | /* test audit_pid since printk is always losey, why bother? */ |
207 | if (audit_pid) | |
208 | panic("audit: %s\n", message); | |
1da177e4 LT |
209 | break; |
210 | } | |
211 | } | |
212 | ||
213 | static inline int audit_rate_check(void) | |
214 | { | |
215 | static unsigned long last_check = 0; | |
216 | static int messages = 0; | |
217 | static DEFINE_SPINLOCK(lock); | |
218 | unsigned long flags; | |
219 | unsigned long now; | |
220 | unsigned long elapsed; | |
221 | int retval = 0; | |
222 | ||
223 | if (!audit_rate_limit) return 1; | |
224 | ||
225 | spin_lock_irqsave(&lock, flags); | |
226 | if (++messages < audit_rate_limit) { | |
227 | retval = 1; | |
228 | } else { | |
229 | now = jiffies; | |
230 | elapsed = now - last_check; | |
231 | if (elapsed > HZ) { | |
232 | last_check = now; | |
233 | messages = 0; | |
234 | retval = 1; | |
235 | } | |
236 | } | |
237 | spin_unlock_irqrestore(&lock, flags); | |
238 | ||
239 | return retval; | |
240 | } | |
241 | ||
b0dd25a8 RD |
242 | /** |
243 | * audit_log_lost - conditionally log lost audit message event | |
244 | * @message: the message stating reason for lost audit message | |
245 | * | |
246 | * Emit at least 1 message per second, even if audit_rate_check is | |
247 | * throttling. | |
248 | * Always increment the lost messages counter. | |
249 | */ | |
1da177e4 LT |
250 | void audit_log_lost(const char *message) |
251 | { | |
252 | static unsigned long last_msg = 0; | |
253 | static DEFINE_SPINLOCK(lock); | |
254 | unsigned long flags; | |
255 | unsigned long now; | |
256 | int print; | |
257 | ||
258 | atomic_inc(&audit_lost); | |
259 | ||
260 | print = (audit_failure == AUDIT_FAIL_PANIC || !audit_rate_limit); | |
261 | ||
262 | if (!print) { | |
263 | spin_lock_irqsave(&lock, flags); | |
264 | now = jiffies; | |
265 | if (now - last_msg > HZ) { | |
266 | print = 1; | |
267 | last_msg = now; | |
268 | } | |
269 | spin_unlock_irqrestore(&lock, flags); | |
270 | } | |
271 | ||
272 | if (print) { | |
320f1b1e EP |
273 | if (printk_ratelimit()) |
274 | printk(KERN_WARNING | |
275 | "audit: audit_lost=%d audit_rate_limit=%d " | |
276 | "audit_backlog_limit=%d\n", | |
277 | atomic_read(&audit_lost), | |
278 | audit_rate_limit, | |
279 | audit_backlog_limit); | |
1da177e4 LT |
280 | audit_panic(message); |
281 | } | |
1da177e4 LT |
282 | } |
283 | ||
1a6b9f23 | 284 | static int audit_log_config_change(char *function_name, int new, int old, |
2532386f | 285 | int allow_changes) |
1da177e4 | 286 | { |
1a6b9f23 EP |
287 | struct audit_buffer *ab; |
288 | int rc = 0; | |
ce29b682 | 289 | |
1a6b9f23 | 290 | ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE); |
0644ec0c KC |
291 | if (unlikely(!ab)) |
292 | return rc; | |
4d3fb709 EP |
293 | audit_log_format(ab, "%s=%d old=%d", function_name, new, old); |
294 | audit_log_session_info(ab); | |
b122c376 EP |
295 | rc = audit_log_task_context(ab); |
296 | if (rc) | |
297 | allow_changes = 0; /* Something weird, deny request */ | |
1a6b9f23 EP |
298 | audit_log_format(ab, " res=%d", allow_changes); |
299 | audit_log_end(ab); | |
6a01b07f | 300 | return rc; |
1da177e4 LT |
301 | } |
302 | ||
dc9eb698 | 303 | static int audit_do_config_change(char *function_name, int *to_change, int new) |
1da177e4 | 304 | { |
1a6b9f23 | 305 | int allow_changes, rc = 0, old = *to_change; |
6a01b07f SG |
306 | |
307 | /* check if we are locked */ | |
1a6b9f23 EP |
308 | if (audit_enabled == AUDIT_LOCKED) |
309 | allow_changes = 0; | |
6a01b07f | 310 | else |
1a6b9f23 | 311 | allow_changes = 1; |
ce29b682 | 312 | |
1a6b9f23 | 313 | if (audit_enabled != AUDIT_OFF) { |
dc9eb698 | 314 | rc = audit_log_config_change(function_name, new, old, allow_changes); |
1a6b9f23 EP |
315 | if (rc) |
316 | allow_changes = 0; | |
6a01b07f | 317 | } |
6a01b07f SG |
318 | |
319 | /* If we are allowed, make the change */ | |
1a6b9f23 EP |
320 | if (allow_changes == 1) |
321 | *to_change = new; | |
6a01b07f SG |
322 | /* Not allowed, update reason */ |
323 | else if (rc == 0) | |
324 | rc = -EPERM; | |
325 | return rc; | |
1da177e4 LT |
326 | } |
327 | ||
dc9eb698 | 328 | static int audit_set_rate_limit(int limit) |
1da177e4 | 329 | { |
dc9eb698 | 330 | return audit_do_config_change("audit_rate_limit", &audit_rate_limit, limit); |
1a6b9f23 | 331 | } |
ce29b682 | 332 | |
dc9eb698 | 333 | static int audit_set_backlog_limit(int limit) |
1a6b9f23 | 334 | { |
dc9eb698 | 335 | return audit_do_config_change("audit_backlog_limit", &audit_backlog_limit, limit); |
1a6b9f23 | 336 | } |
6a01b07f | 337 | |
51cc83f0 RGB |
338 | static int audit_set_backlog_wait_time(int timeout) |
339 | { | |
340 | return audit_do_config_change("audit_backlog_wait_time", | |
341 | &audit_backlog_wait_time, timeout); | |
342 | } | |
343 | ||
dc9eb698 | 344 | static int audit_set_enabled(int state) |
1a6b9f23 | 345 | { |
b593d384 | 346 | int rc; |
1a6b9f23 EP |
347 | if (state < AUDIT_OFF || state > AUDIT_LOCKED) |
348 | return -EINVAL; | |
6a01b07f | 349 | |
dc9eb698 | 350 | rc = audit_do_config_change("audit_enabled", &audit_enabled, state); |
b593d384 EP |
351 | if (!rc) |
352 | audit_ever_enabled |= !!state; | |
353 | ||
354 | return rc; | |
1da177e4 LT |
355 | } |
356 | ||
dc9eb698 | 357 | static int audit_set_failure(int state) |
1da177e4 | 358 | { |
1da177e4 LT |
359 | if (state != AUDIT_FAIL_SILENT |
360 | && state != AUDIT_FAIL_PRINTK | |
361 | && state != AUDIT_FAIL_PANIC) | |
362 | return -EINVAL; | |
ce29b682 | 363 | |
dc9eb698 | 364 | return audit_do_config_change("audit_failure", &audit_failure, state); |
1da177e4 LT |
365 | } |
366 | ||
f3d357b0 EP |
367 | /* |
368 | * Queue skbs to be sent to auditd when/if it comes back. These skbs should | |
369 | * already have been sent via prink/syslog and so if these messages are dropped | |
370 | * it is not a huge concern since we already passed the audit_log_lost() | |
371 | * notification and stuff. This is just nice to get audit messages during | |
372 | * boot before auditd is running or messages generated while auditd is stopped. | |
373 | * This only holds messages is audit_default is set, aka booting with audit=1 | |
374 | * or building your kernel that way. | |
375 | */ | |
376 | static void audit_hold_skb(struct sk_buff *skb) | |
377 | { | |
378 | if (audit_default && | |
40c0775e RGB |
379 | (!audit_backlog_limit || |
380 | skb_queue_len(&audit_skb_hold_queue) < audit_backlog_limit)) | |
f3d357b0 EP |
381 | skb_queue_tail(&audit_skb_hold_queue, skb); |
382 | else | |
383 | kfree_skb(skb); | |
384 | } | |
385 | ||
038cbcf6 EP |
386 | /* |
387 | * For one reason or another this nlh isn't getting delivered to the userspace | |
388 | * audit daemon, just send it to printk. | |
389 | */ | |
390 | static void audit_printk_skb(struct sk_buff *skb) | |
391 | { | |
392 | struct nlmsghdr *nlh = nlmsg_hdr(skb); | |
c64e66c6 | 393 | char *data = nlmsg_data(nlh); |
038cbcf6 EP |
394 | |
395 | if (nlh->nlmsg_type != AUDIT_EOE) { | |
396 | if (printk_ratelimit()) | |
397 | printk(KERN_NOTICE "type=%d %s\n", nlh->nlmsg_type, data); | |
398 | else | |
399 | audit_log_lost("printk limit exceeded\n"); | |
400 | } | |
401 | ||
402 | audit_hold_skb(skb); | |
403 | } | |
404 | ||
f3d357b0 EP |
405 | static void kauditd_send_skb(struct sk_buff *skb) |
406 | { | |
407 | int err; | |
408 | /* take a reference in case we can't send it and we want to hold it */ | |
409 | skb_get(skb); | |
15e47304 | 410 | err = netlink_unicast(audit_sock, skb, audit_nlk_portid, 0); |
f3d357b0 | 411 | if (err < 0) { |
c9404c9c | 412 | BUG_ON(err != -ECONNREFUSED); /* Shouldn't happen */ |
04ee1a3b RGB |
413 | if (audit_pid) { |
414 | printk(KERN_ERR "audit: *NO* daemon at audit_pid=%d\n", audit_pid); | |
415 | audit_log_lost("auditd disappeared\n"); | |
416 | audit_pid = 0; | |
417 | audit_sock = NULL; | |
418 | } | |
f3d357b0 EP |
419 | /* we might get lucky and get this in the next auditd */ |
420 | audit_hold_skb(skb); | |
421 | } else | |
422 | /* drop the extra reference if sent ok */ | |
70d4bf6d | 423 | consume_skb(skb); |
f3d357b0 EP |
424 | } |
425 | ||
b551d1d9 RGB |
426 | /* |
427 | * flush_hold_queue - empty the hold queue if auditd appears | |
428 | * | |
429 | * If auditd just started, drain the queue of messages already | |
430 | * sent to syslog/printk. Remember loss here is ok. We already | |
431 | * called audit_log_lost() if it didn't go out normally. so the | |
432 | * race between the skb_dequeue and the next check for audit_pid | |
433 | * doesn't matter. | |
434 | * | |
435 | * If you ever find kauditd to be too slow we can get a perf win | |
436 | * by doing our own locking and keeping better track if there | |
437 | * are messages in this queue. I don't see the need now, but | |
438 | * in 5 years when I want to play with this again I'll see this | |
439 | * note and still have no friggin idea what i'm thinking today. | |
440 | */ | |
441 | static void flush_hold_queue(void) | |
b7d11258 DW |
442 | { |
443 | struct sk_buff *skb; | |
444 | ||
b551d1d9 RGB |
445 | if (!audit_default || !audit_pid) |
446 | return; | |
447 | ||
448 | skb = skb_dequeue(&audit_skb_hold_queue); | |
449 | if (likely(!skb)) | |
450 | return; | |
451 | ||
452 | while (skb && audit_pid) { | |
453 | kauditd_send_skb(skb); | |
454 | skb = skb_dequeue(&audit_skb_hold_queue); | |
455 | } | |
456 | ||
457 | /* | |
458 | * if auditd just disappeared but we | |
459 | * dequeued an skb we need to drop ref | |
460 | */ | |
461 | if (skb) | |
462 | consume_skb(skb); | |
463 | } | |
464 | ||
97a41e26 | 465 | static int kauditd_thread(void *dummy) |
b7d11258 | 466 | { |
83144186 | 467 | set_freezable(); |
4899b8b1 | 468 | while (!kthread_should_stop()) { |
3320c513 RGB |
469 | struct sk_buff *skb; |
470 | DECLARE_WAITQUEUE(wait, current); | |
471 | ||
b551d1d9 | 472 | flush_hold_queue(); |
f3d357b0 | 473 | |
b7d11258 | 474 | skb = skb_dequeue(&audit_skb_queue); |
db897319 | 475 | |
b7d11258 | 476 | if (skb) { |
db897319 DD |
477 | if (skb_queue_len(&audit_skb_queue) <= audit_backlog_limit) |
478 | wake_up(&audit_backlog_wait); | |
f3d357b0 EP |
479 | if (audit_pid) |
480 | kauditd_send_skb(skb); | |
038cbcf6 EP |
481 | else |
482 | audit_printk_skb(skb); | |
3320c513 RGB |
483 | continue; |
484 | } | |
485 | set_current_state(TASK_INTERRUPTIBLE); | |
486 | add_wait_queue(&kauditd_wait, &wait); | |
b7d11258 | 487 | |
3320c513 RGB |
488 | if (!skb_queue_len(&audit_skb_queue)) { |
489 | try_to_freeze(); | |
490 | schedule(); | |
b7d11258 | 491 | } |
3320c513 RGB |
492 | |
493 | __set_current_state(TASK_RUNNING); | |
494 | remove_wait_queue(&kauditd_wait, &wait); | |
b7d11258 | 495 | } |
4899b8b1 | 496 | return 0; |
b7d11258 DW |
497 | } |
498 | ||
9044e6bc AV |
499 | int audit_send_list(void *_dest) |
500 | { | |
501 | struct audit_netlink_list *dest = _dest; | |
9044e6bc | 502 | struct sk_buff *skb; |
33faba7f RGB |
503 | struct net *net = get_net_ns_by_pid(dest->pid); |
504 | struct audit_net *aunet = net_generic(net, audit_net_id); | |
9044e6bc AV |
505 | |
506 | /* wait for parent to finish and send an ACK */ | |
f368c07d AG |
507 | mutex_lock(&audit_cmd_mutex); |
508 | mutex_unlock(&audit_cmd_mutex); | |
9044e6bc AV |
509 | |
510 | while ((skb = __skb_dequeue(&dest->q)) != NULL) | |
33faba7f | 511 | netlink_unicast(aunet->nlsk, skb, dest->portid, 0); |
9044e6bc AV |
512 | |
513 | kfree(dest); | |
514 | ||
515 | return 0; | |
516 | } | |
517 | ||
f9441639 | 518 | struct sk_buff *audit_make_reply(__u32 portid, int seq, int type, int done, |
b8800aa5 | 519 | int multi, const void *payload, int size) |
9044e6bc AV |
520 | { |
521 | struct sk_buff *skb; | |
522 | struct nlmsghdr *nlh; | |
9044e6bc AV |
523 | void *data; |
524 | int flags = multi ? NLM_F_MULTI : 0; | |
525 | int t = done ? NLMSG_DONE : type; | |
526 | ||
ee080e6c | 527 | skb = nlmsg_new(size, GFP_KERNEL); |
9044e6bc AV |
528 | if (!skb) |
529 | return NULL; | |
530 | ||
f9441639 | 531 | nlh = nlmsg_put(skb, portid, seq, t, size, flags); |
c64e66c6 DM |
532 | if (!nlh) |
533 | goto out_kfree_skb; | |
534 | data = nlmsg_data(nlh); | |
9044e6bc AV |
535 | memcpy(data, payload, size); |
536 | return skb; | |
537 | ||
c64e66c6 DM |
538 | out_kfree_skb: |
539 | kfree_skb(skb); | |
9044e6bc AV |
540 | return NULL; |
541 | } | |
542 | ||
f09ac9db EP |
543 | static int audit_send_reply_thread(void *arg) |
544 | { | |
545 | struct audit_reply *reply = (struct audit_reply *)arg; | |
33faba7f RGB |
546 | struct net *net = get_net_ns_by_pid(reply->pid); |
547 | struct audit_net *aunet = net_generic(net, audit_net_id); | |
f09ac9db EP |
548 | |
549 | mutex_lock(&audit_cmd_mutex); | |
550 | mutex_unlock(&audit_cmd_mutex); | |
551 | ||
552 | /* Ignore failure. It'll only happen if the sender goes away, | |
553 | because our timeout is set to infinite. */ | |
33faba7f | 554 | netlink_unicast(aunet->nlsk , reply->skb, reply->portid, 0); |
f09ac9db EP |
555 | kfree(reply); |
556 | return 0; | |
557 | } | |
b0dd25a8 RD |
558 | /** |
559 | * audit_send_reply - send an audit reply message via netlink | |
f9441639 | 560 | * @portid: netlink port to which to send reply |
b0dd25a8 RD |
561 | * @seq: sequence number |
562 | * @type: audit message type | |
563 | * @done: done (last) flag | |
564 | * @multi: multi-part message flag | |
565 | * @payload: payload data | |
566 | * @size: payload size | |
567 | * | |
f9441639 | 568 | * Allocates an skb, builds the netlink message, and sends it to the port id. |
b0dd25a8 RD |
569 | * No failure notifications. |
570 | */ | |
f9441639 RGB |
571 | static void audit_send_reply(__u32 portid, int seq, int type, int done, |
572 | int multi, const void *payload, int size) | |
1da177e4 | 573 | { |
f09ac9db EP |
574 | struct sk_buff *skb; |
575 | struct task_struct *tsk; | |
576 | struct audit_reply *reply = kmalloc(sizeof(struct audit_reply), | |
577 | GFP_KERNEL); | |
578 | ||
579 | if (!reply) | |
580 | return; | |
581 | ||
f9441639 | 582 | skb = audit_make_reply(portid, seq, type, done, multi, payload, size); |
1da177e4 | 583 | if (!skb) |
fcaf1eb8 | 584 | goto out; |
f09ac9db | 585 | |
f9441639 | 586 | reply->portid = portid; |
33faba7f | 587 | reply->pid = task_pid_vnr(current); |
f09ac9db EP |
588 | reply->skb = skb; |
589 | ||
590 | tsk = kthread_run(audit_send_reply_thread, reply, "audit_send_reply"); | |
fcaf1eb8 AM |
591 | if (!IS_ERR(tsk)) |
592 | return; | |
593 | kfree_skb(skb); | |
594 | out: | |
595 | kfree(reply); | |
1da177e4 LT |
596 | } |
597 | ||
598 | /* | |
599 | * Check for appropriate CAP_AUDIT_ capabilities on incoming audit | |
600 | * control messages. | |
601 | */ | |
c7bdb545 | 602 | static int audit_netlink_ok(struct sk_buff *skb, u16 msg_type) |
1da177e4 LT |
603 | { |
604 | int err = 0; | |
605 | ||
34e36d8e EB |
606 | /* Only support the initial namespaces for now. */ |
607 | if ((current_user_ns() != &init_user_ns) || | |
608 | (task_active_pid_ns(current) != &init_pid_ns)) | |
609 | return -EPERM; | |
610 | ||
1da177e4 | 611 | switch (msg_type) { |
1da177e4 | 612 | case AUDIT_LIST: |
1da177e4 LT |
613 | case AUDIT_ADD: |
614 | case AUDIT_DEL: | |
18900909 EP |
615 | return -EOPNOTSUPP; |
616 | case AUDIT_GET: | |
617 | case AUDIT_SET: | |
b0fed402 EP |
618 | case AUDIT_GET_FEATURE: |
619 | case AUDIT_SET_FEATURE: | |
18900909 EP |
620 | case AUDIT_LIST_RULES: |
621 | case AUDIT_ADD_RULE: | |
93315ed6 | 622 | case AUDIT_DEL_RULE: |
c2f0c7c3 | 623 | case AUDIT_SIGNAL_INFO: |
522ed776 MT |
624 | case AUDIT_TTY_GET: |
625 | case AUDIT_TTY_SET: | |
74c3cbe3 AV |
626 | case AUDIT_TRIM: |
627 | case AUDIT_MAKE_EQUIV: | |
fd778461 | 628 | if (!capable(CAP_AUDIT_CONTROL)) |
1da177e4 LT |
629 | err = -EPERM; |
630 | break; | |
05474106 | 631 | case AUDIT_USER: |
039b6b3e RD |
632 | case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG: |
633 | case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2: | |
fd778461 | 634 | if (!capable(CAP_AUDIT_WRITE)) |
1da177e4 LT |
635 | err = -EPERM; |
636 | break; | |
637 | default: /* bad msg */ | |
638 | err = -EINVAL; | |
639 | } | |
640 | ||
641 | return err; | |
642 | } | |
643 | ||
dc9eb698 | 644 | static int audit_log_common_recv_msg(struct audit_buffer **ab, u16 msg_type) |
50397bd1 EP |
645 | { |
646 | int rc = 0; | |
dc9eb698 | 647 | uid_t uid = from_kuid(&init_user_ns, current_uid()); |
50397bd1 | 648 | |
0868a5e1 | 649 | if (!audit_enabled && msg_type != AUDIT_USER_AVC) { |
50397bd1 EP |
650 | *ab = NULL; |
651 | return rc; | |
652 | } | |
653 | ||
654 | *ab = audit_log_start(NULL, GFP_KERNEL, msg_type); | |
0644ec0c KC |
655 | if (unlikely(!*ab)) |
656 | return rc; | |
4d3fb709 EP |
657 | audit_log_format(*ab, "pid=%d uid=%u", task_tgid_vnr(current), uid); |
658 | audit_log_session_info(*ab); | |
b122c376 | 659 | audit_log_task_context(*ab); |
50397bd1 EP |
660 | |
661 | return rc; | |
662 | } | |
663 | ||
b0fed402 EP |
664 | int is_audit_feature_set(int i) |
665 | { | |
666 | return af.features & AUDIT_FEATURE_TO_MASK(i); | |
667 | } | |
668 | ||
669 | ||
670 | static int audit_get_feature(struct sk_buff *skb) | |
671 | { | |
672 | u32 seq; | |
673 | ||
674 | seq = nlmsg_hdr(skb)->nlmsg_seq; | |
675 | ||
676 | audit_send_reply(NETLINK_CB(skb).portid, seq, AUDIT_GET, 0, 0, | |
677 | &af, sizeof(af)); | |
678 | ||
679 | return 0; | |
680 | } | |
681 | ||
682 | static void audit_log_feature_change(int which, u32 old_feature, u32 new_feature, | |
683 | u32 old_lock, u32 new_lock, int res) | |
684 | { | |
685 | struct audit_buffer *ab; | |
686 | ||
b6c50fe0 G |
687 | if (audit_enabled == AUDIT_OFF) |
688 | return; | |
689 | ||
b0fed402 | 690 | ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_FEATURE_CHANGE); |
aabce351 | 691 | audit_log_format(ab, "feature=%s old=%d new=%d old_lock=%d new_lock=%d res=%d", |
b0fed402 EP |
692 | audit_feature_names[which], !!old_feature, !!new_feature, |
693 | !!old_lock, !!new_lock, res); | |
694 | audit_log_end(ab); | |
695 | } | |
696 | ||
697 | static int audit_set_feature(struct sk_buff *skb) | |
698 | { | |
699 | struct audit_features *uaf; | |
700 | int i; | |
701 | ||
702 | BUILD_BUG_ON(AUDIT_LAST_FEATURE + 1 > sizeof(audit_feature_names)/sizeof(audit_feature_names[0])); | |
703 | uaf = nlmsg_data(nlmsg_hdr(skb)); | |
704 | ||
705 | /* if there is ever a version 2 we should handle that here */ | |
706 | ||
707 | for (i = 0; i <= AUDIT_LAST_FEATURE; i++) { | |
708 | u32 feature = AUDIT_FEATURE_TO_MASK(i); | |
709 | u32 old_feature, new_feature, old_lock, new_lock; | |
710 | ||
711 | /* if we are not changing this feature, move along */ | |
712 | if (!(feature & uaf->mask)) | |
713 | continue; | |
714 | ||
715 | old_feature = af.features & feature; | |
716 | new_feature = uaf->features & feature; | |
717 | new_lock = (uaf->lock | af.lock) & feature; | |
718 | old_lock = af.lock & feature; | |
719 | ||
720 | /* are we changing a locked feature? */ | |
4547b3bc | 721 | if (old_lock && (new_feature != old_feature)) { |
b0fed402 EP |
722 | audit_log_feature_change(i, old_feature, new_feature, |
723 | old_lock, new_lock, 0); | |
724 | return -EPERM; | |
725 | } | |
726 | } | |
727 | /* nothing invalid, do the changes */ | |
728 | for (i = 0; i <= AUDIT_LAST_FEATURE; i++) { | |
729 | u32 feature = AUDIT_FEATURE_TO_MASK(i); | |
730 | u32 old_feature, new_feature, old_lock, new_lock; | |
731 | ||
732 | /* if we are not changing this feature, move along */ | |
733 | if (!(feature & uaf->mask)) | |
734 | continue; | |
735 | ||
736 | old_feature = af.features & feature; | |
737 | new_feature = uaf->features & feature; | |
738 | old_lock = af.lock & feature; | |
739 | new_lock = (uaf->lock | af.lock) & feature; | |
740 | ||
741 | if (new_feature != old_feature) | |
742 | audit_log_feature_change(i, old_feature, new_feature, | |
743 | old_lock, new_lock, 1); | |
744 | ||
745 | if (new_feature) | |
746 | af.features |= feature; | |
747 | else | |
748 | af.features &= ~feature; | |
749 | af.lock |= new_lock; | |
750 | } | |
751 | ||
752 | return 0; | |
753 | } | |
754 | ||
1da177e4 LT |
755 | static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) |
756 | { | |
dc9eb698 | 757 | u32 seq; |
1da177e4 | 758 | void *data; |
1da177e4 | 759 | int err; |
c0404993 | 760 | struct audit_buffer *ab; |
1da177e4 | 761 | u16 msg_type = nlh->nlmsg_type; |
e1396065 | 762 | struct audit_sig_info *sig_data; |
50397bd1 | 763 | char *ctx = NULL; |
e1396065 | 764 | u32 len; |
1da177e4 | 765 | |
c7bdb545 | 766 | err = audit_netlink_ok(skb, msg_type); |
1da177e4 LT |
767 | if (err) |
768 | return err; | |
769 | ||
b0dd25a8 RD |
770 | /* As soon as there's any sign of userspace auditd, |
771 | * start kauditd to talk to it */ | |
13f51e1c | 772 | if (!kauditd_task) { |
b7d11258 | 773 | kauditd_task = kthread_run(kauditd_thread, NULL, "kauditd"); |
13f51e1c G |
774 | if (IS_ERR(kauditd_task)) { |
775 | err = PTR_ERR(kauditd_task); | |
776 | kauditd_task = NULL; | |
777 | return err; | |
778 | } | |
b7d11258 | 779 | } |
1da177e4 | 780 | seq = nlh->nlmsg_seq; |
c64e66c6 | 781 | data = nlmsg_data(nlh); |
1da177e4 LT |
782 | |
783 | switch (msg_type) { | |
09f883a9 RGB |
784 | case AUDIT_GET: { |
785 | struct audit_status s; | |
786 | memset(&s, 0, sizeof(s)); | |
787 | s.enabled = audit_enabled; | |
788 | s.failure = audit_failure; | |
789 | s.pid = audit_pid; | |
790 | s.rate_limit = audit_rate_limit; | |
791 | s.backlog_limit = audit_backlog_limit; | |
792 | s.lost = atomic_read(&audit_lost); | |
793 | s.backlog = skb_queue_len(&audit_skb_queue); | |
51cc83f0 RGB |
794 | s.version = 2; |
795 | s.backlog_wait_time = audit_backlog_wait_time; | |
15e47304 | 796 | audit_send_reply(NETLINK_CB(skb).portid, seq, AUDIT_GET, 0, 0, |
09f883a9 | 797 | &s, sizeof(s)); |
1da177e4 | 798 | break; |
09f883a9 RGB |
799 | } |
800 | case AUDIT_SET: { | |
801 | struct audit_status s; | |
802 | memset(&s, 0, sizeof(s)); | |
803 | /* guard against past and future API changes */ | |
804 | memcpy(&s, data, min_t(size_t, sizeof(s), nlmsg_len(nlh))); | |
805 | if (s.mask & AUDIT_STATUS_ENABLED) { | |
806 | err = audit_set_enabled(s.enabled); | |
20c6aaa3 | 807 | if (err < 0) |
808 | return err; | |
1da177e4 | 809 | } |
09f883a9 RGB |
810 | if (s.mask & AUDIT_STATUS_FAILURE) { |
811 | err = audit_set_failure(s.failure); | |
20c6aaa3 | 812 | if (err < 0) |
813 | return err; | |
1da177e4 | 814 | } |
09f883a9 RGB |
815 | if (s.mask & AUDIT_STATUS_PID) { |
816 | int new_pid = s.pid; | |
1a6b9f23 EP |
817 | |
818 | if (audit_enabled != AUDIT_OFF) | |
dc9eb698 | 819 | audit_log_config_change("audit_pid", new_pid, audit_pid, 1); |
1a6b9f23 | 820 | audit_pid = new_pid; |
15e47304 | 821 | audit_nlk_portid = NETLINK_CB(skb).portid; |
33faba7f | 822 | audit_sock = NETLINK_CB(skb).sk; |
1da177e4 | 823 | } |
09f883a9 RGB |
824 | if (s.mask & AUDIT_STATUS_RATE_LIMIT) { |
825 | err = audit_set_rate_limit(s.rate_limit); | |
20c6aaa3 | 826 | if (err < 0) |
827 | return err; | |
828 | } | |
51cc83f0 | 829 | if (s.mask & AUDIT_STATUS_BACKLOG_LIMIT) { |
09f883a9 | 830 | err = audit_set_backlog_limit(s.backlog_limit); |
51cc83f0 RGB |
831 | if (err < 0) |
832 | return err; | |
833 | } | |
834 | switch (s.version) { | |
835 | /* add future vers # cases immediately below and allow | |
836 | * to fall through */ | |
837 | case 2: | |
838 | if (s.mask & AUDIT_STATUS_BACKLOG_WAIT_TIME) { | |
839 | if (sizeof(s) > (size_t)nlh->nlmsg_len) | |
840 | return -EINVAL; | |
841 | if (s.backlog_wait_time < 0 || | |
842 | s.backlog_wait_time > 10*AUDIT_BACKLOG_WAIT_TIME) | |
843 | return -EINVAL; | |
844 | err = audit_set_backlog_wait_time(s.backlog_wait_time); | |
845 | if (err < 0) | |
846 | return err; | |
847 | } | |
848 | default: | |
849 | break; | |
850 | } | |
1da177e4 | 851 | break; |
09f883a9 | 852 | } |
b0fed402 EP |
853 | case AUDIT_GET_FEATURE: |
854 | err = audit_get_feature(skb); | |
855 | if (err) | |
856 | return err; | |
857 | break; | |
858 | case AUDIT_SET_FEATURE: | |
859 | err = audit_set_feature(skb); | |
860 | if (err) | |
861 | return err; | |
862 | break; | |
05474106 | 863 | case AUDIT_USER: |
039b6b3e RD |
864 | case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG: |
865 | case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2: | |
4a4cd633 DW |
866 | if (!audit_enabled && msg_type != AUDIT_USER_AVC) |
867 | return 0; | |
868 | ||
62062cf8 | 869 | err = audit_filter_user(msg_type); |
4a4cd633 DW |
870 | if (err == 1) { |
871 | err = 0; | |
522ed776 | 872 | if (msg_type == AUDIT_USER_TTY) { |
152f497b | 873 | err = tty_audit_push_current(); |
522ed776 MT |
874 | if (err) |
875 | break; | |
876 | } | |
dc9eb698 | 877 | audit_log_common_recv_msg(&ab, msg_type); |
50397bd1 | 878 | if (msg_type != AUDIT_USER_TTY) |
b50eba7e RGB |
879 | audit_log_format(ab, " msg='%.*s'", |
880 | AUDIT_MESSAGE_TEXT_MAX, | |
50397bd1 EP |
881 | (char *)data); |
882 | else { | |
883 | int size; | |
884 | ||
f7616102 | 885 | audit_log_format(ab, " data="); |
50397bd1 | 886 | size = nlmsg_len(nlh); |
55ad2f8d MT |
887 | if (size > 0 && |
888 | ((unsigned char *)data)[size - 1] == '\0') | |
889 | size--; | |
b556f8ad | 890 | audit_log_n_untrustedstring(ab, data, size); |
4a4cd633 | 891 | } |
f9441639 | 892 | audit_set_portid(ab, NETLINK_CB(skb).portid); |
50397bd1 | 893 | audit_log_end(ab); |
0f45aa18 | 894 | } |
1da177e4 | 895 | break; |
93315ed6 AG |
896 | case AUDIT_ADD_RULE: |
897 | case AUDIT_DEL_RULE: | |
898 | if (nlmsg_len(nlh) < sizeof(struct audit_rule_data)) | |
899 | return -EINVAL; | |
1a6b9f23 | 900 | if (audit_enabled == AUDIT_LOCKED) { |
dc9eb698 EP |
901 | audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE); |
902 | audit_log_format(ab, " audit_enabled=%d res=0", audit_enabled); | |
50397bd1 | 903 | audit_log_end(ab); |
6a01b07f SG |
904 | return -EPERM; |
905 | } | |
93315ed6 AG |
906 | /* fallthrough */ |
907 | case AUDIT_LIST_RULES: | |
15e47304 | 908 | err = audit_receive_filter(msg_type, NETLINK_CB(skb).portid, |
dc9eb698 | 909 | seq, data, nlmsg_len(nlh)); |
1da177e4 | 910 | break; |
74c3cbe3 AV |
911 | case AUDIT_TRIM: |
912 | audit_trim_trees(); | |
dc9eb698 | 913 | audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE); |
74c3cbe3 AV |
914 | audit_log_format(ab, " op=trim res=1"); |
915 | audit_log_end(ab); | |
916 | break; | |
917 | case AUDIT_MAKE_EQUIV: { | |
918 | void *bufp = data; | |
919 | u32 sizes[2]; | |
7719e437 | 920 | size_t msglen = nlmsg_len(nlh); |
74c3cbe3 AV |
921 | char *old, *new; |
922 | ||
923 | err = -EINVAL; | |
7719e437 | 924 | if (msglen < 2 * sizeof(u32)) |
74c3cbe3 AV |
925 | break; |
926 | memcpy(sizes, bufp, 2 * sizeof(u32)); | |
927 | bufp += 2 * sizeof(u32); | |
7719e437 HH |
928 | msglen -= 2 * sizeof(u32); |
929 | old = audit_unpack_string(&bufp, &msglen, sizes[0]); | |
74c3cbe3 AV |
930 | if (IS_ERR(old)) { |
931 | err = PTR_ERR(old); | |
932 | break; | |
933 | } | |
7719e437 | 934 | new = audit_unpack_string(&bufp, &msglen, sizes[1]); |
74c3cbe3 AV |
935 | if (IS_ERR(new)) { |
936 | err = PTR_ERR(new); | |
937 | kfree(old); | |
938 | break; | |
939 | } | |
940 | /* OK, here comes... */ | |
941 | err = audit_tag_tree(old, new); | |
942 | ||
dc9eb698 | 943 | audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE); |
50397bd1 | 944 | |
74c3cbe3 AV |
945 | audit_log_format(ab, " op=make_equiv old="); |
946 | audit_log_untrustedstring(ab, old); | |
947 | audit_log_format(ab, " new="); | |
948 | audit_log_untrustedstring(ab, new); | |
949 | audit_log_format(ab, " res=%d", !err); | |
950 | audit_log_end(ab); | |
951 | kfree(old); | |
952 | kfree(new); | |
953 | break; | |
954 | } | |
c2f0c7c3 | 955 | case AUDIT_SIGNAL_INFO: |
939cbf26 EP |
956 | len = 0; |
957 | if (audit_sig_sid) { | |
958 | err = security_secid_to_secctx(audit_sig_sid, &ctx, &len); | |
959 | if (err) | |
960 | return err; | |
961 | } | |
e1396065 AV |
962 | sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL); |
963 | if (!sig_data) { | |
939cbf26 EP |
964 | if (audit_sig_sid) |
965 | security_release_secctx(ctx, len); | |
e1396065 AV |
966 | return -ENOMEM; |
967 | } | |
cca080d9 | 968 | sig_data->uid = from_kuid(&init_user_ns, audit_sig_uid); |
e1396065 | 969 | sig_data->pid = audit_sig_pid; |
939cbf26 EP |
970 | if (audit_sig_sid) { |
971 | memcpy(sig_data->ctx, ctx, len); | |
972 | security_release_secctx(ctx, len); | |
973 | } | |
15e47304 | 974 | audit_send_reply(NETLINK_CB(skb).portid, seq, AUDIT_SIGNAL_INFO, |
e1396065 AV |
975 | 0, 0, sig_data, sizeof(*sig_data) + len); |
976 | kfree(sig_data); | |
c2f0c7c3 | 977 | break; |
522ed776 MT |
978 | case AUDIT_TTY_GET: { |
979 | struct audit_tty_status s; | |
8aa14b64 EB |
980 | struct task_struct *tsk = current; |
981 | ||
7173c54e | 982 | spin_lock(&tsk->sighand->siglock); |
b95d77fe | 983 | s.enabled = tsk->signal->audit_tty; |
46e959ea | 984 | s.log_passwd = tsk->signal->audit_tty_log_passwd; |
7173c54e | 985 | spin_unlock(&tsk->sighand->siglock); |
8aa14b64 | 986 | |
aecdc33e | 987 | audit_send_reply(NETLINK_CB(skb).portid, seq, |
8aa14b64 | 988 | AUDIT_TTY_GET, 0, 0, &s, sizeof(s)); |
522ed776 MT |
989 | break; |
990 | } | |
991 | case AUDIT_TTY_SET: { | |
46e959ea | 992 | struct audit_tty_status s; |
8aa14b64 | 993 | struct task_struct *tsk = current; |
522ed776 | 994 | |
46e959ea RGB |
995 | memset(&s, 0, sizeof(s)); |
996 | /* guard against past and future API changes */ | |
4d8fe737 | 997 | memcpy(&s, data, min_t(size_t, sizeof(s), nlmsg_len(nlh))); |
46e959ea RGB |
998 | if ((s.enabled != 0 && s.enabled != 1) || |
999 | (s.log_passwd != 0 && s.log_passwd != 1)) | |
522ed776 | 1000 | return -EINVAL; |
8aa14b64 | 1001 | |
7173c54e | 1002 | spin_lock(&tsk->sighand->siglock); |
46e959ea RGB |
1003 | tsk->signal->audit_tty = s.enabled; |
1004 | tsk->signal->audit_tty_log_passwd = s.log_passwd; | |
7173c54e | 1005 | spin_unlock(&tsk->sighand->siglock); |
522ed776 MT |
1006 | break; |
1007 | } | |
1da177e4 LT |
1008 | default: |
1009 | err = -EINVAL; | |
1010 | break; | |
1011 | } | |
1012 | ||
1013 | return err < 0 ? err : 0; | |
1014 | } | |
1015 | ||
b0dd25a8 | 1016 | /* |
ea7ae60b EP |
1017 | * Get message from skb. Each message is processed by audit_receive_msg. |
1018 | * Malformed skbs with wrong length are discarded silently. | |
b0dd25a8 | 1019 | */ |
2a0a6ebe | 1020 | static void audit_receive_skb(struct sk_buff *skb) |
1da177e4 | 1021 | { |
ea7ae60b EP |
1022 | struct nlmsghdr *nlh; |
1023 | /* | |
94191213 | 1024 | * len MUST be signed for nlmsg_next to be able to dec it below 0 |
ea7ae60b EP |
1025 | * if the nlmsg_len was not aligned |
1026 | */ | |
1027 | int len; | |
1028 | int err; | |
1029 | ||
1030 | nlh = nlmsg_hdr(skb); | |
1031 | len = skb->len; | |
1032 | ||
94191213 | 1033 | while (nlmsg_ok(nlh, len)) { |
ea7ae60b EP |
1034 | err = audit_receive_msg(skb, nlh); |
1035 | /* if err or if this message says it wants a response */ | |
1036 | if (err || (nlh->nlmsg_flags & NLM_F_ACK)) | |
1da177e4 | 1037 | netlink_ack(skb, nlh, err); |
ea7ae60b | 1038 | |
2851da57 | 1039 | nlh = nlmsg_next(nlh, &len); |
1da177e4 | 1040 | } |
1da177e4 LT |
1041 | } |
1042 | ||
1043 | /* Receive messages from netlink socket. */ | |
cd40b7d3 | 1044 | static void audit_receive(struct sk_buff *skb) |
1da177e4 | 1045 | { |
f368c07d | 1046 | mutex_lock(&audit_cmd_mutex); |
cd40b7d3 | 1047 | audit_receive_skb(skb); |
f368c07d | 1048 | mutex_unlock(&audit_cmd_mutex); |
1da177e4 LT |
1049 | } |
1050 | ||
33faba7f | 1051 | static int __net_init audit_net_init(struct net *net) |
1da177e4 | 1052 | { |
a31f2d17 PNA |
1053 | struct netlink_kernel_cfg cfg = { |
1054 | .input = audit_receive, | |
1055 | }; | |
f368c07d | 1056 | |
33faba7f RGB |
1057 | struct audit_net *aunet = net_generic(net, audit_net_id); |
1058 | ||
1059 | pr_info("audit: initializing netlink socket in namespace\n"); | |
1060 | ||
1061 | aunet->nlsk = netlink_kernel_create(net, NETLINK_AUDIT, &cfg); | |
1062 | if (aunet->nlsk == NULL) | |
1063 | return -ENOMEM; | |
1064 | if (!aunet->nlsk) | |
1065 | audit_panic("cannot initialize netlink socket in namespace"); | |
1066 | else | |
1067 | aunet->nlsk->sk_sndtimeo = MAX_SCHEDULE_TIMEOUT; | |
1068 | return 0; | |
1069 | } | |
1070 | ||
1071 | static void __net_exit audit_net_exit(struct net *net) | |
1072 | { | |
1073 | struct audit_net *aunet = net_generic(net, audit_net_id); | |
1074 | struct sock *sock = aunet->nlsk; | |
1075 | if (sock == audit_sock) { | |
1076 | audit_pid = 0; | |
1077 | audit_sock = NULL; | |
1078 | } | |
1079 | ||
1080 | rcu_assign_pointer(aunet->nlsk, NULL); | |
1081 | synchronize_net(); | |
1082 | netlink_kernel_release(sock); | |
1083 | } | |
1084 | ||
1085 | static struct pernet_operations __net_initdata audit_net_ops = { | |
1086 | .init = audit_net_init, | |
1087 | .exit = audit_net_exit, | |
1088 | .id = &audit_net_id, | |
1089 | .size = sizeof(struct audit_net), | |
1090 | }; | |
1091 | ||
1092 | /* Initialize audit support at boot time. */ | |
1093 | static int __init audit_init(void) | |
1094 | { | |
1095 | int i; | |
1096 | ||
a3f07114 EP |
1097 | if (audit_initialized == AUDIT_DISABLED) |
1098 | return 0; | |
1099 | ||
33faba7f | 1100 | pr_info("audit: initializing netlink subsys (%s)\n", |
1da177e4 | 1101 | audit_default ? "enabled" : "disabled"); |
33faba7f | 1102 | register_pernet_subsys(&audit_net_ops); |
1da177e4 | 1103 | |
b7d11258 | 1104 | skb_queue_head_init(&audit_skb_queue); |
f3d357b0 | 1105 | skb_queue_head_init(&audit_skb_hold_queue); |
a3f07114 | 1106 | audit_initialized = AUDIT_INITIALIZED; |
1da177e4 | 1107 | audit_enabled = audit_default; |
b593d384 | 1108 | audit_ever_enabled |= !!audit_default; |
3dc7e315 | 1109 | |
9ad9ad38 | 1110 | audit_log(NULL, GFP_KERNEL, AUDIT_KERNEL, "initialized"); |
f368c07d | 1111 | |
f368c07d AG |
1112 | for (i = 0; i < AUDIT_INODE_BUCKETS; i++) |
1113 | INIT_LIST_HEAD(&audit_inode_hash[i]); | |
f368c07d | 1114 | |
1da177e4 LT |
1115 | return 0; |
1116 | } | |
1da177e4 LT |
1117 | __initcall(audit_init); |
1118 | ||
1119 | /* Process kernel command-line parameter at boot time. audit=0 or audit=1. */ | |
1120 | static int __init audit_enable(char *str) | |
1121 | { | |
1122 | audit_default = !!simple_strtol(str, NULL, 0); | |
a3f07114 EP |
1123 | if (!audit_default) |
1124 | audit_initialized = AUDIT_DISABLED; | |
1125 | ||
d3ca0344 G |
1126 | pr_info("audit: %s\n", audit_default ? |
1127 | "enabled (after initialization)" : "disabled (until reboot)"); | |
a3f07114 | 1128 | |
9b41046c | 1129 | return 1; |
1da177e4 | 1130 | } |
1da177e4 LT |
1131 | __setup("audit=", audit_enable); |
1132 | ||
f910fde7 RGB |
1133 | /* Process kernel command-line parameter at boot time. |
1134 | * audit_backlog_limit=<n> */ | |
1135 | static int __init audit_backlog_limit_set(char *str) | |
1136 | { | |
1137 | long int audit_backlog_limit_arg; | |
1138 | pr_info("audit_backlog_limit: "); | |
1139 | if (kstrtol(str, 0, &audit_backlog_limit_arg)) { | |
1140 | printk("using default of %d, unable to parse %s\n", | |
1141 | audit_backlog_limit, str); | |
1142 | return 1; | |
1143 | } | |
1144 | if (audit_backlog_limit_arg >= 0) | |
1145 | audit_backlog_limit = (int)audit_backlog_limit_arg; | |
1146 | printk("%d\n", audit_backlog_limit); | |
1147 | ||
1148 | return 1; | |
1149 | } | |
1150 | __setup("audit_backlog_limit=", audit_backlog_limit_set); | |
1151 | ||
16e1904e CW |
1152 | static void audit_buffer_free(struct audit_buffer *ab) |
1153 | { | |
1154 | unsigned long flags; | |
1155 | ||
8fc6115c CW |
1156 | if (!ab) |
1157 | return; | |
1158 | ||
5ac52f33 CW |
1159 | if (ab->skb) |
1160 | kfree_skb(ab->skb); | |
b7d11258 | 1161 | |
16e1904e | 1162 | spin_lock_irqsave(&audit_freelist_lock, flags); |
5d136a01 | 1163 | if (audit_freelist_count > AUDIT_MAXFREE) |
16e1904e | 1164 | kfree(ab); |
5d136a01 SH |
1165 | else { |
1166 | audit_freelist_count++; | |
16e1904e | 1167 | list_add(&ab->list, &audit_freelist); |
5d136a01 | 1168 | } |
16e1904e CW |
1169 | spin_unlock_irqrestore(&audit_freelist_lock, flags); |
1170 | } | |
1171 | ||
c0404993 | 1172 | static struct audit_buffer * audit_buffer_alloc(struct audit_context *ctx, |
dd0fc66f | 1173 | gfp_t gfp_mask, int type) |
16e1904e CW |
1174 | { |
1175 | unsigned long flags; | |
1176 | struct audit_buffer *ab = NULL; | |
c0404993 | 1177 | struct nlmsghdr *nlh; |
16e1904e CW |
1178 | |
1179 | spin_lock_irqsave(&audit_freelist_lock, flags); | |
1180 | if (!list_empty(&audit_freelist)) { | |
1181 | ab = list_entry(audit_freelist.next, | |
1182 | struct audit_buffer, list); | |
1183 | list_del(&ab->list); | |
1184 | --audit_freelist_count; | |
1185 | } | |
1186 | spin_unlock_irqrestore(&audit_freelist_lock, flags); | |
1187 | ||
1188 | if (!ab) { | |
4332bdd3 | 1189 | ab = kmalloc(sizeof(*ab), gfp_mask); |
16e1904e | 1190 | if (!ab) |
8fc6115c | 1191 | goto err; |
16e1904e | 1192 | } |
8fc6115c | 1193 | |
b7d11258 | 1194 | ab->ctx = ctx; |
9ad9ad38 | 1195 | ab->gfp_mask = gfp_mask; |
ee080e6c EP |
1196 | |
1197 | ab->skb = nlmsg_new(AUDIT_BUFSIZ, gfp_mask); | |
1198 | if (!ab->skb) | |
c64e66c6 | 1199 | goto err; |
ee080e6c | 1200 | |
c64e66c6 DM |
1201 | nlh = nlmsg_put(ab->skb, 0, 0, type, 0, 0); |
1202 | if (!nlh) | |
1203 | goto out_kfree_skb; | |
ee080e6c | 1204 | |
16e1904e | 1205 | return ab; |
ee080e6c | 1206 | |
c64e66c6 | 1207 | out_kfree_skb: |
ee080e6c EP |
1208 | kfree_skb(ab->skb); |
1209 | ab->skb = NULL; | |
8fc6115c CW |
1210 | err: |
1211 | audit_buffer_free(ab); | |
1212 | return NULL; | |
16e1904e | 1213 | } |
1da177e4 | 1214 | |
b0dd25a8 RD |
1215 | /** |
1216 | * audit_serial - compute a serial number for the audit record | |
1217 | * | |
1218 | * Compute a serial number for the audit record. Audit records are | |
bfb4496e DW |
1219 | * written to user-space as soon as they are generated, so a complete |
1220 | * audit record may be written in several pieces. The timestamp of the | |
1221 | * record and this serial number are used by the user-space tools to | |
1222 | * determine which pieces belong to the same audit record. The | |
1223 | * (timestamp,serial) tuple is unique for each syscall and is live from | |
1224 | * syscall entry to syscall exit. | |
1225 | * | |
bfb4496e DW |
1226 | * NOTE: Another possibility is to store the formatted records off the |
1227 | * audit context (for those records that have a context), and emit them | |
1228 | * all at syscall exit. However, this could delay the reporting of | |
1229 | * significant errors until syscall exit (or never, if the system | |
b0dd25a8 RD |
1230 | * halts). |
1231 | */ | |
bfb4496e DW |
1232 | unsigned int audit_serial(void) |
1233 | { | |
34af946a | 1234 | static DEFINE_SPINLOCK(serial_lock); |
d5b454f2 DW |
1235 | static unsigned int serial = 0; |
1236 | ||
1237 | unsigned long flags; | |
1238 | unsigned int ret; | |
bfb4496e | 1239 | |
d5b454f2 | 1240 | spin_lock_irqsave(&serial_lock, flags); |
bfb4496e | 1241 | do { |
ce625a80 DW |
1242 | ret = ++serial; |
1243 | } while (unlikely(!ret)); | |
d5b454f2 | 1244 | spin_unlock_irqrestore(&serial_lock, flags); |
bfb4496e | 1245 | |
d5b454f2 | 1246 | return ret; |
bfb4496e DW |
1247 | } |
1248 | ||
5600b892 | 1249 | static inline void audit_get_stamp(struct audit_context *ctx, |
bfb4496e DW |
1250 | struct timespec *t, unsigned int *serial) |
1251 | { | |
48887e63 | 1252 | if (!ctx || !auditsc_get_stamp(ctx, t, serial)) { |
bfb4496e DW |
1253 | *t = CURRENT_TIME; |
1254 | *serial = audit_serial(); | |
1255 | } | |
1256 | } | |
1257 | ||
82919919 AM |
1258 | /* |
1259 | * Wait for auditd to drain the queue a little | |
1260 | */ | |
ae887e0b | 1261 | static unsigned long wait_for_auditd(unsigned long sleep_time) |
82919919 | 1262 | { |
ae887e0b | 1263 | unsigned long timeout = sleep_time; |
82919919 | 1264 | DECLARE_WAITQUEUE(wait, current); |
f000cfdd | 1265 | set_current_state(TASK_UNINTERRUPTIBLE); |
7ecf69bf | 1266 | add_wait_queue_exclusive(&audit_backlog_wait, &wait); |
82919919 AM |
1267 | |
1268 | if (audit_backlog_limit && | |
1269 | skb_queue_len(&audit_skb_queue) > audit_backlog_limit) | |
ae887e0b | 1270 | timeout = schedule_timeout(sleep_time); |
82919919 AM |
1271 | |
1272 | __set_current_state(TASK_RUNNING); | |
1273 | remove_wait_queue(&audit_backlog_wait, &wait); | |
ae887e0b RGB |
1274 | |
1275 | return timeout; | |
82919919 AM |
1276 | } |
1277 | ||
b0dd25a8 RD |
1278 | /** |
1279 | * audit_log_start - obtain an audit buffer | |
1280 | * @ctx: audit_context (may be NULL) | |
1281 | * @gfp_mask: type of allocation | |
1282 | * @type: audit message type | |
1283 | * | |
1284 | * Returns audit_buffer pointer on success or NULL on error. | |
1285 | * | |
1286 | * Obtain an audit buffer. This routine does locking to obtain the | |
1287 | * audit buffer, but then no locking is required for calls to | |
1288 | * audit_log_*format. If the task (ctx) is a task that is currently in a | |
1289 | * syscall, then the syscall is marked as auditable and an audit record | |
1290 | * will be written at syscall exit. If there is no associated task, then | |
1291 | * task context (ctx) should be NULL. | |
1292 | */ | |
9796fdd8 | 1293 | struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask, |
9ad9ad38 | 1294 | int type) |
1da177e4 LT |
1295 | { |
1296 | struct audit_buffer *ab = NULL; | |
1da177e4 | 1297 | struct timespec t; |
ef00be05 | 1298 | unsigned int uninitialized_var(serial); |
9ad9ad38 | 1299 | int reserve; |
ac4cec44 | 1300 | unsigned long timeout_start = jiffies; |
1da177e4 | 1301 | |
a3f07114 | 1302 | if (audit_initialized != AUDIT_INITIALIZED) |
1da177e4 LT |
1303 | return NULL; |
1304 | ||
c8edc80c DK |
1305 | if (unlikely(audit_filter_type(type))) |
1306 | return NULL; | |
1307 | ||
9ad9ad38 DW |
1308 | if (gfp_mask & __GFP_WAIT) |
1309 | reserve = 0; | |
1310 | else | |
5600b892 | 1311 | reserve = 5; /* Allow atomic callers to go up to five |
9ad9ad38 DW |
1312 | entries over the normal backlog limit */ |
1313 | ||
1314 | while (audit_backlog_limit | |
1315 | && skb_queue_len(&audit_skb_queue) > audit_backlog_limit + reserve) { | |
82919919 AM |
1316 | if (gfp_mask & __GFP_WAIT && audit_backlog_wait_time) { |
1317 | unsigned long sleep_time; | |
9ad9ad38 | 1318 | |
82919919 AM |
1319 | sleep_time = timeout_start + audit_backlog_wait_time - |
1320 | jiffies; | |
8ac1c8d5 | 1321 | if ((long)sleep_time > 0) { |
ae887e0b RGB |
1322 | sleep_time = wait_for_auditd(sleep_time); |
1323 | if ((long)sleep_time > 0) | |
1324 | continue; | |
8ac1c8d5 | 1325 | } |
9ad9ad38 | 1326 | } |
320f1b1e | 1327 | if (audit_rate_check() && printk_ratelimit()) |
fb19b4c6 DW |
1328 | printk(KERN_WARNING |
1329 | "audit: audit_backlog=%d > " | |
1330 | "audit_backlog_limit=%d\n", | |
1331 | skb_queue_len(&audit_skb_queue), | |
1332 | audit_backlog_limit); | |
1333 | audit_log_lost("backlog limit exceeded"); | |
ac4cec44 DW |
1334 | audit_backlog_wait_time = audit_backlog_wait_overflow; |
1335 | wake_up(&audit_backlog_wait); | |
fb19b4c6 DW |
1336 | return NULL; |
1337 | } | |
1338 | ||
e789e561 RGB |
1339 | audit_backlog_wait_time = AUDIT_BACKLOG_WAIT_TIME; |
1340 | ||
9ad9ad38 | 1341 | ab = audit_buffer_alloc(ctx, gfp_mask, type); |
1da177e4 LT |
1342 | if (!ab) { |
1343 | audit_log_lost("out of memory in audit_log_start"); | |
1344 | return NULL; | |
1345 | } | |
1346 | ||
bfb4496e | 1347 | audit_get_stamp(ab->ctx, &t, &serial); |
197c69c6 | 1348 | |
1da177e4 LT |
1349 | audit_log_format(ab, "audit(%lu.%03lu:%u): ", |
1350 | t.tv_sec, t.tv_nsec/1000000, serial); | |
1351 | return ab; | |
1352 | } | |
1353 | ||
8fc6115c | 1354 | /** |
5ac52f33 | 1355 | * audit_expand - expand skb in the audit buffer |
8fc6115c | 1356 | * @ab: audit_buffer |
b0dd25a8 | 1357 | * @extra: space to add at tail of the skb |
8fc6115c CW |
1358 | * |
1359 | * Returns 0 (no space) on failed expansion, or available space if | |
1360 | * successful. | |
1361 | */ | |
e3b926b4 | 1362 | static inline int audit_expand(struct audit_buffer *ab, int extra) |
8fc6115c | 1363 | { |
5ac52f33 | 1364 | struct sk_buff *skb = ab->skb; |
406a1d86 HX |
1365 | int oldtail = skb_tailroom(skb); |
1366 | int ret = pskb_expand_head(skb, 0, extra, ab->gfp_mask); | |
1367 | int newtail = skb_tailroom(skb); | |
1368 | ||
5ac52f33 CW |
1369 | if (ret < 0) { |
1370 | audit_log_lost("out of memory in audit_expand"); | |
8fc6115c | 1371 | return 0; |
5ac52f33 | 1372 | } |
406a1d86 HX |
1373 | |
1374 | skb->truesize += newtail - oldtail; | |
1375 | return newtail; | |
8fc6115c | 1376 | } |
1da177e4 | 1377 | |
b0dd25a8 RD |
1378 | /* |
1379 | * Format an audit message into the audit buffer. If there isn't enough | |
1da177e4 LT |
1380 | * room in the audit buffer, more room will be allocated and vsnprint |
1381 | * will be called a second time. Currently, we assume that a printk | |
b0dd25a8 RD |
1382 | * can't format message larger than 1024 bytes, so we don't either. |
1383 | */ | |
1da177e4 LT |
1384 | static void audit_log_vformat(struct audit_buffer *ab, const char *fmt, |
1385 | va_list args) | |
1386 | { | |
1387 | int len, avail; | |
5ac52f33 | 1388 | struct sk_buff *skb; |
eecb0a73 | 1389 | va_list args2; |
1da177e4 LT |
1390 | |
1391 | if (!ab) | |
1392 | return; | |
1393 | ||
5ac52f33 CW |
1394 | BUG_ON(!ab->skb); |
1395 | skb = ab->skb; | |
1396 | avail = skb_tailroom(skb); | |
1397 | if (avail == 0) { | |
e3b926b4 | 1398 | avail = audit_expand(ab, AUDIT_BUFSIZ); |
8fc6115c CW |
1399 | if (!avail) |
1400 | goto out; | |
1da177e4 | 1401 | } |
eecb0a73 | 1402 | va_copy(args2, args); |
27a884dc | 1403 | len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args); |
1da177e4 LT |
1404 | if (len >= avail) { |
1405 | /* The printk buffer is 1024 bytes long, so if we get | |
1406 | * here and AUDIT_BUFSIZ is at least 1024, then we can | |
1407 | * log everything that printk could have logged. */ | |
b0dd25a8 RD |
1408 | avail = audit_expand(ab, |
1409 | max_t(unsigned, AUDIT_BUFSIZ, 1+len-avail)); | |
8fc6115c | 1410 | if (!avail) |
a0e86bd4 | 1411 | goto out_va_end; |
27a884dc | 1412 | len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args2); |
1da177e4 | 1413 | } |
168b7173 SG |
1414 | if (len > 0) |
1415 | skb_put(skb, len); | |
a0e86bd4 JJ |
1416 | out_va_end: |
1417 | va_end(args2); | |
8fc6115c CW |
1418 | out: |
1419 | return; | |
1da177e4 LT |
1420 | } |
1421 | ||
b0dd25a8 RD |
1422 | /** |
1423 | * audit_log_format - format a message into the audit buffer. | |
1424 | * @ab: audit_buffer | |
1425 | * @fmt: format string | |
1426 | * @...: optional parameters matching @fmt string | |
1427 | * | |
1428 | * All the work is done in audit_log_vformat. | |
1429 | */ | |
1da177e4 LT |
1430 | void audit_log_format(struct audit_buffer *ab, const char *fmt, ...) |
1431 | { | |
1432 | va_list args; | |
1433 | ||
1434 | if (!ab) | |
1435 | return; | |
1436 | va_start(args, fmt); | |
1437 | audit_log_vformat(ab, fmt, args); | |
1438 | va_end(args); | |
1439 | } | |
1440 | ||
b0dd25a8 RD |
1441 | /** |
1442 | * audit_log_hex - convert a buffer to hex and append it to the audit skb | |
1443 | * @ab: the audit_buffer | |
1444 | * @buf: buffer to convert to hex | |
1445 | * @len: length of @buf to be converted | |
1446 | * | |
1447 | * No return value; failure to expand is silently ignored. | |
1448 | * | |
1449 | * This function will take the passed buf and convert it into a string of | |
1450 | * ascii hex digits. The new string is placed onto the skb. | |
1451 | */ | |
b556f8ad | 1452 | void audit_log_n_hex(struct audit_buffer *ab, const unsigned char *buf, |
168b7173 | 1453 | size_t len) |
83c7d091 | 1454 | { |
168b7173 SG |
1455 | int i, avail, new_len; |
1456 | unsigned char *ptr; | |
1457 | struct sk_buff *skb; | |
1458 | static const unsigned char *hex = "0123456789ABCDEF"; | |
1459 | ||
8ef2d304 AG |
1460 | if (!ab) |
1461 | return; | |
1462 | ||
168b7173 SG |
1463 | BUG_ON(!ab->skb); |
1464 | skb = ab->skb; | |
1465 | avail = skb_tailroom(skb); | |
1466 | new_len = len<<1; | |
1467 | if (new_len >= avail) { | |
1468 | /* Round the buffer request up to the next multiple */ | |
1469 | new_len = AUDIT_BUFSIZ*(((new_len-avail)/AUDIT_BUFSIZ) + 1); | |
1470 | avail = audit_expand(ab, new_len); | |
1471 | if (!avail) | |
1472 | return; | |
1473 | } | |
83c7d091 | 1474 | |
27a884dc | 1475 | ptr = skb_tail_pointer(skb); |
168b7173 SG |
1476 | for (i=0; i<len; i++) { |
1477 | *ptr++ = hex[(buf[i] & 0xF0)>>4]; /* Upper nibble */ | |
1478 | *ptr++ = hex[buf[i] & 0x0F]; /* Lower nibble */ | |
1479 | } | |
1480 | *ptr = 0; | |
1481 | skb_put(skb, len << 1); /* new string is twice the old string */ | |
83c7d091 DW |
1482 | } |
1483 | ||
9c937dcc AG |
1484 | /* |
1485 | * Format a string of no more than slen characters into the audit buffer, | |
1486 | * enclosed in quote marks. | |
1487 | */ | |
b556f8ad EP |
1488 | void audit_log_n_string(struct audit_buffer *ab, const char *string, |
1489 | size_t slen) | |
9c937dcc AG |
1490 | { |
1491 | int avail, new_len; | |
1492 | unsigned char *ptr; | |
1493 | struct sk_buff *skb; | |
1494 | ||
8ef2d304 AG |
1495 | if (!ab) |
1496 | return; | |
1497 | ||
9c937dcc AG |
1498 | BUG_ON(!ab->skb); |
1499 | skb = ab->skb; | |
1500 | avail = skb_tailroom(skb); | |
1501 | new_len = slen + 3; /* enclosing quotes + null terminator */ | |
1502 | if (new_len > avail) { | |
1503 | avail = audit_expand(ab, new_len); | |
1504 | if (!avail) | |
1505 | return; | |
1506 | } | |
27a884dc | 1507 | ptr = skb_tail_pointer(skb); |
9c937dcc AG |
1508 | *ptr++ = '"'; |
1509 | memcpy(ptr, string, slen); | |
1510 | ptr += slen; | |
1511 | *ptr++ = '"'; | |
1512 | *ptr = 0; | |
1513 | skb_put(skb, slen + 2); /* don't include null terminator */ | |
1514 | } | |
1515 | ||
de6bbd1d EP |
1516 | /** |
1517 | * audit_string_contains_control - does a string need to be logged in hex | |
f706d5d2 DJ |
1518 | * @string: string to be checked |
1519 | * @len: max length of the string to check | |
de6bbd1d EP |
1520 | */ |
1521 | int audit_string_contains_control(const char *string, size_t len) | |
1522 | { | |
1523 | const unsigned char *p; | |
b3897f56 | 1524 | for (p = string; p < (const unsigned char *)string + len; p++) { |
1d6c9649 | 1525 | if (*p == '"' || *p < 0x21 || *p > 0x7e) |
de6bbd1d EP |
1526 | return 1; |
1527 | } | |
1528 | return 0; | |
1529 | } | |
1530 | ||
b0dd25a8 | 1531 | /** |
522ed776 | 1532 | * audit_log_n_untrustedstring - log a string that may contain random characters |
b0dd25a8 | 1533 | * @ab: audit_buffer |
f706d5d2 | 1534 | * @len: length of string (not including trailing null) |
b0dd25a8 RD |
1535 | * @string: string to be logged |
1536 | * | |
1537 | * This code will escape a string that is passed to it if the string | |
1538 | * contains a control character, unprintable character, double quote mark, | |
168b7173 | 1539 | * or a space. Unescaped strings will start and end with a double quote mark. |
b0dd25a8 | 1540 | * Strings that are escaped are printed in hex (2 digits per char). |
9c937dcc AG |
1541 | * |
1542 | * The caller specifies the number of characters in the string to log, which may | |
1543 | * or may not be the entire string. | |
b0dd25a8 | 1544 | */ |
b556f8ad EP |
1545 | void audit_log_n_untrustedstring(struct audit_buffer *ab, const char *string, |
1546 | size_t len) | |
83c7d091 | 1547 | { |
de6bbd1d | 1548 | if (audit_string_contains_control(string, len)) |
b556f8ad | 1549 | audit_log_n_hex(ab, string, len); |
de6bbd1d | 1550 | else |
b556f8ad | 1551 | audit_log_n_string(ab, string, len); |
83c7d091 DW |
1552 | } |
1553 | ||
9c937dcc | 1554 | /** |
522ed776 | 1555 | * audit_log_untrustedstring - log a string that may contain random characters |
9c937dcc AG |
1556 | * @ab: audit_buffer |
1557 | * @string: string to be logged | |
1558 | * | |
522ed776 | 1559 | * Same as audit_log_n_untrustedstring(), except that strlen is used to |
9c937dcc AG |
1560 | * determine string length. |
1561 | */ | |
de6bbd1d | 1562 | void audit_log_untrustedstring(struct audit_buffer *ab, const char *string) |
9c937dcc | 1563 | { |
b556f8ad | 1564 | audit_log_n_untrustedstring(ab, string, strlen(string)); |
9c937dcc AG |
1565 | } |
1566 | ||
168b7173 | 1567 | /* This is a helper-function to print the escaped d_path */ |
1da177e4 | 1568 | void audit_log_d_path(struct audit_buffer *ab, const char *prefix, |
66b3fad3 | 1569 | const struct path *path) |
1da177e4 | 1570 | { |
44707fdf | 1571 | char *p, *pathname; |
1da177e4 | 1572 | |
8fc6115c | 1573 | if (prefix) |
c158a35c | 1574 | audit_log_format(ab, "%s", prefix); |
1da177e4 | 1575 | |
168b7173 | 1576 | /* We will allow 11 spaces for ' (deleted)' to be appended */ |
44707fdf JB |
1577 | pathname = kmalloc(PATH_MAX+11, ab->gfp_mask); |
1578 | if (!pathname) { | |
def57543 | 1579 | audit_log_string(ab, "<no_memory>"); |
168b7173 | 1580 | return; |
1da177e4 | 1581 | } |
cf28b486 | 1582 | p = d_path(path, pathname, PATH_MAX+11); |
168b7173 SG |
1583 | if (IS_ERR(p)) { /* Should never happen since we send PATH_MAX */ |
1584 | /* FIXME: can we save some information here? */ | |
def57543 | 1585 | audit_log_string(ab, "<too_long>"); |
5600b892 | 1586 | } else |
168b7173 | 1587 | audit_log_untrustedstring(ab, p); |
44707fdf | 1588 | kfree(pathname); |
1da177e4 LT |
1589 | } |
1590 | ||
4d3fb709 EP |
1591 | void audit_log_session_info(struct audit_buffer *ab) |
1592 | { | |
1593 | u32 sessionid = audit_get_sessionid(current); | |
1594 | uid_t auid = from_kuid(&init_user_ns, audit_get_loginuid(current)); | |
1595 | ||
b8f89caa | 1596 | audit_log_format(ab, " auid=%u ses=%u", auid, sessionid); |
4d3fb709 EP |
1597 | } |
1598 | ||
9d960985 EP |
1599 | void audit_log_key(struct audit_buffer *ab, char *key) |
1600 | { | |
1601 | audit_log_format(ab, " key="); | |
1602 | if (key) | |
1603 | audit_log_untrustedstring(ab, key); | |
1604 | else | |
1605 | audit_log_format(ab, "(null)"); | |
1606 | } | |
1607 | ||
b24a30a7 EP |
1608 | void audit_log_cap(struct audit_buffer *ab, char *prefix, kernel_cap_t *cap) |
1609 | { | |
1610 | int i; | |
1611 | ||
1612 | audit_log_format(ab, " %s=", prefix); | |
1613 | CAP_FOR_EACH_U32(i) { | |
1614 | audit_log_format(ab, "%08x", | |
1615 | cap->cap[(_KERNEL_CAPABILITY_U32S-1) - i]); | |
1616 | } | |
1617 | } | |
1618 | ||
1619 | void audit_log_fcaps(struct audit_buffer *ab, struct audit_names *name) | |
1620 | { | |
1621 | kernel_cap_t *perm = &name->fcap.permitted; | |
1622 | kernel_cap_t *inh = &name->fcap.inheritable; | |
1623 | int log = 0; | |
1624 | ||
1625 | if (!cap_isclear(*perm)) { | |
1626 | audit_log_cap(ab, "cap_fp", perm); | |
1627 | log = 1; | |
1628 | } | |
1629 | if (!cap_isclear(*inh)) { | |
1630 | audit_log_cap(ab, "cap_fi", inh); | |
1631 | log = 1; | |
1632 | } | |
1633 | ||
1634 | if (log) | |
1635 | audit_log_format(ab, " cap_fe=%d cap_fver=%x", | |
1636 | name->fcap.fE, name->fcap_ver); | |
1637 | } | |
1638 | ||
1639 | static inline int audit_copy_fcaps(struct audit_names *name, | |
1640 | const struct dentry *dentry) | |
1641 | { | |
1642 | struct cpu_vfs_cap_data caps; | |
1643 | int rc; | |
1644 | ||
1645 | if (!dentry) | |
1646 | return 0; | |
1647 | ||
1648 | rc = get_vfs_caps_from_disk(dentry, &caps); | |
1649 | if (rc) | |
1650 | return rc; | |
1651 | ||
1652 | name->fcap.permitted = caps.permitted; | |
1653 | name->fcap.inheritable = caps.inheritable; | |
1654 | name->fcap.fE = !!(caps.magic_etc & VFS_CAP_FLAGS_EFFECTIVE); | |
1655 | name->fcap_ver = (caps.magic_etc & VFS_CAP_REVISION_MASK) >> | |
1656 | VFS_CAP_REVISION_SHIFT; | |
1657 | ||
1658 | return 0; | |
1659 | } | |
1660 | ||
1661 | /* Copy inode data into an audit_names. */ | |
1662 | void audit_copy_inode(struct audit_names *name, const struct dentry *dentry, | |
1663 | const struct inode *inode) | |
1664 | { | |
1665 | name->ino = inode->i_ino; | |
1666 | name->dev = inode->i_sb->s_dev; | |
1667 | name->mode = inode->i_mode; | |
1668 | name->uid = inode->i_uid; | |
1669 | name->gid = inode->i_gid; | |
1670 | name->rdev = inode->i_rdev; | |
1671 | security_inode_getsecid(inode, &name->osid); | |
1672 | audit_copy_fcaps(name, dentry); | |
1673 | } | |
1674 | ||
1675 | /** | |
1676 | * audit_log_name - produce AUDIT_PATH record from struct audit_names | |
1677 | * @context: audit_context for the task | |
1678 | * @n: audit_names structure with reportable details | |
1679 | * @path: optional path to report instead of audit_names->name | |
1680 | * @record_num: record number to report when handling a list of names | |
1681 | * @call_panic: optional pointer to int that will be updated if secid fails | |
1682 | */ | |
1683 | void audit_log_name(struct audit_context *context, struct audit_names *n, | |
1684 | struct path *path, int record_num, int *call_panic) | |
1685 | { | |
1686 | struct audit_buffer *ab; | |
1687 | ab = audit_log_start(context, GFP_KERNEL, AUDIT_PATH); | |
1688 | if (!ab) | |
1689 | return; | |
1690 | ||
1691 | audit_log_format(ab, "item=%d", record_num); | |
1692 | ||
1693 | if (path) | |
1694 | audit_log_d_path(ab, " name=", path); | |
1695 | else if (n->name) { | |
1696 | switch (n->name_len) { | |
1697 | case AUDIT_NAME_FULL: | |
1698 | /* log the full path */ | |
1699 | audit_log_format(ab, " name="); | |
1700 | audit_log_untrustedstring(ab, n->name->name); | |
1701 | break; | |
1702 | case 0: | |
1703 | /* name was specified as a relative path and the | |
1704 | * directory component is the cwd */ | |
1705 | audit_log_d_path(ab, " name=", &context->pwd); | |
1706 | break; | |
1707 | default: | |
1708 | /* log the name's directory component */ | |
1709 | audit_log_format(ab, " name="); | |
1710 | audit_log_n_untrustedstring(ab, n->name->name, | |
1711 | n->name_len); | |
1712 | } | |
1713 | } else | |
1714 | audit_log_format(ab, " name=(null)"); | |
1715 | ||
1716 | if (n->ino != (unsigned long)-1) { | |
1717 | audit_log_format(ab, " inode=%lu" | |
1718 | " dev=%02x:%02x mode=%#ho" | |
1719 | " ouid=%u ogid=%u rdev=%02x:%02x", | |
1720 | n->ino, | |
1721 | MAJOR(n->dev), | |
1722 | MINOR(n->dev), | |
1723 | n->mode, | |
1724 | from_kuid(&init_user_ns, n->uid), | |
1725 | from_kgid(&init_user_ns, n->gid), | |
1726 | MAJOR(n->rdev), | |
1727 | MINOR(n->rdev)); | |
1728 | } | |
1729 | if (n->osid != 0) { | |
1730 | char *ctx = NULL; | |
1731 | u32 len; | |
1732 | if (security_secid_to_secctx( | |
1733 | n->osid, &ctx, &len)) { | |
1734 | audit_log_format(ab, " osid=%u", n->osid); | |
1735 | if (call_panic) | |
1736 | *call_panic = 2; | |
1737 | } else { | |
1738 | audit_log_format(ab, " obj=%s", ctx); | |
1739 | security_release_secctx(ctx, len); | |
1740 | } | |
1741 | } | |
1742 | ||
d3aea84a JL |
1743 | /* log the audit_names record type */ |
1744 | audit_log_format(ab, " nametype="); | |
1745 | switch(n->type) { | |
1746 | case AUDIT_TYPE_NORMAL: | |
1747 | audit_log_format(ab, "NORMAL"); | |
1748 | break; | |
1749 | case AUDIT_TYPE_PARENT: | |
1750 | audit_log_format(ab, "PARENT"); | |
1751 | break; | |
1752 | case AUDIT_TYPE_CHILD_DELETE: | |
1753 | audit_log_format(ab, "DELETE"); | |
1754 | break; | |
1755 | case AUDIT_TYPE_CHILD_CREATE: | |
1756 | audit_log_format(ab, "CREATE"); | |
1757 | break; | |
1758 | default: | |
1759 | audit_log_format(ab, "UNKNOWN"); | |
1760 | break; | |
1761 | } | |
1762 | ||
b24a30a7 EP |
1763 | audit_log_fcaps(ab, n); |
1764 | audit_log_end(ab); | |
1765 | } | |
1766 | ||
1767 | int audit_log_task_context(struct audit_buffer *ab) | |
1768 | { | |
1769 | char *ctx = NULL; | |
1770 | unsigned len; | |
1771 | int error; | |
1772 | u32 sid; | |
1773 | ||
1774 | security_task_getsecid(current, &sid); | |
1775 | if (!sid) | |
1776 | return 0; | |
1777 | ||
1778 | error = security_secid_to_secctx(sid, &ctx, &len); | |
1779 | if (error) { | |
1780 | if (error != -EINVAL) | |
1781 | goto error_path; | |
1782 | return 0; | |
1783 | } | |
1784 | ||
1785 | audit_log_format(ab, " subj=%s", ctx); | |
1786 | security_release_secctx(ctx, len); | |
1787 | return 0; | |
1788 | ||
1789 | error_path: | |
1790 | audit_panic("error in audit_log_task_context"); | |
1791 | return error; | |
1792 | } | |
1793 | EXPORT_SYMBOL(audit_log_task_context); | |
1794 | ||
1795 | void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk) | |
1796 | { | |
1797 | const struct cred *cred; | |
1798 | char name[sizeof(tsk->comm)]; | |
1799 | struct mm_struct *mm = tsk->mm; | |
1800 | char *tty; | |
1801 | ||
1802 | if (!ab) | |
1803 | return; | |
1804 | ||
1805 | /* tsk == current */ | |
1806 | cred = current_cred(); | |
1807 | ||
1808 | spin_lock_irq(&tsk->sighand->siglock); | |
1809 | if (tsk->signal && tsk->signal->tty && tsk->signal->tty->name) | |
1810 | tty = tsk->signal->tty->name; | |
1811 | else | |
1812 | tty = "(none)"; | |
1813 | spin_unlock_irq(&tsk->sighand->siglock); | |
1814 | ||
1815 | audit_log_format(ab, | |
1816 | " ppid=%ld pid=%d auid=%u uid=%u gid=%u" | |
1817 | " euid=%u suid=%u fsuid=%u" | |
2f2ad101 | 1818 | " egid=%u sgid=%u fsgid=%u tty=%s ses=%u", |
b24a30a7 EP |
1819 | sys_getppid(), |
1820 | tsk->pid, | |
1821 | from_kuid(&init_user_ns, audit_get_loginuid(tsk)), | |
1822 | from_kuid(&init_user_ns, cred->uid), | |
1823 | from_kgid(&init_user_ns, cred->gid), | |
1824 | from_kuid(&init_user_ns, cred->euid), | |
1825 | from_kuid(&init_user_ns, cred->suid), | |
1826 | from_kuid(&init_user_ns, cred->fsuid), | |
1827 | from_kgid(&init_user_ns, cred->egid), | |
1828 | from_kgid(&init_user_ns, cred->sgid), | |
1829 | from_kgid(&init_user_ns, cred->fsgid), | |
2f2ad101 | 1830 | tty, audit_get_sessionid(tsk)); |
b24a30a7 EP |
1831 | |
1832 | get_task_comm(name, tsk); | |
1833 | audit_log_format(ab, " comm="); | |
1834 | audit_log_untrustedstring(ab, name); | |
1835 | ||
1836 | if (mm) { | |
1837 | down_read(&mm->mmap_sem); | |
1838 | if (mm->exe_file) | |
1839 | audit_log_d_path(ab, " exe=", &mm->exe_file->f_path); | |
1840 | up_read(&mm->mmap_sem); | |
1841 | } | |
1842 | audit_log_task_context(ab); | |
1843 | } | |
1844 | EXPORT_SYMBOL(audit_log_task_info); | |
1845 | ||
a51d9eaa KC |
1846 | /** |
1847 | * audit_log_link_denied - report a link restriction denial | |
1848 | * @operation: specific link opreation | |
1849 | * @link: the path that triggered the restriction | |
1850 | */ | |
1851 | void audit_log_link_denied(const char *operation, struct path *link) | |
1852 | { | |
1853 | struct audit_buffer *ab; | |
b24a30a7 EP |
1854 | struct audit_names *name; |
1855 | ||
1856 | name = kzalloc(sizeof(*name), GFP_NOFS); | |
1857 | if (!name) | |
1858 | return; | |
a51d9eaa | 1859 | |
b24a30a7 | 1860 | /* Generate AUDIT_ANOM_LINK with subject, operation, outcome. */ |
a51d9eaa KC |
1861 | ab = audit_log_start(current->audit_context, GFP_KERNEL, |
1862 | AUDIT_ANOM_LINK); | |
d1c7d97a | 1863 | if (!ab) |
b24a30a7 EP |
1864 | goto out; |
1865 | audit_log_format(ab, "op=%s", operation); | |
1866 | audit_log_task_info(ab, current); | |
1867 | audit_log_format(ab, " res=0"); | |
a51d9eaa | 1868 | audit_log_end(ab); |
b24a30a7 EP |
1869 | |
1870 | /* Generate AUDIT_PATH record with object. */ | |
1871 | name->type = AUDIT_TYPE_NORMAL; | |
1872 | audit_copy_inode(name, link->dentry, link->dentry->d_inode); | |
1873 | audit_log_name(current->audit_context, name, link, 0, NULL); | |
1874 | out: | |
1875 | kfree(name); | |
a51d9eaa KC |
1876 | } |
1877 | ||
b0dd25a8 RD |
1878 | /** |
1879 | * audit_log_end - end one audit record | |
1880 | * @ab: the audit_buffer | |
1881 | * | |
1882 | * The netlink_* functions cannot be called inside an irq context, so | |
1883 | * the audit buffer is placed on a queue and a tasklet is scheduled to | |
1da177e4 | 1884 | * remove them from the queue outside the irq context. May be called in |
b0dd25a8 RD |
1885 | * any context. |
1886 | */ | |
b7d11258 | 1887 | void audit_log_end(struct audit_buffer *ab) |
1da177e4 | 1888 | { |
1da177e4 LT |
1889 | if (!ab) |
1890 | return; | |
1891 | if (!audit_rate_check()) { | |
1892 | audit_log_lost("rate limit exceeded"); | |
1893 | } else { | |
8d07a67c | 1894 | struct nlmsghdr *nlh = nlmsg_hdr(ab->skb); |
94191213 | 1895 | nlh->nlmsg_len = ab->skb->len - NLMSG_HDRLEN; |
f3d357b0 | 1896 | |
b7d11258 | 1897 | if (audit_pid) { |
b7d11258 | 1898 | skb_queue_tail(&audit_skb_queue, ab->skb); |
b7d11258 | 1899 | wake_up_interruptible(&kauditd_wait); |
f3d357b0 | 1900 | } else { |
038cbcf6 | 1901 | audit_printk_skb(ab->skb); |
b7d11258 | 1902 | } |
f3d357b0 | 1903 | ab->skb = NULL; |
1da177e4 | 1904 | } |
16e1904e | 1905 | audit_buffer_free(ab); |
1da177e4 LT |
1906 | } |
1907 | ||
b0dd25a8 RD |
1908 | /** |
1909 | * audit_log - Log an audit record | |
1910 | * @ctx: audit context | |
1911 | * @gfp_mask: type of allocation | |
1912 | * @type: audit message type | |
1913 | * @fmt: format string to use | |
1914 | * @...: variable parameters matching the format string | |
1915 | * | |
1916 | * This is a convenience function that calls audit_log_start, | |
1917 | * audit_log_vformat, and audit_log_end. It may be called | |
1918 | * in any context. | |
1919 | */ | |
5600b892 | 1920 | void audit_log(struct audit_context *ctx, gfp_t gfp_mask, int type, |
9ad9ad38 | 1921 | const char *fmt, ...) |
1da177e4 LT |
1922 | { |
1923 | struct audit_buffer *ab; | |
1924 | va_list args; | |
1925 | ||
9ad9ad38 | 1926 | ab = audit_log_start(ctx, gfp_mask, type); |
1da177e4 LT |
1927 | if (ab) { |
1928 | va_start(args, fmt); | |
1929 | audit_log_vformat(ab, fmt, args); | |
1930 | va_end(args); | |
1931 | audit_log_end(ab); | |
1932 | } | |
1933 | } | |
bf45da97 | 1934 | |
131ad62d MDF |
1935 | #ifdef CONFIG_SECURITY |
1936 | /** | |
1937 | * audit_log_secctx - Converts and logs SELinux context | |
1938 | * @ab: audit_buffer | |
1939 | * @secid: security number | |
1940 | * | |
1941 | * This is a helper function that calls security_secid_to_secctx to convert | |
1942 | * secid to secctx and then adds the (converted) SELinux context to the audit | |
1943 | * log by calling audit_log_format, thus also preventing leak of internal secid | |
1944 | * to userspace. If secid cannot be converted audit_panic is called. | |
1945 | */ | |
1946 | void audit_log_secctx(struct audit_buffer *ab, u32 secid) | |
1947 | { | |
1948 | u32 len; | |
1949 | char *secctx; | |
1950 | ||
1951 | if (security_secid_to_secctx(secid, &secctx, &len)) { | |
1952 | audit_panic("Cannot convert secid to context"); | |
1953 | } else { | |
1954 | audit_log_format(ab, " obj=%s", secctx); | |
1955 | security_release_secctx(secctx, len); | |
1956 | } | |
1957 | } | |
1958 | EXPORT_SYMBOL(audit_log_secctx); | |
1959 | #endif | |
1960 | ||
bf45da97 | 1961 | EXPORT_SYMBOL(audit_log_start); |
1962 | EXPORT_SYMBOL(audit_log_end); | |
1963 | EXPORT_SYMBOL(audit_log_format); | |
1964 | EXPORT_SYMBOL(audit_log); |