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