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 | ||
d957f7b7 JP |
44 | #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt |
45 | ||
5b282552 | 46 | #include <linux/file.h> |
1da177e4 | 47 | #include <linux/init.h> |
7153e402 | 48 | #include <linux/types.h> |
60063497 | 49 | #include <linux/atomic.h> |
1da177e4 | 50 | #include <linux/mm.h> |
9984de1a | 51 | #include <linux/export.h> |
5a0e3ad6 | 52 | #include <linux/slab.h> |
b7d11258 DW |
53 | #include <linux/err.h> |
54 | #include <linux/kthread.h> | |
46e959ea | 55 | #include <linux/kernel.h> |
b24a30a7 | 56 | #include <linux/syscalls.h> |
1da177e4 LT |
57 | |
58 | #include <linux/audit.h> | |
59 | ||
60 | #include <net/sock.h> | |
93315ed6 | 61 | #include <net/netlink.h> |
1da177e4 | 62 | #include <linux/skbuff.h> |
131ad62d MDF |
63 | #ifdef CONFIG_SECURITY |
64 | #include <linux/security.h> | |
65 | #endif | |
7dfb7103 | 66 | #include <linux/freezer.h> |
522ed776 | 67 | #include <linux/tty.h> |
34e36d8e | 68 | #include <linux/pid_namespace.h> |
33faba7f | 69 | #include <net/netns/generic.h> |
3dc7e315 DG |
70 | |
71 | #include "audit.h" | |
1da177e4 | 72 | |
a3f07114 | 73 | /* No auditing will take place until audit_initialized == AUDIT_INITIALIZED. |
1da177e4 | 74 | * (Initialization happens after skb_init is called.) */ |
a3f07114 EP |
75 | #define AUDIT_DISABLED -1 |
76 | #define AUDIT_UNINITIALIZED 0 | |
77 | #define AUDIT_INITIALIZED 1 | |
1da177e4 LT |
78 | static int audit_initialized; |
79 | ||
1a6b9f23 EP |
80 | #define AUDIT_OFF 0 |
81 | #define AUDIT_ON 1 | |
82 | #define AUDIT_LOCKED 2 | |
3e1d0bb6 JP |
83 | u32 audit_enabled; |
84 | u32 audit_ever_enabled; | |
1da177e4 | 85 | |
ae9d67af JE |
86 | EXPORT_SYMBOL_GPL(audit_enabled); |
87 | ||
1da177e4 | 88 | /* Default state when kernel boots without any parameters. */ |
3e1d0bb6 | 89 | static u32 audit_default; |
1da177e4 LT |
90 | |
91 | /* If auditing cannot proceed, audit_failure selects what happens. */ | |
3e1d0bb6 | 92 | static u32 audit_failure = AUDIT_FAIL_PRINTK; |
1da177e4 | 93 | |
75c0371a PE |
94 | /* |
95 | * If audit records are to be written to the netlink socket, audit_pid | |
15e47304 EB |
96 | * contains the pid of the auditd process and audit_nlk_portid contains |
97 | * the portid to use to send netlink messages to that process. | |
75c0371a | 98 | */ |
c2f0c7c3 | 99 | int audit_pid; |
f9441639 | 100 | static __u32 audit_nlk_portid; |
1da177e4 | 101 | |
b0dd25a8 | 102 | /* If audit_rate_limit is non-zero, limit the rate of sending audit records |
1da177e4 LT |
103 | * to that number per second. This prevents DoS attacks, but results in |
104 | * audit records being dropped. */ | |
3e1d0bb6 | 105 | static u32 audit_rate_limit; |
1da177e4 | 106 | |
40c0775e RGB |
107 | /* Number of outstanding audit_buffers allowed. |
108 | * When set to zero, this means unlimited. */ | |
3e1d0bb6 | 109 | static u32 audit_backlog_limit = 64; |
e789e561 | 110 | #define AUDIT_BACKLOG_WAIT_TIME (60 * HZ) |
a77ed4e5 | 111 | static u32 audit_backlog_wait_time_master = AUDIT_BACKLOG_WAIT_TIME; |
3e1d0bb6 | 112 | static u32 audit_backlog_wait_time = AUDIT_BACKLOG_WAIT_TIME; |
1da177e4 | 113 | |
c2f0c7c3 | 114 | /* The identity of the user shutting down the audit system. */ |
cca080d9 | 115 | kuid_t audit_sig_uid = INVALID_UID; |
c2f0c7c3 | 116 | pid_t audit_sig_pid = -1; |
e1396065 | 117 | u32 audit_sig_sid = 0; |
c2f0c7c3 | 118 | |
1da177e4 LT |
119 | /* Records can be lost in several ways: |
120 | 0) [suppressed in audit_alloc] | |
121 | 1) out of memory in audit_log_start [kmalloc of struct audit_buffer] | |
122 | 2) out of memory in audit_log_move [alloc_skb] | |
123 | 3) suppressed due to audit_rate_limit | |
124 | 4) suppressed due to audit_backlog_limit | |
125 | */ | |
126 | static atomic_t audit_lost = ATOMIC_INIT(0); | |
127 | ||
128 | /* The netlink socket. */ | |
129 | static struct sock *audit_sock; | |
c0a8d9b0 | 130 | static int audit_net_id; |
1da177e4 | 131 | |
f368c07d AG |
132 | /* Hash for inode-based rules */ |
133 | struct list_head audit_inode_hash[AUDIT_INODE_BUCKETS]; | |
134 | ||
b7d11258 | 135 | /* The audit_freelist is a list of pre-allocated audit buffers (if more |
1da177e4 LT |
136 | * than AUDIT_MAXFREE are in use, the audit buffer is freed instead of |
137 | * being placed on the freelist). */ | |
1da177e4 | 138 | static DEFINE_SPINLOCK(audit_freelist_lock); |
b0dd25a8 | 139 | static int audit_freelist_count; |
1da177e4 LT |
140 | static LIST_HEAD(audit_freelist); |
141 | ||
b7d11258 | 142 | static struct sk_buff_head audit_skb_queue; |
f3d357b0 EP |
143 | /* queue of skbs to send to auditd when/if it comes back */ |
144 | static struct sk_buff_head audit_skb_hold_queue; | |
b7d11258 DW |
145 | static struct task_struct *kauditd_task; |
146 | static DECLARE_WAIT_QUEUE_HEAD(kauditd_wait); | |
9ad9ad38 | 147 | static DECLARE_WAIT_QUEUE_HEAD(audit_backlog_wait); |
1da177e4 | 148 | |
b0fed402 EP |
149 | static struct audit_features af = {.vers = AUDIT_FEATURE_VERSION, |
150 | .mask = -1, | |
151 | .features = 0, | |
152 | .lock = 0,}; | |
153 | ||
21b85c31 | 154 | static char *audit_feature_names[2] = { |
d040e5af | 155 | "only_unset_loginuid", |
21b85c31 | 156 | "loginuid_immutable", |
b0fed402 EP |
157 | }; |
158 | ||
159 | ||
f368c07d | 160 | /* Serialize requests from userspace. */ |
916d7576 | 161 | DEFINE_MUTEX(audit_cmd_mutex); |
1da177e4 LT |
162 | |
163 | /* AUDIT_BUFSIZ is the size of the temporary buffer used for formatting | |
164 | * audit records. Since printk uses a 1024 byte buffer, this buffer | |
165 | * should be at least that large. */ | |
166 | #define AUDIT_BUFSIZ 1024 | |
167 | ||
168 | /* AUDIT_MAXFREE is the number of empty audit_buffers we keep on the | |
169 | * audit_freelist. Doing so eliminates many kmalloc/kfree calls. */ | |
170 | #define AUDIT_MAXFREE (2*NR_CPUS) | |
171 | ||
172 | /* The audit_buffer is used when formatting an audit record. The caller | |
173 | * locks briefly to get the record off the freelist or to allocate the | |
174 | * buffer, and locks briefly to send the buffer to the netlink layer or | |
175 | * to place it on a transmit queue. Multiple audit_buffers can be in | |
176 | * use simultaneously. */ | |
177 | struct audit_buffer { | |
178 | struct list_head list; | |
8fc6115c | 179 | struct sk_buff *skb; /* formatted skb ready to send */ |
1da177e4 | 180 | struct audit_context *ctx; /* NULL or associated context */ |
9796fdd8 | 181 | gfp_t gfp_mask; |
1da177e4 LT |
182 | }; |
183 | ||
f09ac9db | 184 | struct audit_reply { |
f9441639 | 185 | __u32 portid; |
638a0fd2 | 186 | struct net *net; |
f09ac9db EP |
187 | struct sk_buff *skb; |
188 | }; | |
189 | ||
f9441639 | 190 | static void audit_set_portid(struct audit_buffer *ab, __u32 portid) |
c0404993 | 191 | { |
50397bd1 EP |
192 | if (ab) { |
193 | struct nlmsghdr *nlh = nlmsg_hdr(ab->skb); | |
f9441639 | 194 | nlh->nlmsg_pid = portid; |
50397bd1 | 195 | } |
c0404993 SG |
196 | } |
197 | ||
8c8570fb | 198 | void audit_panic(const char *message) |
1da177e4 | 199 | { |
d957f7b7 | 200 | switch (audit_failure) { |
1da177e4 LT |
201 | case AUDIT_FAIL_SILENT: |
202 | break; | |
203 | case AUDIT_FAIL_PRINTK: | |
320f1b1e | 204 | if (printk_ratelimit()) |
d957f7b7 | 205 | pr_err("%s\n", message); |
1da177e4 LT |
206 | break; |
207 | case AUDIT_FAIL_PANIC: | |
b29ee87e EP |
208 | /* test audit_pid since printk is always losey, why bother? */ |
209 | if (audit_pid) | |
210 | panic("audit: %s\n", message); | |
1da177e4 LT |
211 | break; |
212 | } | |
213 | } | |
214 | ||
215 | static inline int audit_rate_check(void) | |
216 | { | |
217 | static unsigned long last_check = 0; | |
218 | static int messages = 0; | |
219 | static DEFINE_SPINLOCK(lock); | |
220 | unsigned long flags; | |
221 | unsigned long now; | |
222 | unsigned long elapsed; | |
223 | int retval = 0; | |
224 | ||
225 | if (!audit_rate_limit) return 1; | |
226 | ||
227 | spin_lock_irqsave(&lock, flags); | |
228 | if (++messages < audit_rate_limit) { | |
229 | retval = 1; | |
230 | } else { | |
231 | now = jiffies; | |
232 | elapsed = now - last_check; | |
233 | if (elapsed > HZ) { | |
234 | last_check = now; | |
235 | messages = 0; | |
236 | retval = 1; | |
237 | } | |
238 | } | |
239 | spin_unlock_irqrestore(&lock, flags); | |
240 | ||
241 | return retval; | |
242 | } | |
243 | ||
b0dd25a8 RD |
244 | /** |
245 | * audit_log_lost - conditionally log lost audit message event | |
246 | * @message: the message stating reason for lost audit message | |
247 | * | |
248 | * Emit at least 1 message per second, even if audit_rate_check is | |
249 | * throttling. | |
250 | * Always increment the lost messages counter. | |
251 | */ | |
1da177e4 LT |
252 | void audit_log_lost(const char *message) |
253 | { | |
254 | static unsigned long last_msg = 0; | |
255 | static DEFINE_SPINLOCK(lock); | |
256 | unsigned long flags; | |
257 | unsigned long now; | |
258 | int print; | |
259 | ||
260 | atomic_inc(&audit_lost); | |
261 | ||
262 | print = (audit_failure == AUDIT_FAIL_PANIC || !audit_rate_limit); | |
263 | ||
264 | if (!print) { | |
265 | spin_lock_irqsave(&lock, flags); | |
266 | now = jiffies; | |
267 | if (now - last_msg > HZ) { | |
268 | print = 1; | |
269 | last_msg = now; | |
270 | } | |
271 | spin_unlock_irqrestore(&lock, flags); | |
272 | } | |
273 | ||
274 | if (print) { | |
320f1b1e | 275 | if (printk_ratelimit()) |
3e1d0bb6 | 276 | pr_warn("audit_lost=%u audit_rate_limit=%u audit_backlog_limit=%u\n", |
320f1b1e EP |
277 | atomic_read(&audit_lost), |
278 | audit_rate_limit, | |
279 | audit_backlog_limit); | |
1da177e4 LT |
280 | audit_panic(message); |
281 | } | |
1da177e4 LT |
282 | } |
283 | ||
3e1d0bb6 | 284 | static int audit_log_config_change(char *function_name, u32 new, u32 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; | |
3e1d0bb6 | 293 | audit_log_format(ab, "%s=%u old=%u", function_name, new, old); |
4d3fb709 | 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 | ||
3e1d0bb6 | 303 | static int audit_do_config_change(char *function_name, u32 *to_change, u32 new) |
1da177e4 | 304 | { |
3e1d0bb6 JP |
305 | int allow_changes, rc = 0; |
306 | u32 old = *to_change; | |
6a01b07f SG |
307 | |
308 | /* check if we are locked */ | |
1a6b9f23 EP |
309 | if (audit_enabled == AUDIT_LOCKED) |
310 | allow_changes = 0; | |
6a01b07f | 311 | else |
1a6b9f23 | 312 | allow_changes = 1; |
ce29b682 | 313 | |
1a6b9f23 | 314 | if (audit_enabled != AUDIT_OFF) { |
dc9eb698 | 315 | rc = audit_log_config_change(function_name, new, old, allow_changes); |
1a6b9f23 EP |
316 | if (rc) |
317 | allow_changes = 0; | |
6a01b07f | 318 | } |
6a01b07f SG |
319 | |
320 | /* If we are allowed, make the change */ | |
1a6b9f23 EP |
321 | if (allow_changes == 1) |
322 | *to_change = new; | |
6a01b07f SG |
323 | /* Not allowed, update reason */ |
324 | else if (rc == 0) | |
325 | rc = -EPERM; | |
326 | return rc; | |
1da177e4 LT |
327 | } |
328 | ||
3e1d0bb6 | 329 | static int audit_set_rate_limit(u32 limit) |
1da177e4 | 330 | { |
dc9eb698 | 331 | return audit_do_config_change("audit_rate_limit", &audit_rate_limit, limit); |
1a6b9f23 | 332 | } |
ce29b682 | 333 | |
3e1d0bb6 | 334 | static int audit_set_backlog_limit(u32 limit) |
1a6b9f23 | 335 | { |
dc9eb698 | 336 | return audit_do_config_change("audit_backlog_limit", &audit_backlog_limit, limit); |
1a6b9f23 | 337 | } |
6a01b07f | 338 | |
3e1d0bb6 | 339 | static int audit_set_backlog_wait_time(u32 timeout) |
51cc83f0 RGB |
340 | { |
341 | return audit_do_config_change("audit_backlog_wait_time", | |
a77ed4e5 | 342 | &audit_backlog_wait_time_master, timeout); |
51cc83f0 RGB |
343 | } |
344 | ||
3e1d0bb6 | 345 | static int audit_set_enabled(u32 state) |
1a6b9f23 | 346 | { |
b593d384 | 347 | int rc; |
724e7bfc | 348 | if (state > AUDIT_LOCKED) |
1a6b9f23 | 349 | return -EINVAL; |
6a01b07f | 350 | |
dc9eb698 | 351 | rc = audit_do_config_change("audit_enabled", &audit_enabled, state); |
b593d384 EP |
352 | if (!rc) |
353 | audit_ever_enabled |= !!state; | |
354 | ||
355 | return rc; | |
1da177e4 LT |
356 | } |
357 | ||
3e1d0bb6 | 358 | static int audit_set_failure(u32 state) |
1da177e4 | 359 | { |
1da177e4 LT |
360 | if (state != AUDIT_FAIL_SILENT |
361 | && state != AUDIT_FAIL_PRINTK | |
362 | && state != AUDIT_FAIL_PANIC) | |
363 | return -EINVAL; | |
ce29b682 | 364 | |
dc9eb698 | 365 | return audit_do_config_change("audit_failure", &audit_failure, state); |
1da177e4 LT |
366 | } |
367 | ||
f3d357b0 EP |
368 | /* |
369 | * Queue skbs to be sent to auditd when/if it comes back. These skbs should | |
370 | * already have been sent via prink/syslog and so if these messages are dropped | |
371 | * it is not a huge concern since we already passed the audit_log_lost() | |
372 | * notification and stuff. This is just nice to get audit messages during | |
373 | * boot before auditd is running or messages generated while auditd is stopped. | |
374 | * This only holds messages is audit_default is set, aka booting with audit=1 | |
375 | * or building your kernel that way. | |
376 | */ | |
377 | static void audit_hold_skb(struct sk_buff *skb) | |
378 | { | |
379 | if (audit_default && | |
40c0775e RGB |
380 | (!audit_backlog_limit || |
381 | skb_queue_len(&audit_skb_hold_queue) < audit_backlog_limit)) | |
f3d357b0 EP |
382 | skb_queue_tail(&audit_skb_hold_queue, skb); |
383 | else | |
384 | kfree_skb(skb); | |
385 | } | |
386 | ||
038cbcf6 EP |
387 | /* |
388 | * For one reason or another this nlh isn't getting delivered to the userspace | |
389 | * audit daemon, just send it to printk. | |
390 | */ | |
391 | static void audit_printk_skb(struct sk_buff *skb) | |
392 | { | |
393 | struct nlmsghdr *nlh = nlmsg_hdr(skb); | |
c64e66c6 | 394 | char *data = nlmsg_data(nlh); |
038cbcf6 EP |
395 | |
396 | if (nlh->nlmsg_type != AUDIT_EOE) { | |
397 | if (printk_ratelimit()) | |
d957f7b7 | 398 | pr_notice("type=%d %s\n", nlh->nlmsg_type, data); |
038cbcf6 | 399 | else |
f1283527 | 400 | audit_log_lost("printk limit exceeded"); |
038cbcf6 EP |
401 | } |
402 | ||
403 | audit_hold_skb(skb); | |
404 | } | |
405 | ||
f3d357b0 EP |
406 | static void kauditd_send_skb(struct sk_buff *skb) |
407 | { | |
408 | int err; | |
32a1dbae RGB |
409 | int attempts = 0; |
410 | #define AUDITD_RETRIES 5 | |
411 | ||
412 | restart: | |
f3d357b0 EP |
413 | /* take a reference in case we can't send it and we want to hold it */ |
414 | skb_get(skb); | |
15e47304 | 415 | err = netlink_unicast(audit_sock, skb, audit_nlk_portid, 0); |
f3d357b0 | 416 | if (err < 0) { |
32a1dbae RGB |
417 | pr_err("netlink_unicast sending to audit_pid=%d returned error: %d\n", |
418 | audit_pid, err); | |
04ee1a3b | 419 | if (audit_pid) { |
32a1dbae RGB |
420 | if (err == -ECONNREFUSED || err == -EPERM |
421 | || ++attempts >= AUDITD_RETRIES) { | |
422 | char s[32]; | |
423 | ||
424 | snprintf(s, sizeof(s), "audit_pid=%d reset", audit_pid); | |
425 | audit_log_lost(s); | |
426 | audit_pid = 0; | |
427 | audit_sock = NULL; | |
428 | } else { | |
429 | pr_warn("re-scheduling(#%d) write to audit_pid=%d\n", | |
430 | attempts, audit_pid); | |
431 | set_current_state(TASK_INTERRUPTIBLE); | |
432 | schedule(); | |
32a1dbae RGB |
433 | goto restart; |
434 | } | |
04ee1a3b | 435 | } |
f3d357b0 EP |
436 | /* we might get lucky and get this in the next auditd */ |
437 | audit_hold_skb(skb); | |
438 | } else | |
439 | /* drop the extra reference if sent ok */ | |
70d4bf6d | 440 | consume_skb(skb); |
f3d357b0 EP |
441 | } |
442 | ||
451f9216 RGB |
443 | /* |
444 | * kauditd_send_multicast_skb - send the skb to multicast userspace listeners | |
445 | * | |
446 | * This function doesn't consume an skb as might be expected since it has to | |
447 | * copy it anyways. | |
448 | */ | |
54dc77d9 | 449 | static void kauditd_send_multicast_skb(struct sk_buff *skb, gfp_t gfp_mask) |
451f9216 RGB |
450 | { |
451 | struct sk_buff *copy; | |
452 | struct audit_net *aunet = net_generic(&init_net, audit_net_id); | |
453 | struct sock *sock = aunet->nlsk; | |
454 | ||
7f74ecd7 RGB |
455 | if (!netlink_has_listeners(sock, AUDIT_NLGRP_READLOG)) |
456 | return; | |
457 | ||
451f9216 RGB |
458 | /* |
459 | * The seemingly wasteful skb_copy() rather than bumping the refcount | |
460 | * using skb_get() is necessary because non-standard mods are made to | |
461 | * the skb by the original kaudit unicast socket send routine. The | |
462 | * existing auditd daemon assumes this breakage. Fixing this would | |
463 | * require co-ordinating a change in the established protocol between | |
464 | * the kaudit kernel subsystem and the auditd userspace code. There is | |
465 | * no reason for new multicast clients to continue with this | |
466 | * non-compliance. | |
467 | */ | |
54dc77d9 | 468 | copy = skb_copy(skb, gfp_mask); |
451f9216 RGB |
469 | if (!copy) |
470 | return; | |
471 | ||
54dc77d9 | 472 | nlmsg_multicast(sock, copy, 0, AUDIT_NLGRP_READLOG, gfp_mask); |
451f9216 RGB |
473 | } |
474 | ||
b551d1d9 RGB |
475 | /* |
476 | * flush_hold_queue - empty the hold queue if auditd appears | |
477 | * | |
478 | * If auditd just started, drain the queue of messages already | |
479 | * sent to syslog/printk. Remember loss here is ok. We already | |
480 | * called audit_log_lost() if it didn't go out normally. so the | |
481 | * race between the skb_dequeue and the next check for audit_pid | |
482 | * doesn't matter. | |
483 | * | |
484 | * If you ever find kauditd to be too slow we can get a perf win | |
485 | * by doing our own locking and keeping better track if there | |
486 | * are messages in this queue. I don't see the need now, but | |
487 | * in 5 years when I want to play with this again I'll see this | |
488 | * note and still have no friggin idea what i'm thinking today. | |
489 | */ | |
490 | static void flush_hold_queue(void) | |
b7d11258 DW |
491 | { |
492 | struct sk_buff *skb; | |
493 | ||
b551d1d9 RGB |
494 | if (!audit_default || !audit_pid) |
495 | return; | |
496 | ||
497 | skb = skb_dequeue(&audit_skb_hold_queue); | |
498 | if (likely(!skb)) | |
499 | return; | |
500 | ||
501 | while (skb && audit_pid) { | |
502 | kauditd_send_skb(skb); | |
503 | skb = skb_dequeue(&audit_skb_hold_queue); | |
504 | } | |
505 | ||
506 | /* | |
507 | * if auditd just disappeared but we | |
508 | * dequeued an skb we need to drop ref | |
509 | */ | |
d865e573 | 510 | consume_skb(skb); |
b551d1d9 RGB |
511 | } |
512 | ||
97a41e26 | 513 | static int kauditd_thread(void *dummy) |
b7d11258 | 514 | { |
83144186 | 515 | set_freezable(); |
4899b8b1 | 516 | while (!kthread_should_stop()) { |
3320c513 | 517 | struct sk_buff *skb; |
3320c513 | 518 | |
b551d1d9 | 519 | flush_hold_queue(); |
f3d357b0 | 520 | |
b7d11258 | 521 | skb = skb_dequeue(&audit_skb_queue); |
db897319 | 522 | |
b7d11258 | 523 | if (skb) { |
1194b994 RGB |
524 | if (!audit_backlog_limit || |
525 | (skb_queue_len(&audit_skb_queue) <= audit_backlog_limit)) | |
db897319 | 526 | wake_up(&audit_backlog_wait); |
f3d357b0 EP |
527 | if (audit_pid) |
528 | kauditd_send_skb(skb); | |
038cbcf6 EP |
529 | else |
530 | audit_printk_skb(skb); | |
3320c513 RGB |
531 | continue; |
532 | } | |
b7d11258 | 533 | |
6b55fc63 | 534 | wait_event_freezable(kauditd_wait, skb_queue_len(&audit_skb_queue)); |
b7d11258 | 535 | } |
4899b8b1 | 536 | return 0; |
b7d11258 DW |
537 | } |
538 | ||
9044e6bc AV |
539 | int audit_send_list(void *_dest) |
540 | { | |
541 | struct audit_netlink_list *dest = _dest; | |
9044e6bc | 542 | struct sk_buff *skb; |
48095d99 | 543 | struct net *net = dest->net; |
33faba7f | 544 | struct audit_net *aunet = net_generic(net, audit_net_id); |
9044e6bc AV |
545 | |
546 | /* wait for parent to finish and send an ACK */ | |
f368c07d AG |
547 | mutex_lock(&audit_cmd_mutex); |
548 | mutex_unlock(&audit_cmd_mutex); | |
9044e6bc AV |
549 | |
550 | while ((skb = __skb_dequeue(&dest->q)) != NULL) | |
33faba7f | 551 | netlink_unicast(aunet->nlsk, skb, dest->portid, 0); |
9044e6bc | 552 | |
48095d99 | 553 | put_net(net); |
9044e6bc AV |
554 | kfree(dest); |
555 | ||
556 | return 0; | |
557 | } | |
558 | ||
f9441639 | 559 | struct sk_buff *audit_make_reply(__u32 portid, int seq, int type, int done, |
b8800aa5 | 560 | int multi, const void *payload, int size) |
9044e6bc AV |
561 | { |
562 | struct sk_buff *skb; | |
563 | struct nlmsghdr *nlh; | |
9044e6bc AV |
564 | void *data; |
565 | int flags = multi ? NLM_F_MULTI : 0; | |
566 | int t = done ? NLMSG_DONE : type; | |
567 | ||
ee080e6c | 568 | skb = nlmsg_new(size, GFP_KERNEL); |
9044e6bc AV |
569 | if (!skb) |
570 | return NULL; | |
571 | ||
f9441639 | 572 | nlh = nlmsg_put(skb, portid, seq, t, size, flags); |
c64e66c6 DM |
573 | if (!nlh) |
574 | goto out_kfree_skb; | |
575 | data = nlmsg_data(nlh); | |
9044e6bc AV |
576 | memcpy(data, payload, size); |
577 | return skb; | |
578 | ||
c64e66c6 DM |
579 | out_kfree_skb: |
580 | kfree_skb(skb); | |
9044e6bc AV |
581 | return NULL; |
582 | } | |
583 | ||
f09ac9db EP |
584 | static int audit_send_reply_thread(void *arg) |
585 | { | |
586 | struct audit_reply *reply = (struct audit_reply *)arg; | |
48095d99 | 587 | struct net *net = reply->net; |
33faba7f | 588 | struct audit_net *aunet = net_generic(net, audit_net_id); |
f09ac9db EP |
589 | |
590 | mutex_lock(&audit_cmd_mutex); | |
591 | mutex_unlock(&audit_cmd_mutex); | |
592 | ||
593 | /* Ignore failure. It'll only happen if the sender goes away, | |
594 | because our timeout is set to infinite. */ | |
33faba7f | 595 | netlink_unicast(aunet->nlsk , reply->skb, reply->portid, 0); |
48095d99 | 596 | put_net(net); |
f09ac9db EP |
597 | kfree(reply); |
598 | return 0; | |
599 | } | |
b0dd25a8 RD |
600 | /** |
601 | * audit_send_reply - send an audit reply message via netlink | |
d211f177 | 602 | * @request_skb: skb of request we are replying to (used to target the reply) |
b0dd25a8 RD |
603 | * @seq: sequence number |
604 | * @type: audit message type | |
605 | * @done: done (last) flag | |
606 | * @multi: multi-part message flag | |
607 | * @payload: payload data | |
608 | * @size: payload size | |
609 | * | |
f9441639 | 610 | * Allocates an skb, builds the netlink message, and sends it to the port id. |
b0dd25a8 RD |
611 | * No failure notifications. |
612 | */ | |
6f285b19 | 613 | static void audit_send_reply(struct sk_buff *request_skb, int seq, int type, int done, |
f9441639 | 614 | int multi, const void *payload, int size) |
1da177e4 | 615 | { |
6f285b19 EB |
616 | u32 portid = NETLINK_CB(request_skb).portid; |
617 | struct net *net = sock_net(NETLINK_CB(request_skb).sk); | |
f09ac9db EP |
618 | struct sk_buff *skb; |
619 | struct task_struct *tsk; | |
620 | struct audit_reply *reply = kmalloc(sizeof(struct audit_reply), | |
621 | GFP_KERNEL); | |
622 | ||
623 | if (!reply) | |
624 | return; | |
625 | ||
f9441639 | 626 | skb = audit_make_reply(portid, seq, type, done, multi, payload, size); |
1da177e4 | 627 | if (!skb) |
fcaf1eb8 | 628 | goto out; |
f09ac9db | 629 | |
6f285b19 | 630 | reply->net = get_net(net); |
f9441639 | 631 | reply->portid = portid; |
f09ac9db EP |
632 | reply->skb = skb; |
633 | ||
634 | tsk = kthread_run(audit_send_reply_thread, reply, "audit_send_reply"); | |
fcaf1eb8 AM |
635 | if (!IS_ERR(tsk)) |
636 | return; | |
637 | kfree_skb(skb); | |
638 | out: | |
639 | kfree(reply); | |
1da177e4 LT |
640 | } |
641 | ||
642 | /* | |
643 | * Check for appropriate CAP_AUDIT_ capabilities on incoming audit | |
644 | * control messages. | |
645 | */ | |
c7bdb545 | 646 | static int audit_netlink_ok(struct sk_buff *skb, u16 msg_type) |
1da177e4 LT |
647 | { |
648 | int err = 0; | |
649 | ||
5a3cb3b6 | 650 | /* Only support initial user namespace for now. */ |
aa4af831 EP |
651 | /* |
652 | * We return ECONNREFUSED because it tricks userspace into thinking | |
653 | * that audit was not configured into the kernel. Lots of users | |
654 | * configure their PAM stack (because that's what the distro does) | |
655 | * to reject login if unable to send messages to audit. If we return | |
656 | * ECONNREFUSED the PAM stack thinks the kernel does not have audit | |
657 | * configured in and will let login proceed. If we return EPERM | |
658 | * userspace will reject all logins. This should be removed when we | |
659 | * support non init namespaces!! | |
660 | */ | |
0b747172 | 661 | if (current_user_ns() != &init_user_ns) |
aa4af831 | 662 | return -ECONNREFUSED; |
34e36d8e | 663 | |
1da177e4 | 664 | switch (msg_type) { |
1da177e4 | 665 | case AUDIT_LIST: |
1da177e4 LT |
666 | case AUDIT_ADD: |
667 | case AUDIT_DEL: | |
18900909 EP |
668 | return -EOPNOTSUPP; |
669 | case AUDIT_GET: | |
670 | case AUDIT_SET: | |
b0fed402 EP |
671 | case AUDIT_GET_FEATURE: |
672 | case AUDIT_SET_FEATURE: | |
18900909 EP |
673 | case AUDIT_LIST_RULES: |
674 | case AUDIT_ADD_RULE: | |
93315ed6 | 675 | case AUDIT_DEL_RULE: |
c2f0c7c3 | 676 | case AUDIT_SIGNAL_INFO: |
522ed776 MT |
677 | case AUDIT_TTY_GET: |
678 | case AUDIT_TTY_SET: | |
74c3cbe3 AV |
679 | case AUDIT_TRIM: |
680 | case AUDIT_MAKE_EQUIV: | |
5a3cb3b6 RGB |
681 | /* Only support auditd and auditctl in initial pid namespace |
682 | * for now. */ | |
5985de67 | 683 | if (task_active_pid_ns(current) != &init_pid_ns) |
5a3cb3b6 RGB |
684 | return -EPERM; |
685 | ||
90f62cf3 | 686 | if (!netlink_capable(skb, CAP_AUDIT_CONTROL)) |
1da177e4 LT |
687 | err = -EPERM; |
688 | break; | |
05474106 | 689 | case AUDIT_USER: |
039b6b3e RD |
690 | case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG: |
691 | case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2: | |
90f62cf3 | 692 | if (!netlink_capable(skb, CAP_AUDIT_WRITE)) |
1da177e4 LT |
693 | err = -EPERM; |
694 | break; | |
695 | default: /* bad msg */ | |
696 | err = -EINVAL; | |
697 | } | |
698 | ||
699 | return err; | |
700 | } | |
701 | ||
233a6866 | 702 | static void audit_log_common_recv_msg(struct audit_buffer **ab, u16 msg_type) |
50397bd1 | 703 | { |
dc9eb698 | 704 | uid_t uid = from_kuid(&init_user_ns, current_uid()); |
f1dc4867 | 705 | pid_t pid = task_tgid_nr(current); |
50397bd1 | 706 | |
0868a5e1 | 707 | if (!audit_enabled && msg_type != AUDIT_USER_AVC) { |
50397bd1 | 708 | *ab = NULL; |
233a6866 | 709 | return; |
50397bd1 EP |
710 | } |
711 | ||
712 | *ab = audit_log_start(NULL, GFP_KERNEL, msg_type); | |
0644ec0c | 713 | if (unlikely(!*ab)) |
233a6866 | 714 | return; |
f1dc4867 | 715 | audit_log_format(*ab, "pid=%d uid=%u", pid, uid); |
4d3fb709 | 716 | audit_log_session_info(*ab); |
b122c376 | 717 | audit_log_task_context(*ab); |
50397bd1 EP |
718 | } |
719 | ||
b0fed402 EP |
720 | int is_audit_feature_set(int i) |
721 | { | |
722 | return af.features & AUDIT_FEATURE_TO_MASK(i); | |
723 | } | |
724 | ||
725 | ||
726 | static int audit_get_feature(struct sk_buff *skb) | |
727 | { | |
728 | u32 seq; | |
729 | ||
730 | seq = nlmsg_hdr(skb)->nlmsg_seq; | |
731 | ||
9ef91514 | 732 | audit_send_reply(skb, seq, AUDIT_GET_FEATURE, 0, 0, &af, sizeof(af)); |
b0fed402 EP |
733 | |
734 | return 0; | |
735 | } | |
736 | ||
737 | static void audit_log_feature_change(int which, u32 old_feature, u32 new_feature, | |
738 | u32 old_lock, u32 new_lock, int res) | |
739 | { | |
740 | struct audit_buffer *ab; | |
741 | ||
b6c50fe0 G |
742 | if (audit_enabled == AUDIT_OFF) |
743 | return; | |
744 | ||
b0fed402 | 745 | ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_FEATURE_CHANGE); |
ad2ac263 | 746 | audit_log_task_info(ab, current); |
897f1acb | 747 | audit_log_format(ab, " feature=%s old=%u new=%u old_lock=%u new_lock=%u res=%d", |
b0fed402 EP |
748 | audit_feature_names[which], !!old_feature, !!new_feature, |
749 | !!old_lock, !!new_lock, res); | |
750 | audit_log_end(ab); | |
751 | } | |
752 | ||
753 | static int audit_set_feature(struct sk_buff *skb) | |
754 | { | |
755 | struct audit_features *uaf; | |
756 | int i; | |
757 | ||
6eed9b26 | 758 | BUILD_BUG_ON(AUDIT_LAST_FEATURE + 1 > ARRAY_SIZE(audit_feature_names)); |
b0fed402 EP |
759 | uaf = nlmsg_data(nlmsg_hdr(skb)); |
760 | ||
761 | /* if there is ever a version 2 we should handle that here */ | |
762 | ||
763 | for (i = 0; i <= AUDIT_LAST_FEATURE; i++) { | |
764 | u32 feature = AUDIT_FEATURE_TO_MASK(i); | |
765 | u32 old_feature, new_feature, old_lock, new_lock; | |
766 | ||
767 | /* if we are not changing this feature, move along */ | |
768 | if (!(feature & uaf->mask)) | |
769 | continue; | |
770 | ||
771 | old_feature = af.features & feature; | |
772 | new_feature = uaf->features & feature; | |
773 | new_lock = (uaf->lock | af.lock) & feature; | |
774 | old_lock = af.lock & feature; | |
775 | ||
776 | /* are we changing a locked feature? */ | |
4547b3bc | 777 | if (old_lock && (new_feature != old_feature)) { |
b0fed402 EP |
778 | audit_log_feature_change(i, old_feature, new_feature, |
779 | old_lock, new_lock, 0); | |
780 | return -EPERM; | |
781 | } | |
782 | } | |
783 | /* nothing invalid, do the changes */ | |
784 | for (i = 0; i <= AUDIT_LAST_FEATURE; i++) { | |
785 | u32 feature = AUDIT_FEATURE_TO_MASK(i); | |
786 | u32 old_feature, new_feature, old_lock, new_lock; | |
787 | ||
788 | /* if we are not changing this feature, move along */ | |
789 | if (!(feature & uaf->mask)) | |
790 | continue; | |
791 | ||
792 | old_feature = af.features & feature; | |
793 | new_feature = uaf->features & feature; | |
794 | old_lock = af.lock & feature; | |
795 | new_lock = (uaf->lock | af.lock) & feature; | |
796 | ||
797 | if (new_feature != old_feature) | |
798 | audit_log_feature_change(i, old_feature, new_feature, | |
799 | old_lock, new_lock, 1); | |
800 | ||
801 | if (new_feature) | |
802 | af.features |= feature; | |
803 | else | |
804 | af.features &= ~feature; | |
805 | af.lock |= new_lock; | |
806 | } | |
807 | ||
808 | return 0; | |
809 | } | |
810 | ||
1da177e4 LT |
811 | static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) |
812 | { | |
dc9eb698 | 813 | u32 seq; |
1da177e4 | 814 | void *data; |
1da177e4 | 815 | int err; |
c0404993 | 816 | struct audit_buffer *ab; |
1da177e4 | 817 | u16 msg_type = nlh->nlmsg_type; |
e1396065 | 818 | struct audit_sig_info *sig_data; |
50397bd1 | 819 | char *ctx = NULL; |
e1396065 | 820 | u32 len; |
1da177e4 | 821 | |
c7bdb545 | 822 | err = audit_netlink_ok(skb, msg_type); |
1da177e4 LT |
823 | if (err) |
824 | return err; | |
825 | ||
b0dd25a8 RD |
826 | /* As soon as there's any sign of userspace auditd, |
827 | * start kauditd to talk to it */ | |
13f51e1c | 828 | if (!kauditd_task) { |
b7d11258 | 829 | kauditd_task = kthread_run(kauditd_thread, NULL, "kauditd"); |
13f51e1c G |
830 | if (IS_ERR(kauditd_task)) { |
831 | err = PTR_ERR(kauditd_task); | |
832 | kauditd_task = NULL; | |
833 | return err; | |
834 | } | |
b7d11258 | 835 | } |
1da177e4 | 836 | seq = nlh->nlmsg_seq; |
c64e66c6 | 837 | data = nlmsg_data(nlh); |
1da177e4 LT |
838 | |
839 | switch (msg_type) { | |
09f883a9 RGB |
840 | case AUDIT_GET: { |
841 | struct audit_status s; | |
842 | memset(&s, 0, sizeof(s)); | |
843 | s.enabled = audit_enabled; | |
844 | s.failure = audit_failure; | |
845 | s.pid = audit_pid; | |
846 | s.rate_limit = audit_rate_limit; | |
847 | s.backlog_limit = audit_backlog_limit; | |
848 | s.lost = atomic_read(&audit_lost); | |
849 | s.backlog = skb_queue_len(&audit_skb_queue); | |
0288d718 | 850 | s.feature_bitmap = AUDIT_FEATURE_BITMAP_ALL; |
a77ed4e5 | 851 | s.backlog_wait_time = audit_backlog_wait_time_master; |
6f285b19 | 852 | audit_send_reply(skb, seq, AUDIT_GET, 0, 0, &s, sizeof(s)); |
1da177e4 | 853 | break; |
09f883a9 RGB |
854 | } |
855 | case AUDIT_SET: { | |
856 | struct audit_status s; | |
857 | memset(&s, 0, sizeof(s)); | |
858 | /* guard against past and future API changes */ | |
859 | memcpy(&s, data, min_t(size_t, sizeof(s), nlmsg_len(nlh))); | |
860 | if (s.mask & AUDIT_STATUS_ENABLED) { | |
861 | err = audit_set_enabled(s.enabled); | |
20c6aaa3 | 862 | if (err < 0) |
863 | return err; | |
1da177e4 | 864 | } |
09f883a9 RGB |
865 | if (s.mask & AUDIT_STATUS_FAILURE) { |
866 | err = audit_set_failure(s.failure); | |
20c6aaa3 | 867 | if (err < 0) |
868 | return err; | |
1da177e4 | 869 | } |
09f883a9 RGB |
870 | if (s.mask & AUDIT_STATUS_PID) { |
871 | int new_pid = s.pid; | |
1a6b9f23 | 872 | |
34eab0a7 RGB |
873 | if ((!new_pid) && (task_tgid_vnr(current) != audit_pid)) |
874 | return -EACCES; | |
1a6b9f23 | 875 | if (audit_enabled != AUDIT_OFF) |
dc9eb698 | 876 | audit_log_config_change("audit_pid", new_pid, audit_pid, 1); |
1a6b9f23 | 877 | audit_pid = new_pid; |
15e47304 | 878 | audit_nlk_portid = NETLINK_CB(skb).portid; |
de92fc97 | 879 | audit_sock = skb->sk; |
1da177e4 | 880 | } |
09f883a9 RGB |
881 | if (s.mask & AUDIT_STATUS_RATE_LIMIT) { |
882 | err = audit_set_rate_limit(s.rate_limit); | |
20c6aaa3 | 883 | if (err < 0) |
884 | return err; | |
885 | } | |
51cc83f0 | 886 | if (s.mask & AUDIT_STATUS_BACKLOG_LIMIT) { |
09f883a9 | 887 | err = audit_set_backlog_limit(s.backlog_limit); |
51cc83f0 RGB |
888 | if (err < 0) |
889 | return err; | |
890 | } | |
3f0c5fad EP |
891 | if (s.mask & AUDIT_STATUS_BACKLOG_WAIT_TIME) { |
892 | if (sizeof(s) > (size_t)nlh->nlmsg_len) | |
893 | return -EINVAL; | |
724e7bfc | 894 | if (s.backlog_wait_time > 10*AUDIT_BACKLOG_WAIT_TIME) |
3f0c5fad EP |
895 | return -EINVAL; |
896 | err = audit_set_backlog_wait_time(s.backlog_wait_time); | |
897 | if (err < 0) | |
898 | return err; | |
51cc83f0 | 899 | } |
1da177e4 | 900 | break; |
09f883a9 | 901 | } |
b0fed402 EP |
902 | case AUDIT_GET_FEATURE: |
903 | err = audit_get_feature(skb); | |
904 | if (err) | |
905 | return err; | |
906 | break; | |
907 | case AUDIT_SET_FEATURE: | |
908 | err = audit_set_feature(skb); | |
909 | if (err) | |
910 | return err; | |
911 | break; | |
05474106 | 912 | case AUDIT_USER: |
039b6b3e RD |
913 | case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG: |
914 | case AUDIT_FIRST_USER_MSG2 ... AUDIT_LAST_USER_MSG2: | |
4a4cd633 DW |
915 | if (!audit_enabled && msg_type != AUDIT_USER_AVC) |
916 | return 0; | |
917 | ||
62062cf8 | 918 | err = audit_filter_user(msg_type); |
724e4fcc | 919 | if (err == 1) { /* match or error */ |
4a4cd633 | 920 | err = 0; |
522ed776 | 921 | if (msg_type == AUDIT_USER_TTY) { |
152f497b | 922 | err = tty_audit_push_current(); |
522ed776 MT |
923 | if (err) |
924 | break; | |
925 | } | |
1b7b533f | 926 | mutex_unlock(&audit_cmd_mutex); |
dc9eb698 | 927 | audit_log_common_recv_msg(&ab, msg_type); |
50397bd1 | 928 | if (msg_type != AUDIT_USER_TTY) |
b50eba7e RGB |
929 | audit_log_format(ab, " msg='%.*s'", |
930 | AUDIT_MESSAGE_TEXT_MAX, | |
50397bd1 EP |
931 | (char *)data); |
932 | else { | |
933 | int size; | |
934 | ||
f7616102 | 935 | audit_log_format(ab, " data="); |
50397bd1 | 936 | size = nlmsg_len(nlh); |
55ad2f8d MT |
937 | if (size > 0 && |
938 | ((unsigned char *)data)[size - 1] == '\0') | |
939 | size--; | |
b556f8ad | 940 | audit_log_n_untrustedstring(ab, data, size); |
4a4cd633 | 941 | } |
f9441639 | 942 | audit_set_portid(ab, NETLINK_CB(skb).portid); |
50397bd1 | 943 | audit_log_end(ab); |
1b7b533f | 944 | mutex_lock(&audit_cmd_mutex); |
0f45aa18 | 945 | } |
1da177e4 | 946 | break; |
93315ed6 AG |
947 | case AUDIT_ADD_RULE: |
948 | case AUDIT_DEL_RULE: | |
949 | if (nlmsg_len(nlh) < sizeof(struct audit_rule_data)) | |
950 | return -EINVAL; | |
1a6b9f23 | 951 | if (audit_enabled == AUDIT_LOCKED) { |
dc9eb698 EP |
952 | audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE); |
953 | audit_log_format(ab, " audit_enabled=%d res=0", audit_enabled); | |
50397bd1 | 954 | audit_log_end(ab); |
6a01b07f SG |
955 | return -EPERM; |
956 | } | |
ce0d9f04 | 957 | err = audit_rule_change(msg_type, NETLINK_CB(skb).portid, |
dc9eb698 | 958 | seq, data, nlmsg_len(nlh)); |
1da177e4 | 959 | break; |
ce0d9f04 | 960 | case AUDIT_LIST_RULES: |
6f285b19 | 961 | err = audit_list_rules_send(skb, seq); |
ce0d9f04 | 962 | break; |
74c3cbe3 AV |
963 | case AUDIT_TRIM: |
964 | audit_trim_trees(); | |
dc9eb698 | 965 | audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE); |
74c3cbe3 AV |
966 | audit_log_format(ab, " op=trim res=1"); |
967 | audit_log_end(ab); | |
968 | break; | |
969 | case AUDIT_MAKE_EQUIV: { | |
970 | void *bufp = data; | |
971 | u32 sizes[2]; | |
7719e437 | 972 | size_t msglen = nlmsg_len(nlh); |
74c3cbe3 AV |
973 | char *old, *new; |
974 | ||
975 | err = -EINVAL; | |
7719e437 | 976 | if (msglen < 2 * sizeof(u32)) |
74c3cbe3 AV |
977 | break; |
978 | memcpy(sizes, bufp, 2 * sizeof(u32)); | |
979 | bufp += 2 * sizeof(u32); | |
7719e437 HH |
980 | msglen -= 2 * sizeof(u32); |
981 | old = audit_unpack_string(&bufp, &msglen, sizes[0]); | |
74c3cbe3 AV |
982 | if (IS_ERR(old)) { |
983 | err = PTR_ERR(old); | |
984 | break; | |
985 | } | |
7719e437 | 986 | new = audit_unpack_string(&bufp, &msglen, sizes[1]); |
74c3cbe3 AV |
987 | if (IS_ERR(new)) { |
988 | err = PTR_ERR(new); | |
989 | kfree(old); | |
990 | break; | |
991 | } | |
992 | /* OK, here comes... */ | |
993 | err = audit_tag_tree(old, new); | |
994 | ||
dc9eb698 | 995 | audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE); |
50397bd1 | 996 | |
74c3cbe3 AV |
997 | audit_log_format(ab, " op=make_equiv old="); |
998 | audit_log_untrustedstring(ab, old); | |
999 | audit_log_format(ab, " new="); | |
1000 | audit_log_untrustedstring(ab, new); | |
1001 | audit_log_format(ab, " res=%d", !err); | |
1002 | audit_log_end(ab); | |
1003 | kfree(old); | |
1004 | kfree(new); | |
1005 | break; | |
1006 | } | |
c2f0c7c3 | 1007 | case AUDIT_SIGNAL_INFO: |
939cbf26 EP |
1008 | len = 0; |
1009 | if (audit_sig_sid) { | |
1010 | err = security_secid_to_secctx(audit_sig_sid, &ctx, &len); | |
1011 | if (err) | |
1012 | return err; | |
1013 | } | |
e1396065 AV |
1014 | sig_data = kmalloc(sizeof(*sig_data) + len, GFP_KERNEL); |
1015 | if (!sig_data) { | |
939cbf26 EP |
1016 | if (audit_sig_sid) |
1017 | security_release_secctx(ctx, len); | |
e1396065 AV |
1018 | return -ENOMEM; |
1019 | } | |
cca080d9 | 1020 | sig_data->uid = from_kuid(&init_user_ns, audit_sig_uid); |
e1396065 | 1021 | sig_data->pid = audit_sig_pid; |
939cbf26 EP |
1022 | if (audit_sig_sid) { |
1023 | memcpy(sig_data->ctx, ctx, len); | |
1024 | security_release_secctx(ctx, len); | |
1025 | } | |
6f285b19 EB |
1026 | audit_send_reply(skb, seq, AUDIT_SIGNAL_INFO, 0, 0, |
1027 | sig_data, sizeof(*sig_data) + len); | |
e1396065 | 1028 | kfree(sig_data); |
c2f0c7c3 | 1029 | break; |
522ed776 MT |
1030 | case AUDIT_TTY_GET: { |
1031 | struct audit_tty_status s; | |
8aa14b64 EB |
1032 | struct task_struct *tsk = current; |
1033 | ||
7173c54e | 1034 | spin_lock(&tsk->sighand->siglock); |
b95d77fe | 1035 | s.enabled = tsk->signal->audit_tty; |
46e959ea | 1036 | s.log_passwd = tsk->signal->audit_tty_log_passwd; |
7173c54e | 1037 | spin_unlock(&tsk->sighand->siglock); |
8aa14b64 | 1038 | |
6f285b19 | 1039 | audit_send_reply(skb, seq, AUDIT_TTY_GET, 0, 0, &s, sizeof(s)); |
522ed776 MT |
1040 | break; |
1041 | } | |
1042 | case AUDIT_TTY_SET: { | |
a06e56b2 | 1043 | struct audit_tty_status s, old; |
8aa14b64 | 1044 | struct task_struct *tsk = current; |
a06e56b2 | 1045 | struct audit_buffer *ab; |
0e23bacc EP |
1046 | |
1047 | memset(&s, 0, sizeof(s)); | |
1048 | /* guard against past and future API changes */ | |
1049 | memcpy(&s, data, min_t(size_t, sizeof(s), nlmsg_len(nlh))); | |
1050 | /* check if new data is valid */ | |
1051 | if ((s.enabled != 0 && s.enabled != 1) || | |
1052 | (s.log_passwd != 0 && s.log_passwd != 1)) | |
1053 | err = -EINVAL; | |
a06e56b2 RGB |
1054 | |
1055 | spin_lock(&tsk->sighand->siglock); | |
1056 | old.enabled = tsk->signal->audit_tty; | |
1057 | old.log_passwd = tsk->signal->audit_tty_log_passwd; | |
0e23bacc EP |
1058 | if (!err) { |
1059 | tsk->signal->audit_tty = s.enabled; | |
1060 | tsk->signal->audit_tty_log_passwd = s.log_passwd; | |
1061 | } | |
a06e56b2 | 1062 | spin_unlock(&tsk->sighand->siglock); |
522ed776 | 1063 | |
a06e56b2 | 1064 | audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE); |
1ce319f1 EP |
1065 | audit_log_format(ab, " op=tty_set old-enabled=%d new-enabled=%d" |
1066 | " old-log_passwd=%d new-log_passwd=%d res=%d", | |
1067 | old.enabled, s.enabled, old.log_passwd, | |
1068 | s.log_passwd, !err); | |
a06e56b2 | 1069 | audit_log_end(ab); |
522ed776 MT |
1070 | break; |
1071 | } | |
1da177e4 LT |
1072 | default: |
1073 | err = -EINVAL; | |
1074 | break; | |
1075 | } | |
1076 | ||
1077 | return err < 0 ? err : 0; | |
1078 | } | |
1079 | ||
b0dd25a8 | 1080 | /* |
ea7ae60b EP |
1081 | * Get message from skb. Each message is processed by audit_receive_msg. |
1082 | * Malformed skbs with wrong length are discarded silently. | |
b0dd25a8 | 1083 | */ |
2a0a6ebe | 1084 | static void audit_receive_skb(struct sk_buff *skb) |
1da177e4 | 1085 | { |
ea7ae60b EP |
1086 | struct nlmsghdr *nlh; |
1087 | /* | |
94191213 | 1088 | * len MUST be signed for nlmsg_next to be able to dec it below 0 |
ea7ae60b EP |
1089 | * if the nlmsg_len was not aligned |
1090 | */ | |
1091 | int len; | |
1092 | int err; | |
1093 | ||
1094 | nlh = nlmsg_hdr(skb); | |
1095 | len = skb->len; | |
1096 | ||
94191213 | 1097 | while (nlmsg_ok(nlh, len)) { |
ea7ae60b EP |
1098 | err = audit_receive_msg(skb, nlh); |
1099 | /* if err or if this message says it wants a response */ | |
1100 | if (err || (nlh->nlmsg_flags & NLM_F_ACK)) | |
1da177e4 | 1101 | netlink_ack(skb, nlh, err); |
ea7ae60b | 1102 | |
2851da57 | 1103 | nlh = nlmsg_next(nlh, &len); |
1da177e4 | 1104 | } |
1da177e4 LT |
1105 | } |
1106 | ||
1107 | /* Receive messages from netlink socket. */ | |
cd40b7d3 | 1108 | static void audit_receive(struct sk_buff *skb) |
1da177e4 | 1109 | { |
f368c07d | 1110 | mutex_lock(&audit_cmd_mutex); |
cd40b7d3 | 1111 | audit_receive_skb(skb); |
f368c07d | 1112 | mutex_unlock(&audit_cmd_mutex); |
1da177e4 LT |
1113 | } |
1114 | ||
3a101b8d | 1115 | /* Run custom bind function on netlink socket group connect or bind requests. */ |
023e2cfa | 1116 | static int audit_bind(struct net *net, int group) |
3a101b8d RGB |
1117 | { |
1118 | if (!capable(CAP_AUDIT_READ)) | |
1119 | return -EPERM; | |
1120 | ||
1121 | return 0; | |
1122 | } | |
1123 | ||
33faba7f | 1124 | static int __net_init audit_net_init(struct net *net) |
1da177e4 | 1125 | { |
a31f2d17 PNA |
1126 | struct netlink_kernel_cfg cfg = { |
1127 | .input = audit_receive, | |
3a101b8d | 1128 | .bind = audit_bind, |
451f9216 RGB |
1129 | .flags = NL_CFG_F_NONROOT_RECV, |
1130 | .groups = AUDIT_NLGRP_MAX, | |
a31f2d17 | 1131 | }; |
f368c07d | 1132 | |
33faba7f RGB |
1133 | struct audit_net *aunet = net_generic(net, audit_net_id); |
1134 | ||
33faba7f | 1135 | aunet->nlsk = netlink_kernel_create(net, NETLINK_AUDIT, &cfg); |
11ee39eb | 1136 | if (aunet->nlsk == NULL) { |
33faba7f | 1137 | audit_panic("cannot initialize netlink socket in namespace"); |
11ee39eb G |
1138 | return -ENOMEM; |
1139 | } | |
1140 | aunet->nlsk->sk_sndtimeo = MAX_SCHEDULE_TIMEOUT; | |
33faba7f RGB |
1141 | return 0; |
1142 | } | |
1143 | ||
1144 | static void __net_exit audit_net_exit(struct net *net) | |
1145 | { | |
1146 | struct audit_net *aunet = net_generic(net, audit_net_id); | |
1147 | struct sock *sock = aunet->nlsk; | |
1148 | if (sock == audit_sock) { | |
1149 | audit_pid = 0; | |
1150 | audit_sock = NULL; | |
1151 | } | |
1152 | ||
e231d54c | 1153 | RCU_INIT_POINTER(aunet->nlsk, NULL); |
33faba7f RGB |
1154 | synchronize_net(); |
1155 | netlink_kernel_release(sock); | |
1156 | } | |
1157 | ||
8626877b | 1158 | static struct pernet_operations audit_net_ops __net_initdata = { |
33faba7f RGB |
1159 | .init = audit_net_init, |
1160 | .exit = audit_net_exit, | |
1161 | .id = &audit_net_id, | |
1162 | .size = sizeof(struct audit_net), | |
1163 | }; | |
1164 | ||
1165 | /* Initialize audit support at boot time. */ | |
1166 | static int __init audit_init(void) | |
1167 | { | |
1168 | int i; | |
1169 | ||
a3f07114 EP |
1170 | if (audit_initialized == AUDIT_DISABLED) |
1171 | return 0; | |
1172 | ||
d957f7b7 JP |
1173 | pr_info("initializing netlink subsys (%s)\n", |
1174 | audit_default ? "enabled" : "disabled"); | |
33faba7f | 1175 | register_pernet_subsys(&audit_net_ops); |
1da177e4 | 1176 | |
b7d11258 | 1177 | skb_queue_head_init(&audit_skb_queue); |
f3d357b0 | 1178 | skb_queue_head_init(&audit_skb_hold_queue); |
a3f07114 | 1179 | audit_initialized = AUDIT_INITIALIZED; |
1da177e4 | 1180 | audit_enabled = audit_default; |
b593d384 | 1181 | audit_ever_enabled |= !!audit_default; |
3dc7e315 | 1182 | |
9ad9ad38 | 1183 | audit_log(NULL, GFP_KERNEL, AUDIT_KERNEL, "initialized"); |
f368c07d | 1184 | |
f368c07d AG |
1185 | for (i = 0; i < AUDIT_INODE_BUCKETS; i++) |
1186 | INIT_LIST_HEAD(&audit_inode_hash[i]); | |
f368c07d | 1187 | |
1da177e4 LT |
1188 | return 0; |
1189 | } | |
1da177e4 LT |
1190 | __initcall(audit_init); |
1191 | ||
1192 | /* Process kernel command-line parameter at boot time. audit=0 or audit=1. */ | |
1193 | static int __init audit_enable(char *str) | |
1194 | { | |
1195 | audit_default = !!simple_strtol(str, NULL, 0); | |
a3f07114 EP |
1196 | if (!audit_default) |
1197 | audit_initialized = AUDIT_DISABLED; | |
1198 | ||
d957f7b7 | 1199 | pr_info("%s\n", audit_default ? |
d3ca0344 | 1200 | "enabled (after initialization)" : "disabled (until reboot)"); |
a3f07114 | 1201 | |
9b41046c | 1202 | return 1; |
1da177e4 | 1203 | } |
1da177e4 LT |
1204 | __setup("audit=", audit_enable); |
1205 | ||
f910fde7 RGB |
1206 | /* Process kernel command-line parameter at boot time. |
1207 | * audit_backlog_limit=<n> */ | |
1208 | static int __init audit_backlog_limit_set(char *str) | |
1209 | { | |
3e1d0bb6 | 1210 | u32 audit_backlog_limit_arg; |
d957f7b7 | 1211 | |
f910fde7 | 1212 | pr_info("audit_backlog_limit: "); |
3e1d0bb6 JP |
1213 | if (kstrtouint(str, 0, &audit_backlog_limit_arg)) { |
1214 | pr_cont("using default of %u, unable to parse %s\n", | |
d957f7b7 | 1215 | audit_backlog_limit, str); |
f910fde7 RGB |
1216 | return 1; |
1217 | } | |
3e1d0bb6 JP |
1218 | |
1219 | audit_backlog_limit = audit_backlog_limit_arg; | |
d957f7b7 | 1220 | pr_cont("%d\n", audit_backlog_limit); |
f910fde7 RGB |
1221 | |
1222 | return 1; | |
1223 | } | |
1224 | __setup("audit_backlog_limit=", audit_backlog_limit_set); | |
1225 | ||
16e1904e CW |
1226 | static void audit_buffer_free(struct audit_buffer *ab) |
1227 | { | |
1228 | unsigned long flags; | |
1229 | ||
8fc6115c CW |
1230 | if (!ab) |
1231 | return; | |
1232 | ||
d865e573 | 1233 | kfree_skb(ab->skb); |
16e1904e | 1234 | spin_lock_irqsave(&audit_freelist_lock, flags); |
5d136a01 | 1235 | if (audit_freelist_count > AUDIT_MAXFREE) |
16e1904e | 1236 | kfree(ab); |
5d136a01 SH |
1237 | else { |
1238 | audit_freelist_count++; | |
16e1904e | 1239 | list_add(&ab->list, &audit_freelist); |
5d136a01 | 1240 | } |
16e1904e CW |
1241 | spin_unlock_irqrestore(&audit_freelist_lock, flags); |
1242 | } | |
1243 | ||
c0404993 | 1244 | static struct audit_buffer * audit_buffer_alloc(struct audit_context *ctx, |
dd0fc66f | 1245 | gfp_t gfp_mask, int type) |
16e1904e CW |
1246 | { |
1247 | unsigned long flags; | |
1248 | struct audit_buffer *ab = NULL; | |
c0404993 | 1249 | struct nlmsghdr *nlh; |
16e1904e CW |
1250 | |
1251 | spin_lock_irqsave(&audit_freelist_lock, flags); | |
1252 | if (!list_empty(&audit_freelist)) { | |
1253 | ab = list_entry(audit_freelist.next, | |
1254 | struct audit_buffer, list); | |
1255 | list_del(&ab->list); | |
1256 | --audit_freelist_count; | |
1257 | } | |
1258 | spin_unlock_irqrestore(&audit_freelist_lock, flags); | |
1259 | ||
1260 | if (!ab) { | |
4332bdd3 | 1261 | ab = kmalloc(sizeof(*ab), gfp_mask); |
16e1904e | 1262 | if (!ab) |
8fc6115c | 1263 | goto err; |
16e1904e | 1264 | } |
8fc6115c | 1265 | |
b7d11258 | 1266 | ab->ctx = ctx; |
9ad9ad38 | 1267 | ab->gfp_mask = gfp_mask; |
ee080e6c EP |
1268 | |
1269 | ab->skb = nlmsg_new(AUDIT_BUFSIZ, gfp_mask); | |
1270 | if (!ab->skb) | |
c64e66c6 | 1271 | goto err; |
ee080e6c | 1272 | |
c64e66c6 DM |
1273 | nlh = nlmsg_put(ab->skb, 0, 0, type, 0, 0); |
1274 | if (!nlh) | |
1275 | goto out_kfree_skb; | |
ee080e6c | 1276 | |
16e1904e | 1277 | return ab; |
ee080e6c | 1278 | |
c64e66c6 | 1279 | out_kfree_skb: |
ee080e6c EP |
1280 | kfree_skb(ab->skb); |
1281 | ab->skb = NULL; | |
8fc6115c CW |
1282 | err: |
1283 | audit_buffer_free(ab); | |
1284 | return NULL; | |
16e1904e | 1285 | } |
1da177e4 | 1286 | |
b0dd25a8 RD |
1287 | /** |
1288 | * audit_serial - compute a serial number for the audit record | |
1289 | * | |
1290 | * Compute a serial number for the audit record. Audit records are | |
bfb4496e DW |
1291 | * written to user-space as soon as they are generated, so a complete |
1292 | * audit record may be written in several pieces. The timestamp of the | |
1293 | * record and this serial number are used by the user-space tools to | |
1294 | * determine which pieces belong to the same audit record. The | |
1295 | * (timestamp,serial) tuple is unique for each syscall and is live from | |
1296 | * syscall entry to syscall exit. | |
1297 | * | |
bfb4496e DW |
1298 | * NOTE: Another possibility is to store the formatted records off the |
1299 | * audit context (for those records that have a context), and emit them | |
1300 | * all at syscall exit. However, this could delay the reporting of | |
1301 | * significant errors until syscall exit (or never, if the system | |
b0dd25a8 RD |
1302 | * halts). |
1303 | */ | |
bfb4496e DW |
1304 | unsigned int audit_serial(void) |
1305 | { | |
01478d7d | 1306 | static atomic_t serial = ATOMIC_INIT(0); |
d5b454f2 | 1307 | |
01478d7d | 1308 | return atomic_add_return(1, &serial); |
bfb4496e DW |
1309 | } |
1310 | ||
5600b892 | 1311 | static inline void audit_get_stamp(struct audit_context *ctx, |
bfb4496e DW |
1312 | struct timespec *t, unsigned int *serial) |
1313 | { | |
48887e63 | 1314 | if (!ctx || !auditsc_get_stamp(ctx, t, serial)) { |
bfb4496e DW |
1315 | *t = CURRENT_TIME; |
1316 | *serial = audit_serial(); | |
1317 | } | |
1318 | } | |
1319 | ||
82919919 AM |
1320 | /* |
1321 | * Wait for auditd to drain the queue a little | |
1322 | */ | |
c81825dd | 1323 | static long wait_for_auditd(long sleep_time) |
82919919 AM |
1324 | { |
1325 | DECLARE_WAITQUEUE(wait, current); | |
82919919 AM |
1326 | |
1327 | if (audit_backlog_limit && | |
7ffb8e31 PM |
1328 | skb_queue_len(&audit_skb_queue) > audit_backlog_limit) { |
1329 | add_wait_queue_exclusive(&audit_backlog_wait, &wait); | |
1330 | set_current_state(TASK_UNINTERRUPTIBLE); | |
c81825dd | 1331 | sleep_time = schedule_timeout(sleep_time); |
7ffb8e31 PM |
1332 | remove_wait_queue(&audit_backlog_wait, &wait); |
1333 | } | |
ae887e0b | 1334 | |
c81825dd | 1335 | return sleep_time; |
82919919 AM |
1336 | } |
1337 | ||
b0dd25a8 RD |
1338 | /** |
1339 | * audit_log_start - obtain an audit buffer | |
1340 | * @ctx: audit_context (may be NULL) | |
1341 | * @gfp_mask: type of allocation | |
1342 | * @type: audit message type | |
1343 | * | |
1344 | * Returns audit_buffer pointer on success or NULL on error. | |
1345 | * | |
1346 | * Obtain an audit buffer. This routine does locking to obtain the | |
1347 | * audit buffer, but then no locking is required for calls to | |
1348 | * audit_log_*format. If the task (ctx) is a task that is currently in a | |
1349 | * syscall, then the syscall is marked as auditable and an audit record | |
1350 | * will be written at syscall exit. If there is no associated task, then | |
1351 | * task context (ctx) should be NULL. | |
1352 | */ | |
9796fdd8 | 1353 | struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask, |
9ad9ad38 | 1354 | int type) |
1da177e4 LT |
1355 | { |
1356 | struct audit_buffer *ab = NULL; | |
1da177e4 | 1357 | struct timespec t; |
ef00be05 | 1358 | unsigned int uninitialized_var(serial); |
6dd80aba TO |
1359 | int reserve = 5; /* Allow atomic callers to go up to five |
1360 | entries over the normal backlog limit */ | |
ac4cec44 | 1361 | unsigned long timeout_start = jiffies; |
1da177e4 | 1362 | |
a3f07114 | 1363 | if (audit_initialized != AUDIT_INITIALIZED) |
1da177e4 LT |
1364 | return NULL; |
1365 | ||
c8edc80c DK |
1366 | if (unlikely(audit_filter_type(type))) |
1367 | return NULL; | |
1368 | ||
d0164adc | 1369 | if (gfp_mask & __GFP_DIRECT_RECLAIM) { |
f48a9429 | 1370 | if (audit_pid && audit_pid == current->tgid) |
d0164adc | 1371 | gfp_mask &= ~__GFP_DIRECT_RECLAIM; |
6dd80aba TO |
1372 | else |
1373 | reserve = 0; | |
1374 | } | |
9ad9ad38 DW |
1375 | |
1376 | while (audit_backlog_limit | |
1377 | && skb_queue_len(&audit_skb_queue) > audit_backlog_limit + reserve) { | |
d0164adc | 1378 | if (gfp_mask & __GFP_DIRECT_RECLAIM && audit_backlog_wait_time) { |
c81825dd | 1379 | long sleep_time; |
9ad9ad38 | 1380 | |
c81825dd EP |
1381 | sleep_time = timeout_start + audit_backlog_wait_time - jiffies; |
1382 | if (sleep_time > 0) { | |
ae887e0b | 1383 | sleep_time = wait_for_auditd(sleep_time); |
c81825dd | 1384 | if (sleep_time > 0) |
ae887e0b | 1385 | continue; |
8ac1c8d5 | 1386 | } |
9ad9ad38 | 1387 | } |
320f1b1e | 1388 | if (audit_rate_check() && printk_ratelimit()) |
d957f7b7 JP |
1389 | pr_warn("audit_backlog=%d > audit_backlog_limit=%d\n", |
1390 | skb_queue_len(&audit_skb_queue), | |
1391 | audit_backlog_limit); | |
fb19b4c6 | 1392 | audit_log_lost("backlog limit exceeded"); |
eb8baf6a | 1393 | audit_backlog_wait_time = 0; |
ac4cec44 | 1394 | wake_up(&audit_backlog_wait); |
fb19b4c6 DW |
1395 | return NULL; |
1396 | } | |
1397 | ||
c4b7a775 | 1398 | if (!reserve && !audit_backlog_wait_time) |
efef73a1 | 1399 | audit_backlog_wait_time = audit_backlog_wait_time_master; |
e789e561 | 1400 | |
9ad9ad38 | 1401 | ab = audit_buffer_alloc(ctx, gfp_mask, type); |
1da177e4 LT |
1402 | if (!ab) { |
1403 | audit_log_lost("out of memory in audit_log_start"); | |
1404 | return NULL; | |
1405 | } | |
1406 | ||
bfb4496e | 1407 | audit_get_stamp(ab->ctx, &t, &serial); |
197c69c6 | 1408 | |
1da177e4 LT |
1409 | audit_log_format(ab, "audit(%lu.%03lu:%u): ", |
1410 | t.tv_sec, t.tv_nsec/1000000, serial); | |
1411 | return ab; | |
1412 | } | |
1413 | ||
8fc6115c | 1414 | /** |
5ac52f33 | 1415 | * audit_expand - expand skb in the audit buffer |
8fc6115c | 1416 | * @ab: audit_buffer |
b0dd25a8 | 1417 | * @extra: space to add at tail of the skb |
8fc6115c CW |
1418 | * |
1419 | * Returns 0 (no space) on failed expansion, or available space if | |
1420 | * successful. | |
1421 | */ | |
e3b926b4 | 1422 | static inline int audit_expand(struct audit_buffer *ab, int extra) |
8fc6115c | 1423 | { |
5ac52f33 | 1424 | struct sk_buff *skb = ab->skb; |
406a1d86 HX |
1425 | int oldtail = skb_tailroom(skb); |
1426 | int ret = pskb_expand_head(skb, 0, extra, ab->gfp_mask); | |
1427 | int newtail = skb_tailroom(skb); | |
1428 | ||
5ac52f33 CW |
1429 | if (ret < 0) { |
1430 | audit_log_lost("out of memory in audit_expand"); | |
8fc6115c | 1431 | return 0; |
5ac52f33 | 1432 | } |
406a1d86 HX |
1433 | |
1434 | skb->truesize += newtail - oldtail; | |
1435 | return newtail; | |
8fc6115c | 1436 | } |
1da177e4 | 1437 | |
b0dd25a8 RD |
1438 | /* |
1439 | * Format an audit message into the audit buffer. If there isn't enough | |
1da177e4 LT |
1440 | * room in the audit buffer, more room will be allocated and vsnprint |
1441 | * will be called a second time. Currently, we assume that a printk | |
b0dd25a8 RD |
1442 | * can't format message larger than 1024 bytes, so we don't either. |
1443 | */ | |
1da177e4 LT |
1444 | static void audit_log_vformat(struct audit_buffer *ab, const char *fmt, |
1445 | va_list args) | |
1446 | { | |
1447 | int len, avail; | |
5ac52f33 | 1448 | struct sk_buff *skb; |
eecb0a73 | 1449 | va_list args2; |
1da177e4 LT |
1450 | |
1451 | if (!ab) | |
1452 | return; | |
1453 | ||
5ac52f33 CW |
1454 | BUG_ON(!ab->skb); |
1455 | skb = ab->skb; | |
1456 | avail = skb_tailroom(skb); | |
1457 | if (avail == 0) { | |
e3b926b4 | 1458 | avail = audit_expand(ab, AUDIT_BUFSIZ); |
8fc6115c CW |
1459 | if (!avail) |
1460 | goto out; | |
1da177e4 | 1461 | } |
eecb0a73 | 1462 | va_copy(args2, args); |
27a884dc | 1463 | len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args); |
1da177e4 LT |
1464 | if (len >= avail) { |
1465 | /* The printk buffer is 1024 bytes long, so if we get | |
1466 | * here and AUDIT_BUFSIZ is at least 1024, then we can | |
1467 | * log everything that printk could have logged. */ | |
b0dd25a8 RD |
1468 | avail = audit_expand(ab, |
1469 | max_t(unsigned, AUDIT_BUFSIZ, 1+len-avail)); | |
8fc6115c | 1470 | if (!avail) |
a0e86bd4 | 1471 | goto out_va_end; |
27a884dc | 1472 | len = vsnprintf(skb_tail_pointer(skb), avail, fmt, args2); |
1da177e4 | 1473 | } |
168b7173 SG |
1474 | if (len > 0) |
1475 | skb_put(skb, len); | |
a0e86bd4 JJ |
1476 | out_va_end: |
1477 | va_end(args2); | |
8fc6115c CW |
1478 | out: |
1479 | return; | |
1da177e4 LT |
1480 | } |
1481 | ||
b0dd25a8 RD |
1482 | /** |
1483 | * audit_log_format - format a message into the audit buffer. | |
1484 | * @ab: audit_buffer | |
1485 | * @fmt: format string | |
1486 | * @...: optional parameters matching @fmt string | |
1487 | * | |
1488 | * All the work is done in audit_log_vformat. | |
1489 | */ | |
1da177e4 LT |
1490 | void audit_log_format(struct audit_buffer *ab, const char *fmt, ...) |
1491 | { | |
1492 | va_list args; | |
1493 | ||
1494 | if (!ab) | |
1495 | return; | |
1496 | va_start(args, fmt); | |
1497 | audit_log_vformat(ab, fmt, args); | |
1498 | va_end(args); | |
1499 | } | |
1500 | ||
b0dd25a8 RD |
1501 | /** |
1502 | * audit_log_hex - convert a buffer to hex and append it to the audit skb | |
1503 | * @ab: the audit_buffer | |
1504 | * @buf: buffer to convert to hex | |
1505 | * @len: length of @buf to be converted | |
1506 | * | |
1507 | * No return value; failure to expand is silently ignored. | |
1508 | * | |
1509 | * This function will take the passed buf and convert it into a string of | |
1510 | * ascii hex digits. The new string is placed onto the skb. | |
1511 | */ | |
b556f8ad | 1512 | void audit_log_n_hex(struct audit_buffer *ab, const unsigned char *buf, |
168b7173 | 1513 | size_t len) |
83c7d091 | 1514 | { |
168b7173 SG |
1515 | int i, avail, new_len; |
1516 | unsigned char *ptr; | |
1517 | struct sk_buff *skb; | |
168b7173 | 1518 | |
8ef2d304 AG |
1519 | if (!ab) |
1520 | return; | |
1521 | ||
168b7173 SG |
1522 | BUG_ON(!ab->skb); |
1523 | skb = ab->skb; | |
1524 | avail = skb_tailroom(skb); | |
1525 | new_len = len<<1; | |
1526 | if (new_len >= avail) { | |
1527 | /* Round the buffer request up to the next multiple */ | |
1528 | new_len = AUDIT_BUFSIZ*(((new_len-avail)/AUDIT_BUFSIZ) + 1); | |
1529 | avail = audit_expand(ab, new_len); | |
1530 | if (!avail) | |
1531 | return; | |
1532 | } | |
83c7d091 | 1533 | |
27a884dc | 1534 | ptr = skb_tail_pointer(skb); |
b8dbc324 JP |
1535 | for (i = 0; i < len; i++) |
1536 | ptr = hex_byte_pack_upper(ptr, buf[i]); | |
168b7173 SG |
1537 | *ptr = 0; |
1538 | skb_put(skb, len << 1); /* new string is twice the old string */ | |
83c7d091 | 1539 | } |
1540 | ||
9c937dcc AG |
1541 | /* |
1542 | * Format a string of no more than slen characters into the audit buffer, | |
1543 | * enclosed in quote marks. | |
1544 | */ | |
b556f8ad EP |
1545 | void audit_log_n_string(struct audit_buffer *ab, const char *string, |
1546 | size_t slen) | |
9c937dcc AG |
1547 | { |
1548 | int avail, new_len; | |
1549 | unsigned char *ptr; | |
1550 | struct sk_buff *skb; | |
1551 | ||
8ef2d304 AG |
1552 | if (!ab) |
1553 | return; | |
1554 | ||
9c937dcc AG |
1555 | BUG_ON(!ab->skb); |
1556 | skb = ab->skb; | |
1557 | avail = skb_tailroom(skb); | |
1558 | new_len = slen + 3; /* enclosing quotes + null terminator */ | |
1559 | if (new_len > avail) { | |
1560 | avail = audit_expand(ab, new_len); | |
1561 | if (!avail) | |
1562 | return; | |
1563 | } | |
27a884dc | 1564 | ptr = skb_tail_pointer(skb); |
9c937dcc AG |
1565 | *ptr++ = '"'; |
1566 | memcpy(ptr, string, slen); | |
1567 | ptr += slen; | |
1568 | *ptr++ = '"'; | |
1569 | *ptr = 0; | |
1570 | skb_put(skb, slen + 2); /* don't include null terminator */ | |
1571 | } | |
1572 | ||
de6bbd1d EP |
1573 | /** |
1574 | * audit_string_contains_control - does a string need to be logged in hex | |
f706d5d2 DJ |
1575 | * @string: string to be checked |
1576 | * @len: max length of the string to check | |
de6bbd1d | 1577 | */ |
9fcf836b | 1578 | bool audit_string_contains_control(const char *string, size_t len) |
de6bbd1d EP |
1579 | { |
1580 | const unsigned char *p; | |
b3897f56 | 1581 | for (p = string; p < (const unsigned char *)string + len; p++) { |
1d6c9649 | 1582 | if (*p == '"' || *p < 0x21 || *p > 0x7e) |
9fcf836b | 1583 | return true; |
de6bbd1d | 1584 | } |
9fcf836b | 1585 | return false; |
de6bbd1d EP |
1586 | } |
1587 | ||
b0dd25a8 | 1588 | /** |
522ed776 | 1589 | * audit_log_n_untrustedstring - log a string that may contain random characters |
b0dd25a8 | 1590 | * @ab: audit_buffer |
f706d5d2 | 1591 | * @len: length of string (not including trailing null) |
b0dd25a8 RD |
1592 | * @string: string to be logged |
1593 | * | |
1594 | * This code will escape a string that is passed to it if the string | |
1595 | * contains a control character, unprintable character, double quote mark, | |
168b7173 | 1596 | * or a space. Unescaped strings will start and end with a double quote mark. |
b0dd25a8 | 1597 | * Strings that are escaped are printed in hex (2 digits per char). |
9c937dcc AG |
1598 | * |
1599 | * The caller specifies the number of characters in the string to log, which may | |
1600 | * or may not be the entire string. | |
b0dd25a8 | 1601 | */ |
b556f8ad EP |
1602 | void audit_log_n_untrustedstring(struct audit_buffer *ab, const char *string, |
1603 | size_t len) | |
83c7d091 | 1604 | { |
de6bbd1d | 1605 | if (audit_string_contains_control(string, len)) |
b556f8ad | 1606 | audit_log_n_hex(ab, string, len); |
de6bbd1d | 1607 | else |
b556f8ad | 1608 | audit_log_n_string(ab, string, len); |
83c7d091 | 1609 | } |
1610 | ||
9c937dcc | 1611 | /** |
522ed776 | 1612 | * audit_log_untrustedstring - log a string that may contain random characters |
9c937dcc AG |
1613 | * @ab: audit_buffer |
1614 | * @string: string to be logged | |
1615 | * | |
522ed776 | 1616 | * Same as audit_log_n_untrustedstring(), except that strlen is used to |
9c937dcc AG |
1617 | * determine string length. |
1618 | */ | |
de6bbd1d | 1619 | void audit_log_untrustedstring(struct audit_buffer *ab, const char *string) |
9c937dcc | 1620 | { |
b556f8ad | 1621 | audit_log_n_untrustedstring(ab, string, strlen(string)); |
9c937dcc AG |
1622 | } |
1623 | ||
168b7173 | 1624 | /* This is a helper-function to print the escaped d_path */ |
1da177e4 | 1625 | void audit_log_d_path(struct audit_buffer *ab, const char *prefix, |
66b3fad3 | 1626 | const struct path *path) |
1da177e4 | 1627 | { |
44707fdf | 1628 | char *p, *pathname; |
1da177e4 | 1629 | |
8fc6115c | 1630 | if (prefix) |
c158a35c | 1631 | audit_log_format(ab, "%s", prefix); |
1da177e4 | 1632 | |
168b7173 | 1633 | /* We will allow 11 spaces for ' (deleted)' to be appended */ |
44707fdf JB |
1634 | pathname = kmalloc(PATH_MAX+11, ab->gfp_mask); |
1635 | if (!pathname) { | |
def57543 | 1636 | audit_log_string(ab, "<no_memory>"); |
168b7173 | 1637 | return; |
1da177e4 | 1638 | } |
cf28b486 | 1639 | p = d_path(path, pathname, PATH_MAX+11); |
168b7173 SG |
1640 | if (IS_ERR(p)) { /* Should never happen since we send PATH_MAX */ |
1641 | /* FIXME: can we save some information here? */ | |
def57543 | 1642 | audit_log_string(ab, "<too_long>"); |
5600b892 | 1643 | } else |
168b7173 | 1644 | audit_log_untrustedstring(ab, p); |
44707fdf | 1645 | kfree(pathname); |
1da177e4 LT |
1646 | } |
1647 | ||
4d3fb709 EP |
1648 | void audit_log_session_info(struct audit_buffer *ab) |
1649 | { | |
4440e854 | 1650 | unsigned int sessionid = audit_get_sessionid(current); |
4d3fb709 EP |
1651 | uid_t auid = from_kuid(&init_user_ns, audit_get_loginuid(current)); |
1652 | ||
b8f89caa | 1653 | audit_log_format(ab, " auid=%u ses=%u", auid, sessionid); |
4d3fb709 EP |
1654 | } |
1655 | ||
9d960985 EP |
1656 | void audit_log_key(struct audit_buffer *ab, char *key) |
1657 | { | |
1658 | audit_log_format(ab, " key="); | |
1659 | if (key) | |
1660 | audit_log_untrustedstring(ab, key); | |
1661 | else | |
1662 | audit_log_format(ab, "(null)"); | |
1663 | } | |
1664 | ||
b24a30a7 EP |
1665 | void audit_log_cap(struct audit_buffer *ab, char *prefix, kernel_cap_t *cap) |
1666 | { | |
1667 | int i; | |
1668 | ||
1669 | audit_log_format(ab, " %s=", prefix); | |
1670 | CAP_FOR_EACH_U32(i) { | |
1671 | audit_log_format(ab, "%08x", | |
7d8b6c63 | 1672 | cap->cap[CAP_LAST_U32 - i]); |
b24a30a7 EP |
1673 | } |
1674 | } | |
1675 | ||
691e6d59 | 1676 | static void audit_log_fcaps(struct audit_buffer *ab, struct audit_names *name) |
b24a30a7 EP |
1677 | { |
1678 | kernel_cap_t *perm = &name->fcap.permitted; | |
1679 | kernel_cap_t *inh = &name->fcap.inheritable; | |
1680 | int log = 0; | |
1681 | ||
1682 | if (!cap_isclear(*perm)) { | |
1683 | audit_log_cap(ab, "cap_fp", perm); | |
1684 | log = 1; | |
1685 | } | |
1686 | if (!cap_isclear(*inh)) { | |
1687 | audit_log_cap(ab, "cap_fi", inh); | |
1688 | log = 1; | |
1689 | } | |
1690 | ||
1691 | if (log) | |
1692 | audit_log_format(ab, " cap_fe=%d cap_fver=%x", | |
1693 | name->fcap.fE, name->fcap_ver); | |
1694 | } | |
1695 | ||
1696 | static inline int audit_copy_fcaps(struct audit_names *name, | |
1697 | const struct dentry *dentry) | |
1698 | { | |
1699 | struct cpu_vfs_cap_data caps; | |
1700 | int rc; | |
1701 | ||
1702 | if (!dentry) | |
1703 | return 0; | |
1704 | ||
1705 | rc = get_vfs_caps_from_disk(dentry, &caps); | |
1706 | if (rc) | |
1707 | return rc; | |
1708 | ||
1709 | name->fcap.permitted = caps.permitted; | |
1710 | name->fcap.inheritable = caps.inheritable; | |
1711 | name->fcap.fE = !!(caps.magic_etc & VFS_CAP_FLAGS_EFFECTIVE); | |
1712 | name->fcap_ver = (caps.magic_etc & VFS_CAP_REVISION_MASK) >> | |
1713 | VFS_CAP_REVISION_SHIFT; | |
1714 | ||
1715 | return 0; | |
1716 | } | |
1717 | ||
1718 | /* Copy inode data into an audit_names. */ | |
1719 | void audit_copy_inode(struct audit_names *name, const struct dentry *dentry, | |
d6335d77 | 1720 | struct inode *inode) |
b24a30a7 EP |
1721 | { |
1722 | name->ino = inode->i_ino; | |
1723 | name->dev = inode->i_sb->s_dev; | |
1724 | name->mode = inode->i_mode; | |
1725 | name->uid = inode->i_uid; | |
1726 | name->gid = inode->i_gid; | |
1727 | name->rdev = inode->i_rdev; | |
1728 | security_inode_getsecid(inode, &name->osid); | |
1729 | audit_copy_fcaps(name, dentry); | |
1730 | } | |
1731 | ||
1732 | /** | |
1733 | * audit_log_name - produce AUDIT_PATH record from struct audit_names | |
1734 | * @context: audit_context for the task | |
1735 | * @n: audit_names structure with reportable details | |
1736 | * @path: optional path to report instead of audit_names->name | |
1737 | * @record_num: record number to report when handling a list of names | |
1738 | * @call_panic: optional pointer to int that will be updated if secid fails | |
1739 | */ | |
1740 | void audit_log_name(struct audit_context *context, struct audit_names *n, | |
1741 | struct path *path, int record_num, int *call_panic) | |
1742 | { | |
1743 | struct audit_buffer *ab; | |
1744 | ab = audit_log_start(context, GFP_KERNEL, AUDIT_PATH); | |
1745 | if (!ab) | |
1746 | return; | |
1747 | ||
1748 | audit_log_format(ab, "item=%d", record_num); | |
1749 | ||
1750 | if (path) | |
1751 | audit_log_d_path(ab, " name=", path); | |
1752 | else if (n->name) { | |
1753 | switch (n->name_len) { | |
1754 | case AUDIT_NAME_FULL: | |
1755 | /* log the full path */ | |
1756 | audit_log_format(ab, " name="); | |
1757 | audit_log_untrustedstring(ab, n->name->name); | |
1758 | break; | |
1759 | case 0: | |
1760 | /* name was specified as a relative path and the | |
1761 | * directory component is the cwd */ | |
1762 | audit_log_d_path(ab, " name=", &context->pwd); | |
1763 | break; | |
1764 | default: | |
1765 | /* log the name's directory component */ | |
1766 | audit_log_format(ab, " name="); | |
1767 | audit_log_n_untrustedstring(ab, n->name->name, | |
1768 | n->name_len); | |
1769 | } | |
1770 | } else | |
1771 | audit_log_format(ab, " name=(null)"); | |
1772 | ||
425afcff | 1773 | if (n->ino != AUDIT_INO_UNSET) |
b24a30a7 EP |
1774 | audit_log_format(ab, " inode=%lu" |
1775 | " dev=%02x:%02x mode=%#ho" | |
1776 | " ouid=%u ogid=%u rdev=%02x:%02x", | |
1777 | n->ino, | |
1778 | MAJOR(n->dev), | |
1779 | MINOR(n->dev), | |
1780 | n->mode, | |
1781 | from_kuid(&init_user_ns, n->uid), | |
1782 | from_kgid(&init_user_ns, n->gid), | |
1783 | MAJOR(n->rdev), | |
1784 | MINOR(n->rdev)); | |
b24a30a7 EP |
1785 | if (n->osid != 0) { |
1786 | char *ctx = NULL; | |
1787 | u32 len; | |
1788 | if (security_secid_to_secctx( | |
1789 | n->osid, &ctx, &len)) { | |
1790 | audit_log_format(ab, " osid=%u", n->osid); | |
1791 | if (call_panic) | |
1792 | *call_panic = 2; | |
1793 | } else { | |
1794 | audit_log_format(ab, " obj=%s", ctx); | |
1795 | security_release_secctx(ctx, len); | |
1796 | } | |
1797 | } | |
1798 | ||
d3aea84a JL |
1799 | /* log the audit_names record type */ |
1800 | audit_log_format(ab, " nametype="); | |
1801 | switch(n->type) { | |
1802 | case AUDIT_TYPE_NORMAL: | |
1803 | audit_log_format(ab, "NORMAL"); | |
1804 | break; | |
1805 | case AUDIT_TYPE_PARENT: | |
1806 | audit_log_format(ab, "PARENT"); | |
1807 | break; | |
1808 | case AUDIT_TYPE_CHILD_DELETE: | |
1809 | audit_log_format(ab, "DELETE"); | |
1810 | break; | |
1811 | case AUDIT_TYPE_CHILD_CREATE: | |
1812 | audit_log_format(ab, "CREATE"); | |
1813 | break; | |
1814 | default: | |
1815 | audit_log_format(ab, "UNKNOWN"); | |
1816 | break; | |
1817 | } | |
1818 | ||
b24a30a7 EP |
1819 | audit_log_fcaps(ab, n); |
1820 | audit_log_end(ab); | |
1821 | } | |
1822 | ||
1823 | int audit_log_task_context(struct audit_buffer *ab) | |
1824 | { | |
1825 | char *ctx = NULL; | |
1826 | unsigned len; | |
1827 | int error; | |
1828 | u32 sid; | |
1829 | ||
1830 | security_task_getsecid(current, &sid); | |
1831 | if (!sid) | |
1832 | return 0; | |
1833 | ||
1834 | error = security_secid_to_secctx(sid, &ctx, &len); | |
1835 | if (error) { | |
1836 | if (error != -EINVAL) | |
1837 | goto error_path; | |
1838 | return 0; | |
1839 | } | |
1840 | ||
1841 | audit_log_format(ab, " subj=%s", ctx); | |
1842 | security_release_secctx(ctx, len); | |
1843 | return 0; | |
1844 | ||
1845 | error_path: | |
1846 | audit_panic("error in audit_log_task_context"); | |
1847 | return error; | |
1848 | } | |
1849 | EXPORT_SYMBOL(audit_log_task_context); | |
1850 | ||
4766b199 DB |
1851 | void audit_log_d_path_exe(struct audit_buffer *ab, |
1852 | struct mm_struct *mm) | |
1853 | { | |
5b282552 DB |
1854 | struct file *exe_file; |
1855 | ||
1856 | if (!mm) | |
1857 | goto out_null; | |
4766b199 | 1858 | |
5b282552 DB |
1859 | exe_file = get_mm_exe_file(mm); |
1860 | if (!exe_file) | |
1861 | goto out_null; | |
1862 | ||
1863 | audit_log_d_path(ab, " exe=", &exe_file->f_path); | |
1864 | fput(exe_file); | |
1865 | return; | |
1866 | out_null: | |
1867 | audit_log_format(ab, " exe=(null)"); | |
4766b199 DB |
1868 | } |
1869 | ||
b24a30a7 EP |
1870 | void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk) |
1871 | { | |
1872 | const struct cred *cred; | |
9eab339b | 1873 | char comm[sizeof(tsk->comm)]; |
b24a30a7 EP |
1874 | char *tty; |
1875 | ||
1876 | if (!ab) | |
1877 | return; | |
1878 | ||
1879 | /* tsk == current */ | |
1880 | cred = current_cred(); | |
1881 | ||
1882 | spin_lock_irq(&tsk->sighand->siglock); | |
1883 | if (tsk->signal && tsk->signal->tty && tsk->signal->tty->name) | |
1884 | tty = tsk->signal->tty->name; | |
1885 | else | |
1886 | tty = "(none)"; | |
1887 | spin_unlock_irq(&tsk->sighand->siglock); | |
1888 | ||
1889 | audit_log_format(ab, | |
c92cdeb4 | 1890 | " ppid=%d pid=%d auid=%u uid=%u gid=%u" |
b24a30a7 | 1891 | " euid=%u suid=%u fsuid=%u" |
2f2ad101 | 1892 | " egid=%u sgid=%u fsgid=%u tty=%s ses=%u", |
c92cdeb4 | 1893 | task_ppid_nr(tsk), |
f1dc4867 | 1894 | task_pid_nr(tsk), |
b24a30a7 EP |
1895 | from_kuid(&init_user_ns, audit_get_loginuid(tsk)), |
1896 | from_kuid(&init_user_ns, cred->uid), | |
1897 | from_kgid(&init_user_ns, cred->gid), | |
1898 | from_kuid(&init_user_ns, cred->euid), | |
1899 | from_kuid(&init_user_ns, cred->suid), | |
1900 | from_kuid(&init_user_ns, cred->fsuid), | |
1901 | from_kgid(&init_user_ns, cred->egid), | |
1902 | from_kgid(&init_user_ns, cred->sgid), | |
1903 | from_kgid(&init_user_ns, cred->fsgid), | |
2f2ad101 | 1904 | tty, audit_get_sessionid(tsk)); |
b24a30a7 | 1905 | |
b24a30a7 | 1906 | audit_log_format(ab, " comm="); |
9eab339b | 1907 | audit_log_untrustedstring(ab, get_task_comm(comm, tsk)); |
b24a30a7 | 1908 | |
4766b199 | 1909 | audit_log_d_path_exe(ab, tsk->mm); |
b24a30a7 EP |
1910 | audit_log_task_context(ab); |
1911 | } | |
1912 | EXPORT_SYMBOL(audit_log_task_info); | |
1913 | ||
a51d9eaa KC |
1914 | /** |
1915 | * audit_log_link_denied - report a link restriction denial | |
22011964 | 1916 | * @operation: specific link operation |
a51d9eaa KC |
1917 | * @link: the path that triggered the restriction |
1918 | */ | |
1919 | void audit_log_link_denied(const char *operation, struct path *link) | |
1920 | { | |
1921 | struct audit_buffer *ab; | |
b24a30a7 EP |
1922 | struct audit_names *name; |
1923 | ||
1924 | name = kzalloc(sizeof(*name), GFP_NOFS); | |
1925 | if (!name) | |
1926 | return; | |
a51d9eaa | 1927 | |
b24a30a7 | 1928 | /* Generate AUDIT_ANOM_LINK with subject, operation, outcome. */ |
a51d9eaa KC |
1929 | ab = audit_log_start(current->audit_context, GFP_KERNEL, |
1930 | AUDIT_ANOM_LINK); | |
d1c7d97a | 1931 | if (!ab) |
b24a30a7 EP |
1932 | goto out; |
1933 | audit_log_format(ab, "op=%s", operation); | |
1934 | audit_log_task_info(ab, current); | |
1935 | audit_log_format(ab, " res=0"); | |
a51d9eaa | 1936 | audit_log_end(ab); |
b24a30a7 EP |
1937 | |
1938 | /* Generate AUDIT_PATH record with object. */ | |
1939 | name->type = AUDIT_TYPE_NORMAL; | |
3b362157 | 1940 | audit_copy_inode(name, link->dentry, d_backing_inode(link->dentry)); |
b24a30a7 EP |
1941 | audit_log_name(current->audit_context, name, link, 0, NULL); |
1942 | out: | |
1943 | kfree(name); | |
a51d9eaa KC |
1944 | } |
1945 | ||
b0dd25a8 RD |
1946 | /** |
1947 | * audit_log_end - end one audit record | |
1948 | * @ab: the audit_buffer | |
1949 | * | |
451f9216 RGB |
1950 | * netlink_unicast() cannot be called inside an irq context because it blocks |
1951 | * (last arg, flags, is not set to MSG_DONTWAIT), so the audit buffer is placed | |
1952 | * on a queue and a tasklet is scheduled to remove them from the queue outside | |
1953 | * the irq context. May be called in any context. | |
b0dd25a8 | 1954 | */ |
b7d11258 | 1955 | void audit_log_end(struct audit_buffer *ab) |
1da177e4 | 1956 | { |
1da177e4 LT |
1957 | if (!ab) |
1958 | return; | |
1959 | if (!audit_rate_check()) { | |
1960 | audit_log_lost("rate limit exceeded"); | |
1961 | } else { | |
8d07a67c | 1962 | struct nlmsghdr *nlh = nlmsg_hdr(ab->skb); |
451f9216 | 1963 | |
54e05edd | 1964 | nlh->nlmsg_len = ab->skb->len; |
54dc77d9 | 1965 | kauditd_send_multicast_skb(ab->skb, ab->gfp_mask); |
451f9216 RGB |
1966 | |
1967 | /* | |
1968 | * The original kaudit unicast socket sends up messages with | |
1969 | * nlmsg_len set to the payload length rather than the entire | |
1970 | * message length. This breaks the standard set by netlink. | |
1971 | * The existing auditd daemon assumes this breakage. Fixing | |
1972 | * this would require co-ordinating a change in the established | |
1973 | * protocol between the kaudit kernel subsystem and the auditd | |
1974 | * userspace code. | |
1975 | */ | |
54e05edd | 1976 | nlh->nlmsg_len -= NLMSG_HDRLEN; |
f3d357b0 | 1977 | |
b7d11258 | 1978 | if (audit_pid) { |
b7d11258 | 1979 | skb_queue_tail(&audit_skb_queue, ab->skb); |
b7d11258 | 1980 | wake_up_interruptible(&kauditd_wait); |
f3d357b0 | 1981 | } else { |
038cbcf6 | 1982 | audit_printk_skb(ab->skb); |
b7d11258 | 1983 | } |
f3d357b0 | 1984 | ab->skb = NULL; |
1da177e4 | 1985 | } |
16e1904e | 1986 | audit_buffer_free(ab); |
1da177e4 LT |
1987 | } |
1988 | ||
b0dd25a8 RD |
1989 | /** |
1990 | * audit_log - Log an audit record | |
1991 | * @ctx: audit context | |
1992 | * @gfp_mask: type of allocation | |
1993 | * @type: audit message type | |
1994 | * @fmt: format string to use | |
1995 | * @...: variable parameters matching the format string | |
1996 | * | |
1997 | * This is a convenience function that calls audit_log_start, | |
1998 | * audit_log_vformat, and audit_log_end. It may be called | |
1999 | * in any context. | |
2000 | */ | |
5600b892 | 2001 | void audit_log(struct audit_context *ctx, gfp_t gfp_mask, int type, |
9ad9ad38 | 2002 | const char *fmt, ...) |
1da177e4 LT |
2003 | { |
2004 | struct audit_buffer *ab; | |
2005 | va_list args; | |
2006 | ||
9ad9ad38 | 2007 | ab = audit_log_start(ctx, gfp_mask, type); |
1da177e4 LT |
2008 | if (ab) { |
2009 | va_start(args, fmt); | |
2010 | audit_log_vformat(ab, fmt, args); | |
2011 | va_end(args); | |
2012 | audit_log_end(ab); | |
2013 | } | |
2014 | } | |
bf45da97 | 2015 | |
131ad62d MDF |
2016 | #ifdef CONFIG_SECURITY |
2017 | /** | |
2018 | * audit_log_secctx - Converts and logs SELinux context | |
2019 | * @ab: audit_buffer | |
2020 | * @secid: security number | |
2021 | * | |
2022 | * This is a helper function that calls security_secid_to_secctx to convert | |
2023 | * secid to secctx and then adds the (converted) SELinux context to the audit | |
2024 | * log by calling audit_log_format, thus also preventing leak of internal secid | |
2025 | * to userspace. If secid cannot be converted audit_panic is called. | |
2026 | */ | |
2027 | void audit_log_secctx(struct audit_buffer *ab, u32 secid) | |
2028 | { | |
2029 | u32 len; | |
2030 | char *secctx; | |
2031 | ||
2032 | if (security_secid_to_secctx(secid, &secctx, &len)) { | |
2033 | audit_panic("Cannot convert secid to context"); | |
2034 | } else { | |
2035 | audit_log_format(ab, " obj=%s", secctx); | |
2036 | security_release_secctx(secctx, len); | |
2037 | } | |
2038 | } | |
2039 | EXPORT_SYMBOL(audit_log_secctx); | |
2040 | #endif | |
2041 | ||
bf45da97 | 2042 | EXPORT_SYMBOL(audit_log_start); |
2043 | EXPORT_SYMBOL(audit_log_end); | |
2044 | EXPORT_SYMBOL(audit_log_format); | |
2045 | EXPORT_SYMBOL(audit_log); |