Commit | Line | Data |
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b2441318 | 1 | // SPDX-License-Identifier: GPL-2.0 |
eadd99cc TH |
2 | /* |
3 | * security/tomoyo/audit.c | |
4 | * | |
0f2a55d5 | 5 | * Copyright (C) 2005-2011 NTT DATA CORPORATION |
eadd99cc TH |
6 | */ |
7 | ||
8 | #include "common.h" | |
9 | #include <linux/slab.h> | |
10 | ||
5b636857 TH |
11 | /** |
12 | * tomoyo_print_bprm - Print "struct linux_binprm" for auditing. | |
13 | * | |
14 | * @bprm: Pointer to "struct linux_binprm". | |
15 | * @dump: Pointer to "struct tomoyo_page_dump". | |
16 | * | |
17 | * Returns the contents of @bprm on success, NULL otherwise. | |
18 | * | |
19 | * This function uses kzalloc(), so caller must kfree() if this function | |
20 | * didn't return NULL. | |
21 | */ | |
22 | static char *tomoyo_print_bprm(struct linux_binprm *bprm, | |
23 | struct tomoyo_page_dump *dump) | |
24 | { | |
25 | static const int tomoyo_buffer_len = 4096 * 2; | |
26 | char *buffer = kzalloc(tomoyo_buffer_len, GFP_NOFS); | |
27 | char *cp; | |
28 | char *last_start; | |
29 | int len; | |
30 | unsigned long pos = bprm->p; | |
31 | int offset = pos % PAGE_SIZE; | |
32 | int argv_count = bprm->argc; | |
33 | int envp_count = bprm->envc; | |
34 | bool truncated = false; | |
35 | if (!buffer) | |
36 | return NULL; | |
37 | len = snprintf(buffer, tomoyo_buffer_len - 1, "argv[]={ "); | |
38 | cp = buffer + len; | |
39 | if (!argv_count) { | |
40 | memmove(cp, "} envp[]={ ", 11); | |
41 | cp += 11; | |
42 | } | |
43 | last_start = cp; | |
44 | while (argv_count || envp_count) { | |
45 | if (!tomoyo_dump_page(bprm, pos, dump)) | |
46 | goto out; | |
47 | pos += PAGE_SIZE - offset; | |
48 | /* Read. */ | |
49 | while (offset < PAGE_SIZE) { | |
50 | const char *kaddr = dump->data; | |
51 | const unsigned char c = kaddr[offset++]; | |
52 | if (cp == last_start) | |
53 | *cp++ = '"'; | |
54 | if (cp >= buffer + tomoyo_buffer_len - 32) { | |
55 | /* Reserve some room for "..." string. */ | |
56 | truncated = true; | |
57 | } else if (c == '\\') { | |
58 | *cp++ = '\\'; | |
59 | *cp++ = '\\'; | |
60 | } else if (c > ' ' && c < 127) { | |
61 | *cp++ = c; | |
62 | } else if (!c) { | |
63 | *cp++ = '"'; | |
64 | *cp++ = ' '; | |
65 | last_start = cp; | |
66 | } else { | |
67 | *cp++ = '\\'; | |
68 | *cp++ = (c >> 6) + '0'; | |
69 | *cp++ = ((c >> 3) & 7) + '0'; | |
70 | *cp++ = (c & 7) + '0'; | |
71 | } | |
72 | if (c) | |
73 | continue; | |
74 | if (argv_count) { | |
75 | if (--argv_count == 0) { | |
76 | if (truncated) { | |
77 | cp = last_start; | |
78 | memmove(cp, "... ", 4); | |
79 | cp += 4; | |
80 | } | |
81 | memmove(cp, "} envp[]={ ", 11); | |
82 | cp += 11; | |
83 | last_start = cp; | |
84 | truncated = false; | |
85 | } | |
86 | } else if (envp_count) { | |
87 | if (--envp_count == 0) { | |
88 | if (truncated) { | |
89 | cp = last_start; | |
90 | memmove(cp, "... ", 4); | |
91 | cp += 4; | |
92 | } | |
93 | } | |
94 | } | |
95 | if (!argv_count && !envp_count) | |
96 | break; | |
97 | } | |
98 | offset = 0; | |
99 | } | |
100 | *cp++ = '}'; | |
101 | *cp = '\0'; | |
102 | return buffer; | |
103 | out: | |
104 | snprintf(buffer, tomoyo_buffer_len - 1, | |
105 | "argv[]={ ... } envp[]= { ... }"); | |
106 | return buffer; | |
107 | } | |
108 | ||
8761afd4 TH |
109 | /** |
110 | * tomoyo_filetype - Get string representation of file type. | |
111 | * | |
112 | * @mode: Mode value for stat(). | |
113 | * | |
114 | * Returns file type string. | |
115 | */ | |
d179333f | 116 | static inline const char *tomoyo_filetype(const umode_t mode) |
8761afd4 TH |
117 | { |
118 | switch (mode & S_IFMT) { | |
119 | case S_IFREG: | |
120 | case 0: | |
121 | return tomoyo_condition_keyword[TOMOYO_TYPE_IS_FILE]; | |
122 | case S_IFDIR: | |
123 | return tomoyo_condition_keyword[TOMOYO_TYPE_IS_DIRECTORY]; | |
124 | case S_IFLNK: | |
125 | return tomoyo_condition_keyword[TOMOYO_TYPE_IS_SYMLINK]; | |
126 | case S_IFIFO: | |
127 | return tomoyo_condition_keyword[TOMOYO_TYPE_IS_FIFO]; | |
128 | case S_IFSOCK: | |
129 | return tomoyo_condition_keyword[TOMOYO_TYPE_IS_SOCKET]; | |
130 | case S_IFBLK: | |
131 | return tomoyo_condition_keyword[TOMOYO_TYPE_IS_BLOCK_DEV]; | |
132 | case S_IFCHR: | |
133 | return tomoyo_condition_keyword[TOMOYO_TYPE_IS_CHAR_DEV]; | |
134 | } | |
135 | return "unknown"; /* This should not happen. */ | |
136 | } | |
137 | ||
eadd99cc TH |
138 | /** |
139 | * tomoyo_print_header - Get header line of audit log. | |
140 | * | |
141 | * @r: Pointer to "struct tomoyo_request_info". | |
142 | * | |
143 | * Returns string representation. | |
144 | * | |
145 | * This function uses kmalloc(), so caller must kfree() if this function | |
146 | * didn't return NULL. | |
147 | */ | |
148 | static char *tomoyo_print_header(struct tomoyo_request_info *r) | |
149 | { | |
150 | struct tomoyo_time stamp; | |
151 | const pid_t gpid = task_pid_nr(current); | |
8761afd4 | 152 | struct tomoyo_obj_info *obj = r->obj; |
eadd99cc TH |
153 | static const int tomoyo_buffer_len = 4096; |
154 | char *buffer = kmalloc(tomoyo_buffer_len, GFP_NOFS); | |
2066a361 | 155 | int pos; |
8761afd4 | 156 | u8 i; |
eadd99cc TH |
157 | if (!buffer) |
158 | return NULL; | |
77f4fa08 | 159 | |
92734092 | 160 | tomoyo_convert_time(ktime_get_real_seconds(), &stamp); |
77f4fa08 | 161 | |
2066a361 TH |
162 | pos = snprintf(buffer, tomoyo_buffer_len - 1, |
163 | "#%04u/%02u/%02u %02u:%02u:%02u# profile=%u mode=%s " | |
164 | "granted=%s (global-pid=%u) task={ pid=%u ppid=%u " | |
165 | "uid=%u gid=%u euid=%u egid=%u suid=%u sgid=%u " | |
166 | "fsuid=%u fsgid=%u }", stamp.year, stamp.month, | |
167 | stamp.day, stamp.hour, stamp.min, stamp.sec, r->profile, | |
168 | tomoyo_mode[r->mode], tomoyo_yesno(r->granted), gpid, | |
169 | tomoyo_sys_getpid(), tomoyo_sys_getppid(), | |
609fcd1b EB |
170 | from_kuid(&init_user_ns, current_uid()), |
171 | from_kgid(&init_user_ns, current_gid()), | |
172 | from_kuid(&init_user_ns, current_euid()), | |
173 | from_kgid(&init_user_ns, current_egid()), | |
174 | from_kuid(&init_user_ns, current_suid()), | |
175 | from_kgid(&init_user_ns, current_sgid()), | |
176 | from_kuid(&init_user_ns, current_fsuid()), | |
177 | from_kgid(&init_user_ns, current_fsgid())); | |
8761afd4 TH |
178 | if (!obj) |
179 | goto no_obj_info; | |
180 | if (!obj->validate_done) { | |
181 | tomoyo_get_attributes(obj); | |
182 | obj->validate_done = true; | |
183 | } | |
184 | for (i = 0; i < TOMOYO_MAX_PATH_STAT; i++) { | |
185 | struct tomoyo_mini_stat *stat; | |
186 | unsigned int dev; | |
d179333f | 187 | umode_t mode; |
8761afd4 TH |
188 | if (!obj->stat_valid[i]) |
189 | continue; | |
190 | stat = &obj->stat[i]; | |
191 | dev = stat->dev; | |
192 | mode = stat->mode; | |
193 | if (i & 1) { | |
194 | pos += snprintf(buffer + pos, | |
195 | tomoyo_buffer_len - 1 - pos, | |
196 | " path%u.parent={ uid=%u gid=%u " | |
197 | "ino=%lu perm=0%o }", (i >> 1) + 1, | |
609fcd1b EB |
198 | from_kuid(&init_user_ns, stat->uid), |
199 | from_kgid(&init_user_ns, stat->gid), | |
200 | (unsigned long)stat->ino, | |
201 | stat->mode & S_IALLUGO); | |
8761afd4 TH |
202 | continue; |
203 | } | |
204 | pos += snprintf(buffer + pos, tomoyo_buffer_len - 1 - pos, | |
205 | " path%u={ uid=%u gid=%u ino=%lu major=%u" | |
206 | " minor=%u perm=0%o type=%s", (i >> 1) + 1, | |
609fcd1b EB |
207 | from_kuid(&init_user_ns, stat->uid), |
208 | from_kgid(&init_user_ns, stat->gid), | |
209 | (unsigned long)stat->ino, | |
210 | MAJOR(dev), MINOR(dev), | |
8761afd4 TH |
211 | mode & S_IALLUGO, tomoyo_filetype(mode)); |
212 | if (S_ISCHR(mode) || S_ISBLK(mode)) { | |
213 | dev = stat->rdev; | |
214 | pos += snprintf(buffer + pos, | |
215 | tomoyo_buffer_len - 1 - pos, | |
216 | " dev_major=%u dev_minor=%u", | |
217 | MAJOR(dev), MINOR(dev)); | |
218 | } | |
219 | pos += snprintf(buffer + pos, tomoyo_buffer_len - 1 - pos, | |
220 | " }"); | |
221 | } | |
222 | no_obj_info: | |
2066a361 TH |
223 | if (pos < tomoyo_buffer_len - 1) |
224 | return buffer; | |
225 | kfree(buffer); | |
226 | return NULL; | |
eadd99cc TH |
227 | } |
228 | ||
229 | /** | |
230 | * tomoyo_init_log - Allocate buffer for audit logs. | |
231 | * | |
232 | * @r: Pointer to "struct tomoyo_request_info". | |
233 | * @len: Buffer size needed for @fmt and @args. | |
234 | * @fmt: The printf()'s format string. | |
235 | * @args: va_list structure for @fmt. | |
236 | * | |
237 | * Returns pointer to allocated memory. | |
238 | * | |
239 | * This function uses kzalloc(), so caller must kfree() if this function | |
240 | * didn't return NULL. | |
241 | */ | |
242 | char *tomoyo_init_log(struct tomoyo_request_info *r, int len, const char *fmt, | |
243 | va_list args) | |
244 | { | |
245 | char *buf = NULL; | |
5b636857 | 246 | char *bprm_info = NULL; |
eadd99cc | 247 | const char *header = NULL; |
2ca9bf45 TH |
248 | char *realpath = NULL; |
249 | const char *symlink = NULL; | |
eadd99cc | 250 | int pos; |
ea504819 | 251 | const char *domainname = r->domain->domainname->name; |
eadd99cc TH |
252 | header = tomoyo_print_header(r); |
253 | if (!header) | |
254 | return NULL; | |
255 | /* +10 is for '\n' etc. and '\0'. */ | |
256 | len += strlen(domainname) + strlen(header) + 10; | |
2ca9bf45 TH |
257 | if (r->ee) { |
258 | struct file *file = r->ee->bprm->file; | |
259 | realpath = tomoyo_realpath_from_path(&file->f_path); | |
5b636857 TH |
260 | bprm_info = tomoyo_print_bprm(r->ee->bprm, &r->ee->dump); |
261 | if (!realpath || !bprm_info) | |
2ca9bf45 | 262 | goto out; |
5b636857 TH |
263 | /* +80 is for " exec={ realpath=\"%s\" argc=%d envc=%d %s }" */ |
264 | len += strlen(realpath) + 80 + strlen(bprm_info); | |
2ca9bf45 TH |
265 | } else if (r->obj && r->obj->symlink_target) { |
266 | symlink = r->obj->symlink_target->name; | |
267 | /* +18 is for " symlink.target=\"%s\"" */ | |
268 | len += 18 + strlen(symlink); | |
269 | } | |
eadd99cc TH |
270 | len = tomoyo_round2(len); |
271 | buf = kzalloc(len, GFP_NOFS); | |
272 | if (!buf) | |
273 | goto out; | |
274 | len--; | |
275 | pos = snprintf(buf, len, "%s", header); | |
2ca9bf45 | 276 | if (realpath) { |
5b636857 | 277 | struct linux_binprm *bprm = r->ee->bprm; |
2ca9bf45 | 278 | pos += snprintf(buf + pos, len - pos, |
5b636857 TH |
279 | " exec={ realpath=\"%s\" argc=%d envc=%d %s }", |
280 | realpath, bprm->argc, bprm->envc, bprm_info); | |
2ca9bf45 TH |
281 | } else if (symlink) |
282 | pos += snprintf(buf + pos, len - pos, " symlink.target=\"%s\"", | |
283 | symlink); | |
eadd99cc TH |
284 | pos += snprintf(buf + pos, len - pos, "\n%s\n", domainname); |
285 | vsnprintf(buf + pos, len - pos, fmt, args); | |
286 | out: | |
2ca9bf45 | 287 | kfree(realpath); |
5b636857 | 288 | kfree(bprm_info); |
eadd99cc TH |
289 | kfree(header); |
290 | return buf; | |
291 | } | |
292 | ||
293 | /* Wait queue for /sys/kernel/security/tomoyo/audit. */ | |
294 | static DECLARE_WAIT_QUEUE_HEAD(tomoyo_log_wait); | |
295 | ||
296 | /* Structure for audit log. */ | |
297 | struct tomoyo_log { | |
298 | struct list_head list; | |
299 | char *log; | |
300 | int size; | |
301 | }; | |
302 | ||
303 | /* The list for "struct tomoyo_log". */ | |
304 | static LIST_HEAD(tomoyo_log); | |
305 | ||
306 | /* Lock for "struct list_head tomoyo_log". */ | |
307 | static DEFINE_SPINLOCK(tomoyo_log_lock); | |
308 | ||
309 | /* Length of "stuct list_head tomoyo_log". */ | |
310 | static unsigned int tomoyo_log_count; | |
311 | ||
312 | /** | |
313 | * tomoyo_get_audit - Get audit mode. | |
314 | * | |
bd03a3e4 | 315 | * @ns: Pointer to "struct tomoyo_policy_namespace". |
eadd99cc TH |
316 | * @profile: Profile number. |
317 | * @index: Index number of functionality. | |
318 | * @is_granted: True if granted log, false otherwise. | |
319 | * | |
320 | * Returns true if this request should be audited, false otherwise. | |
321 | */ | |
bd03a3e4 TH |
322 | static bool tomoyo_get_audit(const struct tomoyo_policy_namespace *ns, |
323 | const u8 profile, const u8 index, | |
1f067a68 | 324 | const struct tomoyo_acl_info *matched_acl, |
eadd99cc TH |
325 | const bool is_granted) |
326 | { | |
327 | u8 mode; | |
2c47ab93 TH |
328 | const u8 category = tomoyo_index2category[index] + |
329 | TOMOYO_MAX_MAC_INDEX; | |
eadd99cc TH |
330 | struct tomoyo_profile *p; |
331 | if (!tomoyo_policy_loaded) | |
332 | return false; | |
bd03a3e4 | 333 | p = tomoyo_profile(ns, profile); |
eadd99cc TH |
334 | if (tomoyo_log_count >= p->pref[TOMOYO_PREF_MAX_AUDIT_LOG]) |
335 | return false; | |
1f067a68 TH |
336 | if (is_granted && matched_acl && matched_acl->cond && |
337 | matched_acl->cond->grant_log != TOMOYO_GRANTLOG_AUTO) | |
338 | return matched_acl->cond->grant_log == TOMOYO_GRANTLOG_YES; | |
eadd99cc TH |
339 | mode = p->config[index]; |
340 | if (mode == TOMOYO_CONFIG_USE_DEFAULT) | |
341 | mode = p->config[category]; | |
342 | if (mode == TOMOYO_CONFIG_USE_DEFAULT) | |
343 | mode = p->default_config; | |
344 | if (is_granted) | |
345 | return mode & TOMOYO_CONFIG_WANT_GRANT_LOG; | |
346 | return mode & TOMOYO_CONFIG_WANT_REJECT_LOG; | |
347 | } | |
348 | ||
349 | /** | |
350 | * tomoyo_write_log2 - Write an audit log. | |
351 | * | |
352 | * @r: Pointer to "struct tomoyo_request_info". | |
353 | * @len: Buffer size needed for @fmt and @args. | |
354 | * @fmt: The printf()'s format string. | |
355 | * @args: va_list structure for @fmt. | |
356 | * | |
357 | * Returns nothing. | |
358 | */ | |
359 | void tomoyo_write_log2(struct tomoyo_request_info *r, int len, const char *fmt, | |
360 | va_list args) | |
361 | { | |
362 | char *buf; | |
363 | struct tomoyo_log *entry; | |
364 | bool quota_exceeded = false; | |
1f067a68 TH |
365 | if (!tomoyo_get_audit(r->domain->ns, r->profile, r->type, |
366 | r->matched_acl, r->granted)) | |
eadd99cc TH |
367 | goto out; |
368 | buf = tomoyo_init_log(r, len, fmt, args); | |
369 | if (!buf) | |
370 | goto out; | |
371 | entry = kzalloc(sizeof(*entry), GFP_NOFS); | |
372 | if (!entry) { | |
373 | kfree(buf); | |
374 | goto out; | |
375 | } | |
376 | entry->log = buf; | |
377 | len = tomoyo_round2(strlen(buf) + 1); | |
378 | /* | |
379 | * The entry->size is used for memory quota checks. | |
380 | * Don't go beyond strlen(entry->log). | |
381 | */ | |
382 | entry->size = len + tomoyo_round2(sizeof(*entry)); | |
383 | spin_lock(&tomoyo_log_lock); | |
384 | if (tomoyo_memory_quota[TOMOYO_MEMORY_AUDIT] && | |
385 | tomoyo_memory_used[TOMOYO_MEMORY_AUDIT] + entry->size >= | |
386 | tomoyo_memory_quota[TOMOYO_MEMORY_AUDIT]) { | |
387 | quota_exceeded = true; | |
388 | } else { | |
389 | tomoyo_memory_used[TOMOYO_MEMORY_AUDIT] += entry->size; | |
390 | list_add_tail(&entry->list, &tomoyo_log); | |
391 | tomoyo_log_count++; | |
392 | } | |
393 | spin_unlock(&tomoyo_log_lock); | |
394 | if (quota_exceeded) { | |
395 | kfree(buf); | |
396 | kfree(entry); | |
397 | goto out; | |
398 | } | |
399 | wake_up(&tomoyo_log_wait); | |
400 | out: | |
401 | return; | |
402 | } | |
403 | ||
404 | /** | |
405 | * tomoyo_write_log - Write an audit log. | |
406 | * | |
407 | * @r: Pointer to "struct tomoyo_request_info". | |
408 | * @fmt: The printf()'s format string, followed by parameters. | |
409 | * | |
410 | * Returns nothing. | |
411 | */ | |
412 | void tomoyo_write_log(struct tomoyo_request_info *r, const char *fmt, ...) | |
413 | { | |
414 | va_list args; | |
415 | int len; | |
416 | va_start(args, fmt); | |
417 | len = vsnprintf((char *) &len, 1, fmt, args) + 1; | |
418 | va_end(args); | |
419 | va_start(args, fmt); | |
420 | tomoyo_write_log2(r, len, fmt, args); | |
421 | va_end(args); | |
422 | } | |
423 | ||
424 | /** | |
425 | * tomoyo_read_log - Read an audit log. | |
426 | * | |
427 | * @head: Pointer to "struct tomoyo_io_buffer". | |
428 | * | |
429 | * Returns nothing. | |
430 | */ | |
431 | void tomoyo_read_log(struct tomoyo_io_buffer *head) | |
432 | { | |
433 | struct tomoyo_log *ptr = NULL; | |
434 | if (head->r.w_pos) | |
435 | return; | |
436 | kfree(head->read_buf); | |
437 | head->read_buf = NULL; | |
438 | spin_lock(&tomoyo_log_lock); | |
439 | if (!list_empty(&tomoyo_log)) { | |
440 | ptr = list_entry(tomoyo_log.next, typeof(*ptr), list); | |
441 | list_del(&ptr->list); | |
442 | tomoyo_log_count--; | |
443 | tomoyo_memory_used[TOMOYO_MEMORY_AUDIT] -= ptr->size; | |
444 | } | |
445 | spin_unlock(&tomoyo_log_lock); | |
446 | if (ptr) { | |
447 | head->read_buf = ptr->log; | |
448 | head->r.w[head->r.w_pos++] = head->read_buf; | |
449 | kfree(ptr); | |
450 | } | |
451 | } | |
452 | ||
453 | /** | |
454 | * tomoyo_poll_log - Wait for an audit log. | |
455 | * | |
456 | * @file: Pointer to "struct file". | |
6041e834 | 457 | * @wait: Pointer to "poll_table". Maybe NULL. |
eadd99cc | 458 | * |
a9a08845 | 459 | * Returns EPOLLIN | EPOLLRDNORM when ready to read an audit log. |
eadd99cc | 460 | */ |
c0d4be28 | 461 | __poll_t tomoyo_poll_log(struct file *file, poll_table *wait) |
eadd99cc TH |
462 | { |
463 | if (tomoyo_log_count) | |
a9a08845 | 464 | return EPOLLIN | EPOLLRDNORM; |
eadd99cc TH |
465 | poll_wait(file, &tomoyo_log_wait, wait); |
466 | if (tomoyo_log_count) | |
a9a08845 | 467 | return EPOLLIN | EPOLLRDNORM; |
eadd99cc TH |
468 | return 0; |
469 | } |