1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* |
3 | * security/tomoyo/audit.c |
4 | * |
5 | * Copyright (C) 2005-2011 NTT DATA CORPORATION |
6 | */ |
7 | |
8 | #include "common.h" |
9 | #include <linux/slab.h> |
10 | |
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(size: 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 | |
36 | if (!buffer) |
37 | return NULL; |
38 | len = snprintf(buf: buffer, size: tomoyo_buffer_len - 1, fmt: "argv[]={ " ); |
39 | cp = buffer + len; |
40 | if (!argv_count) { |
41 | memmove(cp, "} envp[]={ " , 11); |
42 | cp += 11; |
43 | } |
44 | last_start = cp; |
45 | while (argv_count || envp_count) { |
46 | if (!tomoyo_dump_page(bprm, pos, dump)) |
47 | goto out; |
48 | pos += PAGE_SIZE - offset; |
49 | /* Read. */ |
50 | while (offset < PAGE_SIZE) { |
51 | const char *kaddr = dump->data; |
52 | const unsigned char c = kaddr[offset++]; |
53 | |
54 | if (cp == last_start) |
55 | *cp++ = '"'; |
56 | if (cp >= buffer + tomoyo_buffer_len - 32) { |
57 | /* Reserve some room for "..." string. */ |
58 | truncated = true; |
59 | } else if (c == '\\') { |
60 | *cp++ = '\\'; |
61 | *cp++ = '\\'; |
62 | } else if (c > ' ' && c < 127) { |
63 | *cp++ = c; |
64 | } else if (!c) { |
65 | *cp++ = '"'; |
66 | *cp++ = ' '; |
67 | last_start = cp; |
68 | } else { |
69 | *cp++ = '\\'; |
70 | *cp++ = (c >> 6) + '0'; |
71 | *cp++ = ((c >> 3) & 7) + '0'; |
72 | *cp++ = (c & 7) + '0'; |
73 | } |
74 | if (c) |
75 | continue; |
76 | if (argv_count) { |
77 | if (--argv_count == 0) { |
78 | if (truncated) { |
79 | cp = last_start; |
80 | memmove(cp, "... " , 4); |
81 | cp += 4; |
82 | } |
83 | memmove(cp, "} envp[]={ " , 11); |
84 | cp += 11; |
85 | last_start = cp; |
86 | truncated = false; |
87 | } |
88 | } else if (envp_count) { |
89 | if (--envp_count == 0) { |
90 | if (truncated) { |
91 | cp = last_start; |
92 | memmove(cp, "... " , 4); |
93 | cp += 4; |
94 | } |
95 | } |
96 | } |
97 | if (!argv_count && !envp_count) |
98 | break; |
99 | } |
100 | offset = 0; |
101 | } |
102 | *cp++ = '}'; |
103 | *cp = '\0'; |
104 | return buffer; |
105 | out: |
106 | snprintf(buf: buffer, size: tomoyo_buffer_len - 1, |
107 | fmt: "argv[]={ ... } envp[]= { ... }" ); |
108 | return buffer; |
109 | } |
110 | |
111 | /** |
112 | * tomoyo_filetype - Get string representation of file type. |
113 | * |
114 | * @mode: Mode value for stat(). |
115 | * |
116 | * Returns file type string. |
117 | */ |
118 | static inline const char *tomoyo_filetype(const umode_t mode) |
119 | { |
120 | switch (mode & S_IFMT) { |
121 | case S_IFREG: |
122 | case 0: |
123 | return tomoyo_condition_keyword[TOMOYO_TYPE_IS_FILE]; |
124 | case S_IFDIR: |
125 | return tomoyo_condition_keyword[TOMOYO_TYPE_IS_DIRECTORY]; |
126 | case S_IFLNK: |
127 | return tomoyo_condition_keyword[TOMOYO_TYPE_IS_SYMLINK]; |
128 | case S_IFIFO: |
129 | return tomoyo_condition_keyword[TOMOYO_TYPE_IS_FIFO]; |
130 | case S_IFSOCK: |
131 | return tomoyo_condition_keyword[TOMOYO_TYPE_IS_SOCKET]; |
132 | case S_IFBLK: |
133 | return tomoyo_condition_keyword[TOMOYO_TYPE_IS_BLOCK_DEV]; |
134 | case S_IFCHR: |
135 | return tomoyo_condition_keyword[TOMOYO_TYPE_IS_CHAR_DEV]; |
136 | } |
137 | return "unknown" ; /* This should not happen. */ |
138 | } |
139 | |
140 | /** |
141 | * tomoyo_print_header - Get header line of audit log. |
142 | * |
143 | * @r: Pointer to "struct tomoyo_request_info". |
144 | * |
145 | * Returns string representation. |
146 | * |
147 | * This function uses kmalloc(), so caller must kfree() if this function |
148 | * didn't return NULL. |
149 | */ |
150 | static char *(struct tomoyo_request_info *r) |
151 | { |
152 | struct tomoyo_time stamp; |
153 | const pid_t gpid = task_pid_nr(current); |
154 | struct tomoyo_obj_info *obj = r->obj; |
155 | static const int tomoyo_buffer_len = 4096; |
156 | char *buffer = kmalloc(size: tomoyo_buffer_len, GFP_NOFS); |
157 | int pos; |
158 | u8 i; |
159 | |
160 | if (!buffer) |
161 | return NULL; |
162 | |
163 | tomoyo_convert_time(time: ktime_get_real_seconds(), stamp: &stamp); |
164 | |
165 | pos = snprintf(buf: buffer, size: tomoyo_buffer_len - 1, |
166 | fmt: "#%04u/%02u/%02u %02u:%02u:%02u# profile=%u mode=%s granted=%s (global-pid=%u) task={ pid=%u ppid=%u uid=%u gid=%u euid=%u egid=%u suid=%u sgid=%u fsuid=%u fsgid=%u }" , |
167 | stamp.year, stamp.month, stamp.day, stamp.hour, |
168 | stamp.min, stamp.sec, r->profile, tomoyo_mode[r->mode], |
169 | str_yes_no(v: r->granted), gpid, tomoyo_sys_getpid(), |
170 | tomoyo_sys_getppid(), |
171 | from_kuid(to: &init_user_ns, current_uid()), |
172 | from_kgid(to: &init_user_ns, current_gid()), |
173 | from_kuid(to: &init_user_ns, current_euid()), |
174 | from_kgid(to: &init_user_ns, current_egid()), |
175 | from_kuid(to: &init_user_ns, current_suid()), |
176 | from_kgid(to: &init_user_ns, current_sgid()), |
177 | from_kuid(to: &init_user_ns, current_fsuid()), |
178 | from_kgid(to: &init_user_ns, current_fsgid())); |
179 | if (!obj) |
180 | goto no_obj_info; |
181 | if (!obj->validate_done) { |
182 | tomoyo_get_attributes(obj); |
183 | obj->validate_done = true; |
184 | } |
185 | for (i = 0; i < TOMOYO_MAX_PATH_STAT; i++) { |
186 | struct tomoyo_mini_stat *stat; |
187 | unsigned int dev; |
188 | umode_t mode; |
189 | |
190 | if (!obj->stat_valid[i]) |
191 | continue; |
192 | stat = &obj->stat[i]; |
193 | dev = stat->dev; |
194 | mode = stat->mode; |
195 | if (i & 1) { |
196 | pos += snprintf(buf: buffer + pos, |
197 | size: tomoyo_buffer_len - 1 - pos, |
198 | fmt: " path%u.parent={ uid=%u gid=%u ino=%lu perm=0%o }" , |
199 | (i >> 1) + 1, |
200 | from_kuid(to: &init_user_ns, uid: stat->uid), |
201 | from_kgid(to: &init_user_ns, gid: stat->gid), |
202 | (unsigned long)stat->ino, |
203 | stat->mode & S_IALLUGO); |
204 | continue; |
205 | } |
206 | pos += snprintf(buf: buffer + pos, size: tomoyo_buffer_len - 1 - pos, |
207 | fmt: " path%u={ uid=%u gid=%u ino=%lu major=%u minor=%u perm=0%o type=%s" , |
208 | (i >> 1) + 1, |
209 | from_kuid(to: &init_user_ns, uid: stat->uid), |
210 | from_kgid(to: &init_user_ns, gid: stat->gid), |
211 | (unsigned long)stat->ino, |
212 | MAJOR(dev), MINOR(dev), |
213 | mode & S_IALLUGO, tomoyo_filetype(mode)); |
214 | if (S_ISCHR(mode) || S_ISBLK(mode)) { |
215 | dev = stat->rdev; |
216 | pos += snprintf(buf: buffer + pos, |
217 | size: tomoyo_buffer_len - 1 - pos, |
218 | fmt: " dev_major=%u dev_minor=%u" , |
219 | MAJOR(dev), MINOR(dev)); |
220 | } |
221 | pos += snprintf(buf: buffer + pos, size: tomoyo_buffer_len - 1 - pos, |
222 | fmt: " }" ); |
223 | } |
224 | no_obj_info: |
225 | if (pos < tomoyo_buffer_len - 1) |
226 | return buffer; |
227 | kfree(objp: buffer); |
228 | return NULL; |
229 | } |
230 | |
231 | /** |
232 | * tomoyo_init_log - Allocate buffer for audit logs. |
233 | * |
234 | * @r: Pointer to "struct tomoyo_request_info". |
235 | * @len: Buffer size needed for @fmt and @args. |
236 | * @fmt: The printf()'s format string. |
237 | * @args: va_list structure for @fmt. |
238 | * |
239 | * Returns pointer to allocated memory. |
240 | * |
241 | * This function uses kzalloc(), so caller must kfree() if this function |
242 | * didn't return NULL. |
243 | */ |
244 | char *tomoyo_init_log(struct tomoyo_request_info *r, int len, const char *fmt, |
245 | va_list args) |
246 | { |
247 | char *buf = NULL; |
248 | char *bprm_info = NULL; |
249 | const char * = NULL; |
250 | char *realpath = NULL; |
251 | const char *symlink = NULL; |
252 | int pos; |
253 | const char *domainname = r->domain->domainname->name; |
254 | |
255 | header = tomoyo_print_header(r); |
256 | if (!header) |
257 | return NULL; |
258 | /* +10 is for '\n' etc. and '\0'. */ |
259 | len += strlen(domainname) + strlen(header) + 10; |
260 | if (r->ee) { |
261 | struct file *file = r->ee->bprm->file; |
262 | |
263 | realpath = tomoyo_realpath_from_path(path: &file->f_path); |
264 | bprm_info = tomoyo_print_bprm(bprm: r->ee->bprm, dump: &r->ee->dump); |
265 | if (!realpath || !bprm_info) |
266 | goto out; |
267 | /* +80 is for " exec={ realpath=\"%s\" argc=%d envc=%d %s }" */ |
268 | len += strlen(realpath) + 80 + strlen(bprm_info); |
269 | } else if (r->obj && r->obj->symlink_target) { |
270 | symlink = r->obj->symlink_target->name; |
271 | /* +18 is for " symlink.target=\"%s\"" */ |
272 | len += 18 + strlen(symlink); |
273 | } |
274 | len = kmalloc_size_roundup(size: len); |
275 | buf = kzalloc(size: len, GFP_NOFS); |
276 | if (!buf) |
277 | goto out; |
278 | len--; |
279 | pos = snprintf(buf, size: len, fmt: "%s" , header); |
280 | if (realpath) { |
281 | struct linux_binprm *bprm = r->ee->bprm; |
282 | |
283 | pos += snprintf(buf: buf + pos, size: len - pos, |
284 | fmt: " exec={ realpath=\"%s\" argc=%d envc=%d %s }" , |
285 | realpath, bprm->argc, bprm->envc, bprm_info); |
286 | } else if (symlink) |
287 | pos += snprintf(buf: buf + pos, size: len - pos, fmt: " symlink.target=\"%s\"" , |
288 | symlink); |
289 | pos += snprintf(buf: buf + pos, size: len - pos, fmt: "\n%s\n" , domainname); |
290 | vsnprintf(buf: buf + pos, size: len - pos, fmt, args); |
291 | out: |
292 | kfree(objp: realpath); |
293 | kfree(objp: bprm_info); |
294 | kfree(objp: header); |
295 | return buf; |
296 | } |
297 | |
298 | /* Wait queue for /sys/kernel/security/tomoyo/audit. */ |
299 | static DECLARE_WAIT_QUEUE_HEAD(tomoyo_log_wait); |
300 | |
301 | /* Structure for audit log. */ |
302 | struct tomoyo_log { |
303 | struct list_head list; |
304 | char *log; |
305 | int size; |
306 | }; |
307 | |
308 | /* The list for "struct tomoyo_log". */ |
309 | static LIST_HEAD(tomoyo_log); |
310 | |
311 | /* Lock for "struct list_head tomoyo_log". */ |
312 | static DEFINE_SPINLOCK(tomoyo_log_lock); |
313 | |
314 | /* Length of "struct list_head tomoyo_log". */ |
315 | static unsigned int tomoyo_log_count; |
316 | |
317 | /** |
318 | * tomoyo_get_audit - Get audit mode. |
319 | * |
320 | * @ns: Pointer to "struct tomoyo_policy_namespace". |
321 | * @profile: Profile number. |
322 | * @index: Index number of functionality. |
323 | * @matched_acl: Pointer to "struct tomoyo_acl_info". |
324 | * @is_granted: True if granted log, false otherwise. |
325 | * |
326 | * Returns true if this request should be audited, false otherwise. |
327 | */ |
328 | static bool tomoyo_get_audit(const struct tomoyo_policy_namespace *ns, |
329 | const u8 profile, const u8 index, |
330 | const struct tomoyo_acl_info *matched_acl, |
331 | const bool is_granted) |
332 | { |
333 | u8 mode; |
334 | const u8 category = tomoyo_index2category[index] + |
335 | TOMOYO_MAX_MAC_INDEX; |
336 | struct tomoyo_profile *p; |
337 | |
338 | if (!tomoyo_policy_loaded) |
339 | return false; |
340 | p = tomoyo_profile(ns, profile); |
341 | if (tomoyo_log_count >= p->pref[TOMOYO_PREF_MAX_AUDIT_LOG]) |
342 | return false; |
343 | if (is_granted && matched_acl && matched_acl->cond && |
344 | matched_acl->cond->grant_log != TOMOYO_GRANTLOG_AUTO) |
345 | return matched_acl->cond->grant_log == TOMOYO_GRANTLOG_YES; |
346 | mode = p->config[index]; |
347 | if (mode == TOMOYO_CONFIG_USE_DEFAULT) |
348 | mode = p->config[category]; |
349 | if (mode == TOMOYO_CONFIG_USE_DEFAULT) |
350 | mode = p->default_config; |
351 | if (is_granted) |
352 | return mode & TOMOYO_CONFIG_WANT_GRANT_LOG; |
353 | return mode & TOMOYO_CONFIG_WANT_REJECT_LOG; |
354 | } |
355 | |
356 | /** |
357 | * tomoyo_write_log2 - Write an audit log. |
358 | * |
359 | * @r: Pointer to "struct tomoyo_request_info". |
360 | * @len: Buffer size needed for @fmt and @args. |
361 | * @fmt: The printf()'s format string. |
362 | * @args: va_list structure for @fmt. |
363 | * |
364 | * Returns nothing. |
365 | */ |
366 | void tomoyo_write_log2(struct tomoyo_request_info *r, int len, const char *fmt, |
367 | va_list args) |
368 | { |
369 | char *buf; |
370 | struct tomoyo_log *entry; |
371 | bool quota_exceeded = false; |
372 | |
373 | if (!tomoyo_get_audit(ns: r->domain->ns, profile: r->profile, index: r->type, |
374 | matched_acl: r->matched_acl, is_granted: r->granted)) |
375 | goto out; |
376 | buf = tomoyo_init_log(r, len, fmt, args); |
377 | if (!buf) |
378 | goto out; |
379 | entry = kzalloc(size: sizeof(*entry), GFP_NOFS); |
380 | if (!entry) { |
381 | kfree(objp: buf); |
382 | goto out; |
383 | } |
384 | entry->log = buf; |
385 | len = kmalloc_size_roundup(strlen(buf) + 1); |
386 | /* |
387 | * The entry->size is used for memory quota checks. |
388 | * Don't go beyond strlen(entry->log). |
389 | */ |
390 | entry->size = len + kmalloc_size_roundup(size: sizeof(*entry)); |
391 | spin_lock(lock: &tomoyo_log_lock); |
392 | if (tomoyo_memory_quota[TOMOYO_MEMORY_AUDIT] && |
393 | tomoyo_memory_used[TOMOYO_MEMORY_AUDIT] + entry->size >= |
394 | tomoyo_memory_quota[TOMOYO_MEMORY_AUDIT]) { |
395 | quota_exceeded = true; |
396 | } else { |
397 | tomoyo_memory_used[TOMOYO_MEMORY_AUDIT] += entry->size; |
398 | list_add_tail(new: &entry->list, head: &tomoyo_log); |
399 | tomoyo_log_count++; |
400 | } |
401 | spin_unlock(lock: &tomoyo_log_lock); |
402 | if (quota_exceeded) { |
403 | kfree(objp: buf); |
404 | kfree(objp: entry); |
405 | goto out; |
406 | } |
407 | wake_up(&tomoyo_log_wait); |
408 | out: |
409 | return; |
410 | } |
411 | |
412 | /** |
413 | * tomoyo_write_log - Write an audit log. |
414 | * |
415 | * @r: Pointer to "struct tomoyo_request_info". |
416 | * @fmt: The printf()'s format string, followed by parameters. |
417 | * |
418 | * Returns nothing. |
419 | */ |
420 | void tomoyo_write_log(struct tomoyo_request_info *r, const char *fmt, ...) |
421 | { |
422 | va_list args; |
423 | int len; |
424 | |
425 | va_start(args, fmt); |
426 | len = vsnprintf(NULL, size: 0, fmt, args) + 1; |
427 | va_end(args); |
428 | va_start(args, fmt); |
429 | tomoyo_write_log2(r, len, fmt, args); |
430 | va_end(args); |
431 | } |
432 | |
433 | /** |
434 | * tomoyo_read_log - Read an audit log. |
435 | * |
436 | * @head: Pointer to "struct tomoyo_io_buffer". |
437 | * |
438 | * Returns nothing. |
439 | */ |
440 | void tomoyo_read_log(struct tomoyo_io_buffer *head) |
441 | { |
442 | struct tomoyo_log *ptr = NULL; |
443 | |
444 | if (head->r.w_pos) |
445 | return; |
446 | kfree(objp: head->read_buf); |
447 | head->read_buf = NULL; |
448 | spin_lock(lock: &tomoyo_log_lock); |
449 | if (!list_empty(head: &tomoyo_log)) { |
450 | ptr = list_entry(tomoyo_log.next, typeof(*ptr), list); |
451 | list_del(entry: &ptr->list); |
452 | tomoyo_log_count--; |
453 | tomoyo_memory_used[TOMOYO_MEMORY_AUDIT] -= ptr->size; |
454 | } |
455 | spin_unlock(lock: &tomoyo_log_lock); |
456 | if (ptr) { |
457 | head->read_buf = ptr->log; |
458 | head->r.w[head->r.w_pos++] = head->read_buf; |
459 | kfree(objp: ptr); |
460 | } |
461 | } |
462 | |
463 | /** |
464 | * tomoyo_poll_log - Wait for an audit log. |
465 | * |
466 | * @file: Pointer to "struct file". |
467 | * @wait: Pointer to "poll_table". Maybe NULL. |
468 | * |
469 | * Returns EPOLLIN | EPOLLRDNORM when ready to read an audit log. |
470 | */ |
471 | __poll_t tomoyo_poll_log(struct file *file, poll_table *wait) |
472 | { |
473 | if (tomoyo_log_count) |
474 | return EPOLLIN | EPOLLRDNORM; |
475 | poll_wait(filp: file, wait_address: &tomoyo_log_wait, p: wait); |
476 | if (tomoyo_log_count) |
477 | return EPOLLIN | EPOLLRDNORM; |
478 | return 0; |
479 | } |
480 | |