1 /*
2 * security/tomoyo/audit.c
3 *
4 * Copyright (C) 2005-2011 NTT DATA CORPORATION
5 */
6
7 #include "common.h"
8 #include <linux/slab.h>
9
10 /**
11 * tomoyo_print_bprm - Print "struct linux_binprm" for auditing.
12 *
13 * @bprm: Pointer to "struct linux_binprm".
14 * @dump: Pointer to "struct tomoyo_page_dump".
15 *
16 * Returns the contents of @bprm on success, NULL otherwise.
17 *
18 * This function uses kzalloc(), so caller must kfree() if this function
19 * didn't return NULL.
20 */
tomoyo_print_bprm(struct linux_binprm * bprm,struct tomoyo_page_dump * dump)21 static char *tomoyo_print_bprm(struct linux_binprm *bprm,
22 struct tomoyo_page_dump *dump)
23 {
24 static const int tomoyo_buffer_len = 4096 * 2;
25 char *buffer = kzalloc(tomoyo_buffer_len, GFP_NOFS);
26 char *cp;
27 char *last_start;
28 int len;
29 unsigned long pos = bprm->p;
30 int offset = pos % PAGE_SIZE;
31 int argv_count = bprm->argc;
32 int envp_count = bprm->envc;
33 bool truncated = false;
34 if (!buffer)
35 return NULL;
36 len = snprintf(buffer, tomoyo_buffer_len - 1, "argv[]={ ");
37 cp = buffer + len;
38 if (!argv_count) {
39 memmove(cp, "} envp[]={ ", 11);
40 cp += 11;
41 }
42 last_start = cp;
43 while (argv_count || envp_count) {
44 if (!tomoyo_dump_page(bprm, pos, dump))
45 goto out;
46 pos += PAGE_SIZE - offset;
47 /* Read. */
48 while (offset < PAGE_SIZE) {
49 const char *kaddr = dump->data;
50 const unsigned char c = kaddr[offset++];
51 if (cp == last_start)
52 *cp++ = '"';
53 if (cp >= buffer + tomoyo_buffer_len - 32) {
54 /* Reserve some room for "..." string. */
55 truncated = true;
56 } else if (c == '\\') {
57 *cp++ = '\\';
58 *cp++ = '\\';
59 } else if (c > ' ' && c < 127) {
60 *cp++ = c;
61 } else if (!c) {
62 *cp++ = '"';
63 *cp++ = ' ';
64 last_start = cp;
65 } else {
66 *cp++ = '\\';
67 *cp++ = (c >> 6) + '0';
68 *cp++ = ((c >> 3) & 7) + '0';
69 *cp++ = (c & 7) + '0';
70 }
71 if (c)
72 continue;
73 if (argv_count) {
74 if (--argv_count == 0) {
75 if (truncated) {
76 cp = last_start;
77 memmove(cp, "... ", 4);
78 cp += 4;
79 }
80 memmove(cp, "} envp[]={ ", 11);
81 cp += 11;
82 last_start = cp;
83 truncated = false;
84 }
85 } else if (envp_count) {
86 if (--envp_count == 0) {
87 if (truncated) {
88 cp = last_start;
89 memmove(cp, "... ", 4);
90 cp += 4;
91 }
92 }
93 }
94 if (!argv_count && !envp_count)
95 break;
96 }
97 offset = 0;
98 }
99 *cp++ = '}';
100 *cp = '\0';
101 return buffer;
102 out:
103 snprintf(buffer, tomoyo_buffer_len - 1,
104 "argv[]={ ... } envp[]= { ... }");
105 return buffer;
106 }
107
108 /**
109 * tomoyo_filetype - Get string representation of file type.
110 *
111 * @mode: Mode value for stat().
112 *
113 * Returns file type string.
114 */
tomoyo_filetype(const umode_t mode)115 static inline const char *tomoyo_filetype(const umode_t mode)
116 {
117 switch (mode & S_IFMT) {
118 case S_IFREG:
119 case 0:
120 return tomoyo_condition_keyword[TOMOYO_TYPE_IS_FILE];
121 case S_IFDIR:
122 return tomoyo_condition_keyword[TOMOYO_TYPE_IS_DIRECTORY];
123 case S_IFLNK:
124 return tomoyo_condition_keyword[TOMOYO_TYPE_IS_SYMLINK];
125 case S_IFIFO:
126 return tomoyo_condition_keyword[TOMOYO_TYPE_IS_FIFO];
127 case S_IFSOCK:
128 return tomoyo_condition_keyword[TOMOYO_TYPE_IS_SOCKET];
129 case S_IFBLK:
130 return tomoyo_condition_keyword[TOMOYO_TYPE_IS_BLOCK_DEV];
131 case S_IFCHR:
132 return tomoyo_condition_keyword[TOMOYO_TYPE_IS_CHAR_DEV];
133 }
134 return "unknown"; /* This should not happen. */
135 }
136
137 /**
138 * tomoyo_print_header - Get header line of audit log.
139 *
140 * @r: Pointer to "struct tomoyo_request_info".
141 *
142 * Returns string representation.
143 *
144 * This function uses kmalloc(), so caller must kfree() if this function
145 * didn't return NULL.
146 */
tomoyo_print_header(struct tomoyo_request_info * r)147 static char *tomoyo_print_header(struct tomoyo_request_info *r)
148 {
149 struct tomoyo_time stamp;
150 const pid_t gpid = task_pid_nr(current);
151 struct tomoyo_obj_info *obj = r->obj;
152 static const int tomoyo_buffer_len = 4096;
153 char *buffer = kmalloc(tomoyo_buffer_len, GFP_NOFS);
154 int pos;
155 u8 i;
156 if (!buffer)
157 return NULL;
158 {
159 struct timeval tv;
160 do_gettimeofday(&tv);
161 tomoyo_convert_time(tv.tv_sec, &stamp);
162 }
163 pos = snprintf(buffer, tomoyo_buffer_len - 1,
164 "#%04u/%02u/%02u %02u:%02u:%02u# profile=%u mode=%s "
165 "granted=%s (global-pid=%u) task={ pid=%u ppid=%u "
166 "uid=%u gid=%u euid=%u egid=%u suid=%u sgid=%u "
167 "fsuid=%u fsgid=%u }", stamp.year, stamp.month,
168 stamp.day, stamp.hour, stamp.min, stamp.sec, r->profile,
169 tomoyo_mode[r->mode], tomoyo_yesno(r->granted), gpid,
170 tomoyo_sys_getpid(), tomoyo_sys_getppid(),
171 from_kuid(&init_user_ns, current_uid()),
172 from_kgid(&init_user_ns, current_gid()),
173 from_kuid(&init_user_ns, current_euid()),
174 from_kgid(&init_user_ns, current_egid()),
175 from_kuid(&init_user_ns, current_suid()),
176 from_kgid(&init_user_ns, current_sgid()),
177 from_kuid(&init_user_ns, current_fsuid()),
178 from_kgid(&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 if (!obj->stat_valid[i])
190 continue;
191 stat = &obj->stat[i];
192 dev = stat->dev;
193 mode = stat->mode;
194 if (i & 1) {
195 pos += snprintf(buffer + pos,
196 tomoyo_buffer_len - 1 - pos,
197 " path%u.parent={ uid=%u gid=%u "
198 "ino=%lu perm=0%o }", (i >> 1) + 1,
199 from_kuid(&init_user_ns, stat->uid),
200 from_kgid(&init_user_ns, stat->gid),
201 (unsigned long)stat->ino,
202 stat->mode & S_IALLUGO);
203 continue;
204 }
205 pos += snprintf(buffer + pos, tomoyo_buffer_len - 1 - pos,
206 " path%u={ uid=%u gid=%u ino=%lu major=%u"
207 " minor=%u perm=0%o type=%s", (i >> 1) + 1,
208 from_kuid(&init_user_ns, stat->uid),
209 from_kgid(&init_user_ns, stat->gid),
210 (unsigned long)stat->ino,
211 MAJOR(dev), MINOR(dev),
212 mode & S_IALLUGO, tomoyo_filetype(mode));
213 if (S_ISCHR(mode) || S_ISBLK(mode)) {
214 dev = stat->rdev;
215 pos += snprintf(buffer + pos,
216 tomoyo_buffer_len - 1 - pos,
217 " dev_major=%u dev_minor=%u",
218 MAJOR(dev), MINOR(dev));
219 }
220 pos += snprintf(buffer + pos, tomoyo_buffer_len - 1 - pos,
221 " }");
222 }
223 no_obj_info:
224 if (pos < tomoyo_buffer_len - 1)
225 return buffer;
226 kfree(buffer);
227 return NULL;
228 }
229
230 /**
231 * tomoyo_init_log - Allocate buffer for audit logs.
232 *
233 * @r: Pointer to "struct tomoyo_request_info".
234 * @len: Buffer size needed for @fmt and @args.
235 * @fmt: The printf()'s format string.
236 * @args: va_list structure for @fmt.
237 *
238 * Returns pointer to allocated memory.
239 *
240 * This function uses kzalloc(), so caller must kfree() if this function
241 * didn't return NULL.
242 */
tomoyo_init_log(struct tomoyo_request_info * r,int len,const char * fmt,va_list args)243 char *tomoyo_init_log(struct tomoyo_request_info *r, int len, const char *fmt,
244 va_list args)
245 {
246 char *buf = NULL;
247 char *bprm_info = NULL;
248 const char *header = NULL;
249 char *realpath = NULL;
250 const char *symlink = NULL;
251 int pos;
252 const char *domainname = r->domain->domainname->name;
253 header = tomoyo_print_header(r);
254 if (!header)
255 return NULL;
256 /* +10 is for '\n' etc. and '\0'. */
257 len += strlen(domainname) + strlen(header) + 10;
258 if (r->ee) {
259 struct file *file = r->ee->bprm->file;
260 realpath = tomoyo_realpath_from_path(&file->f_path);
261 bprm_info = tomoyo_print_bprm(r->ee->bprm, &r->ee->dump);
262 if (!realpath || !bprm_info)
263 goto out;
264 /* +80 is for " exec={ realpath=\"%s\" argc=%d envc=%d %s }" */
265 len += strlen(realpath) + 80 + strlen(bprm_info);
266 } else if (r->obj && r->obj->symlink_target) {
267 symlink = r->obj->symlink_target->name;
268 /* +18 is for " symlink.target=\"%s\"" */
269 len += 18 + strlen(symlink);
270 }
271 len = tomoyo_round2(len);
272 buf = kzalloc(len, GFP_NOFS);
273 if (!buf)
274 goto out;
275 len--;
276 pos = snprintf(buf, len, "%s", header);
277 if (realpath) {
278 struct linux_binprm *bprm = r->ee->bprm;
279 pos += snprintf(buf + pos, len - pos,
280 " exec={ realpath=\"%s\" argc=%d envc=%d %s }",
281 realpath, bprm->argc, bprm->envc, bprm_info);
282 } else if (symlink)
283 pos += snprintf(buf + pos, len - pos, " symlink.target=\"%s\"",
284 symlink);
285 pos += snprintf(buf + pos, len - pos, "\n%s\n", domainname);
286 vsnprintf(buf + pos, len - pos, fmt, args);
287 out:
288 kfree(realpath);
289 kfree(bprm_info);
290 kfree(header);
291 return buf;
292 }
293
294 /* Wait queue for /sys/kernel/security/tomoyo/audit. */
295 static DECLARE_WAIT_QUEUE_HEAD(tomoyo_log_wait);
296
297 /* Structure for audit log. */
298 struct tomoyo_log {
299 struct list_head list;
300 char *log;
301 int size;
302 };
303
304 /* The list for "struct tomoyo_log". */
305 static LIST_HEAD(tomoyo_log);
306
307 /* Lock for "struct list_head tomoyo_log". */
308 static DEFINE_SPINLOCK(tomoyo_log_lock);
309
310 /* Length of "stuct list_head tomoyo_log". */
311 static unsigned int tomoyo_log_count;
312
313 /**
314 * tomoyo_get_audit - Get audit mode.
315 *
316 * @ns: Pointer to "struct tomoyo_policy_namespace".
317 * @profile: Profile number.
318 * @index: Index number of functionality.
319 * @is_granted: True if granted log, false otherwise.
320 *
321 * Returns true if this request should be audited, false otherwise.
322 */
tomoyo_get_audit(const struct tomoyo_policy_namespace * ns,const u8 profile,const u8 index,const struct tomoyo_acl_info * matched_acl,const bool is_granted)323 static bool tomoyo_get_audit(const struct tomoyo_policy_namespace *ns,
324 const u8 profile, const u8 index,
325 const struct tomoyo_acl_info *matched_acl,
326 const bool is_granted)
327 {
328 u8 mode;
329 const u8 category = tomoyo_index2category[index] +
330 TOMOYO_MAX_MAC_INDEX;
331 struct tomoyo_profile *p;
332 if (!tomoyo_policy_loaded)
333 return false;
334 p = tomoyo_profile(ns, profile);
335 if (tomoyo_log_count >= p->pref[TOMOYO_PREF_MAX_AUDIT_LOG])
336 return false;
337 if (is_granted && matched_acl && matched_acl->cond &&
338 matched_acl->cond->grant_log != TOMOYO_GRANTLOG_AUTO)
339 return matched_acl->cond->grant_log == TOMOYO_GRANTLOG_YES;
340 mode = p->config[index];
341 if (mode == TOMOYO_CONFIG_USE_DEFAULT)
342 mode = p->config[category];
343 if (mode == TOMOYO_CONFIG_USE_DEFAULT)
344 mode = p->default_config;
345 if (is_granted)
346 return mode & TOMOYO_CONFIG_WANT_GRANT_LOG;
347 return mode & TOMOYO_CONFIG_WANT_REJECT_LOG;
348 }
349
350 /**
351 * tomoyo_write_log2 - Write an audit log.
352 *
353 * @r: Pointer to "struct tomoyo_request_info".
354 * @len: Buffer size needed for @fmt and @args.
355 * @fmt: The printf()'s format string.
356 * @args: va_list structure for @fmt.
357 *
358 * Returns nothing.
359 */
tomoyo_write_log2(struct tomoyo_request_info * r,int len,const char * fmt,va_list args)360 void tomoyo_write_log2(struct tomoyo_request_info *r, int len, const char *fmt,
361 va_list args)
362 {
363 char *buf;
364 struct tomoyo_log *entry;
365 bool quota_exceeded = false;
366 if (!tomoyo_get_audit(r->domain->ns, r->profile, r->type,
367 r->matched_acl, r->granted))
368 goto out;
369 buf = tomoyo_init_log(r, len, fmt, args);
370 if (!buf)
371 goto out;
372 entry = kzalloc(sizeof(*entry), GFP_NOFS);
373 if (!entry) {
374 kfree(buf);
375 goto out;
376 }
377 entry->log = buf;
378 len = tomoyo_round2(strlen(buf) + 1);
379 /*
380 * The entry->size is used for memory quota checks.
381 * Don't go beyond strlen(entry->log).
382 */
383 entry->size = len + tomoyo_round2(sizeof(*entry));
384 spin_lock(&tomoyo_log_lock);
385 if (tomoyo_memory_quota[TOMOYO_MEMORY_AUDIT] &&
386 tomoyo_memory_used[TOMOYO_MEMORY_AUDIT] + entry->size >=
387 tomoyo_memory_quota[TOMOYO_MEMORY_AUDIT]) {
388 quota_exceeded = true;
389 } else {
390 tomoyo_memory_used[TOMOYO_MEMORY_AUDIT] += entry->size;
391 list_add_tail(&entry->list, &tomoyo_log);
392 tomoyo_log_count++;
393 }
394 spin_unlock(&tomoyo_log_lock);
395 if (quota_exceeded) {
396 kfree(buf);
397 kfree(entry);
398 goto out;
399 }
400 wake_up(&tomoyo_log_wait);
401 out:
402 return;
403 }
404
405 /**
406 * tomoyo_write_log - Write an audit log.
407 *
408 * @r: Pointer to "struct tomoyo_request_info".
409 * @fmt: The printf()'s format string, followed by parameters.
410 *
411 * Returns nothing.
412 */
tomoyo_write_log(struct tomoyo_request_info * r,const char * fmt,...)413 void tomoyo_write_log(struct tomoyo_request_info *r, const char *fmt, ...)
414 {
415 va_list args;
416 int len;
417 va_start(args, fmt);
418 len = vsnprintf((char *) &len, 1, fmt, args) + 1;
419 va_end(args);
420 va_start(args, fmt);
421 tomoyo_write_log2(r, len, fmt, args);
422 va_end(args);
423 }
424
425 /**
426 * tomoyo_read_log - Read an audit log.
427 *
428 * @head: Pointer to "struct tomoyo_io_buffer".
429 *
430 * Returns nothing.
431 */
tomoyo_read_log(struct tomoyo_io_buffer * head)432 void tomoyo_read_log(struct tomoyo_io_buffer *head)
433 {
434 struct tomoyo_log *ptr = NULL;
435 if (head->r.w_pos)
436 return;
437 kfree(head->read_buf);
438 head->read_buf = NULL;
439 spin_lock(&tomoyo_log_lock);
440 if (!list_empty(&tomoyo_log)) {
441 ptr = list_entry(tomoyo_log.next, typeof(*ptr), list);
442 list_del(&ptr->list);
443 tomoyo_log_count--;
444 tomoyo_memory_used[TOMOYO_MEMORY_AUDIT] -= ptr->size;
445 }
446 spin_unlock(&tomoyo_log_lock);
447 if (ptr) {
448 head->read_buf = ptr->log;
449 head->r.w[head->r.w_pos++] = head->read_buf;
450 kfree(ptr);
451 }
452 }
453
454 /**
455 * tomoyo_poll_log - Wait for an audit log.
456 *
457 * @file: Pointer to "struct file".
458 * @wait: Pointer to "poll_table". Maybe NULL.
459 *
460 * Returns POLLIN | POLLRDNORM when ready to read an audit log.
461 */
tomoyo_poll_log(struct file * file,poll_table * wait)462 unsigned int tomoyo_poll_log(struct file *file, poll_table *wait)
463 {
464 if (tomoyo_log_count)
465 return POLLIN | POLLRDNORM;
466 poll_wait(file, &tomoyo_log_wait, wait);
467 if (tomoyo_log_count)
468 return POLLIN | POLLRDNORM;
469 return 0;
470 }
471