Merge tag 'usb-5.2-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb
[linux-2.6-block.git] / security / tomoyo / audit.c
CommitLineData
b2441318 1// SPDX-License-Identifier: GPL-2.0
eadd99cc
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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 */
22static 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;
cdcf6723 35
5b636857
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36 if (!buffer)
37 return NULL;
38 len = snprintf(buffer, tomoyo_buffer_len - 1, "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++];
cdcf6723 53
5b636857
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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;
105out:
106 snprintf(buffer, tomoyo_buffer_len - 1,
107 "argv[]={ ... } envp[]= { ... }");
108 return buffer;
109}
110
8761afd4
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111/**
112 * tomoyo_filetype - Get string representation of file type.
113 *
114 * @mode: Mode value for stat().
115 *
116 * Returns file type string.
117 */
d179333f 118static inline const char *tomoyo_filetype(const umode_t mode)
8761afd4
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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
eadd99cc
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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 */
150static char *tomoyo_print_header(struct tomoyo_request_info *r)
151{
152 struct tomoyo_time stamp;
153 const pid_t gpid = task_pid_nr(current);
8761afd4 154 struct tomoyo_obj_info *obj = r->obj;
eadd99cc
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155 static const int tomoyo_buffer_len = 4096;
156 char *buffer = kmalloc(tomoyo_buffer_len, GFP_NOFS);
2066a361 157 int pos;
8761afd4 158 u8 i;
cdcf6723 159
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160 if (!buffer)
161 return NULL;
77f4fa08 162
92734092 163 tomoyo_convert_time(ktime_get_real_seconds(), &stamp);
77f4fa08 164
2066a361 165 pos = snprintf(buffer, tomoyo_buffer_len - 1,
cdcf6723
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166 "#%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 tomoyo_yesno(r->granted), gpid, tomoyo_sys_getpid(),
170 tomoyo_sys_getppid(),
609fcd1b
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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()));
8761afd4
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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;
d179333f 188 umode_t mode;
cdcf6723 189
8761afd4
TH
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(buffer + pos,
197 tomoyo_buffer_len - 1 - pos,
cdcf6723
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198 " path%u.parent={ uid=%u gid=%u ino=%lu perm=0%o }",
199 (i >> 1) + 1,
609fcd1b
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200 from_kuid(&init_user_ns, stat->uid),
201 from_kgid(&init_user_ns, stat->gid),
202 (unsigned long)stat->ino,
203 stat->mode & S_IALLUGO);
8761afd4
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204 continue;
205 }
206 pos += snprintf(buffer + pos, tomoyo_buffer_len - 1 - pos,
cdcf6723
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207 " path%u={ uid=%u gid=%u ino=%lu major=%u minor=%u perm=0%o type=%s",
208 (i >> 1) + 1,
609fcd1b
EB
209 from_kuid(&init_user_ns, stat->uid),
210 from_kgid(&init_user_ns, stat->gid),
211 (unsigned long)stat->ino,
212 MAJOR(dev), MINOR(dev),
8761afd4
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213 mode & S_IALLUGO, tomoyo_filetype(mode));
214 if (S_ISCHR(mode) || S_ISBLK(mode)) {
215 dev = stat->rdev;
216 pos += snprintf(buffer + pos,
217 tomoyo_buffer_len - 1 - pos,
218 " dev_major=%u dev_minor=%u",
219 MAJOR(dev), MINOR(dev));
220 }
221 pos += snprintf(buffer + pos, tomoyo_buffer_len - 1 - pos,
222 " }");
223 }
224no_obj_info:
2066a361
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225 if (pos < tomoyo_buffer_len - 1)
226 return buffer;
227 kfree(buffer);
228 return NULL;
eadd99cc
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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 */
244char *tomoyo_init_log(struct tomoyo_request_info *r, int len, const char *fmt,
245 va_list args)
246{
247 char *buf = NULL;
5b636857 248 char *bprm_info = NULL;
eadd99cc 249 const char *header = NULL;
2ca9bf45
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250 char *realpath = NULL;
251 const char *symlink = NULL;
eadd99cc 252 int pos;
ea504819 253 const char *domainname = r->domain->domainname->name;
cdcf6723 254
eadd99cc
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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;
2ca9bf45
TH
260 if (r->ee) {
261 struct file *file = r->ee->bprm->file;
cdcf6723 262
2ca9bf45 263 realpath = tomoyo_realpath_from_path(&file->f_path);
5b636857
TH
264 bprm_info = tomoyo_print_bprm(r->ee->bprm, &r->ee->dump);
265 if (!realpath || !bprm_info)
2ca9bf45 266 goto out;
5b636857
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267 /* +80 is for " exec={ realpath=\"%s\" argc=%d envc=%d %s }" */
268 len += strlen(realpath) + 80 + strlen(bprm_info);
2ca9bf45
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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 }
eadd99cc
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274 len = tomoyo_round2(len);
275 buf = kzalloc(len, GFP_NOFS);
276 if (!buf)
277 goto out;
278 len--;
279 pos = snprintf(buf, len, "%s", header);
2ca9bf45 280 if (realpath) {
5b636857 281 struct linux_binprm *bprm = r->ee->bprm;
cdcf6723 282
2ca9bf45 283 pos += snprintf(buf + pos, len - pos,
5b636857
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284 " exec={ realpath=\"%s\" argc=%d envc=%d %s }",
285 realpath, bprm->argc, bprm->envc, bprm_info);
2ca9bf45
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286 } else if (symlink)
287 pos += snprintf(buf + pos, len - pos, " symlink.target=\"%s\"",
288 symlink);
eadd99cc
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289 pos += snprintf(buf + pos, len - pos, "\n%s\n", domainname);
290 vsnprintf(buf + pos, len - pos, fmt, args);
291out:
2ca9bf45 292 kfree(realpath);
5b636857 293 kfree(bprm_info);
eadd99cc
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294 kfree(header);
295 return buf;
296}
297
298/* Wait queue for /sys/kernel/security/tomoyo/audit. */
299static DECLARE_WAIT_QUEUE_HEAD(tomoyo_log_wait);
300
301/* Structure for audit log. */
302struct tomoyo_log {
303 struct list_head list;
304 char *log;
305 int size;
306};
307
308/* The list for "struct tomoyo_log". */
309static LIST_HEAD(tomoyo_log);
310
311/* Lock for "struct list_head tomoyo_log". */
312static DEFINE_SPINLOCK(tomoyo_log_lock);
313
314/* Length of "stuct list_head tomoyo_log". */
315static unsigned int tomoyo_log_count;
316
317/**
318 * tomoyo_get_audit - Get audit mode.
319 *
bd03a3e4 320 * @ns: Pointer to "struct tomoyo_policy_namespace".
eadd99cc
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321 * @profile: Profile number.
322 * @index: Index number of functionality.
323 * @is_granted: True if granted log, false otherwise.
324 *
325 * Returns true if this request should be audited, false otherwise.
326 */
bd03a3e4
TH
327static bool tomoyo_get_audit(const struct tomoyo_policy_namespace *ns,
328 const u8 profile, const u8 index,
1f067a68 329 const struct tomoyo_acl_info *matched_acl,
eadd99cc
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330 const bool is_granted)
331{
332 u8 mode;
2c47ab93
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333 const u8 category = tomoyo_index2category[index] +
334 TOMOYO_MAX_MAC_INDEX;
eadd99cc 335 struct tomoyo_profile *p;
cdcf6723 336
eadd99cc
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337 if (!tomoyo_policy_loaded)
338 return false;
bd03a3e4 339 p = tomoyo_profile(ns, profile);
eadd99cc
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340 if (tomoyo_log_count >= p->pref[TOMOYO_PREF_MAX_AUDIT_LOG])
341 return false;
1f067a68
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342 if (is_granted && matched_acl && matched_acl->cond &&
343 matched_acl->cond->grant_log != TOMOYO_GRANTLOG_AUTO)
344 return matched_acl->cond->grant_log == TOMOYO_GRANTLOG_YES;
eadd99cc
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345 mode = p->config[index];
346 if (mode == TOMOYO_CONFIG_USE_DEFAULT)
347 mode = p->config[category];
348 if (mode == TOMOYO_CONFIG_USE_DEFAULT)
349 mode = p->default_config;
350 if (is_granted)
351 return mode & TOMOYO_CONFIG_WANT_GRANT_LOG;
352 return mode & TOMOYO_CONFIG_WANT_REJECT_LOG;
353}
354
355/**
356 * tomoyo_write_log2 - Write an audit log.
357 *
358 * @r: Pointer to "struct tomoyo_request_info".
359 * @len: Buffer size needed for @fmt and @args.
360 * @fmt: The printf()'s format string.
361 * @args: va_list structure for @fmt.
362 *
363 * Returns nothing.
364 */
365void tomoyo_write_log2(struct tomoyo_request_info *r, int len, const char *fmt,
366 va_list args)
367{
368 char *buf;
369 struct tomoyo_log *entry;
370 bool quota_exceeded = false;
cdcf6723 371
1f067a68
TH
372 if (!tomoyo_get_audit(r->domain->ns, r->profile, r->type,
373 r->matched_acl, r->granted))
eadd99cc
TH
374 goto out;
375 buf = tomoyo_init_log(r, len, fmt, args);
376 if (!buf)
377 goto out;
378 entry = kzalloc(sizeof(*entry), GFP_NOFS);
379 if (!entry) {
380 kfree(buf);
381 goto out;
382 }
383 entry->log = buf;
384 len = tomoyo_round2(strlen(buf) + 1);
385 /*
386 * The entry->size is used for memory quota checks.
387 * Don't go beyond strlen(entry->log).
388 */
389 entry->size = len + tomoyo_round2(sizeof(*entry));
390 spin_lock(&tomoyo_log_lock);
391 if (tomoyo_memory_quota[TOMOYO_MEMORY_AUDIT] &&
392 tomoyo_memory_used[TOMOYO_MEMORY_AUDIT] + entry->size >=
393 tomoyo_memory_quota[TOMOYO_MEMORY_AUDIT]) {
394 quota_exceeded = true;
395 } else {
396 tomoyo_memory_used[TOMOYO_MEMORY_AUDIT] += entry->size;
397 list_add_tail(&entry->list, &tomoyo_log);
398 tomoyo_log_count++;
399 }
400 spin_unlock(&tomoyo_log_lock);
401 if (quota_exceeded) {
402 kfree(buf);
403 kfree(entry);
404 goto out;
405 }
406 wake_up(&tomoyo_log_wait);
407out:
408 return;
409}
410
411/**
412 * tomoyo_write_log - Write an audit log.
413 *
414 * @r: Pointer to "struct tomoyo_request_info".
415 * @fmt: The printf()'s format string, followed by parameters.
416 *
417 * Returns nothing.
418 */
419void tomoyo_write_log(struct tomoyo_request_info *r, const char *fmt, ...)
420{
421 va_list args;
422 int len;
cdcf6723 423
eadd99cc
TH
424 va_start(args, fmt);
425 len = vsnprintf((char *) &len, 1, fmt, args) + 1;
426 va_end(args);
427 va_start(args, fmt);
428 tomoyo_write_log2(r, len, fmt, args);
429 va_end(args);
430}
431
432/**
433 * tomoyo_read_log - Read an audit log.
434 *
435 * @head: Pointer to "struct tomoyo_io_buffer".
436 *
437 * Returns nothing.
438 */
439void tomoyo_read_log(struct tomoyo_io_buffer *head)
440{
441 struct tomoyo_log *ptr = NULL;
cdcf6723 442
eadd99cc
TH
443 if (head->r.w_pos)
444 return;
445 kfree(head->read_buf);
446 head->read_buf = NULL;
447 spin_lock(&tomoyo_log_lock);
448 if (!list_empty(&tomoyo_log)) {
449 ptr = list_entry(tomoyo_log.next, typeof(*ptr), list);
450 list_del(&ptr->list);
451 tomoyo_log_count--;
452 tomoyo_memory_used[TOMOYO_MEMORY_AUDIT] -= ptr->size;
453 }
454 spin_unlock(&tomoyo_log_lock);
455 if (ptr) {
456 head->read_buf = ptr->log;
457 head->r.w[head->r.w_pos++] = head->read_buf;
458 kfree(ptr);
459 }
460}
461
462/**
463 * tomoyo_poll_log - Wait for an audit log.
464 *
465 * @file: Pointer to "struct file".
6041e834 466 * @wait: Pointer to "poll_table". Maybe NULL.
eadd99cc 467 *
a9a08845 468 * Returns EPOLLIN | EPOLLRDNORM when ready to read an audit log.
eadd99cc 469 */
c0d4be28 470__poll_t tomoyo_poll_log(struct file *file, poll_table *wait)
eadd99cc
TH
471{
472 if (tomoyo_log_count)
a9a08845 473 return EPOLLIN | EPOLLRDNORM;
eadd99cc
TH
474 poll_wait(file, &tomoyo_log_wait, wait);
475 if (tomoyo_log_count)
a9a08845 476 return EPOLLIN | EPOLLRDNORM;
eadd99cc
TH
477 return 0;
478}