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 */ 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 */ 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 */ 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 */ 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 */ 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 */ 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 */ 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 */ 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 */ 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