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 tomoyo_convert_time(get_seconds(), &stamp); 160 161 pos = snprintf(buffer, tomoyo_buffer_len - 1, 162 "#%04u/%02u/%02u %02u:%02u:%02u# profile=%u mode=%s " 163 "granted=%s (global-pid=%u) task={ pid=%u ppid=%u " 164 "uid=%u gid=%u euid=%u egid=%u suid=%u sgid=%u " 165 "fsuid=%u fsgid=%u }", stamp.year, stamp.month, 166 stamp.day, stamp.hour, stamp.min, stamp.sec, r->profile, 167 tomoyo_mode[r->mode], tomoyo_yesno(r->granted), gpid, 168 tomoyo_sys_getpid(), tomoyo_sys_getppid(), 169 from_kuid(&init_user_ns, current_uid()), 170 from_kgid(&init_user_ns, current_gid()), 171 from_kuid(&init_user_ns, current_euid()), 172 from_kgid(&init_user_ns, current_egid()), 173 from_kuid(&init_user_ns, current_suid()), 174 from_kgid(&init_user_ns, current_sgid()), 175 from_kuid(&init_user_ns, current_fsuid()), 176 from_kgid(&init_user_ns, current_fsgid())); 177 if (!obj) 178 goto no_obj_info; 179 if (!obj->validate_done) { 180 tomoyo_get_attributes(obj); 181 obj->validate_done = true; 182 } 183 for (i = 0; i < TOMOYO_MAX_PATH_STAT; i++) { 184 struct tomoyo_mini_stat *stat; 185 unsigned int dev; 186 umode_t mode; 187 if (!obj->stat_valid[i]) 188 continue; 189 stat = &obj->stat[i]; 190 dev = stat->dev; 191 mode = stat->mode; 192 if (i & 1) { 193 pos += snprintf(buffer + pos, 194 tomoyo_buffer_len - 1 - pos, 195 " path%u.parent={ uid=%u gid=%u " 196 "ino=%lu perm=0%o }", (i >> 1) + 1, 197 from_kuid(&init_user_ns, stat->uid), 198 from_kgid(&init_user_ns, stat->gid), 199 (unsigned long)stat->ino, 200 stat->mode & S_IALLUGO); 201 continue; 202 } 203 pos += snprintf(buffer + pos, tomoyo_buffer_len - 1 - pos, 204 " path%u={ uid=%u gid=%u ino=%lu major=%u" 205 " minor=%u perm=0%o type=%s", (i >> 1) + 1, 206 from_kuid(&init_user_ns, stat->uid), 207 from_kgid(&init_user_ns, stat->gid), 208 (unsigned long)stat->ino, 209 MAJOR(dev), MINOR(dev), 210 mode & S_IALLUGO, tomoyo_filetype(mode)); 211 if (S_ISCHR(mode) || S_ISBLK(mode)) { 212 dev = stat->rdev; 213 pos += snprintf(buffer + pos, 214 tomoyo_buffer_len - 1 - pos, 215 " dev_major=%u dev_minor=%u", 216 MAJOR(dev), MINOR(dev)); 217 } 218 pos += snprintf(buffer + pos, tomoyo_buffer_len - 1 - pos, 219 " }"); 220 } 221 no_obj_info: 222 if (pos < tomoyo_buffer_len - 1) 223 return buffer; 224 kfree(buffer); 225 return NULL; 226 } 227 228 /** 229 * tomoyo_init_log - Allocate buffer for audit logs. 230 * 231 * @r: Pointer to "struct tomoyo_request_info". 232 * @len: Buffer size needed for @fmt and @args. 233 * @fmt: The printf()'s format string. 234 * @args: va_list structure for @fmt. 235 * 236 * Returns pointer to allocated memory. 237 * 238 * This function uses kzalloc(), so caller must kfree() if this function 239 * didn't return NULL. 240 */ 241 char *tomoyo_init_log(struct tomoyo_request_info *r, int len, const char *fmt, 242 va_list args) 243 { 244 char *buf = NULL; 245 char *bprm_info = NULL; 246 const char *header = NULL; 247 char *realpath = NULL; 248 const char *symlink = NULL; 249 int pos; 250 const char *domainname = r->domain->domainname->name; 251 header = tomoyo_print_header(r); 252 if (!header) 253 return NULL; 254 /* +10 is for '\n' etc. and '\0'. */ 255 len += strlen(domainname) + strlen(header) + 10; 256 if (r->ee) { 257 struct file *file = r->ee->bprm->file; 258 realpath = tomoyo_realpath_from_path(&file->f_path); 259 bprm_info = tomoyo_print_bprm(r->ee->bprm, &r->ee->dump); 260 if (!realpath || !bprm_info) 261 goto out; 262 /* +80 is for " exec={ realpath=\"%s\" argc=%d envc=%d %s }" */ 263 len += strlen(realpath) + 80 + strlen(bprm_info); 264 } else if (r->obj && r->obj->symlink_target) { 265 symlink = r->obj->symlink_target->name; 266 /* +18 is for " symlink.target=\"%s\"" */ 267 len += 18 + strlen(symlink); 268 } 269 len = tomoyo_round2(len); 270 buf = kzalloc(len, GFP_NOFS); 271 if (!buf) 272 goto out; 273 len--; 274 pos = snprintf(buf, len, "%s", header); 275 if (realpath) { 276 struct linux_binprm *bprm = r->ee->bprm; 277 pos += snprintf(buf + pos, len - pos, 278 " exec={ realpath=\"%s\" argc=%d envc=%d %s }", 279 realpath, bprm->argc, bprm->envc, bprm_info); 280 } else if (symlink) 281 pos += snprintf(buf + pos, len - pos, " symlink.target=\"%s\"", 282 symlink); 283 pos += snprintf(buf + pos, len - pos, "\n%s\n", domainname); 284 vsnprintf(buf + pos, len - pos, fmt, args); 285 out: 286 kfree(realpath); 287 kfree(bprm_info); 288 kfree(header); 289 return buf; 290 } 291 292 /* Wait queue for /sys/kernel/security/tomoyo/audit. */ 293 static DECLARE_WAIT_QUEUE_HEAD(tomoyo_log_wait); 294 295 /* Structure for audit log. */ 296 struct tomoyo_log { 297 struct list_head list; 298 char *log; 299 int size; 300 }; 301 302 /* The list for "struct tomoyo_log". */ 303 static LIST_HEAD(tomoyo_log); 304 305 /* Lock for "struct list_head tomoyo_log". */ 306 static DEFINE_SPINLOCK(tomoyo_log_lock); 307 308 /* Length of "stuct list_head tomoyo_log". */ 309 static unsigned int tomoyo_log_count; 310 311 /** 312 * tomoyo_get_audit - Get audit mode. 313 * 314 * @ns: Pointer to "struct tomoyo_policy_namespace". 315 * @profile: Profile number. 316 * @index: Index number of functionality. 317 * @is_granted: True if granted log, false otherwise. 318 * 319 * Returns true if this request should be audited, false otherwise. 320 */ 321 static bool tomoyo_get_audit(const struct tomoyo_policy_namespace *ns, 322 const u8 profile, const u8 index, 323 const struct tomoyo_acl_info *matched_acl, 324 const bool is_granted) 325 { 326 u8 mode; 327 const u8 category = tomoyo_index2category[index] + 328 TOMOYO_MAX_MAC_INDEX; 329 struct tomoyo_profile *p; 330 if (!tomoyo_policy_loaded) 331 return false; 332 p = tomoyo_profile(ns, profile); 333 if (tomoyo_log_count >= p->pref[TOMOYO_PREF_MAX_AUDIT_LOG]) 334 return false; 335 if (is_granted && matched_acl && matched_acl->cond && 336 matched_acl->cond->grant_log != TOMOYO_GRANTLOG_AUTO) 337 return matched_acl->cond->grant_log == TOMOYO_GRANTLOG_YES; 338 mode = p->config[index]; 339 if (mode == TOMOYO_CONFIG_USE_DEFAULT) 340 mode = p->config[category]; 341 if (mode == TOMOYO_CONFIG_USE_DEFAULT) 342 mode = p->default_config; 343 if (is_granted) 344 return mode & TOMOYO_CONFIG_WANT_GRANT_LOG; 345 return mode & TOMOYO_CONFIG_WANT_REJECT_LOG; 346 } 347 348 /** 349 * tomoyo_write_log2 - Write an audit log. 350 * 351 * @r: Pointer to "struct tomoyo_request_info". 352 * @len: Buffer size needed for @fmt and @args. 353 * @fmt: The printf()'s format string. 354 * @args: va_list structure for @fmt. 355 * 356 * Returns nothing. 357 */ 358 void tomoyo_write_log2(struct tomoyo_request_info *r, int len, const char *fmt, 359 va_list args) 360 { 361 char *buf; 362 struct tomoyo_log *entry; 363 bool quota_exceeded = false; 364 if (!tomoyo_get_audit(r->domain->ns, r->profile, r->type, 365 r->matched_acl, r->granted)) 366 goto out; 367 buf = tomoyo_init_log(r, len, fmt, args); 368 if (!buf) 369 goto out; 370 entry = kzalloc(sizeof(*entry), GFP_NOFS); 371 if (!entry) { 372 kfree(buf); 373 goto out; 374 } 375 entry->log = buf; 376 len = tomoyo_round2(strlen(buf) + 1); 377 /* 378 * The entry->size is used for memory quota checks. 379 * Don't go beyond strlen(entry->log). 380 */ 381 entry->size = len + tomoyo_round2(sizeof(*entry)); 382 spin_lock(&tomoyo_log_lock); 383 if (tomoyo_memory_quota[TOMOYO_MEMORY_AUDIT] && 384 tomoyo_memory_used[TOMOYO_MEMORY_AUDIT] + entry->size >= 385 tomoyo_memory_quota[TOMOYO_MEMORY_AUDIT]) { 386 quota_exceeded = true; 387 } else { 388 tomoyo_memory_used[TOMOYO_MEMORY_AUDIT] += entry->size; 389 list_add_tail(&entry->list, &tomoyo_log); 390 tomoyo_log_count++; 391 } 392 spin_unlock(&tomoyo_log_lock); 393 if (quota_exceeded) { 394 kfree(buf); 395 kfree(entry); 396 goto out; 397 } 398 wake_up(&tomoyo_log_wait); 399 out: 400 return; 401 } 402 403 /** 404 * tomoyo_write_log - Write an audit log. 405 * 406 * @r: Pointer to "struct tomoyo_request_info". 407 * @fmt: The printf()'s format string, followed by parameters. 408 * 409 * Returns nothing. 410 */ 411 void tomoyo_write_log(struct tomoyo_request_info *r, const char *fmt, ...) 412 { 413 va_list args; 414 int len; 415 va_start(args, fmt); 416 len = vsnprintf((char *) &len, 1, fmt, args) + 1; 417 va_end(args); 418 va_start(args, fmt); 419 tomoyo_write_log2(r, len, fmt, args); 420 va_end(args); 421 } 422 423 /** 424 * tomoyo_read_log - Read an audit log. 425 * 426 * @head: Pointer to "struct tomoyo_io_buffer". 427 * 428 * Returns nothing. 429 */ 430 void tomoyo_read_log(struct tomoyo_io_buffer *head) 431 { 432 struct tomoyo_log *ptr = NULL; 433 if (head->r.w_pos) 434 return; 435 kfree(head->read_buf); 436 head->read_buf = NULL; 437 spin_lock(&tomoyo_log_lock); 438 if (!list_empty(&tomoyo_log)) { 439 ptr = list_entry(tomoyo_log.next, typeof(*ptr), list); 440 list_del(&ptr->list); 441 tomoyo_log_count--; 442 tomoyo_memory_used[TOMOYO_MEMORY_AUDIT] -= ptr->size; 443 } 444 spin_unlock(&tomoyo_log_lock); 445 if (ptr) { 446 head->read_buf = ptr->log; 447 head->r.w[head->r.w_pos++] = head->read_buf; 448 kfree(ptr); 449 } 450 } 451 452 /** 453 * tomoyo_poll_log - Wait for an audit log. 454 * 455 * @file: Pointer to "struct file". 456 * @wait: Pointer to "poll_table". Maybe NULL. 457 * 458 * Returns POLLIN | POLLRDNORM when ready to read an audit log. 459 */ 460 unsigned int tomoyo_poll_log(struct file *file, poll_table *wait) 461 { 462 if (tomoyo_log_count) 463 return POLLIN | POLLRDNORM; 464 poll_wait(file, &tomoyo_log_wait, wait); 465 if (tomoyo_log_count) 466 return POLLIN | POLLRDNORM; 467 return 0; 468 } 469