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(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(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++]; 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(buffer, tomoyo_buffer_len - 1, 107 "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 *tomoyo_print_header(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(tomoyo_buffer_len, GFP_NOFS); 157 int pos; 158 u8 i; 159 160 if (!buffer) 161 return NULL; 162 163 tomoyo_convert_time(ktime_get_real_seconds(), &stamp); 164 165 pos = snprintf(buffer, tomoyo_buffer_len - 1, 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 str_yes_no(r->granted), gpid, tomoyo_sys_getpid(), 170 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; 189 190 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, 198 " path%u.parent={ uid=%u gid=%u ino=%llu perm=0%o }", 199 (i >> 1) + 1, 200 from_kuid(&init_user_ns, stat->uid), 201 from_kgid(&init_user_ns, stat->gid), 202 stat->ino, 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=%llu major=%u minor=%u perm=0%o type=%s", 207 (i >> 1) + 1, 208 from_kuid(&init_user_ns, stat->uid), 209 from_kgid(&init_user_ns, stat->gid), 210 stat->ino, MAJOR(dev), MINOR(dev), 211 mode & S_IALLUGO, tomoyo_filetype(mode)); 212 if (S_ISCHR(mode) || S_ISBLK(mode)) { 213 dev = stat->rdev; 214 pos += snprintf(buffer + pos, 215 tomoyo_buffer_len - 1 - pos, 216 " dev_major=%u dev_minor=%u", 217 MAJOR(dev), MINOR(dev)); 218 } 219 pos += snprintf(buffer + pos, tomoyo_buffer_len - 1 - pos, 220 " }"); 221 } 222 no_obj_info: 223 if (pos < tomoyo_buffer_len - 1) 224 return buffer; 225 kfree(buffer); 226 return NULL; 227 } 228 229 /** 230 * tomoyo_init_log - Allocate buffer for audit logs. 231 * 232 * @r: Pointer to "struct tomoyo_request_info". 233 * @len: Buffer size needed for @fmt and @args. 234 * @fmt: The printf()'s format string. 235 * @args: va_list structure for @fmt. 236 * 237 * Returns pointer to allocated memory. 238 * 239 * This function uses kzalloc(), so caller must kfree() if this function 240 * didn't return NULL. 241 */ 242 char *tomoyo_init_log(struct tomoyo_request_info *r, int len, const char *fmt, 243 va_list args) 244 { 245 char *buf = NULL; 246 char *bprm_info = NULL; 247 const char *header = NULL; 248 char *realpath = NULL; 249 const char *symlink = NULL; 250 int pos; 251 const char *domainname = r->domain->domainname->name; 252 253 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; 260 261 realpath = tomoyo_realpath_from_path(&file->f_path); 262 bprm_info = tomoyo_print_bprm(r->ee->bprm, &r->ee->dump); 263 if (!realpath || !bprm_info) 264 goto out; 265 /* +80 is for " exec={ realpath=\"%s\" argc=%d envc=%d %s }" */ 266 len += strlen(realpath) + 80 + strlen(bprm_info); 267 } else if (r->obj && r->obj->symlink_target) { 268 symlink = r->obj->symlink_target->name; 269 /* +18 is for " symlink.target=\"%s\"" */ 270 len += 18 + strlen(symlink); 271 } 272 len = kmalloc_size_roundup(len); 273 buf = kzalloc(len, GFP_NOFS); 274 if (!buf) 275 goto out; 276 len--; 277 pos = snprintf(buf, len, "%s", header); 278 if (realpath) { 279 struct linux_binprm *bprm = r->ee->bprm; 280 281 pos += snprintf(buf + pos, len - pos, 282 " exec={ realpath=\"%s\" argc=%d envc=%d %s }", 283 realpath, bprm->argc, bprm->envc, bprm_info); 284 } else if (symlink) 285 pos += snprintf(buf + pos, len - pos, " symlink.target=\"%s\"", 286 symlink); 287 pos += snprintf(buf + pos, len - pos, "\n%s\n", domainname); 288 vsnprintf(buf + pos, len - pos, fmt, args); 289 out: 290 kfree(realpath); 291 kfree(bprm_info); 292 kfree(header); 293 return buf; 294 } 295 296 /* Wait queue for /sys/kernel/security/tomoyo/audit. */ 297 static DECLARE_WAIT_QUEUE_HEAD(tomoyo_log_wait); 298 299 /* Structure for audit log. */ 300 struct tomoyo_log { 301 struct list_head list; 302 char *log; 303 int size; 304 }; 305 306 /* The list for "struct tomoyo_log". */ 307 static LIST_HEAD(tomoyo_log); 308 309 /* Lock for "struct list_head tomoyo_log". */ 310 static DEFINE_SPINLOCK(tomoyo_log_lock); 311 312 /* Length of "struct list_head tomoyo_log". */ 313 static unsigned int tomoyo_log_count; 314 315 /** 316 * tomoyo_get_audit - Get audit mode. 317 * 318 * @ns: Pointer to "struct tomoyo_policy_namespace". 319 * @profile: Profile number. 320 * @index: Index number of functionality. 321 * @matched_acl: Pointer to "struct tomoyo_acl_info". 322 * @is_granted: True if granted log, false otherwise. 323 * 324 * Returns true if this request should be audited, false otherwise. 325 */ 326 static bool tomoyo_get_audit(const struct tomoyo_policy_namespace *ns, 327 const u8 profile, const u8 index, 328 const struct tomoyo_acl_info *matched_acl, 329 const bool is_granted) 330 { 331 u8 mode; 332 const u8 category = tomoyo_index2category[index] + 333 TOMOYO_MAX_MAC_INDEX; 334 struct tomoyo_profile *p; 335 336 if (!tomoyo_policy_loaded) 337 return false; 338 p = tomoyo_profile(ns, profile); 339 if (tomoyo_log_count >= p->pref[TOMOYO_PREF_MAX_AUDIT_LOG]) 340 return false; 341 if (is_granted && matched_acl && matched_acl->cond && 342 matched_acl->cond->grant_log != TOMOYO_GRANTLOG_AUTO) 343 return matched_acl->cond->grant_log == TOMOYO_GRANTLOG_YES; 344 mode = p->config[index]; 345 if (mode == TOMOYO_CONFIG_USE_DEFAULT) 346 mode = p->config[category]; 347 if (mode == TOMOYO_CONFIG_USE_DEFAULT) 348 mode = p->default_config; 349 if (is_granted) 350 return mode & TOMOYO_CONFIG_WANT_GRANT_LOG; 351 return mode & TOMOYO_CONFIG_WANT_REJECT_LOG; 352 } 353 354 /** 355 * tomoyo_write_log2 - Write an audit log. 356 * 357 * @r: Pointer to "struct tomoyo_request_info". 358 * @len: Buffer size needed for @fmt and @args. 359 * @fmt: The printf()'s format string. 360 * @args: va_list structure for @fmt. 361 * 362 * Returns nothing. 363 */ 364 void tomoyo_write_log2(struct tomoyo_request_info *r, int len, const char *fmt, 365 va_list args) 366 { 367 char *buf; 368 struct tomoyo_log *entry; 369 bool quota_exceeded = false; 370 371 if (!tomoyo_get_audit(r->domain->ns, r->profile, r->type, 372 r->matched_acl, r->granted)) 373 goto out; 374 buf = tomoyo_init_log(r, len, fmt, args); 375 if (!buf) 376 goto out; 377 entry = kzalloc_obj(*entry, GFP_NOFS); 378 if (!entry) { 379 kfree(buf); 380 goto out; 381 } 382 entry->log = buf; 383 len = kmalloc_size_roundup(strlen(buf) + 1); 384 /* 385 * The entry->size is used for memory quota checks. 386 * Don't go beyond strlen(entry->log). 387 */ 388 entry->size = len + kmalloc_size_roundup(sizeof(*entry)); 389 spin_lock(&tomoyo_log_lock); 390 if (tomoyo_memory_quota[TOMOYO_MEMORY_AUDIT] && 391 tomoyo_memory_used[TOMOYO_MEMORY_AUDIT] + entry->size >= 392 tomoyo_memory_quota[TOMOYO_MEMORY_AUDIT]) { 393 quota_exceeded = true; 394 } else { 395 tomoyo_memory_used[TOMOYO_MEMORY_AUDIT] += entry->size; 396 list_add_tail(&entry->list, &tomoyo_log); 397 tomoyo_log_count++; 398 } 399 spin_unlock(&tomoyo_log_lock); 400 if (quota_exceeded) { 401 kfree(buf); 402 kfree(entry); 403 goto out; 404 } 405 wake_up(&tomoyo_log_wait); 406 out: 407 return; 408 } 409 410 /** 411 * tomoyo_write_log - Write an audit log. 412 * 413 * @r: Pointer to "struct tomoyo_request_info". 414 * @fmt: The printf()'s format string, followed by parameters. 415 * 416 * Returns nothing. 417 */ 418 void tomoyo_write_log(struct tomoyo_request_info *r, const char *fmt, ...) 419 { 420 va_list args; 421 int len; 422 423 va_start(args, fmt); 424 len = vsnprintf(NULL, 0, fmt, args) + 1; 425 va_end(args); 426 va_start(args, fmt); 427 tomoyo_write_log2(r, len, fmt, args); 428 va_end(args); 429 } 430 431 /** 432 * tomoyo_read_log - Read an audit log. 433 * 434 * @head: Pointer to "struct tomoyo_io_buffer". 435 * 436 * Returns nothing. 437 */ 438 void tomoyo_read_log(struct tomoyo_io_buffer *head) 439 { 440 struct tomoyo_log *ptr = NULL; 441 442 if (head->r.w_pos) 443 return; 444 kfree(head->read_buf); 445 head->read_buf = NULL; 446 spin_lock(&tomoyo_log_lock); 447 if (!list_empty(&tomoyo_log)) { 448 ptr = list_entry(tomoyo_log.next, typeof(*ptr), list); 449 list_del(&ptr->list); 450 tomoyo_log_count--; 451 tomoyo_memory_used[TOMOYO_MEMORY_AUDIT] -= ptr->size; 452 } 453 spin_unlock(&tomoyo_log_lock); 454 if (ptr) { 455 head->read_buf = ptr->log; 456 head->r.w[head->r.w_pos++] = head->read_buf; 457 kfree(ptr); 458 } 459 } 460 461 /** 462 * tomoyo_poll_log - Wait for an audit log. 463 * 464 * @file: Pointer to "struct file". 465 * @wait: Pointer to "poll_table". Maybe NULL. 466 * 467 * Returns EPOLLIN | EPOLLRDNORM when ready to read an audit log. 468 */ 469 __poll_t tomoyo_poll_log(struct file *file, poll_table *wait) 470 { 471 if (tomoyo_log_count) 472 return EPOLLIN | EPOLLRDNORM; 473 poll_wait(file, &tomoyo_log_wait, wait); 474 if (tomoyo_log_count) 475 return EPOLLIN | EPOLLRDNORM; 476 return 0; 477 } 478