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 if (!buffer) 36 return NULL; 37 len = snprintf(buffer, tomoyo_buffer_len - 1, "argv[]={ "); 38 cp = buffer + len; 39 if (!argv_count) { 40 memmove(cp, "} envp[]={ ", 11); 41 cp += 11; 42 } 43 last_start = cp; 44 while (argv_count || envp_count) { 45 if (!tomoyo_dump_page(bprm, pos, dump)) 46 goto out; 47 pos += PAGE_SIZE - offset; 48 /* Read. */ 49 while (offset < PAGE_SIZE) { 50 const char *kaddr = dump->data; 51 const unsigned char c = kaddr[offset++]; 52 if (cp == last_start) 53 *cp++ = '"'; 54 if (cp >= buffer + tomoyo_buffer_len - 32) { 55 /* Reserve some room for "..." string. */ 56 truncated = true; 57 } else if (c == '\\') { 58 *cp++ = '\\'; 59 *cp++ = '\\'; 60 } else if (c > ' ' && c < 127) { 61 *cp++ = c; 62 } else if (!c) { 63 *cp++ = '"'; 64 *cp++ = ' '; 65 last_start = cp; 66 } else { 67 *cp++ = '\\'; 68 *cp++ = (c >> 6) + '0'; 69 *cp++ = ((c >> 3) & 7) + '0'; 70 *cp++ = (c & 7) + '0'; 71 } 72 if (c) 73 continue; 74 if (argv_count) { 75 if (--argv_count == 0) { 76 if (truncated) { 77 cp = last_start; 78 memmove(cp, "... ", 4); 79 cp += 4; 80 } 81 memmove(cp, "} envp[]={ ", 11); 82 cp += 11; 83 last_start = cp; 84 truncated = false; 85 } 86 } else if (envp_count) { 87 if (--envp_count == 0) { 88 if (truncated) { 89 cp = last_start; 90 memmove(cp, "... ", 4); 91 cp += 4; 92 } 93 } 94 } 95 if (!argv_count && !envp_count) 96 break; 97 } 98 offset = 0; 99 } 100 *cp++ = '}'; 101 *cp = '\0'; 102 return buffer; 103 out: 104 snprintf(buffer, tomoyo_buffer_len - 1, 105 "argv[]={ ... } envp[]= { ... }"); 106 return buffer; 107 } 108 109 /** 110 * tomoyo_filetype - Get string representation of file type. 111 * 112 * @mode: Mode value for stat(). 113 * 114 * Returns file type string. 115 */ 116 static inline const char *tomoyo_filetype(const umode_t mode) 117 { 118 switch (mode & S_IFMT) { 119 case S_IFREG: 120 case 0: 121 return tomoyo_condition_keyword[TOMOYO_TYPE_IS_FILE]; 122 case S_IFDIR: 123 return tomoyo_condition_keyword[TOMOYO_TYPE_IS_DIRECTORY]; 124 case S_IFLNK: 125 return tomoyo_condition_keyword[TOMOYO_TYPE_IS_SYMLINK]; 126 case S_IFIFO: 127 return tomoyo_condition_keyword[TOMOYO_TYPE_IS_FIFO]; 128 case S_IFSOCK: 129 return tomoyo_condition_keyword[TOMOYO_TYPE_IS_SOCKET]; 130 case S_IFBLK: 131 return tomoyo_condition_keyword[TOMOYO_TYPE_IS_BLOCK_DEV]; 132 case S_IFCHR: 133 return tomoyo_condition_keyword[TOMOYO_TYPE_IS_CHAR_DEV]; 134 } 135 return "unknown"; /* This should not happen. */ 136 } 137 138 /** 139 * tomoyo_print_header - Get header line of audit log. 140 * 141 * @r: Pointer to "struct tomoyo_request_info". 142 * 143 * Returns string representation. 144 * 145 * This function uses kmalloc(), so caller must kfree() if this function 146 * didn't return NULL. 147 */ 148 static char *tomoyo_print_header(struct tomoyo_request_info *r) 149 { 150 struct tomoyo_time stamp; 151 const pid_t gpid = task_pid_nr(current); 152 struct tomoyo_obj_info *obj = r->obj; 153 static const int tomoyo_buffer_len = 4096; 154 char *buffer = kmalloc(tomoyo_buffer_len, GFP_NOFS); 155 int pos; 156 u8 i; 157 if (!buffer) 158 return NULL; 159 160 tomoyo_convert_time(ktime_get_real_seconds(), &stamp); 161 162 pos = snprintf(buffer, tomoyo_buffer_len - 1, 163 "#%04u/%02u/%02u %02u:%02u:%02u# profile=%u mode=%s " 164 "granted=%s (global-pid=%u) task={ pid=%u ppid=%u " 165 "uid=%u gid=%u euid=%u egid=%u suid=%u sgid=%u " 166 "fsuid=%u fsgid=%u }", stamp.year, stamp.month, 167 stamp.day, stamp.hour, stamp.min, stamp.sec, r->profile, 168 tomoyo_mode[r->mode], tomoyo_yesno(r->granted), gpid, 169 tomoyo_sys_getpid(), tomoyo_sys_getppid(), 170 from_kuid(&init_user_ns, current_uid()), 171 from_kgid(&init_user_ns, current_gid()), 172 from_kuid(&init_user_ns, current_euid()), 173 from_kgid(&init_user_ns, current_egid()), 174 from_kuid(&init_user_ns, current_suid()), 175 from_kgid(&init_user_ns, current_sgid()), 176 from_kuid(&init_user_ns, current_fsuid()), 177 from_kgid(&init_user_ns, current_fsgid())); 178 if (!obj) 179 goto no_obj_info; 180 if (!obj->validate_done) { 181 tomoyo_get_attributes(obj); 182 obj->validate_done = true; 183 } 184 for (i = 0; i < TOMOYO_MAX_PATH_STAT; i++) { 185 struct tomoyo_mini_stat *stat; 186 unsigned int dev; 187 umode_t mode; 188 if (!obj->stat_valid[i]) 189 continue; 190 stat = &obj->stat[i]; 191 dev = stat->dev; 192 mode = stat->mode; 193 if (i & 1) { 194 pos += snprintf(buffer + pos, 195 tomoyo_buffer_len - 1 - pos, 196 " path%u.parent={ uid=%u gid=%u " 197 "ino=%lu perm=0%o }", (i >> 1) + 1, 198 from_kuid(&init_user_ns, stat->uid), 199 from_kgid(&init_user_ns, stat->gid), 200 (unsigned long)stat->ino, 201 stat->mode & S_IALLUGO); 202 continue; 203 } 204 pos += snprintf(buffer + pos, tomoyo_buffer_len - 1 - pos, 205 " path%u={ uid=%u gid=%u ino=%lu major=%u" 206 " minor=%u perm=0%o type=%s", (i >> 1) + 1, 207 from_kuid(&init_user_ns, stat->uid), 208 from_kgid(&init_user_ns, stat->gid), 209 (unsigned long)stat->ino, 210 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 header = tomoyo_print_header(r); 253 if (!header) 254 return NULL; 255 /* +10 is for '\n' etc. and '\0'. */ 256 len += strlen(domainname) + strlen(header) + 10; 257 if (r->ee) { 258 struct file *file = r->ee->bprm->file; 259 realpath = tomoyo_realpath_from_path(&file->f_path); 260 bprm_info = tomoyo_print_bprm(r->ee->bprm, &r->ee->dump); 261 if (!realpath || !bprm_info) 262 goto out; 263 /* +80 is for " exec={ realpath=\"%s\" argc=%d envc=%d %s }" */ 264 len += strlen(realpath) + 80 + strlen(bprm_info); 265 } else if (r->obj && r->obj->symlink_target) { 266 symlink = r->obj->symlink_target->name; 267 /* +18 is for " symlink.target=\"%s\"" */ 268 len += 18 + strlen(symlink); 269 } 270 len = tomoyo_round2(len); 271 buf = kzalloc(len, GFP_NOFS); 272 if (!buf) 273 goto out; 274 len--; 275 pos = snprintf(buf, len, "%s", header); 276 if (realpath) { 277 struct linux_binprm *bprm = r->ee->bprm; 278 pos += snprintf(buf + pos, len - pos, 279 " exec={ realpath=\"%s\" argc=%d envc=%d %s }", 280 realpath, bprm->argc, bprm->envc, bprm_info); 281 } else if (symlink) 282 pos += snprintf(buf + pos, len - pos, " symlink.target=\"%s\"", 283 symlink); 284 pos += snprintf(buf + pos, len - pos, "\n%s\n", domainname); 285 vsnprintf(buf + pos, len - pos, fmt, args); 286 out: 287 kfree(realpath); 288 kfree(bprm_info); 289 kfree(header); 290 return buf; 291 } 292 293 /* Wait queue for /sys/kernel/security/tomoyo/audit. */ 294 static DECLARE_WAIT_QUEUE_HEAD(tomoyo_log_wait); 295 296 /* Structure for audit log. */ 297 struct tomoyo_log { 298 struct list_head list; 299 char *log; 300 int size; 301 }; 302 303 /* The list for "struct tomoyo_log". */ 304 static LIST_HEAD(tomoyo_log); 305 306 /* Lock for "struct list_head tomoyo_log". */ 307 static DEFINE_SPINLOCK(tomoyo_log_lock); 308 309 /* Length of "stuct list_head tomoyo_log". */ 310 static unsigned int tomoyo_log_count; 311 312 /** 313 * tomoyo_get_audit - Get audit mode. 314 * 315 * @ns: Pointer to "struct tomoyo_policy_namespace". 316 * @profile: Profile number. 317 * @index: Index number of functionality. 318 * @is_granted: True if granted log, false otherwise. 319 * 320 * Returns true if this request should be audited, false otherwise. 321 */ 322 static bool tomoyo_get_audit(const struct tomoyo_policy_namespace *ns, 323 const u8 profile, const u8 index, 324 const struct tomoyo_acl_info *matched_acl, 325 const bool is_granted) 326 { 327 u8 mode; 328 const u8 category = tomoyo_index2category[index] + 329 TOMOYO_MAX_MAC_INDEX; 330 struct tomoyo_profile *p; 331 if (!tomoyo_policy_loaded) 332 return false; 333 p = tomoyo_profile(ns, profile); 334 if (tomoyo_log_count >= p->pref[TOMOYO_PREF_MAX_AUDIT_LOG]) 335 return false; 336 if (is_granted && matched_acl && matched_acl->cond && 337 matched_acl->cond->grant_log != TOMOYO_GRANTLOG_AUTO) 338 return matched_acl->cond->grant_log == TOMOYO_GRANTLOG_YES; 339 mode = p->config[index]; 340 if (mode == TOMOYO_CONFIG_USE_DEFAULT) 341 mode = p->config[category]; 342 if (mode == TOMOYO_CONFIG_USE_DEFAULT) 343 mode = p->default_config; 344 if (is_granted) 345 return mode & TOMOYO_CONFIG_WANT_GRANT_LOG; 346 return mode & TOMOYO_CONFIG_WANT_REJECT_LOG; 347 } 348 349 /** 350 * tomoyo_write_log2 - Write an audit log. 351 * 352 * @r: Pointer to "struct tomoyo_request_info". 353 * @len: Buffer size needed for @fmt and @args. 354 * @fmt: The printf()'s format string. 355 * @args: va_list structure for @fmt. 356 * 357 * Returns nothing. 358 */ 359 void tomoyo_write_log2(struct tomoyo_request_info *r, int len, const char *fmt, 360 va_list args) 361 { 362 char *buf; 363 struct tomoyo_log *entry; 364 bool quota_exceeded = false; 365 if (!tomoyo_get_audit(r->domain->ns, r->profile, r->type, 366 r->matched_acl, r->granted)) 367 goto out; 368 buf = tomoyo_init_log(r, len, fmt, args); 369 if (!buf) 370 goto out; 371 entry = kzalloc(sizeof(*entry), GFP_NOFS); 372 if (!entry) { 373 kfree(buf); 374 goto out; 375 } 376 entry->log = buf; 377 len = tomoyo_round2(strlen(buf) + 1); 378 /* 379 * The entry->size is used for memory quota checks. 380 * Don't go beyond strlen(entry->log). 381 */ 382 entry->size = len + tomoyo_round2(sizeof(*entry)); 383 spin_lock(&tomoyo_log_lock); 384 if (tomoyo_memory_quota[TOMOYO_MEMORY_AUDIT] && 385 tomoyo_memory_used[TOMOYO_MEMORY_AUDIT] + entry->size >= 386 tomoyo_memory_quota[TOMOYO_MEMORY_AUDIT]) { 387 quota_exceeded = true; 388 } else { 389 tomoyo_memory_used[TOMOYO_MEMORY_AUDIT] += entry->size; 390 list_add_tail(&entry->list, &tomoyo_log); 391 tomoyo_log_count++; 392 } 393 spin_unlock(&tomoyo_log_lock); 394 if (quota_exceeded) { 395 kfree(buf); 396 kfree(entry); 397 goto out; 398 } 399 wake_up(&tomoyo_log_wait); 400 out: 401 return; 402 } 403 404 /** 405 * tomoyo_write_log - Write an audit log. 406 * 407 * @r: Pointer to "struct tomoyo_request_info". 408 * @fmt: The printf()'s format string, followed by parameters. 409 * 410 * Returns nothing. 411 */ 412 void tomoyo_write_log(struct tomoyo_request_info *r, const char *fmt, ...) 413 { 414 va_list args; 415 int len; 416 va_start(args, fmt); 417 len = vsnprintf((char *) &len, 1, fmt, args) + 1; 418 va_end(args); 419 va_start(args, fmt); 420 tomoyo_write_log2(r, len, fmt, args); 421 va_end(args); 422 } 423 424 /** 425 * tomoyo_read_log - Read an audit log. 426 * 427 * @head: Pointer to "struct tomoyo_io_buffer". 428 * 429 * Returns nothing. 430 */ 431 void tomoyo_read_log(struct tomoyo_io_buffer *head) 432 { 433 struct tomoyo_log *ptr = NULL; 434 if (head->r.w_pos) 435 return; 436 kfree(head->read_buf); 437 head->read_buf = NULL; 438 spin_lock(&tomoyo_log_lock); 439 if (!list_empty(&tomoyo_log)) { 440 ptr = list_entry(tomoyo_log.next, typeof(*ptr), list); 441 list_del(&ptr->list); 442 tomoyo_log_count--; 443 tomoyo_memory_used[TOMOYO_MEMORY_AUDIT] -= ptr->size; 444 } 445 spin_unlock(&tomoyo_log_lock); 446 if (ptr) { 447 head->read_buf = ptr->log; 448 head->r.w[head->r.w_pos++] = head->read_buf; 449 kfree(ptr); 450 } 451 } 452 453 /** 454 * tomoyo_poll_log - Wait for an audit log. 455 * 456 * @file: Pointer to "struct file". 457 * @wait: Pointer to "poll_table". Maybe NULL. 458 * 459 * Returns EPOLLIN | EPOLLRDNORM when ready to read an audit log. 460 */ 461 __poll_t tomoyo_poll_log(struct file *file, poll_table *wait) 462 { 463 if (tomoyo_log_count) 464 return EPOLLIN | EPOLLRDNORM; 465 poll_wait(file, &tomoyo_log_wait, wait); 466 if (tomoyo_log_count) 467 return EPOLLIN | EPOLLRDNORM; 468 return 0; 469 } 470