audit.c revision d179333f37d33533f4c77118f757b9e7835ccb7c
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 */ 21static 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; 102out: 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 */ 115static 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 */ 147static 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 current_uid(), current_gid(), current_euid(), 172 current_egid(), current_suid(), current_sgid(), 173 current_fsuid(), current_fsgid()); 174 if (!obj) 175 goto no_obj_info; 176 if (!obj->validate_done) { 177 tomoyo_get_attributes(obj); 178 obj->validate_done = true; 179 } 180 for (i = 0; i < TOMOYO_MAX_PATH_STAT; i++) { 181 struct tomoyo_mini_stat *stat; 182 unsigned int dev; 183 umode_t mode; 184 if (!obj->stat_valid[i]) 185 continue; 186 stat = &obj->stat[i]; 187 dev = stat->dev; 188 mode = stat->mode; 189 if (i & 1) { 190 pos += snprintf(buffer + pos, 191 tomoyo_buffer_len - 1 - pos, 192 " path%u.parent={ uid=%u gid=%u " 193 "ino=%lu perm=0%o }", (i >> 1) + 1, 194 stat->uid, stat->gid, (unsigned long) 195 stat->ino, stat->mode & S_IALLUGO); 196 continue; 197 } 198 pos += snprintf(buffer + pos, tomoyo_buffer_len - 1 - pos, 199 " path%u={ uid=%u gid=%u ino=%lu major=%u" 200 " minor=%u perm=0%o type=%s", (i >> 1) + 1, 201 stat->uid, stat->gid, (unsigned long) 202 stat->ino, MAJOR(dev), MINOR(dev), 203 mode & S_IALLUGO, tomoyo_filetype(mode)); 204 if (S_ISCHR(mode) || S_ISBLK(mode)) { 205 dev = stat->rdev; 206 pos += snprintf(buffer + pos, 207 tomoyo_buffer_len - 1 - pos, 208 " dev_major=%u dev_minor=%u", 209 MAJOR(dev), MINOR(dev)); 210 } 211 pos += snprintf(buffer + pos, tomoyo_buffer_len - 1 - pos, 212 " }"); 213 } 214no_obj_info: 215 if (pos < tomoyo_buffer_len - 1) 216 return buffer; 217 kfree(buffer); 218 return NULL; 219} 220 221/** 222 * tomoyo_init_log - Allocate buffer for audit logs. 223 * 224 * @r: Pointer to "struct tomoyo_request_info". 225 * @len: Buffer size needed for @fmt and @args. 226 * @fmt: The printf()'s format string. 227 * @args: va_list structure for @fmt. 228 * 229 * Returns pointer to allocated memory. 230 * 231 * This function uses kzalloc(), so caller must kfree() if this function 232 * didn't return NULL. 233 */ 234char *tomoyo_init_log(struct tomoyo_request_info *r, int len, const char *fmt, 235 va_list args) 236{ 237 char *buf = NULL; 238 char *bprm_info = NULL; 239 const char *header = NULL; 240 char *realpath = NULL; 241 const char *symlink = NULL; 242 int pos; 243 const char *domainname = r->domain->domainname->name; 244 header = tomoyo_print_header(r); 245 if (!header) 246 return NULL; 247 /* +10 is for '\n' etc. and '\0'. */ 248 len += strlen(domainname) + strlen(header) + 10; 249 if (r->ee) { 250 struct file *file = r->ee->bprm->file; 251 realpath = tomoyo_realpath_from_path(&file->f_path); 252 bprm_info = tomoyo_print_bprm(r->ee->bprm, &r->ee->dump); 253 if (!realpath || !bprm_info) 254 goto out; 255 /* +80 is for " exec={ realpath=\"%s\" argc=%d envc=%d %s }" */ 256 len += strlen(realpath) + 80 + strlen(bprm_info); 257 } else if (r->obj && r->obj->symlink_target) { 258 symlink = r->obj->symlink_target->name; 259 /* +18 is for " symlink.target=\"%s\"" */ 260 len += 18 + strlen(symlink); 261 } 262 len = tomoyo_round2(len); 263 buf = kzalloc(len, GFP_NOFS); 264 if (!buf) 265 goto out; 266 len--; 267 pos = snprintf(buf, len, "%s", header); 268 if (realpath) { 269 struct linux_binprm *bprm = r->ee->bprm; 270 pos += snprintf(buf + pos, len - pos, 271 " exec={ realpath=\"%s\" argc=%d envc=%d %s }", 272 realpath, bprm->argc, bprm->envc, bprm_info); 273 } else if (symlink) 274 pos += snprintf(buf + pos, len - pos, " symlink.target=\"%s\"", 275 symlink); 276 pos += snprintf(buf + pos, len - pos, "\n%s\n", domainname); 277 vsnprintf(buf + pos, len - pos, fmt, args); 278out: 279 kfree(realpath); 280 kfree(bprm_info); 281 kfree(header); 282 return buf; 283} 284 285/* Wait queue for /sys/kernel/security/tomoyo/audit. */ 286static DECLARE_WAIT_QUEUE_HEAD(tomoyo_log_wait); 287 288/* Structure for audit log. */ 289struct tomoyo_log { 290 struct list_head list; 291 char *log; 292 int size; 293}; 294 295/* The list for "struct tomoyo_log". */ 296static LIST_HEAD(tomoyo_log); 297 298/* Lock for "struct list_head tomoyo_log". */ 299static DEFINE_SPINLOCK(tomoyo_log_lock); 300 301/* Length of "stuct list_head tomoyo_log". */ 302static unsigned int tomoyo_log_count; 303 304/** 305 * tomoyo_get_audit - Get audit mode. 306 * 307 * @ns: Pointer to "struct tomoyo_policy_namespace". 308 * @profile: Profile number. 309 * @index: Index number of functionality. 310 * @is_granted: True if granted log, false otherwise. 311 * 312 * Returns true if this request should be audited, false otherwise. 313 */ 314static bool tomoyo_get_audit(const struct tomoyo_policy_namespace *ns, 315 const u8 profile, const u8 index, 316 const struct tomoyo_acl_info *matched_acl, 317 const bool is_granted) 318{ 319 u8 mode; 320 const u8 category = tomoyo_index2category[index] + 321 TOMOYO_MAX_MAC_INDEX; 322 struct tomoyo_profile *p; 323 if (!tomoyo_policy_loaded) 324 return false; 325 p = tomoyo_profile(ns, profile); 326 if (tomoyo_log_count >= p->pref[TOMOYO_PREF_MAX_AUDIT_LOG]) 327 return false; 328 if (is_granted && matched_acl && matched_acl->cond && 329 matched_acl->cond->grant_log != TOMOYO_GRANTLOG_AUTO) 330 return matched_acl->cond->grant_log == TOMOYO_GRANTLOG_YES; 331 mode = p->config[index]; 332 if (mode == TOMOYO_CONFIG_USE_DEFAULT) 333 mode = p->config[category]; 334 if (mode == TOMOYO_CONFIG_USE_DEFAULT) 335 mode = p->default_config; 336 if (is_granted) 337 return mode & TOMOYO_CONFIG_WANT_GRANT_LOG; 338 return mode & TOMOYO_CONFIG_WANT_REJECT_LOG; 339} 340 341/** 342 * tomoyo_write_log2 - Write an audit log. 343 * 344 * @r: Pointer to "struct tomoyo_request_info". 345 * @len: Buffer size needed for @fmt and @args. 346 * @fmt: The printf()'s format string. 347 * @args: va_list structure for @fmt. 348 * 349 * Returns nothing. 350 */ 351void tomoyo_write_log2(struct tomoyo_request_info *r, int len, const char *fmt, 352 va_list args) 353{ 354 char *buf; 355 struct tomoyo_log *entry; 356 bool quota_exceeded = false; 357 if (!tomoyo_get_audit(r->domain->ns, r->profile, r->type, 358 r->matched_acl, r->granted)) 359 goto out; 360 buf = tomoyo_init_log(r, len, fmt, args); 361 if (!buf) 362 goto out; 363 entry = kzalloc(sizeof(*entry), GFP_NOFS); 364 if (!entry) { 365 kfree(buf); 366 goto out; 367 } 368 entry->log = buf; 369 len = tomoyo_round2(strlen(buf) + 1); 370 /* 371 * The entry->size is used for memory quota checks. 372 * Don't go beyond strlen(entry->log). 373 */ 374 entry->size = len + tomoyo_round2(sizeof(*entry)); 375 spin_lock(&tomoyo_log_lock); 376 if (tomoyo_memory_quota[TOMOYO_MEMORY_AUDIT] && 377 tomoyo_memory_used[TOMOYO_MEMORY_AUDIT] + entry->size >= 378 tomoyo_memory_quota[TOMOYO_MEMORY_AUDIT]) { 379 quota_exceeded = true; 380 } else { 381 tomoyo_memory_used[TOMOYO_MEMORY_AUDIT] += entry->size; 382 list_add_tail(&entry->list, &tomoyo_log); 383 tomoyo_log_count++; 384 } 385 spin_unlock(&tomoyo_log_lock); 386 if (quota_exceeded) { 387 kfree(buf); 388 kfree(entry); 389 goto out; 390 } 391 wake_up(&tomoyo_log_wait); 392out: 393 return; 394} 395 396/** 397 * tomoyo_write_log - Write an audit log. 398 * 399 * @r: Pointer to "struct tomoyo_request_info". 400 * @fmt: The printf()'s format string, followed by parameters. 401 * 402 * Returns nothing. 403 */ 404void tomoyo_write_log(struct tomoyo_request_info *r, const char *fmt, ...) 405{ 406 va_list args; 407 int len; 408 va_start(args, fmt); 409 len = vsnprintf((char *) &len, 1, fmt, args) + 1; 410 va_end(args); 411 va_start(args, fmt); 412 tomoyo_write_log2(r, len, fmt, args); 413 va_end(args); 414} 415 416/** 417 * tomoyo_read_log - Read an audit log. 418 * 419 * @head: Pointer to "struct tomoyo_io_buffer". 420 * 421 * Returns nothing. 422 */ 423void tomoyo_read_log(struct tomoyo_io_buffer *head) 424{ 425 struct tomoyo_log *ptr = NULL; 426 if (head->r.w_pos) 427 return; 428 kfree(head->read_buf); 429 head->read_buf = NULL; 430 spin_lock(&tomoyo_log_lock); 431 if (!list_empty(&tomoyo_log)) { 432 ptr = list_entry(tomoyo_log.next, typeof(*ptr), list); 433 list_del(&ptr->list); 434 tomoyo_log_count--; 435 tomoyo_memory_used[TOMOYO_MEMORY_AUDIT] -= ptr->size; 436 } 437 spin_unlock(&tomoyo_log_lock); 438 if (ptr) { 439 head->read_buf = ptr->log; 440 head->r.w[head->r.w_pos++] = head->read_buf; 441 kfree(ptr); 442 } 443} 444 445/** 446 * tomoyo_poll_log - Wait for an audit log. 447 * 448 * @file: Pointer to "struct file". 449 * @wait: Pointer to "poll_table". 450 * 451 * Returns POLLIN | POLLRDNORM when ready to read an audit log. 452 */ 453int tomoyo_poll_log(struct file *file, poll_table *wait) 454{ 455 if (tomoyo_log_count) 456 return POLLIN | POLLRDNORM; 457 poll_wait(file, &tomoyo_log_wait, wait); 458 if (tomoyo_log_count) 459 return POLLIN | POLLRDNORM; 460 return 0; 461} 462