1 //===-- dfsan.cpp ---------------------------------------------------------===// 2 // 3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. 4 // See https://llvm.org/LICENSE.txt for license information. 5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception 6 // 7 //===----------------------------------------------------------------------===// 8 // 9 // This file is a part of DataFlowSanitizer. 10 // 11 // This file defines the custom functions listed in done_abilist.txt. 12 //===----------------------------------------------------------------------===// 13 14 #include "sanitizer_common/sanitizer_common.h" 15 #include "sanitizer_common/sanitizer_internal_defs.h" 16 #include "sanitizer_common/sanitizer_linux.h" 17 18 #include "dfsan/dfsan.h" 19 20 #include <arpa/inet.h> 21 #include <assert.h> 22 #include <ctype.h> 23 #include <dlfcn.h> 24 #include <link.h> 25 #include <poll.h> 26 #include <pthread.h> 27 #include <pwd.h> 28 #include <sched.h> 29 #include <signal.h> 30 #include <stdarg.h> 31 #include <stdint.h> 32 #include <stdio.h> 33 #include <stdlib.h> 34 #include <string.h> 35 #include <sys/resource.h> 36 #include <sys/select.h> 37 #include <sys/stat.h> 38 #include <sys/time.h> 39 #include <sys/types.h> 40 #include <time.h> 41 #include <unistd.h> 42 43 using namespace __dfsan; 44 45 #define CALL_WEAK_INTERCEPTOR_HOOK(f, ...) \ 46 do { \ 47 if (f) \ 48 f(__VA_ARGS__); \ 49 } while (false) 50 #define DECLARE_WEAK_INTERCEPTOR_HOOK(f, ...) \ 51 SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE void f(__VA_ARGS__); 52 53 extern "C" { 54 SANITIZER_INTERFACE_ATTRIBUTE int 55 __dfsw_stat(const char *path, struct stat *buf, dfsan_label path_label, 56 dfsan_label buf_label, dfsan_label *ret_label) { 57 int ret = stat(path, buf); 58 if (ret == 0) 59 dfsan_set_label(0, buf, sizeof(struct stat)); 60 *ret_label = 0; 61 return ret; 62 } 63 64 SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_fstat(int fd, struct stat *buf, 65 dfsan_label fd_label, 66 dfsan_label buf_label, 67 dfsan_label *ret_label) { 68 int ret = fstat(fd, buf); 69 if (ret == 0) 70 dfsan_set_label(0, buf, sizeof(struct stat)); 71 *ret_label = 0; 72 return ret; 73 } 74 75 SANITIZER_INTERFACE_ATTRIBUTE char *__dfsw_strchr(const char *s, int c, 76 dfsan_label s_label, 77 dfsan_label c_label, 78 dfsan_label *ret_label) { 79 for (size_t i = 0;; ++i) { 80 if (s[i] == c || s[i] == 0) { 81 if (flags().strict_data_dependencies) { 82 *ret_label = s_label; 83 } else { 84 *ret_label = dfsan_union(dfsan_read_label(s, i + 1), 85 dfsan_union(s_label, c_label)); 86 } 87 88 // If s[i] is the \0 at the end of the string, and \0 is not the 89 // character we are searching for, then return null. 90 if (s[i] == 0 && c != 0) { 91 return nullptr; 92 } 93 return const_cast<char *>(s + i); 94 } 95 } 96 } 97 98 SANITIZER_INTERFACE_ATTRIBUTE char *__dfsw_strpbrk(const char *s, 99 const char *accept, 100 dfsan_label s_label, 101 dfsan_label accept_label, 102 dfsan_label *ret_label) { 103 const char *ret = strpbrk(s, accept); 104 if (flags().strict_data_dependencies) { 105 *ret_label = ret ? s_label : 0; 106 } else { 107 size_t s_bytes_read = (ret ? ret - s : strlen(s)) + 1; 108 *ret_label = 109 dfsan_union(dfsan_read_label(s, s_bytes_read), 110 dfsan_union(dfsan_read_label(accept, strlen(accept) + 1), 111 dfsan_union(s_label, accept_label))); 112 } 113 return const_cast<char *>(ret); 114 } 115 116 static int dfsan_memcmp_bcmp(const void *s1, const void *s2, size_t n, 117 dfsan_label s1_label, dfsan_label s2_label, 118 dfsan_label n_label, dfsan_label *ret_label) { 119 const char *cs1 = (const char *) s1, *cs2 = (const char *) s2; 120 for (size_t i = 0; i != n; ++i) { 121 if (cs1[i] != cs2[i]) { 122 if (flags().strict_data_dependencies) { 123 *ret_label = 0; 124 } else { 125 *ret_label = dfsan_union(dfsan_read_label(cs1, i + 1), 126 dfsan_read_label(cs2, i + 1)); 127 } 128 return cs1[i] - cs2[i]; 129 } 130 } 131 132 if (flags().strict_data_dependencies) { 133 *ret_label = 0; 134 } else { 135 *ret_label = dfsan_union(dfsan_read_label(cs1, n), 136 dfsan_read_label(cs2, n)); 137 } 138 return 0; 139 } 140 141 DECLARE_WEAK_INTERCEPTOR_HOOK(dfsan_weak_hook_memcmp, uptr caller_pc, 142 const void *s1, const void *s2, size_t n, 143 dfsan_label s1_label, dfsan_label s2_label, 144 dfsan_label n_label) 145 146 SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_memcmp(const void *s1, const void *s2, 147 size_t n, dfsan_label s1_label, 148 dfsan_label s2_label, 149 dfsan_label n_label, 150 dfsan_label *ret_label) { 151 CALL_WEAK_INTERCEPTOR_HOOK(dfsan_weak_hook_memcmp, GET_CALLER_PC(), s1, s2, n, 152 s1_label, s2_label, n_label); 153 return dfsan_memcmp_bcmp(s1, s2, n, s1_label, s2_label, n_label, ret_label); 154 } 155 156 SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_bcmp(const void *s1, const void *s2, 157 size_t n, dfsan_label s1_label, 158 dfsan_label s2_label, 159 dfsan_label n_label, 160 dfsan_label *ret_label) { 161 return dfsan_memcmp_bcmp(s1, s2, n, s1_label, s2_label, n_label, ret_label); 162 } 163 164 DECLARE_WEAK_INTERCEPTOR_HOOK(dfsan_weak_hook_strcmp, uptr caller_pc, 165 const char *s1, const char *s2, 166 dfsan_label s1_label, dfsan_label s2_label) 167 168 SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_strcmp(const char *s1, const char *s2, 169 dfsan_label s1_label, 170 dfsan_label s2_label, 171 dfsan_label *ret_label) { 172 CALL_WEAK_INTERCEPTOR_HOOK(dfsan_weak_hook_strcmp, GET_CALLER_PC(), s1, s2, 173 s1_label, s2_label); 174 for (size_t i = 0;; ++i) { 175 if (s1[i] != s2[i] || s1[i] == 0 || s2[i] == 0) { 176 if (flags().strict_data_dependencies) { 177 *ret_label = 0; 178 } else { 179 *ret_label = dfsan_union(dfsan_read_label(s1, i + 1), 180 dfsan_read_label(s2, i + 1)); 181 } 182 return s1[i] - s2[i]; 183 } 184 } 185 return 0; 186 } 187 188 SANITIZER_INTERFACE_ATTRIBUTE int 189 __dfsw_strcasecmp(const char *s1, const char *s2, dfsan_label s1_label, 190 dfsan_label s2_label, dfsan_label *ret_label) { 191 for (size_t i = 0;; ++i) { 192 char s1_lower = tolower(s1[i]); 193 char s2_lower = tolower(s2[i]); 194 195 if (s1_lower != s2_lower || s1[i] == 0 || s2[i] == 0) { 196 if (flags().strict_data_dependencies) { 197 *ret_label = 0; 198 } else { 199 *ret_label = dfsan_union(dfsan_read_label(s1, i + 1), 200 dfsan_read_label(s2, i + 1)); 201 } 202 return s1_lower - s2_lower; 203 } 204 } 205 return 0; 206 } 207 208 DECLARE_WEAK_INTERCEPTOR_HOOK(dfsan_weak_hook_strncmp, uptr caller_pc, 209 const char *s1, const char *s2, size_t n, 210 dfsan_label s1_label, dfsan_label s2_label, 211 dfsan_label n_label) 212 213 SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_strncmp(const char *s1, const char *s2, 214 size_t n, dfsan_label s1_label, 215 dfsan_label s2_label, 216 dfsan_label n_label, 217 dfsan_label *ret_label) { 218 if (n == 0) { 219 *ret_label = 0; 220 return 0; 221 } 222 223 CALL_WEAK_INTERCEPTOR_HOOK(dfsan_weak_hook_strncmp, GET_CALLER_PC(), s1, s2, 224 n, s1_label, s2_label, n_label); 225 226 for (size_t i = 0;; ++i) { 227 if (s1[i] != s2[i] || s1[i] == 0 || s2[i] == 0 || i == n - 1) { 228 if (flags().strict_data_dependencies) { 229 *ret_label = 0; 230 } else { 231 *ret_label = dfsan_union(dfsan_read_label(s1, i + 1), 232 dfsan_read_label(s2, i + 1)); 233 } 234 return s1[i] - s2[i]; 235 } 236 } 237 return 0; 238 } 239 240 SANITIZER_INTERFACE_ATTRIBUTE int 241 __dfsw_strncasecmp(const char *s1, const char *s2, size_t n, 242 dfsan_label s1_label, dfsan_label s2_label, 243 dfsan_label n_label, dfsan_label *ret_label) { 244 if (n == 0) { 245 *ret_label = 0; 246 return 0; 247 } 248 249 for (size_t i = 0;; ++i) { 250 char s1_lower = tolower(s1[i]); 251 char s2_lower = tolower(s2[i]); 252 253 if (s1_lower != s2_lower || s1[i] == 0 || s2[i] == 0 || i == n - 1) { 254 if (flags().strict_data_dependencies) { 255 *ret_label = 0; 256 } else { 257 *ret_label = dfsan_union(dfsan_read_label(s1, i + 1), 258 dfsan_read_label(s2, i + 1)); 259 } 260 return s1_lower - s2_lower; 261 } 262 } 263 return 0; 264 } 265 266 SANITIZER_INTERFACE_ATTRIBUTE void *__dfsw_calloc(size_t nmemb, size_t size, 267 dfsan_label nmemb_label, 268 dfsan_label size_label, 269 dfsan_label *ret_label) { 270 void *p = calloc(nmemb, size); 271 dfsan_set_label(0, p, nmemb * size); 272 *ret_label = 0; 273 return p; 274 } 275 276 SANITIZER_INTERFACE_ATTRIBUTE size_t 277 __dfsw_strlen(const char *s, dfsan_label s_label, dfsan_label *ret_label) { 278 size_t ret = strlen(s); 279 if (flags().strict_data_dependencies) { 280 *ret_label = 0; 281 } else { 282 *ret_label = dfsan_read_label(s, ret + 1); 283 } 284 return ret; 285 } 286 287 288 static void *dfsan_memcpy(void *dest, const void *src, size_t n) { 289 dfsan_label *sdest = shadow_for(dest); 290 const dfsan_label *ssrc = shadow_for(src); 291 internal_memcpy((void *)sdest, (const void *)ssrc, n * sizeof(dfsan_label)); 292 return internal_memcpy(dest, src, n); 293 } 294 295 static void dfsan_memset(void *s, int c, dfsan_label c_label, size_t n) { 296 internal_memset(s, c, n); 297 dfsan_set_label(c_label, s, n); 298 } 299 300 SANITIZER_INTERFACE_ATTRIBUTE 301 void *__dfsw_memcpy(void *dest, const void *src, size_t n, 302 dfsan_label dest_label, dfsan_label src_label, 303 dfsan_label n_label, dfsan_label *ret_label) { 304 *ret_label = dest_label; 305 return dfsan_memcpy(dest, src, n); 306 } 307 308 SANITIZER_INTERFACE_ATTRIBUTE 309 void *__dfsw_memset(void *s, int c, size_t n, 310 dfsan_label s_label, dfsan_label c_label, 311 dfsan_label n_label, dfsan_label *ret_label) { 312 dfsan_memset(s, c, c_label, n); 313 *ret_label = s_label; 314 return s; 315 } 316 317 SANITIZER_INTERFACE_ATTRIBUTE char * 318 __dfsw_strdup(const char *s, dfsan_label s_label, dfsan_label *ret_label) { 319 size_t len = strlen(s); 320 void *p = malloc(len+1); 321 dfsan_memcpy(p, s, len+1); 322 *ret_label = 0; 323 return static_cast<char *>(p); 324 } 325 326 SANITIZER_INTERFACE_ATTRIBUTE char * 327 __dfsw_strncpy(char *s1, const char *s2, size_t n, dfsan_label s1_label, 328 dfsan_label s2_label, dfsan_label n_label, 329 dfsan_label *ret_label) { 330 size_t len = strlen(s2); 331 if (len < n) { 332 dfsan_memcpy(s1, s2, len+1); 333 dfsan_memset(s1+len+1, 0, 0, n-len-1); 334 } else { 335 dfsan_memcpy(s1, s2, n); 336 } 337 338 *ret_label = s1_label; 339 return s1; 340 } 341 342 SANITIZER_INTERFACE_ATTRIBUTE ssize_t 343 __dfsw_pread(int fd, void *buf, size_t count, off_t offset, 344 dfsan_label fd_label, dfsan_label buf_label, 345 dfsan_label count_label, dfsan_label offset_label, 346 dfsan_label *ret_label) { 347 ssize_t ret = pread(fd, buf, count, offset); 348 if (ret > 0) 349 dfsan_set_label(0, buf, ret); 350 *ret_label = 0; 351 return ret; 352 } 353 354 SANITIZER_INTERFACE_ATTRIBUTE ssize_t 355 __dfsw_read(int fd, void *buf, size_t count, 356 dfsan_label fd_label, dfsan_label buf_label, 357 dfsan_label count_label, 358 dfsan_label *ret_label) { 359 ssize_t ret = read(fd, buf, count); 360 if (ret > 0) 361 dfsan_set_label(0, buf, ret); 362 *ret_label = 0; 363 return ret; 364 } 365 366 SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_clock_gettime(clockid_t clk_id, 367 struct timespec *tp, 368 dfsan_label clk_id_label, 369 dfsan_label tp_label, 370 dfsan_label *ret_label) { 371 int ret = clock_gettime(clk_id, tp); 372 if (ret == 0) 373 dfsan_set_label(0, tp, sizeof(struct timespec)); 374 *ret_label = 0; 375 return ret; 376 } 377 378 static void unpoison(const void *ptr, uptr size) { 379 dfsan_set_label(0, const_cast<void *>(ptr), size); 380 } 381 382 // dlopen() ultimately calls mmap() down inside the loader, which generally 383 // doesn't participate in dynamic symbol resolution. Therefore we won't 384 // intercept its calls to mmap, and we have to hook it here. 385 SANITIZER_INTERFACE_ATTRIBUTE void * 386 __dfsw_dlopen(const char *filename, int flag, dfsan_label filename_label, 387 dfsan_label flag_label, dfsan_label *ret_label) { 388 void *handle = dlopen(filename, flag); 389 link_map *map = GET_LINK_MAP_BY_DLOPEN_HANDLE(handle); 390 if (map) 391 ForEachMappedRegion(map, unpoison); 392 *ret_label = 0; 393 return handle; 394 } 395 396 struct pthread_create_info { 397 void *(*start_routine_trampoline)(void *, void *, dfsan_label, dfsan_label *); 398 void *start_routine; 399 void *arg; 400 }; 401 402 static void *pthread_create_cb(void *p) { 403 pthread_create_info pci(*(pthread_create_info *)p); 404 free(p); 405 dfsan_label ret_label; 406 return pci.start_routine_trampoline(pci.start_routine, pci.arg, 0, 407 &ret_label); 408 } 409 410 SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_pthread_create( 411 pthread_t *thread, const pthread_attr_t *attr, 412 void *(*start_routine_trampoline)(void *, void *, dfsan_label, 413 dfsan_label *), 414 void *start_routine, void *arg, dfsan_label thread_label, 415 dfsan_label attr_label, dfsan_label start_routine_label, 416 dfsan_label arg_label, dfsan_label *ret_label) { 417 pthread_create_info *pci = 418 (pthread_create_info *)malloc(sizeof(pthread_create_info)); 419 pci->start_routine_trampoline = start_routine_trampoline; 420 pci->start_routine = start_routine; 421 pci->arg = arg; 422 int rv = pthread_create(thread, attr, pthread_create_cb, (void *)pci); 423 if (rv != 0) 424 free(pci); 425 *ret_label = 0; 426 return rv; 427 } 428 429 struct dl_iterate_phdr_info { 430 int (*callback_trampoline)(void *callback, struct dl_phdr_info *info, 431 size_t size, void *data, dfsan_label info_label, 432 dfsan_label size_label, dfsan_label data_label, 433 dfsan_label *ret_label); 434 void *callback; 435 void *data; 436 }; 437 438 int dl_iterate_phdr_cb(struct dl_phdr_info *info, size_t size, void *data) { 439 dl_iterate_phdr_info *dipi = (dl_iterate_phdr_info *)data; 440 dfsan_set_label(0, *info); 441 dfsan_set_label(0, const_cast<char *>(info->dlpi_name), 442 strlen(info->dlpi_name) + 1); 443 dfsan_set_label( 444 0, const_cast<char *>(reinterpret_cast<const char *>(info->dlpi_phdr)), 445 sizeof(*info->dlpi_phdr) * info->dlpi_phnum); 446 dfsan_label ret_label; 447 return dipi->callback_trampoline(dipi->callback, info, size, dipi->data, 0, 0, 448 0, &ret_label); 449 } 450 451 SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_dl_iterate_phdr( 452 int (*callback_trampoline)(void *callback, struct dl_phdr_info *info, 453 size_t size, void *data, dfsan_label info_label, 454 dfsan_label size_label, dfsan_label data_label, 455 dfsan_label *ret_label), 456 void *callback, void *data, dfsan_label callback_label, 457 dfsan_label data_label, dfsan_label *ret_label) { 458 dl_iterate_phdr_info dipi = { callback_trampoline, callback, data }; 459 *ret_label = 0; 460 return dl_iterate_phdr(dl_iterate_phdr_cb, &dipi); 461 } 462 463 SANITIZER_INTERFACE_ATTRIBUTE 464 char *__dfsw_ctime_r(const time_t *timep, char *buf, dfsan_label timep_label, 465 dfsan_label buf_label, dfsan_label *ret_label) { 466 char *ret = ctime_r(timep, buf); 467 if (ret) { 468 dfsan_set_label(dfsan_read_label(timep, sizeof(time_t)), buf, 469 strlen(buf) + 1); 470 *ret_label = buf_label; 471 } else { 472 *ret_label = 0; 473 } 474 return ret; 475 } 476 477 SANITIZER_INTERFACE_ATTRIBUTE 478 char *__dfsw_fgets(char *s, int size, FILE *stream, dfsan_label s_label, 479 dfsan_label size_label, dfsan_label stream_label, 480 dfsan_label *ret_label) { 481 char *ret = fgets(s, size, stream); 482 if (ret) { 483 dfsan_set_label(0, ret, strlen(ret) + 1); 484 *ret_label = s_label; 485 } else { 486 *ret_label = 0; 487 } 488 return ret; 489 } 490 491 SANITIZER_INTERFACE_ATTRIBUTE 492 char *__dfsw_getcwd(char *buf, size_t size, dfsan_label buf_label, 493 dfsan_label size_label, dfsan_label *ret_label) { 494 char *ret = getcwd(buf, size); 495 if (ret) { 496 dfsan_set_label(0, ret, strlen(ret) + 1); 497 *ret_label = buf_label; 498 } else { 499 *ret_label = 0; 500 } 501 return ret; 502 } 503 504 SANITIZER_INTERFACE_ATTRIBUTE 505 char *__dfsw_get_current_dir_name(dfsan_label *ret_label) { 506 char *ret = get_current_dir_name(); 507 if (ret) { 508 dfsan_set_label(0, ret, strlen(ret) + 1); 509 } 510 *ret_label = 0; 511 return ret; 512 } 513 514 SANITIZER_INTERFACE_ATTRIBUTE 515 int __dfsw_gethostname(char *name, size_t len, dfsan_label name_label, 516 dfsan_label len_label, dfsan_label *ret_label) { 517 int ret = gethostname(name, len); 518 if (ret == 0) { 519 dfsan_set_label(0, name, strlen(name) + 1); 520 } 521 *ret_label = 0; 522 return ret; 523 } 524 525 SANITIZER_INTERFACE_ATTRIBUTE 526 int __dfsw_getrlimit(int resource, struct rlimit *rlim, 527 dfsan_label resource_label, dfsan_label rlim_label, 528 dfsan_label *ret_label) { 529 int ret = getrlimit(resource, rlim); 530 if (ret == 0) { 531 dfsan_set_label(0, rlim, sizeof(struct rlimit)); 532 } 533 *ret_label = 0; 534 return ret; 535 } 536 537 SANITIZER_INTERFACE_ATTRIBUTE 538 int __dfsw_getrusage(int who, struct rusage *usage, dfsan_label who_label, 539 dfsan_label usage_label, dfsan_label *ret_label) { 540 int ret = getrusage(who, usage); 541 if (ret == 0) { 542 dfsan_set_label(0, usage, sizeof(struct rusage)); 543 } 544 *ret_label = 0; 545 return ret; 546 } 547 548 SANITIZER_INTERFACE_ATTRIBUTE 549 char *__dfsw_strcpy(char *dest, const char *src, dfsan_label dst_label, 550 dfsan_label src_label, dfsan_label *ret_label) { 551 char *ret = strcpy(dest, src); // NOLINT 552 if (ret) { 553 internal_memcpy(shadow_for(dest), shadow_for(src), 554 sizeof(dfsan_label) * (strlen(src) + 1)); 555 } 556 *ret_label = dst_label; 557 return ret; 558 } 559 560 SANITIZER_INTERFACE_ATTRIBUTE 561 long int __dfsw_strtol(const char *nptr, char **endptr, int base, 562 dfsan_label nptr_label, dfsan_label endptr_label, 563 dfsan_label base_label, dfsan_label *ret_label) { 564 char *tmp_endptr; 565 long int ret = strtol(nptr, &tmp_endptr, base); 566 if (endptr) { 567 *endptr = tmp_endptr; 568 } 569 if (tmp_endptr > nptr) { 570 // If *tmp_endptr is '\0' include its label as well. 571 *ret_label = dfsan_union( 572 base_label, 573 dfsan_read_label(nptr, tmp_endptr - nptr + (*tmp_endptr ? 0 : 1))); 574 } else { 575 *ret_label = 0; 576 } 577 return ret; 578 } 579 580 SANITIZER_INTERFACE_ATTRIBUTE 581 double __dfsw_strtod(const char *nptr, char **endptr, 582 dfsan_label nptr_label, dfsan_label endptr_label, 583 dfsan_label *ret_label) { 584 char *tmp_endptr; 585 double ret = strtod(nptr, &tmp_endptr); 586 if (endptr) { 587 *endptr = tmp_endptr; 588 } 589 if (tmp_endptr > nptr) { 590 // If *tmp_endptr is '\0' include its label as well. 591 *ret_label = dfsan_read_label( 592 nptr, 593 tmp_endptr - nptr + (*tmp_endptr ? 0 : 1)); 594 } else { 595 *ret_label = 0; 596 } 597 return ret; 598 } 599 600 SANITIZER_INTERFACE_ATTRIBUTE 601 long long int __dfsw_strtoll(const char *nptr, char **endptr, int base, 602 dfsan_label nptr_label, dfsan_label endptr_label, 603 dfsan_label base_label, dfsan_label *ret_label) { 604 char *tmp_endptr; 605 long long int ret = strtoll(nptr, &tmp_endptr, base); 606 if (endptr) { 607 *endptr = tmp_endptr; 608 } 609 if (tmp_endptr > nptr) { 610 // If *tmp_endptr is '\0' include its label as well. 611 *ret_label = dfsan_union( 612 base_label, 613 dfsan_read_label(nptr, tmp_endptr - nptr + (*tmp_endptr ? 0 : 1))); 614 } else { 615 *ret_label = 0; 616 } 617 return ret; 618 } 619 620 SANITIZER_INTERFACE_ATTRIBUTE 621 unsigned long int __dfsw_strtoul(const char *nptr, char **endptr, int base, 622 dfsan_label nptr_label, dfsan_label endptr_label, 623 dfsan_label base_label, dfsan_label *ret_label) { 624 char *tmp_endptr; 625 unsigned long int ret = strtoul(nptr, &tmp_endptr, base); 626 if (endptr) { 627 *endptr = tmp_endptr; 628 } 629 if (tmp_endptr > nptr) { 630 // If *tmp_endptr is '\0' include its label as well. 631 *ret_label = dfsan_union( 632 base_label, 633 dfsan_read_label(nptr, tmp_endptr - nptr + (*tmp_endptr ? 0 : 1))); 634 } else { 635 *ret_label = 0; 636 } 637 return ret; 638 } 639 640 SANITIZER_INTERFACE_ATTRIBUTE 641 long long unsigned int __dfsw_strtoull(const char *nptr, char **endptr, 642 int base, dfsan_label nptr_label, 643 dfsan_label endptr_label, 644 dfsan_label base_label, 645 dfsan_label *ret_label) { 646 char *tmp_endptr; 647 long long unsigned int ret = strtoull(nptr, &tmp_endptr, base); 648 if (endptr) { 649 *endptr = tmp_endptr; 650 } 651 if (tmp_endptr > nptr) { 652 // If *tmp_endptr is '\0' include its label as well. 653 *ret_label = dfsan_union( 654 base_label, 655 dfsan_read_label(nptr, tmp_endptr - nptr + (*tmp_endptr ? 0 : 1))); 656 } else { 657 *ret_label = 0; 658 } 659 return ret; 660 } 661 662 SANITIZER_INTERFACE_ATTRIBUTE 663 time_t __dfsw_time(time_t *t, dfsan_label t_label, dfsan_label *ret_label) { 664 time_t ret = time(t); 665 if (ret != (time_t) -1 && t) { 666 dfsan_set_label(0, t, sizeof(time_t)); 667 } 668 *ret_label = 0; 669 return ret; 670 } 671 672 SANITIZER_INTERFACE_ATTRIBUTE 673 int __dfsw_inet_pton(int af, const char *src, void *dst, dfsan_label af_label, 674 dfsan_label src_label, dfsan_label dst_label, 675 dfsan_label *ret_label) { 676 int ret = inet_pton(af, src, dst); 677 if (ret == 1) { 678 dfsan_set_label(dfsan_read_label(src, strlen(src) + 1), dst, 679 af == AF_INET ? sizeof(struct in_addr) : sizeof(in6_addr)); 680 } 681 *ret_label = 0; 682 return ret; 683 } 684 685 SANITIZER_INTERFACE_ATTRIBUTE 686 struct tm *__dfsw_localtime_r(const time_t *timep, struct tm *result, 687 dfsan_label timep_label, dfsan_label result_label, 688 dfsan_label *ret_label) { 689 struct tm *ret = localtime_r(timep, result); 690 if (ret) { 691 dfsan_set_label(dfsan_read_label(timep, sizeof(time_t)), result, 692 sizeof(struct tm)); 693 *ret_label = result_label; 694 } else { 695 *ret_label = 0; 696 } 697 return ret; 698 } 699 700 SANITIZER_INTERFACE_ATTRIBUTE 701 int __dfsw_getpwuid_r(id_t uid, struct passwd *pwd, 702 char *buf, size_t buflen, struct passwd **result, 703 dfsan_label uid_label, dfsan_label pwd_label, 704 dfsan_label buf_label, dfsan_label buflen_label, 705 dfsan_label result_label, dfsan_label *ret_label) { 706 // Store the data in pwd, the strings referenced from pwd in buf, and the 707 // address of pwd in *result. On failure, NULL is stored in *result. 708 int ret = getpwuid_r(uid, pwd, buf, buflen, result); 709 if (ret == 0) { 710 dfsan_set_label(0, pwd, sizeof(struct passwd)); 711 dfsan_set_label(0, buf, strlen(buf) + 1); 712 } 713 *ret_label = 0; 714 dfsan_set_label(0, result, sizeof(struct passwd*)); 715 return ret; 716 } 717 718 SANITIZER_INTERFACE_ATTRIBUTE 719 int __dfsw_poll(struct pollfd *fds, nfds_t nfds, int timeout, 720 dfsan_label dfs_label, dfsan_label nfds_label, 721 dfsan_label timeout_label, dfsan_label *ret_label) { 722 int ret = poll(fds, nfds, timeout); 723 if (ret >= 0) { 724 for (; nfds > 0; --nfds) { 725 dfsan_set_label(0, &fds[nfds - 1].revents, sizeof(fds[nfds - 1].revents)); 726 } 727 } 728 *ret_label = 0; 729 return ret; 730 } 731 732 SANITIZER_INTERFACE_ATTRIBUTE 733 int __dfsw_select(int nfds, fd_set *readfds, fd_set *writefds, 734 fd_set *exceptfds, struct timeval *timeout, 735 dfsan_label nfds_label, dfsan_label readfds_label, 736 dfsan_label writefds_label, dfsan_label exceptfds_label, 737 dfsan_label timeout_label, dfsan_label *ret_label) { 738 int ret = select(nfds, readfds, writefds, exceptfds, timeout); 739 // Clear everything (also on error) since their content is either set or 740 // undefined. 741 if (readfds) { 742 dfsan_set_label(0, readfds, sizeof(fd_set)); 743 } 744 if (writefds) { 745 dfsan_set_label(0, writefds, sizeof(fd_set)); 746 } 747 if (exceptfds) { 748 dfsan_set_label(0, exceptfds, sizeof(fd_set)); 749 } 750 dfsan_set_label(0, timeout, sizeof(struct timeval)); 751 *ret_label = 0; 752 return ret; 753 } 754 755 SANITIZER_INTERFACE_ATTRIBUTE 756 int __dfsw_sched_getaffinity(pid_t pid, size_t cpusetsize, cpu_set_t *mask, 757 dfsan_label pid_label, 758 dfsan_label cpusetsize_label, 759 dfsan_label mask_label, dfsan_label *ret_label) { 760 int ret = sched_getaffinity(pid, cpusetsize, mask); 761 if (ret == 0) { 762 dfsan_set_label(0, mask, cpusetsize); 763 } 764 *ret_label = 0; 765 return ret; 766 } 767 768 SANITIZER_INTERFACE_ATTRIBUTE 769 int __dfsw_sigemptyset(sigset_t *set, dfsan_label set_label, 770 dfsan_label *ret_label) { 771 int ret = sigemptyset(set); 772 dfsan_set_label(0, set, sizeof(sigset_t)); 773 return ret; 774 } 775 776 SANITIZER_INTERFACE_ATTRIBUTE 777 int __dfsw_sigaction(int signum, const struct sigaction *act, 778 struct sigaction *oldact, dfsan_label signum_label, 779 dfsan_label act_label, dfsan_label oldact_label, 780 dfsan_label *ret_label) { 781 int ret = sigaction(signum, act, oldact); 782 if (oldact) { 783 dfsan_set_label(0, oldact, sizeof(struct sigaction)); 784 } 785 *ret_label = 0; 786 return ret; 787 } 788 789 SANITIZER_INTERFACE_ATTRIBUTE 790 int __dfsw_gettimeofday(struct timeval *tv, struct timezone *tz, 791 dfsan_label tv_label, dfsan_label tz_label, 792 dfsan_label *ret_label) { 793 int ret = gettimeofday(tv, tz); 794 if (tv) { 795 dfsan_set_label(0, tv, sizeof(struct timeval)); 796 } 797 if (tz) { 798 dfsan_set_label(0, tz, sizeof(struct timezone)); 799 } 800 *ret_label = 0; 801 return ret; 802 } 803 804 SANITIZER_INTERFACE_ATTRIBUTE void *__dfsw_memchr(void *s, int c, size_t n, 805 dfsan_label s_label, 806 dfsan_label c_label, 807 dfsan_label n_label, 808 dfsan_label *ret_label) { 809 void *ret = memchr(s, c, n); 810 if (flags().strict_data_dependencies) { 811 *ret_label = ret ? s_label : 0; 812 } else { 813 size_t len = 814 ret ? reinterpret_cast<char *>(ret) - reinterpret_cast<char *>(s) + 1 815 : n; 816 *ret_label = 817 dfsan_union(dfsan_read_label(s, len), dfsan_union(s_label, c_label)); 818 } 819 return ret; 820 } 821 822 SANITIZER_INTERFACE_ATTRIBUTE char *__dfsw_strrchr(char *s, int c, 823 dfsan_label s_label, 824 dfsan_label c_label, 825 dfsan_label *ret_label) { 826 char *ret = strrchr(s, c); 827 if (flags().strict_data_dependencies) { 828 *ret_label = ret ? s_label : 0; 829 } else { 830 *ret_label = 831 dfsan_union(dfsan_read_label(s, strlen(s) + 1), 832 dfsan_union(s_label, c_label)); 833 } 834 835 return ret; 836 } 837 838 SANITIZER_INTERFACE_ATTRIBUTE char *__dfsw_strstr(char *haystack, char *needle, 839 dfsan_label haystack_label, 840 dfsan_label needle_label, 841 dfsan_label *ret_label) { 842 char *ret = strstr(haystack, needle); 843 if (flags().strict_data_dependencies) { 844 *ret_label = ret ? haystack_label : 0; 845 } else { 846 size_t len = ret ? ret + strlen(needle) - haystack : strlen(haystack) + 1; 847 *ret_label = 848 dfsan_union(dfsan_read_label(haystack, len), 849 dfsan_union(dfsan_read_label(needle, strlen(needle) + 1), 850 dfsan_union(haystack_label, needle_label))); 851 } 852 853 return ret; 854 } 855 856 SANITIZER_INTERFACE_ATTRIBUTE int __dfsw_nanosleep(const struct timespec *req, 857 struct timespec *rem, 858 dfsan_label req_label, 859 dfsan_label rem_label, 860 dfsan_label *ret_label) { 861 int ret = nanosleep(req, rem); 862 *ret_label = 0; 863 if (ret == -1) { 864 // Interrupted by a signal, rem is filled with the remaining time. 865 dfsan_set_label(0, rem, sizeof(struct timespec)); 866 } 867 return ret; 868 } 869 870 SANITIZER_INTERFACE_ATTRIBUTE int 871 __dfsw_socketpair(int domain, int type, int protocol, int sv[2], 872 dfsan_label domain_label, dfsan_label type_label, 873 dfsan_label protocol_label, dfsan_label sv_label, 874 dfsan_label *ret_label) { 875 int ret = socketpair(domain, type, protocol, sv); 876 *ret_label = 0; 877 if (ret == 0) { 878 dfsan_set_label(0, sv, sizeof(*sv) * 2); 879 } 880 return ret; 881 } 882 883 // Type of the trampoline function passed to the custom version of 884 // dfsan_set_write_callback. 885 typedef void (*write_trampoline_t)( 886 void *callback, 887 int fd, const void *buf, ssize_t count, 888 dfsan_label fd_label, dfsan_label buf_label, dfsan_label count_label); 889 890 // Calls to dfsan_set_write_callback() set the values in this struct. 891 // Calls to the custom version of write() read (and invoke) them. 892 static struct { 893 write_trampoline_t write_callback_trampoline = nullptr; 894 void *write_callback = nullptr; 895 } write_callback_info; 896 897 SANITIZER_INTERFACE_ATTRIBUTE void 898 __dfsw_dfsan_set_write_callback( 899 write_trampoline_t write_callback_trampoline, 900 void *write_callback, 901 dfsan_label write_callback_label, 902 dfsan_label *ret_label) { 903 write_callback_info.write_callback_trampoline = write_callback_trampoline; 904 write_callback_info.write_callback = write_callback; 905 } 906 907 SANITIZER_INTERFACE_ATTRIBUTE int 908 __dfsw_write(int fd, const void *buf, size_t count, 909 dfsan_label fd_label, dfsan_label buf_label, 910 dfsan_label count_label, dfsan_label *ret_label) { 911 if (write_callback_info.write_callback) { 912 write_callback_info.write_callback_trampoline( 913 write_callback_info.write_callback, 914 fd, buf, count, 915 fd_label, buf_label, count_label); 916 } 917 918 *ret_label = 0; 919 return write(fd, buf, count); 920 } 921 } // namespace __dfsan 922 923 // Type used to extract a dfsan_label with va_arg() 924 typedef int dfsan_label_va; 925 926 // Formats a chunk either a constant string or a single format directive (e.g., 927 // '%.3f'). 928 struct Formatter { 929 Formatter(char *str_, const char *fmt_, size_t size_) 930 : str(str_), str_off(0), size(size_), fmt_start(fmt_), fmt_cur(fmt_), 931 width(-1) {} 932 933 int format() { 934 char *tmp_fmt = build_format_string(); 935 int retval = 936 snprintf(str + str_off, str_off < size ? size - str_off : 0, tmp_fmt, 937 0 /* used only to avoid warnings */); 938 free(tmp_fmt); 939 return retval; 940 } 941 942 template <typename T> int format(T arg) { 943 char *tmp_fmt = build_format_string(); 944 int retval; 945 if (width >= 0) { 946 retval = snprintf(str + str_off, str_off < size ? size - str_off : 0, 947 tmp_fmt, width, arg); 948 } else { 949 retval = snprintf(str + str_off, str_off < size ? size - str_off : 0, 950 tmp_fmt, arg); 951 } 952 free(tmp_fmt); 953 return retval; 954 } 955 956 char *build_format_string() { 957 size_t fmt_size = fmt_cur - fmt_start + 1; 958 char *new_fmt = (char *)malloc(fmt_size + 1); 959 assert(new_fmt); 960 internal_memcpy(new_fmt, fmt_start, fmt_size); 961 new_fmt[fmt_size] = '\0'; 962 return new_fmt; 963 } 964 965 char *str_cur() { return str + str_off; } 966 967 size_t num_written_bytes(int retval) { 968 if (retval < 0) { 969 return 0; 970 } 971 972 size_t num_avail = str_off < size ? size - str_off : 0; 973 if (num_avail == 0) { 974 return 0; 975 } 976 977 size_t num_written = retval; 978 // A return value of {v,}snprintf of size or more means that the output was 979 // truncated. 980 if (num_written >= num_avail) { 981 num_written -= num_avail; 982 } 983 984 return num_written; 985 } 986 987 char *str; 988 size_t str_off; 989 size_t size; 990 const char *fmt_start; 991 const char *fmt_cur; 992 int width; 993 }; 994 995 // Formats the input and propagates the input labels to the output. The output 996 // is stored in 'str'. 'size' bounds the number of output bytes. 'format' and 997 // 'ap' are the format string and the list of arguments for formatting. Returns 998 // the return value vsnprintf would return. 999 // 1000 // The function tokenizes the format string in chunks representing either a 1001 // constant string or a single format directive (e.g., '%.3f') and formats each 1002 // chunk independently into the output string. This approach allows to figure 1003 // out which bytes of the output string depends on which argument and thus to 1004 // propagate labels more precisely. 1005 // 1006 // WARNING: This implementation does not support conversion specifiers with 1007 // positional arguments. 1008 static int format_buffer(char *str, size_t size, const char *fmt, 1009 dfsan_label *va_labels, dfsan_label *ret_label, 1010 va_list ap) { 1011 Formatter formatter(str, fmt, size); 1012 1013 while (*formatter.fmt_cur) { 1014 formatter.fmt_start = formatter.fmt_cur; 1015 formatter.width = -1; 1016 int retval = 0; 1017 1018 if (*formatter.fmt_cur != '%') { 1019 // Ordinary character. Consume all the characters until a '%' or the end 1020 // of the string. 1021 for (; *(formatter.fmt_cur + 1) && *(formatter.fmt_cur + 1) != '%'; 1022 ++formatter.fmt_cur) {} 1023 retval = formatter.format(); 1024 dfsan_set_label(0, formatter.str_cur(), 1025 formatter.num_written_bytes(retval)); 1026 } else { 1027 // Conversion directive. Consume all the characters until a conversion 1028 // specifier or the end of the string. 1029 bool end_fmt = false; 1030 for (; *formatter.fmt_cur && !end_fmt; ) { 1031 switch (*++formatter.fmt_cur) { 1032 case 'd': 1033 case 'i': 1034 case 'o': 1035 case 'u': 1036 case 'x': 1037 case 'X': 1038 switch (*(formatter.fmt_cur - 1)) { 1039 case 'h': 1040 // Also covers the 'hh' case (since the size of the arg is still 1041 // an int). 1042 retval = formatter.format(va_arg(ap, int)); 1043 break; 1044 case 'l': 1045 if (formatter.fmt_cur - formatter.fmt_start >= 2 && 1046 *(formatter.fmt_cur - 2) == 'l') { 1047 retval = formatter.format(va_arg(ap, long long int)); 1048 } else { 1049 retval = formatter.format(va_arg(ap, long int)); 1050 } 1051 break; 1052 case 'q': 1053 retval = formatter.format(va_arg(ap, long long int)); 1054 break; 1055 case 'j': 1056 retval = formatter.format(va_arg(ap, intmax_t)); 1057 break; 1058 case 'z': 1059 case 't': 1060 retval = formatter.format(va_arg(ap, size_t)); 1061 break; 1062 default: 1063 retval = formatter.format(va_arg(ap, int)); 1064 } 1065 dfsan_set_label(*va_labels++, formatter.str_cur(), 1066 formatter.num_written_bytes(retval)); 1067 end_fmt = true; 1068 break; 1069 1070 case 'a': 1071 case 'A': 1072 case 'e': 1073 case 'E': 1074 case 'f': 1075 case 'F': 1076 case 'g': 1077 case 'G': 1078 if (*(formatter.fmt_cur - 1) == 'L') { 1079 retval = formatter.format(va_arg(ap, long double)); 1080 } else { 1081 retval = formatter.format(va_arg(ap, double)); 1082 } 1083 dfsan_set_label(*va_labels++, formatter.str_cur(), 1084 formatter.num_written_bytes(retval)); 1085 end_fmt = true; 1086 break; 1087 1088 case 'c': 1089 retval = formatter.format(va_arg(ap, int)); 1090 dfsan_set_label(*va_labels++, formatter.str_cur(), 1091 formatter.num_written_bytes(retval)); 1092 end_fmt = true; 1093 break; 1094 1095 case 's': { 1096 char *arg = va_arg(ap, char *); 1097 retval = formatter.format(arg); 1098 va_labels++; 1099 internal_memcpy(shadow_for(formatter.str_cur()), shadow_for(arg), 1100 sizeof(dfsan_label) * 1101 formatter.num_written_bytes(retval)); 1102 end_fmt = true; 1103 break; 1104 } 1105 1106 case 'p': 1107 retval = formatter.format(va_arg(ap, void *)); 1108 dfsan_set_label(*va_labels++, formatter.str_cur(), 1109 formatter.num_written_bytes(retval)); 1110 end_fmt = true; 1111 break; 1112 1113 case 'n': { 1114 int *ptr = va_arg(ap, int *); 1115 *ptr = (int)formatter.str_off; 1116 va_labels++; 1117 dfsan_set_label(0, ptr, sizeof(ptr)); 1118 end_fmt = true; 1119 break; 1120 } 1121 1122 case '%': 1123 retval = formatter.format(); 1124 dfsan_set_label(0, formatter.str_cur(), 1125 formatter.num_written_bytes(retval)); 1126 end_fmt = true; 1127 break; 1128 1129 case '*': 1130 formatter.width = va_arg(ap, int); 1131 va_labels++; 1132 break; 1133 1134 default: 1135 break; 1136 } 1137 } 1138 } 1139 1140 if (retval < 0) { 1141 return retval; 1142 } 1143 1144 formatter.fmt_cur++; 1145 formatter.str_off += retval; 1146 } 1147 1148 *ret_label = 0; 1149 1150 // Number of bytes written in total. 1151 return formatter.str_off; 1152 } 1153 1154 extern "C" { 1155 SANITIZER_INTERFACE_ATTRIBUTE 1156 int __dfsw_sprintf(char *str, const char *format, dfsan_label str_label, 1157 dfsan_label format_label, dfsan_label *va_labels, 1158 dfsan_label *ret_label, ...) { 1159 va_list ap; 1160 va_start(ap, ret_label); 1161 int ret = format_buffer(str, ~0ul, format, va_labels, ret_label, ap); 1162 va_end(ap); 1163 return ret; 1164 } 1165 1166 SANITIZER_INTERFACE_ATTRIBUTE 1167 int __dfsw_snprintf(char *str, size_t size, const char *format, 1168 dfsan_label str_label, dfsan_label size_label, 1169 dfsan_label format_label, dfsan_label *va_labels, 1170 dfsan_label *ret_label, ...) { 1171 va_list ap; 1172 va_start(ap, ret_label); 1173 int ret = format_buffer(str, size, format, va_labels, ret_label, ap); 1174 va_end(ap); 1175 return ret; 1176 } 1177 1178 // Default empty implementations (weak). Users should redefine them. 1179 SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_pc_guard, u32 *) {} 1180 SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_pc_guard_init, u32 *, 1181 u32 *) {} 1182 SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_pcs_init, void) {} 1183 SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_cov_trace_pc_indir, void) {} 1184 1185 SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_cmp, void) {} 1186 SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_cmp1, void) {} 1187 SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_cmp2, void) {} 1188 SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_cmp4, void) {} 1189 SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_cmp8, void) {} 1190 SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_const_cmp1, 1191 void) {} 1192 SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_const_cmp2, 1193 void) {} 1194 SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_const_cmp4, 1195 void) {} 1196 SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_const_cmp8, 1197 void) {} 1198 SANITIZER_INTERFACE_WEAK_DEF(void, __dfsw___sanitizer_cov_trace_switch, void) {} 1199 } // extern "C" 1200