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