contrib/compiler-rt/lib/asan/asan_errors.cc

   1 //===-- asan_errors.cc ------------------------------------------*- C++ -*-===//
   2 //
   3 //                     The LLVM Compiler Infrastructure
   4 //
   5 // This file is distributed under the University of Illinois Open Source
   6 // License. See LICENSE.TXT for details.
   7 //
   8 //===----------------------------------------------------------------------===//
   9 //
  10 // This file is a part of AddressSanitizer, an address sanity checker.
  11 //
  12 // ASan implementation for error structures.
  13 //===----------------------------------------------------------------------===//
  14
  15 #include "asan_errors.h"
  16 #include "asan_descriptions.h"
  17 #include "asan_mapping.h"
  18 #include "asan_report.h"
  19 #include "asan_stack.h"
  20 #include "sanitizer_common/sanitizer_stackdepot.h"
  21
  22 namespace __asan {
  23
  24 static void OnStackUnwind(const SignalContext &sig,
  25                           const void *callback_context,
  26                           BufferedStackTrace *stack) {
  27   bool fast = common_flags()->fast_unwind_on_fatal;
  28 #if SANITIZER_FREEBSD || SANITIZER_NETBSD
  29   // On FreeBSD the slow unwinding that leverages _Unwind_Backtrace()
  30   // yields the call stack of the signal's handler and not of the code
  31   // that raised the signal (as it does on Linux).
  32   fast = true;
  33 #endif
  34   // Tests and maybe some users expect that scariness is going to be printed
  35   // just before the stack. As only asan has scariness score we have no
  36   // corresponding code in the sanitizer_common and we use this callback to
  37   // print it.
  38   static_cast<const ScarinessScoreBase *>(callback_context)->Print();
  39   GetStackTrace(stack, kStackTraceMax, sig.pc, sig.bp, sig.context, fast);
  40 }
  41
  42 void ErrorDeadlySignal::Print() {
  43   ReportDeadlySignal(signal, tid, &OnStackUnwind, &scariness);
  44 }
  45
  46 void ErrorDoubleFree::Print() {
  47   Decorator d;
  48   Printf("%s", d.Warning());
  49   char tname[128];
  50   Report(
  51       "ERROR: AddressSanitizer: attempting %s on %p in "
  52       "thread T%d%s:\n",
  53       scariness.GetDescription(), addr_description.addr, tid,
  54       ThreadNameWithParenthesis(tid, tname, sizeof(tname)));
  55   Printf("%s", d.Default());
  56   scariness.Print();
  57   GET_STACK_TRACE_FATAL(second_free_stack->trace[0],
  58                         second_free_stack->top_frame_bp);
  59   stack.Print();
  60   addr_description.Print();
  61   ReportErrorSummary(scariness.GetDescription(), &stack);
  62 }
  63
  64 void ErrorNewDeleteTypeMismatch::Print() {
  65   Decorator d;
  66   Printf("%s", d.Warning());
  67   char tname[128];
  68   Report(
  69       "ERROR: AddressSanitizer: %s on %p in thread "
  70       "T%d%s:\n",
  71       scariness.GetDescription(), addr_description.addr, tid,
  72       ThreadNameWithParenthesis(tid, tname, sizeof(tname)));
  73   Printf("%s  object passed to delete has wrong type:\n", d.Default());
  74   if (delete_size != 0) {
  75     Printf(
  76         "  size of the allocated type:   %zd bytes;\n"
  77         "  size of the deallocated type: %zd bytes.\n",
  78         addr_description.chunk_access.chunk_size, delete_size);
  79   }
  80   const uptr user_alignment =
  81       addr_description.chunk_access.user_requested_alignment;
  82   if (delete_alignment != user_alignment) {
  83     char user_alignment_str[32];
  84     char delete_alignment_str[32];
  85     internal_snprintf(user_alignment_str, sizeof(user_alignment_str),
  86                       "%zd bytes", user_alignment);
  87     internal_snprintf(delete_alignment_str, sizeof(delete_alignment_str),
  88                       "%zd bytes", delete_alignment);
  89     static const char *kDefaultAlignment = "default-aligned";
  90     Printf(
  91         "  alignment of the allocated type:   %s;\n"
  92         "  alignment of the deallocated type: %s.\n",
  93         user_alignment > 0 ? user_alignment_str : kDefaultAlignment,
  94         delete_alignment > 0 ? delete_alignment_str : kDefaultAlignment);
  95   }
  96   CHECK_GT(free_stack->size, 0);
  97   scariness.Print();
  98   GET_STACK_TRACE_FATAL(free_stack->trace[0], free_stack->top_frame_bp);
  99   stack.Print();
 100   addr_description.Print();
 101   ReportErrorSummary(scariness.GetDescription(), &stack);
 102   Report(
 103       "HINT: if you don't care about these errors you may set "
 104       "ASAN_OPTIONS=new_delete_type_mismatch=0\n");
 105 }
 106
 107 void ErrorFreeNotMalloced::Print() {
 108   Decorator d;
 109   Printf("%s", d.Warning());
 110   char tname[128];
 111   Report(
 112       "ERROR: AddressSanitizer: attempting free on address "
 113       "which was not malloc()-ed: %p in thread T%d%s\n",
 114       addr_description.Address(), tid,
 115       ThreadNameWithParenthesis(tid, tname, sizeof(tname)));
 116   Printf("%s", d.Default());
 117   CHECK_GT(free_stack->size, 0);
 118   scariness.Print();
 119   GET_STACK_TRACE_FATAL(free_stack->trace[0], free_stack->top_frame_bp);
 120   stack.Print();
 121   addr_description.Print();
 122   ReportErrorSummary(scariness.GetDescription(), &stack);
 123 }
 124
 125 void ErrorAllocTypeMismatch::Print() {
 126   static const char *alloc_names[] = {"INVALID", "malloc", "operator new",
 127                                       "operator new []"};
 128   static const char *dealloc_names[] = {"INVALID", "free", "operator delete",
 129                                         "operator delete []"};
 130   CHECK_NE(alloc_type, dealloc_type);
 131   Decorator d;
 132   Printf("%s", d.Warning());
 133   Report("ERROR: AddressSanitizer: %s (%s vs %s) on %p\n",
 134          scariness.GetDescription(),
 135          alloc_names[alloc_type], dealloc_names[dealloc_type],
 136          addr_description.addr);
 137   Printf("%s", d.Default());
 138   CHECK_GT(dealloc_stack->size, 0);
 139   scariness.Print();
 140   GET_STACK_TRACE_FATAL(dealloc_stack->trace[0], dealloc_stack->top_frame_bp);
 141   stack.Print();
 142   addr_description.Print();
 143   ReportErrorSummary(scariness.GetDescription(), &stack);
 144   Report(
 145       "HINT: if you don't care about these errors you may set "
 146       "ASAN_OPTIONS=alloc_dealloc_mismatch=0\n");
 147 }
 148
 149 void ErrorMallocUsableSizeNotOwned::Print() {
 150   Decorator d;
 151   Printf("%s", d.Warning());
 152   Report(
 153       "ERROR: AddressSanitizer: attempting to call malloc_usable_size() for "
 154       "pointer which is not owned: %p\n",
 155       addr_description.Address());
 156   Printf("%s", d.Default());
 157   stack->Print();
 158   addr_description.Print();
 159   ReportErrorSummary(scariness.GetDescription(), stack);
 160 }
 161
 162 void ErrorSanitizerGetAllocatedSizeNotOwned::Print() {
 163   Decorator d;
 164   Printf("%s", d.Warning());
 165   Report(
 166       "ERROR: AddressSanitizer: attempting to call "
 167       "__sanitizer_get_allocated_size() for pointer which is not owned: %p\n",
 168       addr_description.Address());
 169   Printf("%s", d.Default());
 170   stack->Print();
 171   addr_description.Print();
 172   ReportErrorSummary(scariness.GetDescription(), stack);
 173 }
 174
 175 void ErrorStringFunctionMemoryRangesOverlap::Print() {
 176   Decorator d;
 177   char bug_type[100];
 178   internal_snprintf(bug_type, sizeof(bug_type), "%s-param-overlap", function);
 179   Printf("%s", d.Warning());
 180   Report(
 181       "ERROR: AddressSanitizer: %s: memory ranges [%p,%p) and [%p, %p) "
 182       "overlap\n",
 183       bug_type, addr1_description.Address(),
 184       addr1_description.Address() + length1, addr2_description.Address(),
 185       addr2_description.Address() + length2);
 186   Printf("%s", d.Default());
 187   scariness.Print();
 188   stack->Print();
 189   addr1_description.Print();
 190   addr2_description.Print();
 191   ReportErrorSummary(bug_type, stack);
 192 }
 193
 194 void ErrorStringFunctionSizeOverflow::Print() {
 195   Decorator d;
 196   Printf("%s", d.Warning());
 197   Report("ERROR: AddressSanitizer: %s: (size=%zd)\n",
 198          scariness.GetDescription(), size);
 199   Printf("%s", d.Default());
 200   scariness.Print();
 201   stack->Print();
 202   addr_description.Print();
 203   ReportErrorSummary(scariness.GetDescription(), stack);
 204 }
 205
 206 void ErrorBadParamsToAnnotateContiguousContainer::Print() {
 207   Report(
 208       "ERROR: AddressSanitizer: bad parameters to "
 209       "__sanitizer_annotate_contiguous_container:\n"
 210       "      beg     : %p\n"
 211       "      end     : %p\n"
 212       "      old_mid : %p\n"
 213       "      new_mid : %p\n",
 214       beg, end, old_mid, new_mid);
 215   uptr granularity = SHADOW_GRANULARITY;
 216   if (!IsAligned(beg, granularity))
 217     Report("ERROR: beg is not aligned by %d\n", granularity);
 218   stack->Print();
 219   ReportErrorSummary(scariness.GetDescription(), stack);
 220 }
 221
 222 void ErrorODRViolation::Print() {
 223   Decorator d;
 224   Printf("%s", d.Warning());
 225   Report("ERROR: AddressSanitizer: %s (%p):\n", scariness.GetDescription(),
 226          global1.beg);
 227   Printf("%s", d.Default());
 228   InternalScopedString g1_loc(256), g2_loc(256);
 229   PrintGlobalLocation(&g1_loc, global1);
 230   PrintGlobalLocation(&g2_loc, global2);
 231   Printf("  [1] size=%zd '%s' %s\n", global1.size,
 232          MaybeDemangleGlobalName(global1.name), g1_loc.data());
 233   Printf("  [2] size=%zd '%s' %s\n", global2.size,
 234          MaybeDemangleGlobalName(global2.name), g2_loc.data());
 235   if (stack_id1 && stack_id2) {
 236     Printf("These globals were registered at these points:\n");
 237     Printf("  [1]:\n");
 238     StackDepotGet(stack_id1).Print();
 239     Printf("  [2]:\n");
 240     StackDepotGet(stack_id2).Print();
 241   }
 242   Report(
 243       "HINT: if you don't care about these errors you may set "
 244       "ASAN_OPTIONS=detect_odr_violation=0\n");
 245   InternalScopedString error_msg(256);
 246   error_msg.append("%s: global '%s' at %s", scariness.GetDescription(),
 247                    MaybeDemangleGlobalName(global1.name), g1_loc.data());
 248   ReportErrorSummary(error_msg.data());
 249 }
 250
 251 void ErrorInvalidPointerPair::Print() {
 252   Decorator d;
 253   Printf("%s", d.Warning());
 254   Report("ERROR: AddressSanitizer: %s: %p %p\n", scariness.GetDescription(),
 255          addr1_description.Address(), addr2_description.Address());
 256   Printf("%s", d.Default());
 257   GET_STACK_TRACE_FATAL(pc, bp);
 258   stack.Print();
 259   addr1_description.Print();
 260   addr2_description.Print();
 261   ReportErrorSummary(scariness.GetDescription(), &stack);
 262 }
 263
 264 static bool AdjacentShadowValuesAreFullyPoisoned(u8 *s) {
 265   return s[-1] > 127 && s[1] > 127;
 266 }
 267
 268 ErrorGeneric::ErrorGeneric(u32 tid, uptr pc_, uptr bp_, uptr sp_, uptr addr,
 269                            bool is_write_, uptr access_size_)
 270     : ErrorBase(tid),
 271       addr_description(addr, access_size_, /*shouldLockThreadRegistry=*/false),
 272       pc(pc_),
 273       bp(bp_),
 274       sp(sp_),
 275       access_size(access_size_),
 276       is_write(is_write_),
 277       shadow_val(0) {
 278   scariness.Clear();
 279   if (access_size) {
 280     if (access_size <= 9) {
 281       char desr[] = "?-byte";
 282       desr[0] = '0' + access_size;
 283       scariness.Scare(access_size + access_size / 2, desr);
 284     } else if (access_size >= 10) {
 285       scariness.Scare(15, "multi-byte");
 286     }
 287     is_write ? scariness.Scare(20, "write") : scariness.Scare(1, "read");
 288
 289     // Determine the error type.
 290     bug_descr = "unknown-crash";
 291     if (AddrIsInMem(addr)) {
 292       u8 *shadow_addr = (u8 *)MemToShadow(addr);
 293       // If we are accessing 16 bytes, look at the second shadow byte.
 294       if (*shadow_addr == 0 && access_size > SHADOW_GRANULARITY) shadow_addr++;
 295       // If we are in the partial right redzone, look at the next shadow byte.
 296       if (*shadow_addr > 0 && *shadow_addr < 128) shadow_addr++;
 297       bool far_from_bounds = false;
 298       shadow_val = *shadow_addr;
 299       int bug_type_score = 0;
 300       // For use-after-frees reads are almost as bad as writes.
 301       int read_after_free_bonus = 0;
 302       switch (shadow_val) {
 303         case kAsanHeapLeftRedzoneMagic:
 304         case kAsanArrayCookieMagic:
 305           bug_descr = "heap-buffer-overflow";
 306           bug_type_score = 10;
 307           far_from_bounds = AdjacentShadowValuesAreFullyPoisoned(shadow_addr);
 308           break;
 309         case kAsanHeapFreeMagic:
 310           bug_descr = "heap-use-after-free";
 311           bug_type_score = 20;
 312           if (!is_write) read_after_free_bonus = 18;
 313           break;
 314         case kAsanStackLeftRedzoneMagic:
 315           bug_descr = "stack-buffer-underflow";
 316           bug_type_score = 25;
 317           far_from_bounds = AdjacentShadowValuesAreFullyPoisoned(shadow_addr);
 318           break;
 319         case kAsanInitializationOrderMagic:
 320           bug_descr = "initialization-order-fiasco";
 321           bug_type_score = 1;
 322           break;
 323         case kAsanStackMidRedzoneMagic:
 324         case kAsanStackRightRedzoneMagic:
 325           bug_descr = "stack-buffer-overflow";
 326           bug_type_score = 25;
 327           far_from_bounds = AdjacentShadowValuesAreFullyPoisoned(shadow_addr);
 328           break;
 329         case kAsanStackAfterReturnMagic:
 330           bug_descr = "stack-use-after-return";
 331           bug_type_score = 30;
 332           if (!is_write) read_after_free_bonus = 18;
 333           break;
 334         case kAsanUserPoisonedMemoryMagic:
 335           bug_descr = "use-after-poison";
 336           bug_type_score = 20;
 337           break;
 338         case kAsanContiguousContainerOOBMagic:
 339           bug_descr = "container-overflow";
 340           bug_type_score = 10;
 341           break;
 342         case kAsanStackUseAfterScopeMagic:
 343           bug_descr = "stack-use-after-scope";
 344           bug_type_score = 10;
 345           break;
 346         case kAsanGlobalRedzoneMagic:
 347           bug_descr = "global-buffer-overflow";
 348           bug_type_score = 10;
 349           far_from_bounds = AdjacentShadowValuesAreFullyPoisoned(shadow_addr);
 350           break;
 351         case kAsanIntraObjectRedzone:
 352           bug_descr = "intra-object-overflow";
 353           bug_type_score = 10;
 354           break;
 355         case kAsanAllocaLeftMagic:
 356         case kAsanAllocaRightMagic:
 357           bug_descr = "dynamic-stack-buffer-overflow";
 358           bug_type_score = 25;
 359           far_from_bounds = AdjacentShadowValuesAreFullyPoisoned(shadow_addr);
 360           break;
 361       }
 362       scariness.Scare(bug_type_score + read_after_free_bonus, bug_descr);
 363       if (far_from_bounds) scariness.Scare(10, "far-from-bounds");
 364     }
 365   }
 366 }
 367
 368 static void PrintContainerOverflowHint() {
 369   Printf("HINT: if you don't care about these errors you may set "
 370          "ASAN_OPTIONS=detect_container_overflow=0.\n"
 371          "If you suspect a false positive see also: "
 372          "https://github.com/google/sanitizers/wiki/"
 373          "AddressSanitizerContainerOverflow.\n");
 374 }
 375
 376 static void PrintShadowByte(InternalScopedString *str, const char *before,
 377     u8 byte, const char *after = "\n") {
 378   PrintMemoryByte(str, before, byte, /*in_shadow*/true, after);
 379 }
 380
 381 static void PrintLegend(InternalScopedString *str) {
 382   str->append(
 383       "Shadow byte legend (one shadow byte represents %d "
 384       "application bytes):\n",
 385       (int)SHADOW_GRANULARITY);
 386   PrintShadowByte(str, "  Addressable:           ", 0);
 387   str->append("  Partially addressable: ");
 388   for (u8 i = 1; i < SHADOW_GRANULARITY; i++) PrintShadowByte(str, "", i, " ");
 389   str->append("\n");
 390   PrintShadowByte(str, "  Heap left redzone:       ",
 391                   kAsanHeapLeftRedzoneMagic);
 392   PrintShadowByte(str, "  Freed heap region:       ", kAsanHeapFreeMagic);
 393   PrintShadowByte(str, "  Stack left redzone:      ",
 394                   kAsanStackLeftRedzoneMagic);
 395   PrintShadowByte(str, "  Stack mid redzone:       ",
 396                   kAsanStackMidRedzoneMagic);
 397   PrintShadowByte(str, "  Stack right redzone:     ",
 398                   kAsanStackRightRedzoneMagic);
 399   PrintShadowByte(str, "  Stack after return:      ",
 400                   kAsanStackAfterReturnMagic);
 401   PrintShadowByte(str, "  Stack use after scope:   ",
 402                   kAsanStackUseAfterScopeMagic);
 403   PrintShadowByte(str, "  Global redzone:          ", kAsanGlobalRedzoneMagic);
 404   PrintShadowByte(str, "  Global init order:       ",
 405                   kAsanInitializationOrderMagic);
 406   PrintShadowByte(str, "  Poisoned by user:        ",
 407                   kAsanUserPoisonedMemoryMagic);
 408   PrintShadowByte(str, "  Container overflow:      ",
 409                   kAsanContiguousContainerOOBMagic);
 410   PrintShadowByte(str, "  Array cookie:            ",
 411                   kAsanArrayCookieMagic);
 412   PrintShadowByte(str, "  Intra object redzone:    ",
 413                   kAsanIntraObjectRedzone);
 414   PrintShadowByte(str, "  ASan internal:           ", kAsanInternalHeapMagic);
 415   PrintShadowByte(str, "  Left alloca redzone:     ", kAsanAllocaLeftMagic);
 416   PrintShadowByte(str, "  Right alloca redzone:    ", kAsanAllocaRightMagic);
 417 }
 418
 419 static void PrintShadowBytes(InternalScopedString *str, const char *before,
 420                              u8 *bytes, u8 *guilty, uptr n) {
 421   Decorator d;
 422   if (before) str->append("%s%p:", before, bytes);
 423   for (uptr i = 0; i < n; i++) {
 424     u8 *p = bytes + i;
 425     const char *before =
 426         p == guilty ? "[" : (p - 1 == guilty && i != 0) ? "" : " ";
 427     const char *after = p == guilty ? "]" : "";
 428     PrintShadowByte(str, before, *p, after);
 429   }
 430   str->append("\n");
 431 }
 432
 433 static void PrintShadowMemoryForAddress(uptr addr) {
 434   if (!AddrIsInMem(addr)) return;
 435   uptr shadow_addr = MemToShadow(addr);
 436   const uptr n_bytes_per_row = 16;
 437   uptr aligned_shadow = shadow_addr & ~(n_bytes_per_row - 1);
 438   InternalScopedString str(4096 * 8);
 439   str.append("Shadow bytes around the buggy address:\n");
 440   for (int i = -5; i <= 5; i++) {
 441     uptr row_shadow_addr = aligned_shadow + i * n_bytes_per_row;
 442     // Skip rows that would be outside the shadow range. This can happen when
 443     // the user address is near the bottom, top, or shadow gap of the address
 444     // space.
 445     if (!AddrIsInShadow(row_shadow_addr)) continue;
 446     const char *prefix = (i == 0) ? "=>" : "  ";
 447     PrintShadowBytes(&str, prefix, (u8 *)row_shadow_addr, (u8 *)shadow_addr,
 448                      n_bytes_per_row);
 449   }
 450   if (flags()->print_legend) PrintLegend(&str);
 451   Printf("%s", str.data());
 452 }
 453
 454 void ErrorGeneric::Print() {
 455   Decorator d;
 456   Printf("%s", d.Warning());
 457   uptr addr = addr_description.Address();
 458   Report("ERROR: AddressSanitizer: %s on address %p at pc %p bp %p sp %p\n",
 459          bug_descr, (void *)addr, pc, bp, sp);
 460   Printf("%s", d.Default());
 461
 462   char tname[128];
 463   Printf("%s%s of size %zu at %p thread T%d%s%s\n", d.Access(),
 464          access_size ? (is_write ? "WRITE" : "READ") : "ACCESS", access_size,
 465          (void *)addr, tid,
 466          ThreadNameWithParenthesis(tid, tname, sizeof(tname)), d.Default());
 467
 468   scariness.Print();
 469   GET_STACK_TRACE_FATAL(pc, bp);
 470   stack.Print();
 471
 472   // Pass bug_descr because we have a special case for
 473   // initialization-order-fiasco
 474   addr_description.Print(bug_descr);
 475   if (shadow_val == kAsanContiguousContainerOOBMagic)
 476     PrintContainerOverflowHint();
 477   ReportErrorSummary(bug_descr, &stack);
 478   PrintShadowMemoryForAddress(addr);
 479 }
 480
 481 }  // namespace __asan