1 //===-- asan_errors.cpp -----------------------------------------*- C++ -*-===//
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 AddressSanitizer, an address sanity checker.
10 //
11 // ASan implementation for error structures.
12 //===----------------------------------------------------------------------===//
13 
14 #include "asan_errors.h"
15 #include "asan_descriptions.h"
16 #include "asan_mapping.h"
17 #include "asan_report.h"
18 #include "asan_stack.h"
19 #include "sanitizer_common/sanitizer_stackdepot.h"
20 
21 namespace __asan {
22 
OnStackUnwind(const SignalContext & sig,const void * callback_context,BufferedStackTrace * stack)23 static void OnStackUnwind(const SignalContext &sig,
24                           const void *callback_context,
25                           BufferedStackTrace *stack) {
26   bool fast = common_flags()->fast_unwind_on_fatal;
27 #if SANITIZER_FREEBSD || SANITIZER_NETBSD
28   // On FreeBSD the slow unwinding that leverages _Unwind_Backtrace()
29   // yields the call stack of the signal's handler and not of the code
30   // that raised the signal (as it does on Linux).
31   fast = true;
32 #endif
33   // Tests and maybe some users expect that scariness is going to be printed
34   // just before the stack. As only asan has scariness score we have no
35   // corresponding code in the sanitizer_common and we use this callback to
36   // print it.
37   static_cast<const ScarinessScoreBase *>(callback_context)->Print();
38   stack->Unwind(StackTrace::GetNextInstructionPc(sig.pc), sig.bp, sig.context,
39                 fast);
40 }
41 
Print()42 void ErrorDeadlySignal::Print() {
43   ReportDeadlySignal(signal, tid, &OnStackUnwind, &scariness);
44 }
45 
Print()46 void ErrorDoubleFree::Print() {
47   Decorator d;
48   Printf("%s", d.Error());
49   Report("ERROR: AddressSanitizer: attempting %s on %p in thread %s:\n",
50          scariness.GetDescription(), (void *)addr_description.addr,
51          AsanThreadIdAndName(tid).c_str());
52   Printf("%s", d.Default());
53   scariness.Print();
54   GET_STACK_TRACE_FATAL(second_free_stack->trace[0],
55                         second_free_stack->top_frame_bp);
56   stack.Print();
57   addr_description.Print();
58   ReportErrorSummary(scariness.GetDescription(), &stack);
59 }
60 
Print()61 void ErrorNewDeleteTypeMismatch::Print() {
62   Decorator d;
63   Printf("%s", d.Error());
64   Report("ERROR: AddressSanitizer: %s on %p in thread %s:\n",
65          scariness.GetDescription(), (void *)addr_description.addr,
66          AsanThreadIdAndName(tid).c_str());
67   Printf("%s  object passed to delete has wrong type:\n", d.Default());
68   if (delete_size != 0) {
69     Printf(
70         "  size of the allocated type:   %zd bytes;\n"
71         "  size of the deallocated type: %zd bytes.\n",
72         addr_description.chunk_access.chunk_size, delete_size);
73   }
74   const uptr user_alignment =
75       addr_description.chunk_access.user_requested_alignment;
76   if (delete_alignment != user_alignment) {
77     char user_alignment_str[32];
78     char delete_alignment_str[32];
79     internal_snprintf(user_alignment_str, sizeof(user_alignment_str),
80                       "%zd bytes", user_alignment);
81     internal_snprintf(delete_alignment_str, sizeof(delete_alignment_str),
82                       "%zd bytes", delete_alignment);
83     static const char *kDefaultAlignment = "default-aligned";
84     Printf(
85         "  alignment of the allocated type:   %s;\n"
86         "  alignment of the deallocated type: %s.\n",
87         user_alignment > 0 ? user_alignment_str : kDefaultAlignment,
88         delete_alignment > 0 ? delete_alignment_str : kDefaultAlignment);
89   }
90   CHECK_GT(free_stack->size, 0);
91   scariness.Print();
92   GET_STACK_TRACE_FATAL(free_stack->trace[0], free_stack->top_frame_bp);
93   stack.Print();
94   addr_description.Print();
95   ReportErrorSummary(scariness.GetDescription(), &stack);
96   Report(
97       "HINT: if you don't care about these errors you may set "
98       "ASAN_OPTIONS=new_delete_type_mismatch=0\n");
99 }
100 
Print()101 void ErrorFreeNotMalloced::Print() {
102   Decorator d;
103   Printf("%s", d.Error());
104   Report(
105       "ERROR: AddressSanitizer: attempting free on address "
106       "which was not malloc()-ed: %p in thread %s\n",
107       (void *)addr_description.Address(), AsanThreadIdAndName(tid).c_str());
108   Printf("%s", d.Default());
109   CHECK_GT(free_stack->size, 0);
110   scariness.Print();
111   GET_STACK_TRACE_FATAL(free_stack->trace[0], free_stack->top_frame_bp);
112   stack.Print();
113   addr_description.Print();
114   ReportErrorSummary(scariness.GetDescription(), &stack);
115 }
116 
Print()117 void ErrorAllocTypeMismatch::Print() {
118   static const char *alloc_names[] = {"INVALID", "malloc", "operator new",
119                                       "operator new []"};
120   static const char *dealloc_names[] = {"INVALID", "free", "operator delete",
121                                         "operator delete []"};
122   CHECK_NE(alloc_type, dealloc_type);
123   Decorator d;
124   Printf("%s", d.Error());
125   Report("ERROR: AddressSanitizer: %s (%s vs %s) on %p\n",
126          scariness.GetDescription(), alloc_names[alloc_type],
127          dealloc_names[dealloc_type], (void *)addr_description.Address());
128   Printf("%s", d.Default());
129   CHECK_GT(dealloc_stack->size, 0);
130   scariness.Print();
131   GET_STACK_TRACE_FATAL(dealloc_stack->trace[0], dealloc_stack->top_frame_bp);
132   stack.Print();
133   addr_description.Print();
134   ReportErrorSummary(scariness.GetDescription(), &stack);
135   Report(
136       "HINT: if you don't care about these errors you may set "
137       "ASAN_OPTIONS=alloc_dealloc_mismatch=0\n");
138 }
139 
Print()140 void ErrorMallocUsableSizeNotOwned::Print() {
141   Decorator d;
142   Printf("%s", d.Error());
143   Report(
144       "ERROR: AddressSanitizer: attempting to call malloc_usable_size() for "
145       "pointer which is not owned: %p\n",
146       (void *)addr_description.Address());
147   Printf("%s", d.Default());
148   stack->Print();
149   addr_description.Print();
150   ReportErrorSummary(scariness.GetDescription(), stack);
151 }
152 
Print()153 void ErrorSanitizerGetAllocatedSizeNotOwned::Print() {
154   Decorator d;
155   Printf("%s", d.Error());
156   Report(
157       "ERROR: AddressSanitizer: attempting to call "
158       "__sanitizer_get_allocated_size() for pointer which is not owned: %p\n",
159       (void *)addr_description.Address());
160   Printf("%s", d.Default());
161   stack->Print();
162   addr_description.Print();
163   ReportErrorSummary(scariness.GetDescription(), stack);
164 }
165 
Print()166 void ErrorCallocOverflow::Print() {
167   Decorator d;
168   Printf("%s", d.Error());
169   Report(
170       "ERROR: AddressSanitizer: calloc parameters overflow: count * size "
171       "(%zd * %zd) cannot be represented in type size_t (thread %s)\n",
172       count, size, AsanThreadIdAndName(tid).c_str());
173   Printf("%s", d.Default());
174   stack->Print();
175   PrintHintAllocatorCannotReturnNull();
176   ReportErrorSummary(scariness.GetDescription(), stack);
177 }
178 
Print()179 void ErrorReallocArrayOverflow::Print() {
180   Decorator d;
181   Printf("%s", d.Error());
182   Report(
183       "ERROR: AddressSanitizer: reallocarray parameters overflow: count * size "
184       "(%zd * %zd) cannot be represented in type size_t (thread %s)\n",
185       count, size, AsanThreadIdAndName(tid).c_str());
186   Printf("%s", d.Default());
187   stack->Print();
188   PrintHintAllocatorCannotReturnNull();
189   ReportErrorSummary(scariness.GetDescription(), stack);
190 }
191 
Print()192 void ErrorPvallocOverflow::Print() {
193   Decorator d;
194   Printf("%s", d.Error());
195   Report(
196       "ERROR: AddressSanitizer: pvalloc parameters overflow: size 0x%zx "
197       "rounded up to system page size 0x%zx cannot be represented in type "
198       "size_t (thread %s)\n",
199       size, GetPageSizeCached(), AsanThreadIdAndName(tid).c_str());
200   Printf("%s", d.Default());
201   stack->Print();
202   PrintHintAllocatorCannotReturnNull();
203   ReportErrorSummary(scariness.GetDescription(), stack);
204 }
205 
Print()206 void ErrorInvalidAllocationAlignment::Print() {
207   Decorator d;
208   Printf("%s", d.Error());
209   Report(
210       "ERROR: AddressSanitizer: invalid allocation alignment: %zd, "
211       "alignment must be a power of two (thread %s)\n",
212       alignment, AsanThreadIdAndName(tid).c_str());
213   Printf("%s", d.Default());
214   stack->Print();
215   PrintHintAllocatorCannotReturnNull();
216   ReportErrorSummary(scariness.GetDescription(), stack);
217 }
218 
Print()219 void ErrorInvalidAlignedAllocAlignment::Print() {
220   Decorator d;
221   Printf("%s", d.Error());
222 #if SANITIZER_POSIX
223   Report("ERROR: AddressSanitizer: invalid alignment requested in "
224          "aligned_alloc: %zd, alignment must be a power of two and the "
225          "requested size 0x%zx must be a multiple of alignment "
226          "(thread %s)\n", alignment, size, AsanThreadIdAndName(tid).c_str());
227 #else
228   Report("ERROR: AddressSanitizer: invalid alignment requested in "
229          "aligned_alloc: %zd, the requested size 0x%zx must be a multiple of "
230          "alignment (thread %s)\n", alignment, size,
231          AsanThreadIdAndName(tid).c_str());
232 #endif
233   Printf("%s", d.Default());
234   stack->Print();
235   PrintHintAllocatorCannotReturnNull();
236   ReportErrorSummary(scariness.GetDescription(), stack);
237 }
238 
Print()239 void ErrorInvalidPosixMemalignAlignment::Print() {
240   Decorator d;
241   Printf("%s", d.Error());
242   Report(
243       "ERROR: AddressSanitizer: invalid alignment requested in posix_memalign: "
244       "%zd, alignment must be a power of two and a multiple of sizeof(void*) "
245       "== %zd (thread %s)\n",
246       alignment, sizeof(void *), AsanThreadIdAndName(tid).c_str());
247   Printf("%s", d.Default());
248   stack->Print();
249   PrintHintAllocatorCannotReturnNull();
250   ReportErrorSummary(scariness.GetDescription(), stack);
251 }
252 
Print()253 void ErrorAllocationSizeTooBig::Print() {
254   Decorator d;
255   Printf("%s", d.Error());
256   Report(
257       "ERROR: AddressSanitizer: requested allocation size 0x%zx (0x%zx after "
258       "adjustments for alignment, red zones etc.) exceeds maximum supported "
259       "size of 0x%zx (thread %s)\n",
260       user_size, total_size, max_size, AsanThreadIdAndName(tid).c_str());
261   Printf("%s", d.Default());
262   stack->Print();
263   PrintHintAllocatorCannotReturnNull();
264   ReportErrorSummary(scariness.GetDescription(), stack);
265 }
266 
Print()267 void ErrorRssLimitExceeded::Print() {
268   Decorator d;
269   Printf("%s", d.Error());
270   Report(
271       "ERROR: AddressSanitizer: specified RSS limit exceeded, currently set to "
272       "soft_rss_limit_mb=%zd\n", common_flags()->soft_rss_limit_mb);
273   Printf("%s", d.Default());
274   stack->Print();
275   PrintHintAllocatorCannotReturnNull();
276   ReportErrorSummary(scariness.GetDescription(), stack);
277 }
278 
Print()279 void ErrorOutOfMemory::Print() {
280   Decorator d;
281   Printf("%s", d.Error());
282   ERROR_OOM("allocator is trying to allocate 0x%zx bytes\n", requested_size);
283   Printf("%s", d.Default());
284   stack->Print();
285   PrintHintAllocatorCannotReturnNull();
286   ReportErrorSummary(scariness.GetDescription(), stack);
287 }
288 
Print()289 void ErrorStringFunctionMemoryRangesOverlap::Print() {
290   Decorator d;
291   char bug_type[100];
292   internal_snprintf(bug_type, sizeof(bug_type), "%s-param-overlap", function);
293   Printf("%s", d.Error());
294   Report(
295       "ERROR: AddressSanitizer: %s: memory ranges [%p,%p) and [%p, %p) "
296       "overlap\n",
297       bug_type, (void *)addr1_description.Address(),
298       (void *)(addr1_description.Address() + length1),
299       (void *)addr2_description.Address(),
300       (void *)(addr2_description.Address() + length2));
301   Printf("%s", d.Default());
302   scariness.Print();
303   stack->Print();
304   addr1_description.Print();
305   addr2_description.Print();
306   ReportErrorSummary(bug_type, stack);
307 }
308 
Print()309 void ErrorStringFunctionSizeOverflow::Print() {
310   Decorator d;
311   Printf("%s", d.Error());
312   Report("ERROR: AddressSanitizer: %s: (size=%zd)\n",
313          scariness.GetDescription(), size);
314   Printf("%s", d.Default());
315   scariness.Print();
316   stack->Print();
317   addr_description.Print();
318   ReportErrorSummary(scariness.GetDescription(), stack);
319 }
320 
Print()321 void ErrorBadParamsToAnnotateContiguousContainer::Print() {
322   Report(
323       "ERROR: AddressSanitizer: bad parameters to "
324       "__sanitizer_annotate_contiguous_container:\n"
325       "      beg     : %p\n"
326       "      end     : %p\n"
327       "      old_mid : %p\n"
328       "      new_mid : %p\n",
329       (void *)beg, (void *)end, (void *)old_mid, (void *)new_mid);
330   uptr granularity = ASAN_SHADOW_GRANULARITY;
331   if (!IsAligned(beg, granularity))
332     Report("ERROR: beg is not aligned by %zu\n", granularity);
333   stack->Print();
334   ReportErrorSummary(scariness.GetDescription(), stack);
335 }
336 
Print()337 void ErrorBadParamsToAnnotateDoubleEndedContiguousContainer::Print() {
338   Report(
339       "ERROR: AddressSanitizer: bad parameters to "
340       "__sanitizer_annotate_double_ended_contiguous_container:\n"
341       "      storage_beg        : %p\n"
342       "      storage_end        : %p\n"
343       "      old_container_beg  : %p\n"
344       "      old_container_end  : %p\n"
345       "      new_container_beg  : %p\n"
346       "      new_container_end  : %p\n",
347       (void *)storage_beg, (void *)storage_end, (void *)old_container_beg,
348       (void *)old_container_end, (void *)new_container_beg,
349       (void *)new_container_end);
350   uptr granularity = ASAN_SHADOW_GRANULARITY;
351   if (!IsAligned(storage_beg, granularity))
352     Report("ERROR: storage_beg is not aligned by %zu\n", granularity);
353   stack->Print();
354   ReportErrorSummary(scariness.GetDescription(), stack);
355 }
356 
Print()357 void ErrorODRViolation::Print() {
358   Decorator d;
359   Printf("%s", d.Error());
360   Report("ERROR: AddressSanitizer: %s (%p):\n", scariness.GetDescription(),
361          (void *)global1.beg);
362   Printf("%s", d.Default());
363   InternalScopedString g1_loc;
364   InternalScopedString g2_loc;
365   PrintGlobalLocation(&g1_loc, global1, /*print_module_name=*/true);
366   PrintGlobalLocation(&g2_loc, global2, /*print_module_name=*/true);
367   Printf("  [1] size=%zd '%s' %s\n", global1.size,
368          MaybeDemangleGlobalName(global1.name), g1_loc.data());
369   Printf("  [2] size=%zd '%s' %s\n", global2.size,
370          MaybeDemangleGlobalName(global2.name), g2_loc.data());
371   if (stack_id1 && stack_id2) {
372     Printf("These globals were registered at these points:\n");
373     Printf("  [1]:\n");
374     StackDepotGet(stack_id1).Print();
375     Printf("  [2]:\n");
376     StackDepotGet(stack_id2).Print();
377   }
378   Report(
379       "HINT: if you don't care about these errors you may set "
380       "ASAN_OPTIONS=detect_odr_violation=0\n");
381   InternalScopedString error_msg;
382   error_msg.AppendF("%s: global '%s' at %s", scariness.GetDescription(),
383                     MaybeDemangleGlobalName(global1.name), g1_loc.data());
384   ReportErrorSummary(error_msg.data());
385 }
386 
Print()387 void ErrorInvalidPointerPair::Print() {
388   Decorator d;
389   Printf("%s", d.Error());
390   Report("ERROR: AddressSanitizer: %s: %p %p\n", scariness.GetDescription(),
391          (void *)addr1_description.Address(),
392          (void *)addr2_description.Address());
393   Printf("%s", d.Default());
394   GET_STACK_TRACE_FATAL(pc, bp);
395   stack.Print();
396   addr1_description.Print();
397   addr2_description.Print();
398   ReportErrorSummary(scariness.GetDescription(), &stack);
399 }
400 
AdjacentShadowValuesAreFullyPoisoned(u8 * s)401 static bool AdjacentShadowValuesAreFullyPoisoned(u8 *s) {
402   return s[-1] > 127 && s[1] > 127;
403 }
404 
ErrorGeneric(u32 tid,uptr pc_,uptr bp_,uptr sp_,uptr addr,bool is_write_,uptr access_size_)405 ErrorGeneric::ErrorGeneric(u32 tid, uptr pc_, uptr bp_, uptr sp_, uptr addr,
406                            bool is_write_, uptr access_size_)
407     : ErrorBase(tid),
408       addr_description(addr, access_size_, /*shouldLockThreadRegistry=*/false),
409       pc(pc_),
410       bp(bp_),
411       sp(sp_),
412       access_size(access_size_),
413       is_write(is_write_),
414       shadow_val(0) {
415   scariness.Clear();
416   if (access_size) {
417     if (access_size <= 9) {
418       char desr[] = "?-byte";
419       desr[0] = '0' + access_size;
420       scariness.Scare(access_size + access_size / 2, desr);
421     } else if (access_size >= 10) {
422       scariness.Scare(15, "multi-byte");
423     }
424     is_write ? scariness.Scare(20, "write") : scariness.Scare(1, "read");
425 
426     // Determine the error type.
427     bug_descr = "unknown-crash";
428     if (AddrIsInMem(addr)) {
429       u8 *shadow_addr = (u8 *)MemToShadow(addr);
430       // If we are accessing 16 bytes, look at the second shadow byte.
431       if (*shadow_addr == 0 && access_size > ASAN_SHADOW_GRANULARITY)
432         shadow_addr++;
433       // If we are in the partial right redzone, look at the next shadow byte.
434       if (*shadow_addr > 0 && *shadow_addr < 128) shadow_addr++;
435       bool far_from_bounds = false;
436       shadow_val = *shadow_addr;
437       int bug_type_score = 0;
438       // For use-after-frees reads are almost as bad as writes.
439       int read_after_free_bonus = 0;
440       switch (shadow_val) {
441         case kAsanHeapLeftRedzoneMagic:
442         case kAsanArrayCookieMagic:
443           bug_descr = "heap-buffer-overflow";
444           bug_type_score = 10;
445           far_from_bounds = AdjacentShadowValuesAreFullyPoisoned(shadow_addr);
446           break;
447         case kAsanHeapFreeMagic:
448           bug_descr = "heap-use-after-free";
449           bug_type_score = 20;
450           if (!is_write) read_after_free_bonus = 18;
451           break;
452         case kAsanStackLeftRedzoneMagic:
453           bug_descr = "stack-buffer-underflow";
454           bug_type_score = 25;
455           far_from_bounds = AdjacentShadowValuesAreFullyPoisoned(shadow_addr);
456           break;
457         case kAsanInitializationOrderMagic:
458           bug_descr = "initialization-order-fiasco";
459           bug_type_score = 1;
460           break;
461         case kAsanStackMidRedzoneMagic:
462         case kAsanStackRightRedzoneMagic:
463           bug_descr = "stack-buffer-overflow";
464           bug_type_score = 25;
465           far_from_bounds = AdjacentShadowValuesAreFullyPoisoned(shadow_addr);
466           break;
467         case kAsanStackAfterReturnMagic:
468           bug_descr = "stack-use-after-return";
469           bug_type_score = 30;
470           if (!is_write) read_after_free_bonus = 18;
471           break;
472         case kAsanUserPoisonedMemoryMagic:
473           bug_descr = "use-after-poison";
474           bug_type_score = 20;
475           break;
476         case kAsanContiguousContainerOOBMagic:
477           bug_descr = "container-overflow";
478           bug_type_score = 10;
479           break;
480         case kAsanStackUseAfterScopeMagic:
481           bug_descr = "stack-use-after-scope";
482           bug_type_score = 10;
483           break;
484         case kAsanGlobalRedzoneMagic:
485           bug_descr = "global-buffer-overflow";
486           bug_type_score = 10;
487           far_from_bounds = AdjacentShadowValuesAreFullyPoisoned(shadow_addr);
488           break;
489         case kAsanIntraObjectRedzone:
490           bug_descr = "intra-object-overflow";
491           bug_type_score = 10;
492           break;
493         case kAsanAllocaLeftMagic:
494         case kAsanAllocaRightMagic:
495           bug_descr = "dynamic-stack-buffer-overflow";
496           bug_type_score = 25;
497           far_from_bounds = AdjacentShadowValuesAreFullyPoisoned(shadow_addr);
498           break;
499       }
500       scariness.Scare(bug_type_score + read_after_free_bonus, bug_descr);
501       if (far_from_bounds) scariness.Scare(10, "far-from-bounds");
502     }
503   }
504 }
505 
PrintContainerOverflowHint()506 static void PrintContainerOverflowHint() {
507   Printf("HINT: if you don't care about these errors you may set "
508          "ASAN_OPTIONS=detect_container_overflow=0.\n"
509          "If you suspect a false positive see also: "
510          "https://github.com/google/sanitizers/wiki/"
511          "AddressSanitizerContainerOverflow.\n");
512 }
513 
PrintShadowByte(InternalScopedString * str,const char * before,u8 byte,const char * after="\\n")514 static void PrintShadowByte(InternalScopedString *str, const char *before,
515     u8 byte, const char *after = "\n") {
516   PrintMemoryByte(str, before, byte, /*in_shadow*/true, after);
517 }
518 
PrintLegend(InternalScopedString * str)519 static void PrintLegend(InternalScopedString *str) {
520   str->AppendF(
521       "Shadow byte legend (one shadow byte represents %d "
522       "application bytes):\n",
523       (int)ASAN_SHADOW_GRANULARITY);
524   PrintShadowByte(str, "  Addressable:           ", 0);
525   str->AppendF("  Partially addressable: ");
526   for (u8 i = 1; i < ASAN_SHADOW_GRANULARITY; i++)
527     PrintShadowByte(str, "", i, " ");
528   str->AppendF("\n");
529   PrintShadowByte(str, "  Heap left redzone:       ",
530                   kAsanHeapLeftRedzoneMagic);
531   PrintShadowByte(str, "  Freed heap region:       ", kAsanHeapFreeMagic);
532   PrintShadowByte(str, "  Stack left redzone:      ",
533                   kAsanStackLeftRedzoneMagic);
534   PrintShadowByte(str, "  Stack mid redzone:       ",
535                   kAsanStackMidRedzoneMagic);
536   PrintShadowByte(str, "  Stack right redzone:     ",
537                   kAsanStackRightRedzoneMagic);
538   PrintShadowByte(str, "  Stack after return:      ",
539                   kAsanStackAfterReturnMagic);
540   PrintShadowByte(str, "  Stack use after scope:   ",
541                   kAsanStackUseAfterScopeMagic);
542   PrintShadowByte(str, "  Global redzone:          ", kAsanGlobalRedzoneMagic);
543   PrintShadowByte(str, "  Global init order:       ",
544                   kAsanInitializationOrderMagic);
545   PrintShadowByte(str, "  Poisoned by user:        ",
546                   kAsanUserPoisonedMemoryMagic);
547   PrintShadowByte(str, "  Container overflow:      ",
548                   kAsanContiguousContainerOOBMagic);
549   PrintShadowByte(str, "  Array cookie:            ",
550                   kAsanArrayCookieMagic);
551   PrintShadowByte(str, "  Intra object redzone:    ",
552                   kAsanIntraObjectRedzone);
553   PrintShadowByte(str, "  ASan internal:           ", kAsanInternalHeapMagic);
554   PrintShadowByte(str, "  Left alloca redzone:     ", kAsanAllocaLeftMagic);
555   PrintShadowByte(str, "  Right alloca redzone:    ", kAsanAllocaRightMagic);
556 }
557 
PrintShadowBytes(InternalScopedString * str,const char * before,u8 * bytes,u8 * guilty,uptr n)558 static void PrintShadowBytes(InternalScopedString *str, const char *before,
559                              u8 *bytes, u8 *guilty, uptr n) {
560   Decorator d;
561   if (before)
562     str->AppendF("%s%p:", before,
563                  (void *)ShadowToMem(reinterpret_cast<uptr>(bytes)));
564   for (uptr i = 0; i < n; i++) {
565     u8 *p = bytes + i;
566     const char *before =
567         p == guilty ? "[" : (p - 1 == guilty && i != 0) ? "" : " ";
568     const char *after = p == guilty ? "]" : "";
569     PrintShadowByte(str, before, *p, after);
570   }
571   str->AppendF("\n");
572 }
573 
PrintShadowMemoryForAddress(uptr addr)574 static void PrintShadowMemoryForAddress(uptr addr) {
575   if (!AddrIsInMem(addr)) return;
576   uptr shadow_addr = MemToShadow(addr);
577   const uptr n_bytes_per_row = 16;
578   uptr aligned_shadow = shadow_addr & ~(n_bytes_per_row - 1);
579   InternalScopedString str;
580   str.AppendF("Shadow bytes around the buggy address:\n");
581   for (int i = -5; i <= 5; i++) {
582     uptr row_shadow_addr = aligned_shadow + i * n_bytes_per_row;
583     // Skip rows that would be outside the shadow range. This can happen when
584     // the user address is near the bottom, top, or shadow gap of the address
585     // space.
586     if (!AddrIsInShadow(row_shadow_addr)) continue;
587     const char *prefix = (i == 0) ? "=>" : "  ";
588     PrintShadowBytes(&str, prefix, (u8 *)row_shadow_addr, (u8 *)shadow_addr,
589                      n_bytes_per_row);
590   }
591   if (flags()->print_legend) PrintLegend(&str);
592   Printf("%s", str.data());
593 }
594 
Print()595 void ErrorGeneric::Print() {
596   Decorator d;
597   Printf("%s", d.Error());
598   uptr addr = addr_description.Address();
599   Report("ERROR: AddressSanitizer: %s on address %p at pc %p bp %p sp %p\n",
600          bug_descr, (void *)addr, (void *)pc, (void *)bp, (void *)sp);
601   Printf("%s", d.Default());
602 
603   Printf("%s%s of size %zu at %p thread %s%s\n", d.Access(),
604          access_size ? (is_write ? "WRITE" : "READ") : "ACCESS", access_size,
605          (void *)addr, AsanThreadIdAndName(tid).c_str(), d.Default());
606 
607   scariness.Print();
608   GET_STACK_TRACE_FATAL(pc, bp);
609   stack.Print();
610 
611   // Pass bug_descr because we have a special case for
612   // initialization-order-fiasco
613   addr_description.Print(bug_descr);
614   if (shadow_val == kAsanContiguousContainerOOBMagic)
615     PrintContainerOverflowHint();
616   ReportErrorSummary(bug_descr, &stack);
617   PrintShadowMemoryForAddress(addr);
618 }
619 
620 }  // namespace __asan
621