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 ErrorODRViolation::Print() {
338   Decorator d;
339   Printf("%s", d.Error());
340   Report("ERROR: AddressSanitizer: %s (%p):\n", scariness.GetDescription(),
341          (void *)global1.beg);
342   Printf("%s", d.Default());
343   InternalScopedString g1_loc;
344   InternalScopedString g2_loc;
345   PrintGlobalLocation(&g1_loc, global1);
346   PrintGlobalLocation(&g2_loc, global2);
347   Printf("  [1] size=%zd '%s' %s\n", global1.size,
348          MaybeDemangleGlobalName(global1.name), g1_loc.data());
349   Printf("  [2] size=%zd '%s' %s\n", global2.size,
350          MaybeDemangleGlobalName(global2.name), g2_loc.data());
351   if (stack_id1 && stack_id2) {
352     Printf("These globals were registered at these points:\n");
353     Printf("  [1]:\n");
354     StackDepotGet(stack_id1).Print();
355     Printf("  [2]:\n");
356     StackDepotGet(stack_id2).Print();
357   }
358   Report(
359       "HINT: if you don't care about these errors you may set "
360       "ASAN_OPTIONS=detect_odr_violation=0\n");
361   InternalScopedString error_msg;
362   error_msg.append("%s: global '%s' at %s", scariness.GetDescription(),
363                    MaybeDemangleGlobalName(global1.name), g1_loc.data());
364   ReportErrorSummary(error_msg.data());
365 }
366 
Print()367 void ErrorInvalidPointerPair::Print() {
368   Decorator d;
369   Printf("%s", d.Error());
370   Report("ERROR: AddressSanitizer: %s: %p %p\n", scariness.GetDescription(),
371          (void *)addr1_description.Address(),
372          (void *)addr2_description.Address());
373   Printf("%s", d.Default());
374   GET_STACK_TRACE_FATAL(pc, bp);
375   stack.Print();
376   addr1_description.Print();
377   addr2_description.Print();
378   ReportErrorSummary(scariness.GetDescription(), &stack);
379 }
380 
AdjacentShadowValuesAreFullyPoisoned(u8 * s)381 static bool AdjacentShadowValuesAreFullyPoisoned(u8 *s) {
382   return s[-1] > 127 && s[1] > 127;
383 }
384 
ErrorGeneric(u32 tid,uptr pc_,uptr bp_,uptr sp_,uptr addr,bool is_write_,uptr access_size_)385 ErrorGeneric::ErrorGeneric(u32 tid, uptr pc_, uptr bp_, uptr sp_, uptr addr,
386                            bool is_write_, uptr access_size_)
387     : ErrorBase(tid),
388       addr_description(addr, access_size_, /*shouldLockThreadRegistry=*/false),
389       pc(pc_),
390       bp(bp_),
391       sp(sp_),
392       access_size(access_size_),
393       is_write(is_write_),
394       shadow_val(0) {
395   scariness.Clear();
396   if (access_size) {
397     if (access_size <= 9) {
398       char desr[] = "?-byte";
399       desr[0] = '0' + access_size;
400       scariness.Scare(access_size + access_size / 2, desr);
401     } else if (access_size >= 10) {
402       scariness.Scare(15, "multi-byte");
403     }
404     is_write ? scariness.Scare(20, "write") : scariness.Scare(1, "read");
405 
406     // Determine the error type.
407     bug_descr = "unknown-crash";
408     if (AddrIsInMem(addr)) {
409       u8 *shadow_addr = (u8 *)MemToShadow(addr);
410       // If we are accessing 16 bytes, look at the second shadow byte.
411       if (*shadow_addr == 0 && access_size > ASAN_SHADOW_GRANULARITY)
412         shadow_addr++;
413       // If we are in the partial right redzone, look at the next shadow byte.
414       if (*shadow_addr > 0 && *shadow_addr < 128) shadow_addr++;
415       bool far_from_bounds = false;
416       shadow_val = *shadow_addr;
417       int bug_type_score = 0;
418       // For use-after-frees reads are almost as bad as writes.
419       int read_after_free_bonus = 0;
420       switch (shadow_val) {
421         case kAsanHeapLeftRedzoneMagic:
422         case kAsanArrayCookieMagic:
423           bug_descr = "heap-buffer-overflow";
424           bug_type_score = 10;
425           far_from_bounds = AdjacentShadowValuesAreFullyPoisoned(shadow_addr);
426           break;
427         case kAsanHeapFreeMagic:
428           bug_descr = "heap-use-after-free";
429           bug_type_score = 20;
430           if (!is_write) read_after_free_bonus = 18;
431           break;
432         case kAsanStackLeftRedzoneMagic:
433           bug_descr = "stack-buffer-underflow";
434           bug_type_score = 25;
435           far_from_bounds = AdjacentShadowValuesAreFullyPoisoned(shadow_addr);
436           break;
437         case kAsanInitializationOrderMagic:
438           bug_descr = "initialization-order-fiasco";
439           bug_type_score = 1;
440           break;
441         case kAsanStackMidRedzoneMagic:
442         case kAsanStackRightRedzoneMagic:
443           bug_descr = "stack-buffer-overflow";
444           bug_type_score = 25;
445           far_from_bounds = AdjacentShadowValuesAreFullyPoisoned(shadow_addr);
446           break;
447         case kAsanStackAfterReturnMagic:
448           bug_descr = "stack-use-after-return";
449           bug_type_score = 30;
450           if (!is_write) read_after_free_bonus = 18;
451           break;
452         case kAsanUserPoisonedMemoryMagic:
453           bug_descr = "use-after-poison";
454           bug_type_score = 20;
455           break;
456         case kAsanContiguousContainerOOBMagic:
457           bug_descr = "container-overflow";
458           bug_type_score = 10;
459           break;
460         case kAsanStackUseAfterScopeMagic:
461           bug_descr = "stack-use-after-scope";
462           bug_type_score = 10;
463           break;
464         case kAsanGlobalRedzoneMagic:
465           bug_descr = "global-buffer-overflow";
466           bug_type_score = 10;
467           far_from_bounds = AdjacentShadowValuesAreFullyPoisoned(shadow_addr);
468           break;
469         case kAsanIntraObjectRedzone:
470           bug_descr = "intra-object-overflow";
471           bug_type_score = 10;
472           break;
473         case kAsanAllocaLeftMagic:
474         case kAsanAllocaRightMagic:
475           bug_descr = "dynamic-stack-buffer-overflow";
476           bug_type_score = 25;
477           far_from_bounds = AdjacentShadowValuesAreFullyPoisoned(shadow_addr);
478           break;
479       }
480       scariness.Scare(bug_type_score + read_after_free_bonus, bug_descr);
481       if (far_from_bounds) scariness.Scare(10, "far-from-bounds");
482     }
483   }
484 }
485 
PrintContainerOverflowHint()486 static void PrintContainerOverflowHint() {
487   Printf("HINT: if you don't care about these errors you may set "
488          "ASAN_OPTIONS=detect_container_overflow=0.\n"
489          "If you suspect a false positive see also: "
490          "https://github.com/google/sanitizers/wiki/"
491          "AddressSanitizerContainerOverflow.\n");
492 }
493 
PrintShadowByte(InternalScopedString * str,const char * before,u8 byte,const char * after="\\n")494 static void PrintShadowByte(InternalScopedString *str, const char *before,
495     u8 byte, const char *after = "\n") {
496   PrintMemoryByte(str, before, byte, /*in_shadow*/true, after);
497 }
498 
PrintLegend(InternalScopedString * str)499 static void PrintLegend(InternalScopedString *str) {
500   str->append(
501       "Shadow byte legend (one shadow byte represents %d "
502       "application bytes):\n",
503       (int)ASAN_SHADOW_GRANULARITY);
504   PrintShadowByte(str, "  Addressable:           ", 0);
505   str->append("  Partially addressable: ");
506   for (u8 i = 1; i < ASAN_SHADOW_GRANULARITY; i++)
507     PrintShadowByte(str, "", i, " ");
508   str->append("\n");
509   PrintShadowByte(str, "  Heap left redzone:       ",
510                   kAsanHeapLeftRedzoneMagic);
511   PrintShadowByte(str, "  Freed heap region:       ", kAsanHeapFreeMagic);
512   PrintShadowByte(str, "  Stack left redzone:      ",
513                   kAsanStackLeftRedzoneMagic);
514   PrintShadowByte(str, "  Stack mid redzone:       ",
515                   kAsanStackMidRedzoneMagic);
516   PrintShadowByte(str, "  Stack right redzone:     ",
517                   kAsanStackRightRedzoneMagic);
518   PrintShadowByte(str, "  Stack after return:      ",
519                   kAsanStackAfterReturnMagic);
520   PrintShadowByte(str, "  Stack use after scope:   ",
521                   kAsanStackUseAfterScopeMagic);
522   PrintShadowByte(str, "  Global redzone:          ", kAsanGlobalRedzoneMagic);
523   PrintShadowByte(str, "  Global init order:       ",
524                   kAsanInitializationOrderMagic);
525   PrintShadowByte(str, "  Poisoned by user:        ",
526                   kAsanUserPoisonedMemoryMagic);
527   PrintShadowByte(str, "  Container overflow:      ",
528                   kAsanContiguousContainerOOBMagic);
529   PrintShadowByte(str, "  Array cookie:            ",
530                   kAsanArrayCookieMagic);
531   PrintShadowByte(str, "  Intra object redzone:    ",
532                   kAsanIntraObjectRedzone);
533   PrintShadowByte(str, "  ASan internal:           ", kAsanInternalHeapMagic);
534   PrintShadowByte(str, "  Left alloca redzone:     ", kAsanAllocaLeftMagic);
535   PrintShadowByte(str, "  Right alloca redzone:    ", kAsanAllocaRightMagic);
536 }
537 
PrintShadowBytes(InternalScopedString * str,const char * before,u8 * bytes,u8 * guilty,uptr n)538 static void PrintShadowBytes(InternalScopedString *str, const char *before,
539                              u8 *bytes, u8 *guilty, uptr n) {
540   Decorator d;
541   if (before)
542     str->append("%s%p:", before, (void *)bytes);
543   for (uptr i = 0; i < n; i++) {
544     u8 *p = bytes + i;
545     const char *before =
546         p == guilty ? "[" : (p - 1 == guilty && i != 0) ? "" : " ";
547     const char *after = p == guilty ? "]" : "";
548     PrintShadowByte(str, before, *p, after);
549   }
550   str->append("\n");
551 }
552 
PrintShadowMemoryForAddress(uptr addr)553 static void PrintShadowMemoryForAddress(uptr addr) {
554   if (!AddrIsInMem(addr)) return;
555   uptr shadow_addr = MemToShadow(addr);
556   const uptr n_bytes_per_row = 16;
557   uptr aligned_shadow = shadow_addr & ~(n_bytes_per_row - 1);
558   InternalScopedString str;
559   str.append("Shadow bytes around the buggy address:\n");
560   for (int i = -5; i <= 5; i++) {
561     uptr row_shadow_addr = aligned_shadow + i * n_bytes_per_row;
562     // Skip rows that would be outside the shadow range. This can happen when
563     // the user address is near the bottom, top, or shadow gap of the address
564     // space.
565     if (!AddrIsInShadow(row_shadow_addr)) continue;
566     const char *prefix = (i == 0) ? "=>" : "  ";
567     PrintShadowBytes(&str, prefix, (u8 *)row_shadow_addr, (u8 *)shadow_addr,
568                      n_bytes_per_row);
569   }
570   if (flags()->print_legend) PrintLegend(&str);
571   Printf("%s", str.data());
572 }
573 
Print()574 void ErrorGeneric::Print() {
575   Decorator d;
576   Printf("%s", d.Error());
577   uptr addr = addr_description.Address();
578   Report("ERROR: AddressSanitizer: %s on address %p at pc %p bp %p sp %p\n",
579          bug_descr, (void *)addr, (void *)pc, (void *)bp, (void *)sp);
580   Printf("%s", d.Default());
581 
582   Printf("%s%s of size %zu at %p thread %s%s\n", d.Access(),
583          access_size ? (is_write ? "WRITE" : "READ") : "ACCESS", access_size,
584          (void *)addr, AsanThreadIdAndName(tid).c_str(), d.Default());
585 
586   scariness.Print();
587   GET_STACK_TRACE_FATAL(pc, bp);
588   stack.Print();
589 
590   // Pass bug_descr because we have a special case for
591   // initialization-order-fiasco
592   addr_description.Print(bug_descr);
593   if (shadow_val == kAsanContiguousContainerOOBMagic)
594     PrintContainerOverflowHint();
595   ReportErrorSummary(bug_descr, &stack);
596   PrintShadowMemoryForAddress(addr);
597 }
598 
599 }  // namespace __asan
600