| //===-- hwasan_report.cpp -------------------------------------------------===// |
| // |
| // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. |
| // See https://llvm.org/LICENSE.txt for license information. |
| // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception |
| // |
| //===----------------------------------------------------------------------===// |
| // |
| // This file is a part of HWAddressSanitizer. |
| // |
| // Error reporting. |
| //===----------------------------------------------------------------------===// |
| |
| #include "hwasan_report.h" |
| |
| #include <dlfcn.h> |
| |
| #include "hwasan.h" |
| #include "hwasan_allocator.h" |
| #include "hwasan_globals.h" |
| #include "hwasan_mapping.h" |
| #include "hwasan_thread.h" |
| #include "hwasan_thread_list.h" |
| #include "sanitizer_common/sanitizer_allocator_internal.h" |
| #include "sanitizer_common/sanitizer_common.h" |
| #include "sanitizer_common/sanitizer_flags.h" |
| #include "sanitizer_common/sanitizer_mutex.h" |
| #include "sanitizer_common/sanitizer_report_decorator.h" |
| #include "sanitizer_common/sanitizer_stackdepot.h" |
| #include "sanitizer_common/sanitizer_stacktrace_printer.h" |
| #include "sanitizer_common/sanitizer_symbolizer.h" |
| |
| using namespace __sanitizer; |
| |
| namespace __hwasan { |
| |
| class ScopedReport { |
| public: |
| ScopedReport(bool fatal = false) : error_message_(1), fatal(fatal) { |
| Lock lock(&error_message_lock_); |
| error_message_ptr_ = fatal ? &error_message_ : nullptr; |
| ++hwasan_report_count; |
| } |
| |
| ~ScopedReport() { |
| void (*report_cb)(const char *); |
| { |
| Lock lock(&error_message_lock_); |
| report_cb = error_report_callback_; |
| error_message_ptr_ = nullptr; |
| } |
| if (report_cb) |
| report_cb(error_message_.data()); |
| if (fatal) |
| SetAbortMessage(error_message_.data()); |
| if (common_flags()->print_module_map >= 2 || |
| (fatal && common_flags()->print_module_map)) |
| DumpProcessMap(); |
| if (fatal) |
| Die(); |
| } |
| |
| static void MaybeAppendToErrorMessage(const char *msg) { |
| Lock lock(&error_message_lock_); |
| if (!error_message_ptr_) |
| return; |
| uptr len = internal_strlen(msg); |
| uptr old_size = error_message_ptr_->size(); |
| error_message_ptr_->resize(old_size + len); |
| // overwrite old trailing '\0', keep new trailing '\0' untouched. |
| internal_memcpy(&(*error_message_ptr_)[old_size - 1], msg, len); |
| } |
| |
| static void SetErrorReportCallback(void (*callback)(const char *)) { |
| Lock lock(&error_message_lock_); |
| error_report_callback_ = callback; |
| } |
| |
| private: |
| ScopedErrorReportLock error_report_lock_; |
| InternalMmapVector<char> error_message_; |
| bool fatal; |
| |
| static InternalMmapVector<char> *error_message_ptr_; |
| static Mutex error_message_lock_; |
| static void (*error_report_callback_)(const char *); |
| }; |
| |
| InternalMmapVector<char> *ScopedReport::error_message_ptr_; |
| Mutex ScopedReport::error_message_lock_; |
| void (*ScopedReport::error_report_callback_)(const char *); |
| |
| // If there is an active ScopedReport, append to its error message. |
| void AppendToErrorMessageBuffer(const char *buffer) { |
| ScopedReport::MaybeAppendToErrorMessage(buffer); |
| } |
| |
| static StackTrace GetStackTraceFromId(u32 id) { |
| CHECK(id); |
| StackTrace res = StackDepotGet(id); |
| CHECK(res.trace); |
| return res; |
| } |
| |
| // A RAII object that holds a copy of the current thread stack ring buffer. |
| // The actual stack buffer may change while we are iterating over it (for |
| // example, Printf may call syslog() which can itself be built with hwasan). |
| class SavedStackAllocations { |
| public: |
| SavedStackAllocations(StackAllocationsRingBuffer *rb) { |
| uptr size = rb->size() * sizeof(uptr); |
| void *storage = |
| MmapAlignedOrDieOnFatalError(size, size * 2, "saved stack allocations"); |
| new (&rb_) StackAllocationsRingBuffer(*rb, storage); |
| } |
| |
| ~SavedStackAllocations() { |
| StackAllocationsRingBuffer *rb = get(); |
| UnmapOrDie(rb->StartOfStorage(), rb->size() * sizeof(uptr)); |
| } |
| |
| StackAllocationsRingBuffer *get() { |
| return (StackAllocationsRingBuffer *)&rb_; |
| } |
| |
| private: |
| uptr rb_; |
| }; |
| |
| class Decorator: public __sanitizer::SanitizerCommonDecorator { |
| public: |
| Decorator() : SanitizerCommonDecorator() { } |
| const char *Access() { return Blue(); } |
| const char *Allocation() const { return Magenta(); } |
| const char *Origin() const { return Magenta(); } |
| const char *Name() const { return Green(); } |
| const char *Location() { return Green(); } |
| const char *Thread() { return Green(); } |
| }; |
| |
| static bool FindHeapAllocation(HeapAllocationsRingBuffer *rb, uptr tagged_addr, |
| HeapAllocationRecord *har, uptr *ring_index, |
| uptr *num_matching_addrs, |
| uptr *num_matching_addrs_4b) { |
| if (!rb) return false; |
| |
| *num_matching_addrs = 0; |
| *num_matching_addrs_4b = 0; |
| for (uptr i = 0, size = rb->size(); i < size; i++) { |
| auto h = (*rb)[i]; |
| if (h.tagged_addr <= tagged_addr && |
| h.tagged_addr + h.requested_size > tagged_addr) { |
| *har = h; |
| *ring_index = i; |
| return true; |
| } |
| |
| // Measure the number of heap ring buffer entries that would have matched |
| // if we had only one entry per address (e.g. if the ring buffer data was |
| // stored at the address itself). This will help us tune the allocator |
| // implementation for MTE. |
| if (UntagAddr(h.tagged_addr) <= UntagAddr(tagged_addr) && |
| UntagAddr(h.tagged_addr) + h.requested_size > UntagAddr(tagged_addr)) { |
| ++*num_matching_addrs; |
| } |
| |
| // Measure the number of heap ring buffer entries that would have matched |
| // if we only had 4 tag bits, which is the case for MTE. |
| auto untag_4b = [](uptr p) { |
| return p & ((1ULL << 60) - 1); |
| }; |
| if (untag_4b(h.tagged_addr) <= untag_4b(tagged_addr) && |
| untag_4b(h.tagged_addr) + h.requested_size > untag_4b(tagged_addr)) { |
| ++*num_matching_addrs_4b; |
| } |
| } |
| return false; |
| } |
| |
| static void PrintStackAllocations(StackAllocationsRingBuffer *sa, |
| tag_t addr_tag, uptr untagged_addr) { |
| uptr frames = Min((uptr)flags()->stack_history_size, sa->size()); |
| bool found_local = false; |
| for (uptr i = 0; i < frames; i++) { |
| const uptr *record_addr = &(*sa)[i]; |
| uptr record = *record_addr; |
| if (!record) |
| break; |
| tag_t base_tag = |
| reinterpret_cast<uptr>(record_addr) >> kRecordAddrBaseTagShift; |
| uptr fp = (record >> kRecordFPShift) << kRecordFPLShift; |
| uptr pc_mask = (1ULL << kRecordFPShift) - 1; |
| uptr pc = record & pc_mask; |
| FrameInfo frame; |
| if (Symbolizer::GetOrInit()->SymbolizeFrame(pc, &frame)) { |
| for (LocalInfo &local : frame.locals) { |
| if (!local.has_frame_offset || !local.has_size || !local.has_tag_offset) |
| continue; |
| tag_t obj_tag = base_tag ^ local.tag_offset; |
| if (obj_tag != addr_tag) |
| continue; |
| // Calculate the offset from the object address to the faulting |
| // address. Because we only store bits 4-19 of FP (bits 0-3 are |
| // guaranteed to be zero), the calculation is performed mod 2^20 and may |
| // harmlessly underflow if the address mod 2^20 is below the object |
| // address. |
| uptr obj_offset = |
| (untagged_addr - fp - local.frame_offset) & (kRecordFPModulus - 1); |
| if (obj_offset >= local.size) |
| continue; |
| if (!found_local) { |
| Printf("Potentially referenced stack objects:\n"); |
| found_local = true; |
| } |
| Printf(" %s in %s %s:%d\n", local.name, local.function_name, |
| local.decl_file, local.decl_line); |
| } |
| frame.Clear(); |
| } |
| } |
| |
| if (found_local) |
| return; |
| |
| // We didn't find any locals. Most likely we don't have symbols, so dump |
| // the information that we have for offline analysis. |
| InternalScopedString frame_desc; |
| Printf("Previously allocated frames:\n"); |
| for (uptr i = 0; i < frames; i++) { |
| const uptr *record_addr = &(*sa)[i]; |
| uptr record = *record_addr; |
| if (!record) |
| break; |
| uptr pc_mask = (1ULL << 48) - 1; |
| uptr pc = record & pc_mask; |
| frame_desc.append(" record_addr:0x%zx record:0x%zx", |
| reinterpret_cast<uptr>(record_addr), record); |
| if (SymbolizedStack *frame = Symbolizer::GetOrInit()->SymbolizePC(pc)) { |
| RenderFrame(&frame_desc, " %F %L", 0, frame->info.address, &frame->info, |
| common_flags()->symbolize_vs_style, |
| common_flags()->strip_path_prefix); |
| frame->ClearAll(); |
| } |
| Printf("%s\n", frame_desc.data()); |
| frame_desc.clear(); |
| } |
| } |
| |
| // Returns true if tag == *tag_ptr, reading tags from short granules if |
| // necessary. This may return a false positive if tags 1-15 are used as a |
| // regular tag rather than a short granule marker. |
| static bool TagsEqual(tag_t tag, tag_t *tag_ptr) { |
| if (tag == *tag_ptr) |
| return true; |
| if (*tag_ptr == 0 || *tag_ptr > kShadowAlignment - 1) |
| return false; |
| uptr mem = ShadowToMem(reinterpret_cast<uptr>(tag_ptr)); |
| tag_t inline_tag = *reinterpret_cast<tag_t *>(mem + kShadowAlignment - 1); |
| return tag == inline_tag; |
| } |
| |
| // HWASan globals store the size of the global in the descriptor. In cases where |
| // we don't have a binary with symbols, we can't grab the size of the global |
| // from the debug info - but we might be able to retrieve it from the |
| // descriptor. Returns zero if the lookup failed. |
| static uptr GetGlobalSizeFromDescriptor(uptr ptr) { |
| // Find the ELF object that this global resides in. |
| Dl_info info; |
| if (dladdr(reinterpret_cast<void *>(ptr), &info) == 0) |
| return 0; |
| auto *ehdr = reinterpret_cast<const ElfW(Ehdr) *>(info.dli_fbase); |
| auto *phdr_begin = reinterpret_cast<const ElfW(Phdr) *>( |
| reinterpret_cast<const u8 *>(ehdr) + ehdr->e_phoff); |
| |
| // Get the load bias. This is normally the same as the dli_fbase address on |
| // position-independent code, but can be different on non-PIE executables, |
| // binaries using LLD's partitioning feature, or binaries compiled with a |
| // linker script. |
| ElfW(Addr) load_bias = 0; |
| for (const auto &phdr : |
| ArrayRef<const ElfW(Phdr)>(phdr_begin, phdr_begin + ehdr->e_phnum)) { |
| if (phdr.p_type != PT_LOAD || phdr.p_offset != 0) |
| continue; |
| load_bias = reinterpret_cast<ElfW(Addr)>(ehdr) - phdr.p_vaddr; |
| break; |
| } |
| |
| // Walk all globals in this ELF object, looking for the one we're interested |
| // in. Once we find it, we can stop iterating and return the size of the |
| // global we're interested in. |
| for (const hwasan_global &global : |
| HwasanGlobalsFor(load_bias, phdr_begin, ehdr->e_phnum)) |
| if (global.addr() <= ptr && ptr < global.addr() + global.size()) |
| return global.size(); |
| |
| return 0; |
| } |
| |
| static void ShowHeapOrGlobalCandidate(uptr untagged_addr, tag_t *candidate, |
| tag_t *left, tag_t *right) { |
| Decorator d; |
| uptr mem = ShadowToMem(reinterpret_cast<uptr>(candidate)); |
| HwasanChunkView chunk = FindHeapChunkByAddress(mem); |
| if (chunk.IsAllocated()) { |
| uptr offset; |
| const char *whence; |
| if (untagged_addr < chunk.End() && untagged_addr >= chunk.Beg()) { |
| offset = untagged_addr - chunk.Beg(); |
| whence = "inside"; |
| } else if (candidate == left) { |
| offset = untagged_addr - chunk.End(); |
| whence = "to the right of"; |
| } else { |
| offset = chunk.Beg() - untagged_addr; |
| whence = "to the left of"; |
| } |
| Printf("%s", d.Error()); |
| Printf("\nCause: heap-buffer-overflow\n"); |
| Printf("%s", d.Default()); |
| Printf("%s", d.Location()); |
| Printf("%p is located %zd bytes %s %zd-byte region [%p,%p)\n", |
| untagged_addr, offset, whence, chunk.UsedSize(), chunk.Beg(), |
| chunk.End()); |
| Printf("%s", d.Allocation()); |
| Printf("allocated here:\n"); |
| Printf("%s", d.Default()); |
| GetStackTraceFromId(chunk.GetAllocStackId()).Print(); |
| return; |
| } |
| // Check whether the address points into a loaded library. If so, this is |
| // most likely a global variable. |
| const char *module_name; |
| uptr module_address; |
| Symbolizer *sym = Symbolizer::GetOrInit(); |
| if (sym->GetModuleNameAndOffsetForPC(mem, &module_name, &module_address)) { |
| Printf("%s", d.Error()); |
| Printf("\nCause: global-overflow\n"); |
| Printf("%s", d.Default()); |
| DataInfo info; |
| Printf("%s", d.Location()); |
| if (sym->SymbolizeData(mem, &info) && info.start) { |
| Printf( |
| "%p is located %zd bytes to the %s of %zd-byte global variable " |
| "%s [%p,%p) in %s\n", |
| untagged_addr, |
| candidate == left ? untagged_addr - (info.start + info.size) |
| : info.start - untagged_addr, |
| candidate == left ? "right" : "left", info.size, info.name, |
| info.start, info.start + info.size, module_name); |
| } else { |
| uptr size = GetGlobalSizeFromDescriptor(mem); |
| if (size == 0) |
| // We couldn't find the size of the global from the descriptors. |
| Printf( |
| "%p is located to the %s of a global variable in " |
| "\n #0 0x%x (%s+0x%x)\n", |
| untagged_addr, candidate == left ? "right" : "left", mem, |
| module_name, module_address); |
| else |
| Printf( |
| "%p is located to the %s of a %zd-byte global variable in " |
| "\n #0 0x%x (%s+0x%x)\n", |
| untagged_addr, candidate == left ? "right" : "left", size, mem, |
| module_name, module_address); |
| } |
| Printf("%s", d.Default()); |
| } |
| } |
| |
| void PrintAddressDescription( |
| uptr tagged_addr, uptr access_size, |
| StackAllocationsRingBuffer *current_stack_allocations) { |
| Decorator d; |
| int num_descriptions_printed = 0; |
| uptr untagged_addr = UntagAddr(tagged_addr); |
| |
| if (MemIsShadow(untagged_addr)) { |
| Printf("%s%p is HWAsan shadow memory.\n%s", d.Location(), untagged_addr, |
| d.Default()); |
| return; |
| } |
| |
| // Print some very basic information about the address, if it's a heap. |
| HwasanChunkView chunk = FindHeapChunkByAddress(untagged_addr); |
| if (uptr beg = chunk.Beg()) { |
| uptr size = chunk.ActualSize(); |
| Printf("%s[%p,%p) is a %s %s heap chunk; " |
| "size: %zd offset: %zd\n%s", |
| d.Location(), |
| beg, beg + size, |
| chunk.FromSmallHeap() ? "small" : "large", |
| chunk.IsAllocated() ? "allocated" : "unallocated", |
| size, untagged_addr - beg, |
| d.Default()); |
| } |
| |
| tag_t addr_tag = GetTagFromPointer(tagged_addr); |
| |
| bool on_stack = false; |
| // Check stack first. If the address is on the stack of a live thread, we |
| // know it cannot be a heap / global overflow. |
| hwasanThreadList().VisitAllLiveThreads([&](Thread *t) { |
| if (t->AddrIsInStack(untagged_addr)) { |
| on_stack = true; |
| // TODO(fmayer): figure out how to distinguish use-after-return and |
| // stack-buffer-overflow. |
| Printf("%s", d.Error()); |
| Printf("\nCause: stack tag-mismatch\n"); |
| Printf("%s", d.Location()); |
| Printf("Address %p is located in stack of thread T%zd\n", untagged_addr, |
| t->unique_id()); |
| Printf("%s", d.Default()); |
| t->Announce(); |
| |
| auto *sa = (t == GetCurrentThread() && current_stack_allocations) |
| ? current_stack_allocations |
| : t->stack_allocations(); |
| PrintStackAllocations(sa, addr_tag, untagged_addr); |
| num_descriptions_printed++; |
| } |
| }); |
| |
| // Check if this looks like a heap buffer overflow by scanning |
| // the shadow left and right and looking for the first adjacent |
| // object with a different memory tag. If that tag matches addr_tag, |
| // check the allocator if it has a live chunk there. |
| tag_t *tag_ptr = reinterpret_cast<tag_t*>(MemToShadow(untagged_addr)); |
| tag_t *candidate = nullptr, *left = tag_ptr, *right = tag_ptr; |
| uptr candidate_distance = 0; |
| for (; candidate_distance < 1000; candidate_distance++) { |
| if (MemIsShadow(reinterpret_cast<uptr>(left)) && |
| TagsEqual(addr_tag, left)) { |
| candidate = left; |
| break; |
| } |
| --left; |
| if (MemIsShadow(reinterpret_cast<uptr>(right)) && |
| TagsEqual(addr_tag, right)) { |
| candidate = right; |
| break; |
| } |
| ++right; |
| } |
| |
| constexpr auto kCloseCandidateDistance = 1; |
| |
| if (!on_stack && candidate && candidate_distance <= kCloseCandidateDistance) { |
| ShowHeapOrGlobalCandidate(untagged_addr, candidate, left, right); |
| num_descriptions_printed++; |
| } |
| |
| hwasanThreadList().VisitAllLiveThreads([&](Thread *t) { |
| // Scan all threads' ring buffers to find if it's a heap-use-after-free. |
| HeapAllocationRecord har; |
| uptr ring_index, num_matching_addrs, num_matching_addrs_4b; |
| if (FindHeapAllocation(t->heap_allocations(), tagged_addr, &har, |
| &ring_index, &num_matching_addrs, |
| &num_matching_addrs_4b)) { |
| Printf("%s", d.Error()); |
| Printf("\nCause: use-after-free\n"); |
| Printf("%s", d.Location()); |
| Printf("%p is located %zd bytes inside of %zd-byte region [%p,%p)\n", |
| untagged_addr, untagged_addr - UntagAddr(har.tagged_addr), |
| har.requested_size, UntagAddr(har.tagged_addr), |
| UntagAddr(har.tagged_addr) + har.requested_size); |
| Printf("%s", d.Allocation()); |
| Printf("freed by thread T%zd here:\n", t->unique_id()); |
| Printf("%s", d.Default()); |
| GetStackTraceFromId(har.free_context_id).Print(); |
| |
| Printf("%s", d.Allocation()); |
| Printf("previously allocated here:\n", t); |
| Printf("%s", d.Default()); |
| GetStackTraceFromId(har.alloc_context_id).Print(); |
| |
| // Print a developer note: the index of this heap object |
| // in the thread's deallocation ring buffer. |
| Printf("hwasan_dev_note_heap_rb_distance: %zd %zd\n", ring_index + 1, |
| flags()->heap_history_size); |
| Printf("hwasan_dev_note_num_matching_addrs: %zd\n", num_matching_addrs); |
| Printf("hwasan_dev_note_num_matching_addrs_4b: %zd\n", |
| num_matching_addrs_4b); |
| |
| t->Announce(); |
| num_descriptions_printed++; |
| } |
| }); |
| |
| if (candidate && num_descriptions_printed == 0) { |
| ShowHeapOrGlobalCandidate(untagged_addr, candidate, left, right); |
| num_descriptions_printed++; |
| } |
| |
| // Print the remaining threads, as an extra information, 1 line per thread. |
| hwasanThreadList().VisitAllLiveThreads([&](Thread *t) { t->Announce(); }); |
| |
| if (!num_descriptions_printed) |
| // We exhausted our possibilities. Bail out. |
| Printf("HWAddressSanitizer can not describe address in more detail.\n"); |
| if (num_descriptions_printed > 1) { |
| Printf( |
| "There are %d potential causes, printed above in order " |
| "of likeliness.\n", |
| num_descriptions_printed); |
| } |
| } |
| |
| void ReportStats() {} |
| |
| static void PrintTagInfoAroundAddr(tag_t *tag_ptr, uptr num_rows, |
| void (*print_tag)(InternalScopedString &s, |
| tag_t *tag)) { |
| const uptr row_len = 16; // better be power of two. |
| tag_t *center_row_beg = reinterpret_cast<tag_t *>( |
| RoundDownTo(reinterpret_cast<uptr>(tag_ptr), row_len)); |
| tag_t *beg_row = center_row_beg - row_len * (num_rows / 2); |
| tag_t *end_row = center_row_beg + row_len * ((num_rows + 1) / 2); |
| InternalScopedString s; |
| for (tag_t *row = beg_row; row < end_row; row += row_len) { |
| s.append("%s", row == center_row_beg ? "=>" : " "); |
| s.append("%p:", row); |
| for (uptr i = 0; i < row_len; i++) { |
| s.append("%s", row + i == tag_ptr ? "[" : " "); |
| print_tag(s, &row[i]); |
| s.append("%s", row + i == tag_ptr ? "]" : " "); |
| } |
| s.append("\n"); |
| } |
| Printf("%s", s.data()); |
| } |
| |
| static void PrintTagsAroundAddr(tag_t *tag_ptr) { |
| Printf( |
| "Memory tags around the buggy address (one tag corresponds to %zd " |
| "bytes):\n", kShadowAlignment); |
| PrintTagInfoAroundAddr(tag_ptr, 17, [](InternalScopedString &s, tag_t *tag) { |
| s.append("%02x", *tag); |
| }); |
| |
| Printf( |
| "Tags for short granules around the buggy address (one tag corresponds " |
| "to %zd bytes):\n", |
| kShadowAlignment); |
| PrintTagInfoAroundAddr(tag_ptr, 3, [](InternalScopedString &s, tag_t *tag) { |
| if (*tag >= 1 && *tag <= kShadowAlignment) { |
| uptr granule_addr = ShadowToMem(reinterpret_cast<uptr>(tag)); |
| s.append("%02x", |
| *reinterpret_cast<u8 *>(granule_addr + kShadowAlignment - 1)); |
| } else { |
| s.append(".."); |
| } |
| }); |
| Printf( |
| "See " |
| "https://clang.llvm.org/docs/" |
| "HardwareAssistedAddressSanitizerDesign.html#short-granules for a " |
| "description of short granule tags\n"); |
| } |
| |
| uptr GetTopPc(StackTrace *stack) { |
| return stack->size ? StackTrace::GetPreviousInstructionPc(stack->trace[0]) |
| : 0; |
| } |
| |
| void ReportInvalidFree(StackTrace *stack, uptr tagged_addr) { |
| ScopedReport R(flags()->halt_on_error); |
| |
| uptr untagged_addr = UntagAddr(tagged_addr); |
| tag_t ptr_tag = GetTagFromPointer(tagged_addr); |
| tag_t *tag_ptr = nullptr; |
| tag_t mem_tag = 0; |
| if (MemIsApp(untagged_addr)) { |
| tag_ptr = reinterpret_cast<tag_t *>(MemToShadow(untagged_addr)); |
| if (MemIsShadow(reinterpret_cast<uptr>(tag_ptr))) |
| mem_tag = *tag_ptr; |
| else |
| tag_ptr = nullptr; |
| } |
| Decorator d; |
| Printf("%s", d.Error()); |
| uptr pc = GetTopPc(stack); |
| const char *bug_type = "invalid-free"; |
| const Thread *thread = GetCurrentThread(); |
| if (thread) { |
| Report("ERROR: %s: %s on address %p at pc %p on thread T%zd\n", |
| SanitizerToolName, bug_type, untagged_addr, pc, thread->unique_id()); |
| } else { |
| Report("ERROR: %s: %s on address %p at pc %p on unknown thread\n", |
| SanitizerToolName, bug_type, untagged_addr, pc); |
| } |
| Printf("%s", d.Access()); |
| if (tag_ptr) |
| Printf("tags: %02x/%02x (ptr/mem)\n", ptr_tag, mem_tag); |
| Printf("%s", d.Default()); |
| |
| stack->Print(); |
| |
| PrintAddressDescription(tagged_addr, 0, nullptr); |
| |
| if (tag_ptr) |
| PrintTagsAroundAddr(tag_ptr); |
| |
| ReportErrorSummary(bug_type, stack); |
| } |
| |
| void ReportTailOverwritten(StackTrace *stack, uptr tagged_addr, uptr orig_size, |
| const u8 *expected) { |
| uptr tail_size = kShadowAlignment - (orig_size % kShadowAlignment); |
| u8 actual_expected[kShadowAlignment]; |
| internal_memcpy(actual_expected, expected, tail_size); |
| tag_t ptr_tag = GetTagFromPointer(tagged_addr); |
| // Short granule is stashed in the last byte of the magic string. To avoid |
| // confusion, make the expected magic string contain the short granule tag. |
| if (orig_size % kShadowAlignment != 0) { |
| actual_expected[tail_size - 1] = ptr_tag; |
| } |
| |
| ScopedReport R(flags()->halt_on_error); |
| Decorator d; |
| uptr untagged_addr = UntagAddr(tagged_addr); |
| Printf("%s", d.Error()); |
| const char *bug_type = "allocation-tail-overwritten"; |
| Report("ERROR: %s: %s; heap object [%p,%p) of size %zd\n", SanitizerToolName, |
| bug_type, untagged_addr, untagged_addr + orig_size, orig_size); |
| Printf("\n%s", d.Default()); |
| Printf( |
| "Stack of invalid access unknown. Issue detected at deallocation " |
| "time.\n"); |
| Printf("%s", d.Allocation()); |
| Printf("deallocated here:\n"); |
| Printf("%s", d.Default()); |
| stack->Print(); |
| HwasanChunkView chunk = FindHeapChunkByAddress(untagged_addr); |
| if (chunk.Beg()) { |
| Printf("%s", d.Allocation()); |
| Printf("allocated here:\n"); |
| Printf("%s", d.Default()); |
| GetStackTraceFromId(chunk.GetAllocStackId()).Print(); |
| } |
| |
| InternalScopedString s; |
| CHECK_GT(tail_size, 0U); |
| CHECK_LT(tail_size, kShadowAlignment); |
| u8 *tail = reinterpret_cast<u8*>(untagged_addr + orig_size); |
| s.append("Tail contains: "); |
| for (uptr i = 0; i < kShadowAlignment - tail_size; i++) |
| s.append(".. "); |
| for (uptr i = 0; i < tail_size; i++) |
| s.append("%02x ", tail[i]); |
| s.append("\n"); |
| s.append("Expected: "); |
| for (uptr i = 0; i < kShadowAlignment - tail_size; i++) |
| s.append(".. "); |
| for (uptr i = 0; i < tail_size; i++) s.append("%02x ", actual_expected[i]); |
| s.append("\n"); |
| s.append(" "); |
| for (uptr i = 0; i < kShadowAlignment - tail_size; i++) |
| s.append(" "); |
| for (uptr i = 0; i < tail_size; i++) |
| s.append("%s ", actual_expected[i] != tail[i] ? "^^" : " "); |
| |
| s.append("\nThis error occurs when a buffer overflow overwrites memory\n" |
| "to the right of a heap object, but within the %zd-byte granule, e.g.\n" |
| " char *x = new char[20];\n" |
| " x[25] = 42;\n" |
| "%s does not detect such bugs in uninstrumented code at the time of write," |
| "\nbut can detect them at the time of free/delete.\n" |
| "To disable this feature set HWASAN_OPTIONS=free_checks_tail_magic=0\n", |
| kShadowAlignment, SanitizerToolName); |
| Printf("%s", s.data()); |
| GetCurrentThread()->Announce(); |
| |
| tag_t *tag_ptr = reinterpret_cast<tag_t*>(MemToShadow(untagged_addr)); |
| PrintTagsAroundAddr(tag_ptr); |
| |
| ReportErrorSummary(bug_type, stack); |
| } |
| |
| void ReportTagMismatch(StackTrace *stack, uptr tagged_addr, uptr access_size, |
| bool is_store, bool fatal, uptr *registers_frame) { |
| ScopedReport R(fatal); |
| SavedStackAllocations current_stack_allocations( |
| GetCurrentThread()->stack_allocations()); |
| |
| Decorator d; |
| uptr untagged_addr = UntagAddr(tagged_addr); |
| // TODO: when possible, try to print heap-use-after-free, etc. |
| const char *bug_type = "tag-mismatch"; |
| uptr pc = GetTopPc(stack); |
| Printf("%s", d.Error()); |
| Report("ERROR: %s: %s on address %p at pc %p\n", SanitizerToolName, bug_type, |
| untagged_addr, pc); |
| |
| Thread *t = GetCurrentThread(); |
| |
| sptr offset = |
| __hwasan_test_shadow(reinterpret_cast<void *>(tagged_addr), access_size); |
| CHECK(offset >= 0 && offset < static_cast<sptr>(access_size)); |
| tag_t ptr_tag = GetTagFromPointer(tagged_addr); |
| tag_t *tag_ptr = |
| reinterpret_cast<tag_t *>(MemToShadow(untagged_addr + offset)); |
| tag_t mem_tag = *tag_ptr; |
| |
| Printf("%s", d.Access()); |
| Printf("%s of size %zu at %p tags: %02x/%02x (ptr/mem) in thread T%zd\n", |
| is_store ? "WRITE" : "READ", access_size, untagged_addr, ptr_tag, |
| mem_tag, t->unique_id()); |
| if (offset != 0) |
| Printf("Invalid access starting at offset [%zu, %zu)\n", offset, |
| Min(access_size, static_cast<uptr>(offset) + (1 << kShadowScale))); |
| Printf("%s", d.Default()); |
| |
| stack->Print(); |
| |
| PrintAddressDescription(tagged_addr, access_size, |
| current_stack_allocations.get()); |
| t->Announce(); |
| |
| PrintTagsAroundAddr(tag_ptr); |
| |
| if (registers_frame) |
| ReportRegisters(registers_frame, pc); |
| |
| ReportErrorSummary(bug_type, stack); |
| } |
| |
| // See the frame breakdown defined in __hwasan_tag_mismatch (from |
| // hwasan_tag_mismatch_aarch64.S). |
| void ReportRegisters(uptr *frame, uptr pc) { |
| Printf("Registers where the failure occurred (pc %p):\n", pc); |
| |
| // We explicitly print a single line (4 registers/line) each iteration to |
| // reduce the amount of logcat error messages printed. Each Printf() will |
| // result in a new logcat line, irrespective of whether a newline is present, |
| // and so we wish to reduce the number of Printf() calls we have to make. |
| Printf(" x0 %016llx x1 %016llx x2 %016llx x3 %016llx\n", |
| frame[0], frame[1], frame[2], frame[3]); |
| Printf(" x4 %016llx x5 %016llx x6 %016llx x7 %016llx\n", |
| frame[4], frame[5], frame[6], frame[7]); |
| Printf(" x8 %016llx x9 %016llx x10 %016llx x11 %016llx\n", |
| frame[8], frame[9], frame[10], frame[11]); |
| Printf(" x12 %016llx x13 %016llx x14 %016llx x15 %016llx\n", |
| frame[12], frame[13], frame[14], frame[15]); |
| Printf(" x16 %016llx x17 %016llx x18 %016llx x19 %016llx\n", |
| frame[16], frame[17], frame[18], frame[19]); |
| Printf(" x20 %016llx x21 %016llx x22 %016llx x23 %016llx\n", |
| frame[20], frame[21], frame[22], frame[23]); |
| Printf(" x24 %016llx x25 %016llx x26 %016llx x27 %016llx\n", |
| frame[24], frame[25], frame[26], frame[27]); |
| // hwasan_check* reduces the stack pointer by 256, then __hwasan_tag_mismatch |
| // passes it to this function. |
| Printf(" x28 %016llx x29 %016llx x30 %016llx sp %016llx\n", frame[28], |
| frame[29], frame[30], reinterpret_cast<u8 *>(frame) + 256); |
| } |
| |
| } // namespace __hwasan |
| |
| void __hwasan_set_error_report_callback(void (*callback)(const char *)) { |
| __hwasan::ScopedReport::SetErrorReportCallback(callback); |
| } |
