diff --git a/libunwindstack/tests/fuzz/UnwinderComponentCreator.cpp b/libunwindstack/tests/fuzz/UnwinderComponentCreator.cpp index 9c5374a5b..65052b6c1 100644 --- a/libunwindstack/tests/fuzz/UnwinderComponentCreator.cpp +++ b/libunwindstack/tests/fuzz/UnwinderComponentCreator.cpp @@ -116,8 +116,12 @@ ElfFake* PopulateElfFake(FuzzedDataProvider* data_provider) { static constexpr size_t kPageSize = 4096; -static constexpr uint64_t AlignToPage(uint64_t address) { - return (address + kPageSize - 1) & ~(kPageSize - 1); +static inline bool AlignToPage(uint64_t address, uint64_t* aligned_address) { + if (__builtin_add_overflow(address, kPageSize - 1, aligned_address)) { + return false; + } + *aligned_address &= ~(kPageSize - 1); + return true; } std::unique_ptr GetMaps(FuzzedDataProvider* data_provider) { @@ -125,8 +129,16 @@ std::unique_ptr GetMaps(FuzzedDataProvider* data_provider) { std::map map_ends; uint8_t entry_count = data_provider->ConsumeIntegralInRange(0, kMaxMapEntryCount); for (uint8_t i = 0; i < entry_count; i++) { - uint64_t start = AlignToPage(data_provider->ConsumeIntegral()); - uint64_t end = AlignToPage(data_provider->ConsumeIntegralInRange(start, UINT64_MAX)); + uint64_t start; + if (!AlignToPage(data_provider->ConsumeIntegral(), &start)) { + // Overflowed. + continue; + } + uint64_t end; + if (!AlignToPage(data_provider->ConsumeIntegralInRange(start, UINT64_MAX), &end)) { + // Overflowed. + continue; + } if (start == end) { // It's impossible to see start == end in the real world, so // make sure the map contains at least one page of data. @@ -142,7 +154,11 @@ std::unique_ptr GetMaps(FuzzedDataProvider* data_provider) { } map_ends[end] = start; - uint64_t offset = AlignToPage(data_provider->ConsumeIntegral()); + uint64_t offset; + if (!AlignToPage(data_provider->ConsumeIntegral(), &offset)) { + // Overflowed. + continue; + } std::string map_info_name = data_provider->ConsumeRandomLengthString(kMaxMapInfoNameLen); uint8_t flags = PROT_READ | PROT_WRITE;