48 lines · cpp
1// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.2// See https://llvm.org/LICENSE.txt for license information.3// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception4 5// Triggers the bug described here:6// https://github.com/google/oss-fuzz/issues/46057//8// Tests that custom mutators do not cause MSan false positives. We are careful9// to use every parameter to ensure none cause false positives.10 11#include <algorithm>12#include <cstddef>13#include <cstdint>14#include <cstdio>15#include <cstring>16 17extern "C" {18 19int LLVMFuzzerTestOneInput(const uint8_t *Data, size_t Size) { return 0; }20 21size_t LLVMFuzzerCustomMutator(uint8_t *Data, size_t Size, size_t MaxSize,22 unsigned int Seed) {23 if (Seed == 7)24 return 0;25 if (MaxSize == 0)26 return 0;27 for (size_t I = 0; I < Size; ++I) {28 if (Data[I] == 42) {29 printf("BINGO\n");30 }31 }32 return Size;33}34 35size_t LLVMFuzzerCustomCrossOver(36 const uint8_t *Data1, size_t Size1, const uint8_t *Data2, size_t Size2,37 uint8_t *Out, size_t MaxOutSize, unsigned int Seed) {38 if (Seed == 7)39 return 0;40 size_t I = 0;41 for (; I < Size1 && I < Size2 && I < MaxOutSize; ++I) {42 Out[I] = std::min(Data1[I], Data2[I]);43 }44 return I;45}46 47} // extern "C"48