ref: 21ac7decfa64e75a566411880a7625881d313b56
dir: /examples/vpx_dec_fuzzer.cc/
/* * Copyright (c) 2018 The WebM project authors. All Rights Reserved. * * Use of this source code is governed by a BSD-style license * that can be found in the LICENSE file in the root of the source * tree. An additional intellectual property rights grant can be found * in the file PATENTS. All contributing project authors may * be found in the AUTHORS file in the root of the source tree. */ /* * Fuzzer for libvpx decoders * ========================== * Requirements * -------------- * Requires Clang 6.0 or above as -fsanitize=fuzzer is used as a linker * option. * Steps to build * -------------- * Clone libvpx repository $git clone https://chromium.googlesource.com/webm/libvpx * Create a directory in parallel to libvpx and change directory $mkdir vpx_dec_fuzzer $cd vpx_dec_fuzzer/ * Enable sanitizers (Supported: address integer memory thread undefined) $source ../libvpx/tools/set_analyzer_env.sh address * Configure libvpx. * Note --size-limit and VPX_MAX_ALLOCABLE_MEMORY are defined to avoid * Out of memory errors when running generated fuzzer binary $../libvpx/configure --disable-unit-tests --size-limit=12288x12288 \ --extra-cflags="-DVPX_MAX_ALLOCABLE_MEMORY=1073741824" \ --disable-webm-io --enable-debug --disable-vp8-encoder \ --disable-vp9-encoder --disable-examples * Build libvpx $make -j32 * Build vp9 fuzzer $ $CXX $CXXFLAGS -std=c++11 -DDECODER=vp9 \ -fsanitize=fuzzer -I../libvpx -I. -Wl,--start-group \ ../libvpx/examples/vpx_dec_fuzzer.cc -o ./vpx_dec_fuzzer_vp9 \ ./libvpx.a -Wl,--end-group * DECODER should be defined as vp9 or vp8 to enable vp9/vp8 * * create a corpus directory and copy some ivf files there. * Based on which codec (vp8/vp9) is being tested, it is recommended to * have corresponding ivf files in corpus directory * Empty corpus directoy also is acceptable, though not recommended $mkdir CORPUS && cp some-files CORPUS * Run fuzzing: $./vpx_dec_fuzzer_vp9 CORPUS * References: * http://llvm.org/docs/LibFuzzer.html * https://github.com/google/oss-fuzz */ #include <stddef.h> #include <stdint.h> #include <stdio.h> #include <stdlib.h> #include <memory> #include "vpx/vp8dx.h" #include "vpx/vpx_decoder.h" #include "vpx_ports/mem_ops.h" #define IVF_FRAME_HDR_SZ (4 + 8) /* 4 byte size + 8 byte timestamp */ #define IVF_FILE_HDR_SZ 32 #define VPXD_INTERFACE(name) VPXD_INTERFACE_(name) #define VPXD_INTERFACE_(name) vpx_codec_##name##_dx() static void CloseFile(FILE *file) { fclose(file); } /* ReadFrame is derived from ivf_read_frame in ivfdec.c * This function doesn't call warn(), but instead ignores those errors. * This is done to minimize the prints on console when running fuzzer * Also if fread fails to read frame_size number of bytes, instead of * returning an error, this returns with partial frames. * This is done to ensure that partial frames are sent to decoder. */ static int ReadFrame(FILE *infile, uint8_t **buffer, size_t *bytes_read, size_t *buffer_size) { char raw_header[IVF_FRAME_HDR_SZ] = { 0 }; size_t frame_size = 0; if (fread(raw_header, IVF_FRAME_HDR_SZ, 1, infile) == 1) { frame_size = mem_get_le32(raw_header); if (frame_size > 256 * 1024 * 1024) { frame_size = 0; } if (frame_size > *buffer_size) { uint8_t *new_buffer = (uint8_t *)realloc(*buffer, 2 * frame_size); if (new_buffer) { *buffer = new_buffer; *buffer_size = 2 * frame_size; } else { frame_size = 0; } } } if (!feof(infile)) { *bytes_read = fread(*buffer, 1, frame_size, infile); return 0; } return 1; } extern "C" void usage_exit(void) { exit(EXIT_FAILURE); } extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) { std::unique_ptr<FILE, decltype(&CloseFile)> file( fmemopen((void *)data, size, "rb"), &CloseFile); if (file == nullptr) { return 0; } // Ensure input contains at least one file header and one frame header if (size < IVF_FILE_HDR_SZ + IVF_FRAME_HDR_SZ) { return 0; } char header[IVF_FILE_HDR_SZ]; if (fread(header, 1, IVF_FILE_HDR_SZ, file.get()) != IVF_FILE_HDR_SZ) { return 0; } vpx_codec_ctx_t codec; // Set thread count in the range [1, 64]. const unsigned int threads = (data[IVF_FILE_HDR_SZ] & 0x3f) + 1; vpx_codec_dec_cfg_t cfg = { threads, 0, 0 }; if (vpx_codec_dec_init(&codec, VPXD_INTERFACE(DECODER), &cfg, 0)) { return 0; } uint8_t *buffer = nullptr; size_t buffer_size = 0; size_t frame_size = 0; while (!ReadFrame(file.get(), &buffer, &frame_size, &buffer_size)) { const vpx_codec_err_t err = vpx_codec_decode(&codec, buffer, frame_size, nullptr, 0); static_cast<void>(err); vpx_codec_iter_t iter = nullptr; vpx_image_t *img = nullptr; while ((img = vpx_codec_get_frame(&codec, &iter)) != nullptr) { } } vpx_codec_destroy(&codec); free(buffer); return 0; }