/* *  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="-fsanitize=fuzzer-no-link \   -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=gnu++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 <algorithm>#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() extern "C" void usage_exit(void) { exit(EXIT_FAILURE); } extern "C" int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {  if (size <= 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;  }   if (threads > 1) {    const int enable = (data[IVF_FILE_HDR_SZ] & 0xa0) != 0;    const vpx_codec_err_t err =        vpx_codec_control(&codec, VP9D_SET_LOOP_FILTER_OPT, enable);    static_cast<void>(err);  }   data += IVF_FILE_HDR_SZ;  size -= IVF_FILE_HDR_SZ;   while (size > IVF_FRAME_HDR_SZ) {    size_t frame_size = mem_get_le32(data);    size -= IVF_FRAME_HDR_SZ;    data += IVF_FRAME_HDR_SZ;    frame_size = std::min(size, frame_size);     const vpx_codec_err_t err =        vpx_codec_decode(&codec, data, 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) {    }    data += frame_size;    size -= frame_size;  }  vpx_codec_destroy(&codec);  return 0;}