third_party/libwebp/fuzzing/fuzz_animation_api.cc

// Copyright 2018 Google Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//      http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
////////////////////////////////////////////////////////////////////////////////

#include "fuzzing/fuzz.h"
#include "src/webp/decode.h"
#include "src/webp/demux.h"
#include "src/webp/mux_types.h"

extern "C" int LLVMFuzzerTestOneInput(const uint8_t* const data, size_t size) {
  WebPData webp_data;
  WebPDataInit(&webp_data);
  webp_data.size = size;
  webp_data.bytes = data;

  // WebPAnimDecoderNew uses WebPDemux internally to calloc canvas size.
  WebPDemuxer* const demux = WebPDemux(&webp_data);
  if (!demux)
    return 0;
  const uint32_t cw = WebPDemuxGetI(demux, WEBP_FF_CANVAS_WIDTH);
  const uint32_t ch = WebPDemuxGetI(demux, WEBP_FF_CANVAS_HEIGHT);
  if ((size_t)cw * ch > kFuzzPxLimit) {
    WebPDemuxDelete(demux);
    return 0;
  }

  // In addition to canvas size, check each frame separately.
  WebPIterator iter;
  for (int i = 0; i < kFuzzFrameLimit; i++) {
    if (!WebPDemuxGetFrame(demux, i + 1, &iter))
      break;
    int w, h;
    if (WebPGetInfo(iter.fragment.bytes, iter.fragment.size, &w, &h)) {
      if ((size_t)w * h > kFuzzPxLimit) {  // image size of the frame payload
        WebPDemuxReleaseIterator(&iter);
        WebPDemuxDelete(demux);
        return 0;
      }
    }
  }

  WebPDemuxReleaseIterator(&iter);
  WebPDemuxDelete(demux);

  WebPAnimDecoderOptions dec_options;
  if (!WebPAnimDecoderOptionsInit(&dec_options))
    return 0;

  dec_options.use_threads = size & 1;
  // Animations only support 4 (of 12) modes.
  dec_options.color_mode = (WEBP_CSP_MODE)(size % MODE_LAST);
  if (dec_options.color_mode != MODE_BGRA &&
      dec_options.color_mode != MODE_rgbA &&
      dec_options.color_mode != MODE_bgrA) {
    dec_options.color_mode = MODE_RGBA;
  }

  WebPAnimDecoder* dec = WebPAnimDecoderNew(&webp_data, &dec_options);
  if (!dec)
    return 0;

  for (int i = 0; i < kFuzzFrameLimit; i++) {
    uint8_t* buf;
    int timestamp;
    if (!WebPAnimDecoderGetNext(dec, &buf, &timestamp))
      break;
  }

  WebPAnimDecoderDelete(dec);
  return 0;
}