VP8DecoderImpl: Fix uninitialized memory crash

webrtc/modules/video_coding/codecs/vp8/vp8_impl.cc

 /*
  *  Copyright (c) 2012 The WebRTC 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.
  */
 
@@ skipping 1062 matching lines @@
   Release();
 }
 
 int VP8DecoderImpl::InitDecode(const VideoCodec* inst, int number_of_cores) {
   int ret_val = Release();
   if (ret_val < 0) {
     return ret_val;
   }
   if (decoder_ == NULL) {
     decoder_ = new vpx_codec_ctx_t;
+    memset(decoder_, 0, sizeof(*decoder_));
   }
   if (inst && inst->codecType == kVideoCodecVP8) {
     feedback_mode_ = inst->VP8().feedbackModeOn;
   }
   vpx_codec_dec_cfg_t cfg;
   // Setting number of threads to a constant value (1)
   cfg.threads = 1;
   cfg.h = cfg.w = 0;  // set after decode
 
   vpx_codec_flags_t flags = 0;
 #if !defined(WEBRTC_ARCH_ARM) && !defined(WEBRTC_ARCH_ARM64) && \
   !defined(ANDROID)
   flags = VPX_CODEC_USE_POSTPROC;
 #endif
 
   if (vpx_codec_dec_init(decoder_, vpx_codec_vp8_dx(), &cfg, flags)) {
+    delete decoder_;
+    decoder_ = nullptr;
     return WEBRTC_VIDEO_CODEC_MEMORY;
   }
 
   // Save VideoCodec instance for later; mainly for duplicating the decoder.
   if (&codec_ != inst)
     codec_ = *inst;
   propagation_cnt_ = -1;
 
   inited_ = true;
 
@@ skipping 225 matching lines @@
     return -1;
   }
   if (vpx_codec_control(copy->decoder_, VP8_SET_REFERENCE, ref_frame_) !=
       VPX_CODEC_OK) {
     return -1;
   }
   return 0;
 }
 
 }  // namespace webrtc