[FFmpeg-cvslog] avcodec/adpcm: Set vqa_version before use in init

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Mon Apr 19 16:20:55 2021 +0200| [7a403da0cb8e5fe308fe307b7ed219110f7021e0] | committer: Michael Niedermayer

avcodec/adpcm: Set vqa_version before use in init

Fixes: null pointer dereference
Fixes: 33172/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_ADPCM_IMA_WS_fuzzer-5200164273913856

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=7a403da0cb8e5fe308fe307b7ed219110f7021e0
---

 libavcodec/adpcm.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/libavcodec/adpcm.c b/libavcodec/adpcm.c
index 94e1fade28..5e0a654caf 100644
--- a/libavcodec/adpcm.c
+++ b/libavcodec/adpcm.c
@@ -193,6 +193,8 @@ static av_cold int adpcm_decode_init(AVCodecContext * avctx)
         avctx->sample_fmt = AV_SAMPLE_FMT_S16P;
         break;
     case AV_CODEC_ID_ADPCM_IMA_WS:
+        if (avctx->extradata && avctx->extradata_size >= 2)
+            c->vqa_version = AV_RL16(avctx->extradata);
         avctx->sample_fmt = c->vqa_version == 3 ? AV_SAMPLE_FMT_S16P :
                                                   AV_SAMPLE_FMT_S16;
         break;