[FFmpeg-cvslog] avcodec/wavpack: Do not allow the sample format to change between channels

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Wed Jun  3 21:13:47 2020 +0200| [bafaf95116b78ab58dbbcbf15f9c3a7c3a123fbd] | committer: Michael Niedermayer

avcodec/wavpack: Do not allow the sample format to change between channels

Fixes: out of array access
Fixes: 22692/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_WAVPACK_fuzzer-5678686190960640

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

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=bafaf95116b78ab58dbbcbf15f9c3a7c3a123fbd
---

 libavcodec/wavpack.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/libavcodec/wavpack.c b/libavcodec/wavpack.c
index ead57063c8..f77548e5a5 100644
--- a/libavcodec/wavpack.c
+++ b/libavcodec/wavpack.c
@@ -1129,6 +1129,9 @@ static int wavpack_decode_block(AVCodecContext *avctx, int block_no,
     else
         sample_fmt          = AV_SAMPLE_FMT_S32P;
 
+    if (wc->ch_offset && avctx->sample_fmt != sample_fmt)
+        return AVERROR_INVALIDDATA;
+
     bpp            = av_get_bytes_per_sample(sample_fmt);
     orig_bpp       = ((s->frame_flags & 0x03) + 1) << 3;
     multiblock     = (s->frame_flags & WV_SINGLE_BLOCK) != WV_SINGLE_BLOCK;