[FFmpeg-cvslog] avcodec/adpcm: Check channels before use for ADPCM_PSX

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Thu Oct 15 22:09:10 2020 +0200| [4ebe40ef6418995a888094f680eb2313850618d4] | committer: Michael Niedermayer

avcodec/adpcm: Check channels before use for ADPCM_PSX

Fixes: division by zero
Fixes: 26293/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_ADPCM_PSX_fuzzer-5176665237618688
Fixes: 26331/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_ADPCM_PSX_fuzzer-5632330364092416

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=4ebe40ef6418995a888094f680eb2313850618d4
---

 libavcodec/adpcm.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavcodec/adpcm.c b/libavcodec/adpcm.c
index f7da3dcf89..d018c1f91b 100644
--- a/libavcodec/adpcm.c
+++ b/libavcodec/adpcm.c
@@ -135,7 +135,7 @@ static av_cold int adpcm_decode_init(AVCodecContext * avctx)
         break;
     case AV_CODEC_ID_ADPCM_PSX:
         max_channels = 8;
-        if (avctx->block_align % (16 * avctx->channels))
+        if (avctx->channels <= 0 || avctx->block_align % (16 * avctx->channels))
             return AVERROR_INVALIDDATA;
         break;
     case AV_CODEC_ID_ADPCM_IMA_DAT4: