[FFmpeg-cvslog] avformat/genh: Check nb_channels for IMA ADPCM

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Sat Sep 17 22:46:35 2022 +0200| [0345a885455dea52fcc570b97f5dc5c75372a39c] | committer: Michael Niedermayer

avformat/genh: Check nb_channels for IMA ADPCM

The check could be made more strict

Fixes: signed integer overflow: 36 * 538976288 cannot be represented in type 'int'
Fixes: 50993/clusterfuzz-testcase-minimized-ffmpeg_dem_GENH_fuzzer-6539389873815552

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=0345a885455dea52fcc570b97f5dc5c75372a39c
---

 libavformat/genh.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/libavformat/genh.c b/libavformat/genh.c
index a25d4d625a..1f707b5555 100644
--- a/libavformat/genh.c
+++ b/libavformat/genh.c
@@ -78,6 +78,8 @@ static int genh_read_header(AVFormatContext *s)
     case  0: st->codecpar->codec_id = AV_CODEC_ID_ADPCM_PSX;        break;
     case  1:
     case 11: st->codecpar->bits_per_coded_sample = 4;
+             if (st->codecpar->ch_layout.nb_channels > INT_MAX / 36)
+                return AVERROR_INVALIDDATA;
              st->codecpar->block_align = 36 * st->codecpar->ch_layout.nb_channels;
              st->codecpar->codec_id = AV_CODEC_ID_ADPCM_IMA_WAV;    break;
     case  2: st->codecpar->codec_id = AV_CODEC_ID_ADPCM_DTK;        break;