[FFmpeg-devel] [PATCH 4/5] avformat/iff: Check nb_channels == 0 in CHNL

[Peter Ross]

On Sat, Jun 21, 2025 at 11:15:20PM +0200, Michael Niedermayer wrote:
> Fixes: division by 0
> Fixes: 418396712/clusterfuzz-testcase-minimized-ffmpeg_dem_IFF_fuzzer-6104388018176000
> Fixes: 418478219/clusterfuzz-testcase-minimized-ffmpeg_dem_IFF_fuzzer-4569544410857472
> 
> Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
> Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
> ---
>  libavformat/iff.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/libavformat/iff.c b/libavformat/iff.c
> index 9402be48c98..4ff10beb38a 100644
> --- a/libavformat/iff.c
> +++ b/libavformat/iff.c
> @@ -284,7 +284,7 @@ static int parse_dsd_prop(AVFormatContext *s, AVStream *st, uint64_t eof)
>                  return AVERROR_INVALIDDATA;
>              st->codecpar->ch_layout.order       = AV_CHANNEL_ORDER_UNSPEC;
>              st->codecpar->ch_layout.nb_channels = avio_rb16(pb);
> -            if (size < 2 + st->codecpar->ch_layout.nb_channels * 4)
> +            if (size < 2 + st->codecpar->ch_layout.nb_channels * 4 || !st->codecpar->ch_layout.nb_channels)
>                  return AVERROR_INVALIDDATA;
>              if (st->codecpar->ch_layout.nb_channels > FF_ARRAY_ELEMS(dsd_layout)) {
>                  avpriv_request_sample(s, "channel layout");

please apply

-- Peter
(A907 E02F A6E5 0CD2 34CD 20D2 6760 79C5 AC40 DD6B)
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