[FFmpeg-devel] [PATCH 07/10] avformat/wavdec: sanity check channels and bps before using them for block_align

[Anton Khirnov]

Quoting Michael Niedermayer (2024-03-26 01:11:48)
> Fixes: 62276/clusterfuzz-testcase-minimized-ffmpeg_dem_W64_fuzzer-4704044498944000
> Fixes: signed integer overflow: 520464 * 8224 cannot be represented in type 'int'
> 
> 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/wavdec.c | 5 ++++-
>  1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/libavformat/wavdec.c b/libavformat/wavdec.c
> index 668c8adc36b..89855670d9c 100644
> --- a/libavformat/wavdec.c
> +++ b/libavformat/wavdec.c
> @@ -34,6 +34,7 @@
>  #include "libavutil/log.h"
>  #include "libavutil/mathematics.h"
>  #include "libavutil/opt.h"
> +#include "libavcodec/internal.h"
>  #include "avformat.h"
>  #include "avio.h"
>  #include "avio_internal.h"
> @@ -908,7 +909,9 @@ static int w64_read_header(AVFormatContext *s)
>              if (ret < 0)
>                  return ret;
>              avio_skip(pb, FFALIGN(size, INT64_C(8)) - size);
> -            if (st->codecpar->block_align) {
> +            if (st->codecpar->block_align &&
> +                st->codecpar->ch_layout.nb_channels < FF_SANE_NB_CHANNELS &&

I objected to this approach.

-- 
Anton Khirnov