[FFmpeg-devel] [PATCH 1/2] avcodec/speexdec: Check frames_per_packet more completely

[Paul B Mahol]

On Fri, Oct 15, 2021 at 12:20 AM James Almer <jamrial at gmail.com> wrote:

> On 10/14/2021 7:13 PM, Michael Niedermayer wrote:
> > Fixes: signed integer overflow: 2105344 * 539033345 cannot be
> represented in type 'int'
> > Fixes: out of array write
> > Fixes:
> 39956/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_SPEEX_fuzzer-4766419250708480
> >
> > Found-by: continuous fuzzing process
> https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
> > Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
> > ---
> >   libavcodec/speexdec.c | 2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> >
> > diff --git a/libavcodec/speexdec.c b/libavcodec/speexdec.c
> > index 4c50f54f27b..05f084de2e5 100644
> > --- a/libavcodec/speexdec.c
> > +++ b/libavcodec/speexdec.c
> > @@ -1428,7 +1428,7 @@ static int parse_speex_extradata(AVCodecContext
> *avctx,
> >           return AVERROR_INVALIDDATA;
> >       s->vbr = bytestream_get_le32(&buf);
> >       s->frames_per_packet = bytestream_get_le32(&buf);
> > -    if (s->frames_per_packet <= 0)
> > +    if (s->frames_per_packet <= 0 || s->frames_per_packet >= INT32_MAX
> / s->frame_size)
>
> s->frames_per_packet * s->frame_size is then multiplied by channel count
> (which can be at most 2) for the vector_fmul_scalar() call, so might as
> well check for that here too.
>
> Alternatively, all floatdsp functions could be adapted to take size_t
> buffer lengths.
>

Limit it to 32/64.

>
> >           return AVERROR_INVALIDDATA;
> >       s->extra_headers = bytestream_get_le32(&buf);
> >
> >
>
> _______________________________________________
> ffmpeg-devel mailing list
> ffmpeg-devel at ffmpeg.org
> https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
>
> To unsubscribe, visit link above, or email
> ffmpeg-devel-request at ffmpeg.org with subject "unsubscribe".
>