[FFmpeg-devel] [PATCH 2/9] 4xm: prevent overflow during block alignment calculation

[Ronald S. Bultje]

Hi,

On Fri, Jan 6, 2017 at 2:47 PM, Andreas Cadhalpun <
andreas.cadhalpun at googlemail.com> wrote:

> Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun at googlemail.com>
> ---
>  libavformat/4xm.c | 1 +
>  1 file changed, 1 insertion(+)
>
> diff --git a/libavformat/4xm.c b/libavformat/4xm.c
> index 2758b69d29..45949c4e97 100644
> --- a/libavformat/4xm.c
> +++ b/libavformat/4xm.c
> @@ -187,6 +187,7 @@ static int parse_strk(AVFormatContext *s,
>      st->codecpar->bit_rate              = (int64_t)st->codecpar->channels
> *
>                                            st->codecpar->sample_rate *
>                                            st->codecpar->bits_per_coded_
> sample;
> +    FF_RETURN_ON_OVERFLOW(s, st->codecpar->channels &&
> st->codecpar->bits_per_coded_sample > INT_MAX / st->codecpar->channels)
>      st->codecpar->block_align           = st->codecpar->channels *
>                                            st->codecpar->bits_per_coded_
> sample;
>
> --
> 2.11.0


To an innocent reader (who doesn't know/care about SIGFPE), this might look
like channels = 0 is an actual valid decoder condition that is explicitly
handled here.

Ronald