[FFmpeg-devel] [PATCH] avcodec/apedec: use int64_t for FFABS

[Ganesh Ajjanagadde]

On Fri, Oct 9, 2015 at 1:48 PM, Ganesh Ajjanagadde
<gajjanagadde at gmail.com> wrote:
> res, absres are currently int's, which on most platforms is 32 bits.
> Unfortunately, data is untrusted, and on line 1267 res is manipulated
> with data. Thus, res can take on INT32_MIN/INT_MIN with crafted data,
> making FFABS on line 1282 unsafe.
>
> Once again, using FFNABS will make it less readable: logic is less
> clear, diff is bigger, and there is scope for mistakes during the
> expression rewrites.
>
> Tested with FATE.
>
> Signed-off-by: Ganesh Ajjanagadde <gajjanagadde at gmail.com>
> ---
>  libavcodec/apedec.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/libavcodec/apedec.c b/libavcodec/apedec.c
> index fcccfbe..e46558e 100644
> --- a/libavcodec/apedec.c
> +++ b/libavcodec/apedec.c
> @@ -1254,8 +1254,8 @@ static void init_filter(APEContext *ctx, APEFilter *f, int16_t *buf, int order)
>  static void do_apply_filter(APEContext *ctx, int version, APEFilter *f,
>                              int32_t *data, int count, int order, int fracbits)
>  {
> -    int res;
> -    int absres;
> +    int64_t res;
> +    int64_t absres;
>
>      while (count--) {
>          /* round fixedpoint scalar product */
> --
> 2.6.1
>

ping