[FFmpeg-devel] [PATCH 1/3] avcodec/exr: fix undefined shift in pxr24_uncompress()

[Paul B Mahol]

On 11/4/17, Michael Niedermayer <michael at niedermayer.cc> wrote:
> Fixes: runtime error: left shift of 255 by 24 places cannot be represented
> in type 'int'
> Fixes: 3787/clusterfuzz-testcase-minimized-5728764920070144
>
> 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/exr.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/libavcodec/exr.c b/libavcodec/exr.c
> index 0b755db3cb..b1ecde4ebd 100644
> --- a/libavcodec/exr.c
> +++ b/libavcodec/exr.c
> @@ -855,7 +855,7 @@ static int pxr24_uncompress(EXRContext *s, const uint8_t
> *src,
>                  in     = ptr[2] + td->xsize;
>
>                  for (j = 0; j < td->xsize; ++j) {
> -                    uint32_t diff = (*(ptr[0]++) << 24) |
> +                    uint32_t diff = ((unsigned)*(ptr[0]++) << 24) |
>                                      (*(ptr[1]++) << 16) |
>                                      (*(ptr[2]++) << 8);
>                      pixel += diff;
> --
> 2.15.0
>
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>

ok