[FFmpeg-devel] [PATCH 2/6] avformat/vividas: Fixes overflow in shift in recover_key()

[Reimar Döffinger]

On 13 July 2019 22:25:02 CEST, Michael Niedermayer <michael at niedermayer.cc> wrote:
>Fixes: left shift of 133 by 24 places cannot be represented in type
>'int'
>Fixes:
>15365/clusterfuzz-testcase-minimized-ffmpeg_DEMUXER_fuzzer-5716153105645568
>
>Found-by: continuous fuzzing process
>https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
>Suggested-by: Reimar Döffinger <Reimar.Doeffinger at gmx.de>
>Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
>---
> libavformat/vividas.c | 5 +----
> 1 file changed, 1 insertion(+), 4 deletions(-)
>
>diff --git a/libavformat/vividas.c b/libavformat/vividas.c
>index 350c7aa70a..830e318645 100644
>--- a/libavformat/vividas.c
>+++ b/libavformat/vividas.c
>@@ -115,10 +115,7 @@ static unsigned recover_key(unsigned char
>sample[4], unsigned expected_size)
> 
>     put_v(plaintext+2, expected_size);
> 
>-    return (sample[0]^plaintext[0])|
>-        ((sample[1]^plaintext[1])<<8)|
>-        ((sample[2]^plaintext[2])<<16)|
>-        ((sample[3]^plaintext[3])<<24);
>+    return AV_RL32(sample) ^ AV_RL32(plaintext);
> }
> 
>static void xor_block(void *p1, void *p2, unsigned size, int key,
>unsigned *key_ptr)

Looks good to me.