From d1bfa80ec464d475a0de3f513bbb62bcd356099a Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Tue, 1 Aug 2017 19:56:07 +0200 Subject: [PATCH] avcodec/h264idct_template: Fix integer overflow in ff_h264_idct_add() Fixes: runtime error: signed integer overflow: 26215360 + 2121330944 cannot be represented in type 'int' Fixes: 2809/clusterfuzz-testcase-minimized-4785181833560064 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg --- libavcodec/h264idct_template.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/libavcodec/h264idct_template.c b/libavcodec/h264idct_template.c index e1ef68756c7..288107d5a4f 100644 --- a/libavcodec/h264idct_template.c +++ b/libavcodec/h264idct_template.c @@ -40,10 +40,10 @@ void FUNCC(ff_h264_idct_add)(uint8_t *_dst, int16_t *_block, int stride) block[0] += 1 << 5; for(i=0; i<4; i++){ - const SUINT z0= block[i + 4*0] + block[i + 4*2]; - const SUINT z1= block[i + 4*0] - block[i + 4*2]; - const SUINT z2= (block[i + 4*1]>>1) - block[i + 4*3]; - const SUINT z3= block[i + 4*1] + (block[i + 4*3]>>1); + const SUINT z0= block[i + 4*0] + (unsigned)block[i + 4*2]; + const SUINT z1= block[i + 4*0] - (unsigned)block[i + 4*2]; + const SUINT z2= (block[i + 4*1]>>1) - (unsigned)block[i + 4*3]; + const SUINT z3= block[i + 4*1] + (unsigned)(block[i + 4*3]>>1); block[i + 4*0]= z0 + z3; block[i + 4*1]= z1 + z2; -- 2.39.2