From e131b8cedb00043dcc97cc05ca04749ec8ff57de Mon Sep 17 00:00:00 2001 From: Michael Niedermayer Date: Sat, 4 Nov 2017 01:19:20 +0100 Subject: [PATCH] avcodec/h264idct_template: Fix integer overflows in ff_h264_idct8_add() Fixes: runtime error: signed integer overflow: -503316480 + -2013265038 cannot be represented in type 'int' Fixes: 3805/clusterfuzz-testcase-minimized-6578427831255040 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer --- 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 fbd07cb8d5..7526bdd812 100644 --- a/libavcodec/h264idct_template.c +++ b/libavcodec/h264idct_template.c @@ -91,10 +91,10 @@ void FUNCC(ff_h264_idct8_add)(uint8_t *_dst, int16_t *_block, int stride){ const int a5 = -block[i+1*8] + (unsigned)block[i+7*8] + block[i+5*8] + (block[i+5*8]>>1); const int a7 = block[i+3*8] + (unsigned)block[i+5*8] + block[i+1*8] + (block[i+1*8]>>1); - const int b1 = (a7>>2) + a1; - const int b3 = a3 + (a5>>2); - const int b5 = (a3>>2) - a5; - const int b7 = a7 - (a1>>2); + const int b1 = (a7>>2) + (unsigned)a1; + const int b3 = (unsigned)a3 + (a5>>2); + const int b5 = (a3>>2) - (unsigned)a5; + const int b7 = (unsigned)a7 - (a1>>2); block[i+0*8] = b0 + b7; block[i+7*8] = b0 - b7;