From 9f353e376b161eb16a78fd7ad727c9513ac60d13 Mon Sep 17 00:00:00 2001 From: Mengye Lv Date: Wed, 2 Oct 2019 10:30:45 +0800 Subject: [PATCH] avutil/common: Fix underflow for ROUNDED_DIV with unsigned integer When used ROUNDED_DIV(a,b), if a is unsigned integer zero, it's will lead to an underflow issue(it called unsigned integer wrapping). Fixes #8062 Reviewed-by: Michael Niedermayer Signed-off-by: Mengye Lv Signed-off-by: Jun Zhao --- libavutil/common.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/libavutil/common.h b/libavutil/common.h index af35397eb9..f09f0b486b 100644 --- a/libavutil/common.h +++ b/libavutil/common.h @@ -53,7 +53,7 @@ //rounded division & shift #define RSHIFT(a,b) ((a) > 0 ? ((a) + ((1<<(b))>>1))>>(b) : ((a) + ((1<<(b))>>1)-1)>>(b)) /* assume b>0 */ -#define ROUNDED_DIV(a,b) (((a)>0 ? (a) + ((b)>>1) : (a) - ((b)>>1))/(b)) +#define ROUNDED_DIV(a,b) (((a)>=0 ? (a) + ((b)>>1) : (a) - ((b)>>1))/(b)) /* Fast a/(1<=0 and b>=0 */ #define AV_CEIL_RSHIFT(a,b) (!av_builtin_constant_p(b) ? -((-(a)) >> (b)) \ : ((a) + (1<<(b)) - 1) >> (b))