From 34b4ca8696de64ca756e7aed7bdefa9ff6bb5fac Mon Sep 17 00:00:00 2001 From: Sean McGovern Date: Tue, 9 Jul 2024 17:41:32 -0400 Subject: [PATCH] swscale: prevent undefined behaviour in the PUTRGBA macro For even small values of 'asrc[x]', shifting them by 24 bits or more will cause arithmetic overflow and be caught by GCC's undefined behaviour sanitizer. Ensure the values do not overflow by up-casting the bracketed expressions involving 'asrc' to uint32_t. Signed-off-by: Michael Niedermayer --- libswscale/yuv2rgb.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/libswscale/yuv2rgb.c b/libswscale/yuv2rgb.c index 977eb3a7dd..cfbc54abd0 100644 --- a/libswscale/yuv2rgb.c +++ b/libswscale/yuv2rgb.c @@ -100,9 +100,9 @@ const int *sws_getCoefficients(int colorspace) #define PUTRGBA(dst, ysrc, asrc, i, abase) \ Y = ysrc[2 * i]; \ - dst[2 * i] = r[Y] + g[Y] + b[Y] + (asrc[2 * i] << abase); \ + dst[2 * i] = r[Y] + g[Y] + b[Y] + ((uint32_t)(asrc[2 * i]) << abase); \ Y = ysrc[2 * i + 1]; \ - dst[2 * i + 1] = r[Y] + g[Y] + b[Y] + (asrc[2 * i + 1] << abase); + dst[2 * i + 1] = r[Y] + g[Y] + b[Y] + ((uint32_t)(asrc[2 * i + 1]) << abase); #define PUTRGB48(dst, src, asrc, i, abase) \ Y = src[ 2 * i]; \