fbdev: core: Fix ubsan warning in pixel_to_pat

[ Upstream commit aad1d99beaaf132e2024a52727c24894cdf9474a ]

It could be triggered on 32 bit big endian machines at 32 bpp in the
pattern realignment. In this case just return early as the result is
an identity.

Signed-off-by: Zsolt Kajtar <soci@c64.rulez.org>
Signed-off-by: Helge Deller <deller@gmx.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/video/fbdev/core/fb_fillrect.h b/drivers/video/fbdev/core/fb_fillrect.h
index 66042e534de77168d044b7ba34cb72db6b1a1d12..f366670a53af824fb31770f194fa3290817a4a35 100644 (file)
--- a/drivers/video/fbdev/core/fb_fillrect.h
+++ b/drivers/video/fbdev/core/fb_fillrect.h
@@ -92,8 +92,7 @@ static unsigned long pixel_to_pat(int bpp, u32 color)
                pattern = pattern | pattern << bpp;
                break;
        default:
-               pattern = color;
-               break;
+               return color;
        }
 #ifndef __LITTLE_ENDIAN
        pattern <<= (BITS_PER_LONG % bpp);