[PATCH] fbdev: core: fix ubsan warning in pixel_to_pat

[PATCH] fbdev: core: fix ubsan warning in pixel_to_pat

[Zsolt Kajtar]

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>
---
 drivers/video/fbdev/core/fb_fillrect.h | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/drivers/video/fbdev/core/fb_fillrect.h b/drivers/video/fbdev/core/fb_fillrect.h
index 66042e534..f366670a5 100644
--- 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);
-- 
2.30.2

Re: [PATCH] fbdev: core: fix ubsan warning in pixel_to_pat

[Helge Deller]

On 8/21/25 04:42, Zsolt Kajtar wrote:
> 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>
> ---
>   drivers/video/fbdev/core/fb_fillrect.h | 3 +--
>   1 file changed, 1 insertion(+), 2 deletions(-)

applied.

Thanks!
Helge