Re: [PATCH] video: fbdev: kyro: Validate overlay viewport coordinates

[Helge Deller <deller@gmx.de>]

On 7/24/26 02:42, Danila Chernetsov wrote:
> The overlay viewport end coordinates are computed from the viewport
> origin and dimensions using 32-bit unsigned arithmetic. Large input
> values can cause these calculations to wrap around before the resulting
> coordinates are passed to SetOverlayViewPort().
> 
> SetOverlayViewPort() packs the viewport coordinates into 16-bit
> register fields. The X coordinates are additionally adjusted by +2
> and +1 before being written. Validate the coordinate calculations
> for 32-bit wraparound and ensure that the adjusted coordinates fit
> within their 16-bit register fields before calling
> SetOverlayViewPort().
> 
> Found by Linux Verification Center (linuxtesting.org) with SVACE.
> 
> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
> Signed-off-by: Danila Chernetsov <listdansp@mail.ru>
> ---
>   drivers/video/fbdev/kyro/fbdev.c | 24 +++++++++++++++++++++++-
>   1 file changed, 23 insertions(+), 1 deletion(-)
applied.

Thanks!
Helge