On Tue, 02 Jun 2026, Thomas Zimmermann <[email protected]> wrote:
> The size limits break some of the CI tests. So drop them for now. Keep
> the other overflow tests from commit 5ab62dd3687b ("drm: prevent integer
> overflows in dumb buffer creation helpers") in place.
>
> There is still a pre-existing overflow check for 32-bit type limits in
> drm_mode_create_dumb() that will catch the really absurd size requests.
> Drivers that still do not use drm_mode_size_dumb() should be updated. The
> helper calculates dumb-buffer geometry with overflow checks.
>
> Signed-off-by: Thomas Zimmermann <[email protected]>
> Fixes: 5ab62dd3687b ("drm: prevent integer overflows in dumb buffer creation 
> helpers")
> Reported-by: Jani Nikula <[email protected]>
> Closes: 
> https://lore.kernel.org/dri-devel/[email protected]/
> Cc: Rajat Gupta <[email protected]>
> Cc: Thomas Zimmermann <[email protected]>
> Cc: Maarten Lankhorst <[email protected]>
> Cc: Maxime Ripard <[email protected]>

Thanks for following up. Maybe we need to return to this with less
urgency.

Acked-by: Jani Nikula <[email protected]>

> ---
>  drivers/gpu/drm/drm_dumb_buffers.c | 7 -------
>  1 file changed, 7 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_dumb_buffers.c 
> b/drivers/gpu/drm/drm_dumb_buffers.c
> index e60130b2bb0c..8e9ff17538e7 100644
> --- a/drivers/gpu/drm/drm_dumb_buffers.c
> +++ b/drivers/gpu/drm/drm_dumb_buffers.c
> @@ -201,13 +201,6 @@ int drm_mode_create_dumb(struct drm_device *dev,
>       if (!args->width || !args->height || !args->bpp)
>               return -EINVAL;
>  
> -     /* Reject unreasonable inputs early.  Dumb buffers are for software
> -      * rendering; nothing legitimate needs more than 8192x8192 at 32bpp.
> -      * This prevents overflows in downstream alignment helpers.
> -      */
> -     if (args->width >= 8192 || args->height >= 8192 || args->bpp > 32)
> -             return -EINVAL;
> -
>       /* overflow checks for 32bit size calculations */
>       if (args->bpp > U32_MAX - 8)
>               return -EINVAL;
>
> base-commit: a980196655477a8f5067112946401fe52e510664

-- 
Jani Nikula, Intel

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