RE: [PATCH] drm/dumb-buffer: Drop buffer-size limits for now

["Saarinen, Jani" <jani.saarinen@intel.com>]

Hi, 
> -----Original Message-----
> From: Thomas Zimmermann <tzimmermann@suse.de>
> Sent: Tuesday, 2 June 2026 14.24
> To: rajat.gupta@oss.qualcomm.com; jani.nikula@linux.intel.com; Saarinen,
> Jani <jani.saarinen@intel.com>; simona@ffwll.ch; airlied@gmail.com;
> mripard@kernel.org; maarten.lankhorst@linux.intel.com
> Cc: dri-devel@lists.freedesktop.org; intel-gfx@lists.freedesktop.org; intel-
> xe@lists.freedesktop.org; Thomas Zimmermann <tzimmermann@suse.de>
> Subject: [PATCH] drm/dumb-buffer: Drop buffer-size limits for now
> 
> 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 <tzimmermann@suse.de>
> Fixes: 5ab62dd3687b ("drm: prevent integer overflows in dumb buffer
> creation helpers")
> Reported-by: Jani Nikula <jani.nikula@linux.intel.com>
> Closes: https://lore.kernel.org/dri-
> devel/ddf0233e50044059c85279f928661563ef6a55bf@intel.com/
> Cc: Rajat Gupta <rajat.gupta@oss.qualcomm.com>
> Cc: Thomas Zimmermann <tzimmermann@suse.de>
> Cc: Maarten Lankhorst <maarten.lankhorst@linux.intel.com>
> Cc: Maxime Ripard <mripard@kernel.org>
Seems to satisfy CI :
https://intel-gfx-ci.01.org/tree/drm-tip/Patchwork_167736v1/index.html?testfilter=vgem%7Ckms_big.*line

Br,
Jani
> ---
>  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
> --
> 2.54.0