[PATCH] drm/mediatek: Add 0 size check to mtk_drm_gem_obj

[AngeloGioacchino Del Regno]

Il 06/03/24 21:37, Justin Green ha scritto:
> Add a check to mtk_drm_gem_init if we attempt to allocate a GEM object
> of 0 bytes. Currently, no such check exists and the kernel will panic if
> a userspace application attempts to allocate a 0x0 GBM buffer.
> 
> Tested by attempting to allocate a 0x0 GBM buffer on an MT8188 and
> verifying that we now return EINVAL.
> 
> Signed-off-by: Justin green <greenjustin at chromium.org>

You need a Fixes tag for this one. Please add the right one and resend.

After adding the correct Fixes tag,

Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno at collabora.com>

Cheers,
Angelo

> ---
>   drivers/gpu/drm/mediatek/mtk_drm_gem.c | 3 +++
>   1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/gpu/drm/mediatek/mtk_drm_gem.c b/drivers/gpu/drm/mediatek/mtk_drm_gem.c
> index 4f2e3feabc0f..ee49367b6138 100644
> --- a/drivers/gpu/drm/mediatek/mtk_drm_gem.c
> +++ b/drivers/gpu/drm/mediatek/mtk_drm_gem.c
> @@ -38,6 +38,9 @@ static struct mtk_drm_gem_obj *mtk_drm_gem_init(struct drm_device *dev,
>   
>   	size = round_up(size, PAGE_SIZE);
>   
> +        if (size == 0)
> +		return ERR_PTR(-EINVAL);
> +
>   	mtk_gem_obj = kzalloc(sizeof(*mtk_gem_obj), GFP_KERNEL);
>   	if (!mtk_gem_obj)
>   		return ERR_PTR(-ENOMEM);