Re: [PATCH] drm/virtio: Fix GEM handle creation UAF

From: Chia-I Wu
Date: Fri Dec 16 2022 - 18:50:40 EST


On Fri, Dec 16, 2022 at 3:33 PM Rob Clark <robdclark@xxxxxxxxx> wrote:
>
> From: Rob Clark <robdclark@xxxxxxxxxxxx>
>
> Userspace can guess the handle value and try to race GEM object creation
> with handle close, resulting in a use-after-free if we dereference the
> object after dropping the handle's reference. For that reason, dropping
> the handle's reference must be done *after* we are done dereferencing
> the object.
>
> Signed-off-by: Rob Clark <robdclark@xxxxxxxxxxxx>
Reviewed-by: Chia-I Wu <olvaffe@xxxxxxxxx>