Re: [PATCH] drm/i915: Fix reporting of size of created GEM object

From: Chris Wilson
Date: Tue Jul 09 2019 - 03:04:28 EST


Quoting Janusz Krzysztofik (2019-07-09 07:58:00)
> Commit e163484afa8d ("drm/i915: Update size upon return from
> GEM_CREATE") (re)introduced reporting of actual size of created GEM
> objects, possibly rounded up on object alignment. Unfortunately, its
> implementation resulted in a possible use-after-free bug. The bug has
> been fixed by commit 929eec99f5fd ("drm/i915: Avoid use-after-free in
> reporting create.size") at the cost of possibly incorrect value being
> reported as actual object size.
>
> Safely restore correct reporting by capturing actual size of created
> GEM object before a reference to the object is put.
>
> Fixes: 929eec99f5fd ("drm/i915: Avoid use-after-free in reporting create.size")

This doesn't do anything.
-Chris