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Date:   Wed, 29 Jul 2020 12:19:35 -0700
From:   Kees Cook <keescook@chromium.org>
To:     Linus Torvalds <torvalds@linux-foundation.org>
Cc:     Lionel Landwerlin <lionel.g.landwerlin@intel.com>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        intel-gfx <intel-gfx@lists.freedesktop.org>
Subject: Re: [Intel-gfx] [PATCH v12 2/3] drm/i915: add syncobj timeline
 support
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On Wed, Jul 29, 2020 at 10:51:23AM -0700, Linus Torvalds wrote:
> On Wed, Jul 29, 2020 at 5:24 AM Daniel Vetter <daniel@ffwll.ch> wrote:
> >
> > Do we have a access_ok_array or so? Instead of duplicating overflow checks
> > everywhere and getting it all wrong ...
> 
> I really really think you should get away from access_ok() entirely.
> 
> Please just get rid of it, and use "copy_from_user()" instead.

Yes please. :) It also makes code SO much easier to audit (both
automatically and manually).

-- 
Kees Cook