From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?ISO-8859-1?Q?Terje_Bergstr=F6m?= Subject: Re: [RFC v2 8/8] drm: tegra: Add gr2d device Date: Tue, 27 Nov 2012 10:45:28 +0200 Message-ID: <50B47DA8.60609@nvidia.com> References: <1353935954-13763-1-git-send-email-tbergstrom@nvidia.com> <1353935954-13763-9-git-send-email-tbergstrom@nvidia.com> <50B46336.8030605@nvidia.com> <50B476E1.4070403@nvidia.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: In-Reply-To: Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Dave Airlie Cc: "thierry.reding-RM9K5IK7kjKj5M59NBduVrNAH6kLmebB@public.gmane.org" , "linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "dri-devel-PD4FTy7X32lNgt0PjOBp9y5qC8QIuHrW@public.gmane.org" , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Arto Merilainen List-Id: dri-devel@lists.freedesktop.org On 27.11.2012 10:32, Dave Airlie wrote: > On Tue, Nov 27, 2012 at 8:16 AM, Terje Bergstr=F6m wrote: >> Thanks for the pointer, I looked at exynos code. It indeed checks th= e >> registers written to, but it doesn't prevent overrun by checking siz= es >> of buffers and compare against requests. > They probably need to add that, its not as important as the base > addresses, unless it takes negative strides, generally base addresses > means you can target current->uid quite easily! Ok. We'll implement the firewall, unless we come up with even a better choice. >> If this is the way to go, I'll put the firewall behind a Kconfig fla= g so >> that system integrator can decide if his system needs it. > We don't generally make security like this optional :-) >=20 > If you do that you should restrict the drm device to root users only, > and never let a user with a browser anywhere near it. My thinking was that the system integrator can decide how much he trust= s the binaries (incl. browser plugins) in the system. If he trusts the binaries, the firewall can be turned off. > Like I know what you guys get away with in closed source world, but > here we don't write root holes into our driver deliberately. Duly noted. :-) Terje