Re: [PATCH 1/2] drm/core: Preserve the framebuffer after removing it.

Daniel Vetter
2015-09-09T16:07:29Z

On Wed, Sep 9, 2015 at 6:03 PM, Tvrtko Ursulin
<tvrtko.ursulin@linux.intel.com> wrote:
> It was just an example of a class of vulnerabilities which would be possible
> with these changes. If they, as you said, will preserve the last frame on
> screen when the compositor crashes.

If your compositor crashes something should take over, either fbdev
(which force-restores) or a new compositor (system one or just the one
that crashed, restarted). And on modern userspace logind has copies of
the fds which it uses to make sure priviledges (i.e. master rights)
don't escape to the wrong person.

> For me this is serious enough not to go this route.

If that doesn't happen you have yet another bug in userspace. I don't
think there's a real problem really.
-Daniel
--
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch