From: Pavel Machek <pavel@ucw.cz>
To: Kees Cook <kees.cook@canonical.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: [Security] proactive defense: using read-only memory
Date: Wed, 17 Nov 2010 11:00:54 +0100 [thread overview]
Message-ID: <20101117100053.GA1574@ucw.cz> (raw)
In-Reply-To: <20101107193520.GO5327@outflux.net>
Hi!
> - Modules need to be correctly marked RO/NX. This patch exists[3], but is
> not in mainline. It needs to be in mainline.
Why not.
> - Pointers to function table also need to be marked read-only after
> they are set. An example of this is the security_ops table pointer. It
> gets set once at boot, and never changes again. These need to be handled
> so it isn't possible to just trivially reaim the entire security_ops
> table lookup somewhere else.
But there are too many of those. You can't block them all...
> - Entry points to set_kernel_text_rw() and similar need to be blockable.
> Having these symbols available make kernel memory modification trivial;
What prevents attacker to just inlining those functions in the
exploit?
If you want protection domain inside kernel, perhaps you should take
ukernel approach?
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
next prev parent reply other threads:[~2010-11-17 10:01 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2010-11-07 19:35 [Security] proactive defense: using read-only memory Kees Cook
2010-11-08 6:13 ` [Security] proactive defense: using read-only memory, RO/NX modules Ingo Molnar
2010-11-08 10:03 ` Alan Cox
2010-11-08 21:42 ` Kees Cook
2010-11-10 9:04 ` Ingo Molnar
2010-11-11 6:56 ` Kees Cook
2010-11-11 9:07 ` Ingo Molnar
2010-11-13 19:59 ` matthieu castet
2010-11-14 9:56 ` Ingo Molnar
2010-11-17 10:00 ` Pavel Machek [this message]
2010-11-17 22:14 ` [Security] proactive defense: using read-only memory Kees Cook
2011-01-02 9:09 ` Pavel Machek
2010-11-18 0:12 ` Valdis.Kletnieks
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