From: Pekka Enberg <penberg@kernel.org>
To: Dan Rosenberg <drosenberg@vsecurity.com>
Cc: Matt Mackall <mpm@selenic.com>,
Linus Torvalds <torvalds@linux-foundation.org>,
Dave Hansen <dave@linux.vnet.ibm.com>,
Theodore Tso <tytso@mit.edu>,
cl@linux-foundation.org, linux-mm@kvack.org,
linux-kernel@vger.kernel.org, Ingo Molnar <mingo@elte.hu>,
Andrew Morton <akpm@linux-foundation.org>
Subject: Re: [PATCH] Make /proc/slabinfo 0400
Date: Sat, 5 Mar 2011 00:10:39 +0200 [thread overview]
Message-ID: <AANLkTikA=88EMs8RRm0RPQ+Q9nKj=2G+G86h5nCnV7Se@mail.gmail.com> (raw)
In-Reply-To: <1299275042.2071.1422.camel@dan>
Hi Dan,
On Fri, Mar 4, 2011 at 11:44 PM, Dan Rosenberg <drosenberg@vsecurity.com> wrote:
> This is a good point, and one that I've come to accept as a result of
> having this conversation. Consider the patch dropped, unless there are
> other reasons I've missed. I still think it's worth brainstorming
> techniques for hardening the kernel heap in ways that don't create
> performance impact, but I admit that the presence or absence of this
> debugging information isn't a crucial factor in successful exploitation.
I can think of four things that will make things harder for the
attacker (in the order of least theoretical performance impact):
(1) disable slub merging
(2) pin down random objects in the slab during setup (i.e. don't
allow them to be allocated)
(3) randomize the initial freelist
(4) randomize padding between objects in a slab
AFAICT, all of them will make brute force attacks using the kernel
heap as an attack vector harder but won't prevent them.
Pekka
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next prev parent reply other threads:[~2011-03-04 22:10 UTC|newest]
Thread overview: 39+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-03-03 17:50 Dan Rosenberg
2011-03-03 18:17 ` Dave Hansen
2011-03-03 18:29 ` Dan Rosenberg
2011-03-03 20:58 ` Matt Mackall
2011-03-03 21:16 ` Dan Rosenberg
2011-03-03 21:44 ` Matt Mackall
2011-03-03 22:30 ` Dan Rosenberg
2011-03-03 23:08 ` Matt Mackall
2011-03-04 0:32 ` Dave Hansen
2011-03-04 0:50 ` Theodore Tso
2011-03-04 6:52 ` Pekka Enberg
2011-03-04 17:36 ` Dave Hansen
2011-03-04 17:48 ` Linus Torvalds
2011-03-04 18:14 ` Matt Mackall
2011-03-04 20:02 ` Pekka Enberg
2011-03-04 20:31 ` Matt Mackall
2011-03-04 20:42 ` Dan Rosenberg
2011-03-04 20:56 ` Pekka Enberg
2011-03-04 21:08 ` Dan Rosenberg
2011-03-04 21:30 ` Pekka Enberg
2011-03-04 21:44 ` Dan Rosenberg
2011-03-04 22:10 ` Pekka Enberg [this message]
2011-03-04 22:14 ` Pekka Enberg
2011-03-04 23:02 ` Matt Mackall
2011-03-05 16:25 ` Ted Ts'o
2011-03-06 13:19 ` Alan Cox
2011-03-07 14:56 ` Dan Rosenberg
2011-03-07 16:02 ` Matt Mackall
2011-03-04 20:37 ` Dan Rosenberg
2011-03-04 20:58 ` Pekka Enberg
2011-03-04 21:10 ` Dan Rosenberg
2011-03-06 0:42 ` Jesper Juhl
2011-03-06 0:57 ` Dan Rosenberg
2011-03-06 1:09 ` Matt Mackall
2011-03-06 1:15 ` Jesper Juhl
2011-03-07 16:40 ` Christoph Lameter
2011-03-04 21:12 ` Matt Mackall
2011-03-04 11:58 ` Alan Cox
2011-03-07 14:19 [PATCH] Make /proc/slabinfo 040 George Spelvin
2011-03-07 17:49 ` [PATCH] Make /proc/slabinfo 0400 George Spelvin
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