From: Pekka Enberg <penberg@cs.helsinki.fi>
To: Dave Hansen <dave@linux.vnet.ibm.com>
Cc: Vasiliy Kulikov <segoon@openwall.com>,
Andrew Morton <akpm@linux-foundation.org>,
kernel-hardening@lists.openwall.com, Kees Cook <kees@ubuntu.com>,
Cyrill Gorcunov <gorcunov@gmail.com>,
Al Viro <viro@zeniv.linux.org.uk>,
Christoph Lameter <cl@linux-foundation.org>,
Matt Mackall <mpm@selenic.com>,
linux-kernel@vger.kernel.org, linux-mm@kvack.org,
Dan Rosenberg <drosenberg@vsecurity.com>,
Theodore Tso <tytso@mit.edu>, Alan Cox <alan@linux.intel.com>,
Jesper Juhl <jj@chaosbits.net>,
Linus Torvalds <torvalds@linux-foundation.org>
Subject: Re: [kernel-hardening] Re: [RFC PATCH 2/2] mm: restrict access to /proc/slabinfo
Date: Mon, 19 Sep 2011 21:21:15 +0300 [thread overview]
Message-ID: <CAOJsxLFe=i=TUbHuppHTSWPE1DXUw_fSujpR4Kn65_aXr4Hrdg@mail.gmail.com> (raw)
In-Reply-To: <1316455395.16137.160.camel@nimitz>
On Mon, 2011-09-19 at 20:51 +0300, Pekka Enberg wrote:
>> How is the attacker able to identify that we kmalloc()'d from ecryptfs or
>> VFS based on non-root /proc/slabinfo when the slab allocator itself does
>> not have that sort of information if you mix up the allocations? Isn't this
>> much stronger protection especially if you combine that with /proc/slabinfo
>> restriction?
On Mon, Sep 19, 2011 at 9:03 PM, Dave Hansen <dave@linux.vnet.ibm.com> wrote:
> Mixing it up just adds noise. It makes the attack somewhat more
> difficult, but it still leaves open the possibility that the attacker
> can filter out the noise somehow.
So that would mean the attacker has somewhat fine-grained control over
kernel memory allocations, no? Can they use /proc/meminfo to deduce
the same kind of information? Should we close that down too?
Pekka
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next prev parent reply other threads:[~2011-09-19 18:21 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <20110910164001.GA2342@albatros>
2011-09-10 16:41 ` Vasiliy Kulikov
2011-09-12 15:06 ` Cyrill Gorcunov
2011-09-13 6:28 ` Vasiliy Kulikov
2011-09-14 13:16 ` Vasiliy Kulikov
2011-09-14 15:18 ` Dave Hansen
2011-09-14 15:42 ` [kernel-hardening] " Vasiliy Kulikov
2011-09-14 15:48 ` Vasiliy Kulikov
2011-09-14 18:24 ` Dave Hansen
2011-09-14 18:41 ` Dave Hansen
2011-09-14 19:14 ` Vasiliy Kulikov
2011-09-14 19:27 ` Kees Cook
2011-09-18 17:05 ` [kernel-hardening] " Vasiliy Kulikov
2011-09-19 13:42 ` Christoph Lameter
2011-09-19 14:30 ` Pekka Enberg
2011-09-19 14:46 ` Vasiliy Kulikov
2011-09-19 15:13 ` Pekka Enberg
2011-09-19 15:57 ` Vasiliy Kulikov
2011-09-19 16:11 ` Pekka Enberg
2011-09-19 16:18 ` Vasiliy Kulikov
2011-09-19 17:31 ` Pekka Enberg
2011-09-19 17:35 ` Vasiliy Kulikov
2011-09-19 17:51 ` Christoph Lameter
2011-09-19 19:59 ` Valdis.Kletnieks
2011-09-19 20:02 ` Christoph Lameter
2011-09-19 20:36 ` Valdis.Kletnieks
2011-09-19 17:51 ` Pekka Enberg
2011-09-19 17:58 ` Vasiliy Kulikov
2011-09-19 18:46 ` Pekka Enberg
2011-09-19 18:55 ` Vasiliy Kulikov
2011-09-19 19:20 ` Pekka Enberg
2011-09-19 19:33 ` Pekka Enberg
2011-09-19 18:55 ` Linus Torvalds
2011-09-19 19:18 ` Pekka Enberg
2011-09-19 19:45 ` Pekka Enberg
2011-09-19 20:59 ` David Rientjes
2011-09-19 18:03 ` Dave Hansen
2011-09-19 18:21 ` Pekka Enberg [this message]
2011-09-19 19:45 ` Valdis.Kletnieks
2011-09-19 19:55 ` Alan Cox
2011-09-21 17:05 ` Vasiliy Kulikov
2011-09-22 2:20 ` Valdis.Kletnieks
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