From: Pekka Enberg <penberg@kernel.org>
To: Matt Mackall <mpm@selenic.com>
Cc: George Spelvin <linux@horizon.com>,
penberg@cs.helsinki.fi, herbert@gondor.apana.org.au,
linux-mm@kvack.org, linux-kernel@vger.kernel.org,
Christoph Lameter <cl@linux.com>,
Dan Rosenberg <drosenberg@vsecurity.com>,
Linus Torvalds <torvalds@linux-foundation.org>
Subject: Re: [PATCH 0/8] mm/slub: Add SLUB_RANDOMIZE support
Date: Wed, 16 Mar 2011 08:23:50 +0200 [thread overview]
Message-ID: <AANLkTimZRnaf6C-vOkkM-uhVVzn8NO8_V9Xb16rN7BKK@mail.gmail.com> (raw)
In-Reply-To: <1300244238.3128.420.camel@calx>
Hi Matt,
On Sun, 2011-03-13 at 20:20 -0400, George Spelvin wrote:
>> As a followup to the "[PATCH] Make /proc/slabinfo 0400" thread, this
>> is a patch series to randomize the order of object allocations within
>> a page. It can be extended to SLAB and SLOB if desired. Mostly it's
>> for benchmarking and discussion.
On Wed, Mar 16, 2011 at 4:57 AM, Matt Mackall <mpm@selenic.com> wrote:
> I've spent a while thinking about this over the past few weeks, and I
> really don't think it's productive to try to randomize the allocators.
> It provides negligible defense and just makes life harder for kernel
> hackers.
If it's an optional feature and the impact on the code is low (as it
seems to be), what's the downside? Combined with disabling SLUB's slab
merging, randomization should definitely make it more difficult to
have full control over a full slab. I don't know how much defense it
will provide but I think randomization is definitely an option worth
exploring.
> (And you definitely can't randomize SLOB like this.)
No, you can't but heap exploits like the one we discuss are slightly
harder with SLOB anyway, no?
Pekka
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@kvack.org. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
next prev parent reply other threads:[~2011-03-16 6:23 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-03-14 0:20 [PATCH 0/8] mm/slub: Add SLUB_RANDOMIZE support George Spelvin
2011-03-16 2:57 ` Matt Mackall
2011-03-16 6:23 ` Pekka Enberg [this message]
2011-03-16 12:38 ` Matt Mackall
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=AANLkTimZRnaf6C-vOkkM-uhVVzn8NO8_V9Xb16rN7BKK@mail.gmail.com \
--to=penberg@kernel.org \
--cc=cl@linux.com \
--cc=drosenberg@vsecurity.com \
--cc=herbert@gondor.apana.org.au \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=linux@horizon.com \
--cc=mpm@selenic.com \
--cc=penberg@cs.helsinki.fi \
--cc=torvalds@linux-foundation.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).