linux-kernel - Re: [PATCH] Make /proc/slabinfo 0400

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Fri, 4 Mar 2011 22:58:27 +0200
From:	Pekka Enberg <penberg@...nel.org>
To:	Dan Rosenberg <drosenberg@...curity.com>
Cc:	Matt Mackall <mpm@...enic.com>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Dave Hansen <dave@...ux.vnet.ibm.com>,
	Theodore Tso <tytso@....edu>, cl@...ux-foundation.org,
	linux-mm@...ck.org, linux-kernel@...r.kernel.org,
	Ingo Molnar <mingo@...e.hu>,
	Andrew Morton <akpm@...ux-foundation.org>
Subject: Re: [PATCH] Make /proc/slabinfo 0400

On Fri, Mar 4, 2011 at 10:37 PM, Dan Rosenberg <drosenberg@...curity.com> wrote:
> This patch makes these techniques more difficult by making it hard to
> know whether the last attacker-allocated object resides before a free or
> allocated object.  Especially with vulnerabilities that only allow one
> attempt at exploitation before recovery is needed to avoid trashing too
> much heap state and causing a crash, this could go a long way.  I'd
> still argue in favor of removing the ability to know how many objects
> are used in a given slab, since randomizing objects doesn't help if you
> know every object is allocated.

So if the attacker knows every object is allocated, how does that help
if we're randomizing the initial freelist?
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/