From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail203.messagelabs.com (mail203.messagelabs.com [216.82.254.243]) by kanga.kvack.org (Postfix) with ESMTP id 8003C8D0039 for ; Fri, 4 Mar 2011 17:14:59 -0500 (EST) Received: by yib2 with SMTP id 2so1201923yib.14 for ; Fri, 04 Mar 2011 14:14:57 -0800 (PST) MIME-Version: 1.0 In-Reply-To: References: <1299174652.2071.12.camel@dan> <1299185882.3062.233.camel@calx> <1299186986.2071.90.camel@dan> <1299188667.3062.259.camel@calx> <1299191400.2071.203.camel@dan> <2DD7330B-2FED-4E58-A76D-93794A877A00@mit.edu> <1299260164.8493.4071.camel@nimitz> <1299262495.3062.298.camel@calx> <1299270709.3062.313.camel@calx> <1299271377.2071.1406.camel@dan> <1299272907.2071.1415.camel@dan> <1299275042.2071.1422.camel@dan> Date: Sat, 5 Mar 2011 00:14:57 +0200 Message-ID: Subject: Re: [PATCH] Make /proc/slabinfo 0400 From: Pekka Enberg Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Sender: owner-linux-mm@kvack.org List-ID: To: Dan Rosenberg Cc: Matt Mackall , Linus Torvalds , Dave Hansen , Theodore Tso , cl@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Ingo Molnar , Andrew Morton On Sat, Mar 5, 2011 at 12:10 AM, Pekka Enberg wrote: > I can think of four things that will make things harder for the > attacker (in the order of least theoretical performance impact): > > =A0(1) disable slub merging > > =A0(2) pin down random objects in the slab during setup (i.e. don't > allow them to be allocated) > > =A0(3) randomize the initial freelist > > =A0(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. There's also a fifth one: (5) randomize slab page allocation order which will make it harder to make sure you have full control over a slab and figure out which allocation lands on it. 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: email@kvack.org