From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail137.messagelabs.com (mail137.messagelabs.com [216.82.249.19]) by kanga.kvack.org (Postfix) with ESMTP id 32C8E8D0039 for ; Fri, 4 Mar 2011 15:58:30 -0500 (EST) Received: by gyb13 with SMTP id 13so1223680gyb.14 for ; Fri, 04 Mar 2011 12:58:27 -0800 (PST) MIME-Version: 1.0 In-Reply-To: <1299271041.2071.1398.camel@dan> 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> <1299271041.2071.1398.camel@dan> Date: Fri, 4 Mar 2011 22:58:27 +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 Fri, Mar 4, 2011 at 10:37 PM, Dan Rosenberg w= rote: > 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. =A0Especially 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. =A0I'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, 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