Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932696AbXHNVKM (ORCPT ); Tue, 14 Aug 2007 17:10:12 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754368AbXHNVJ6 (ORCPT ); Tue, 14 Aug 2007 17:09:58 -0400 Received: from sovereign.computergmbh.de ([85.214.69.204]:55625 "EHLO sovereign.computergmbh.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754360AbXHNVJ5 (ORCPT ); Tue, 14 Aug 2007 17:09:57 -0400 Date: Tue, 14 Aug 2007 23:09:56 +0200 (CEST) From: Jan Engelhardt To: Andi Kleen cc: Hajime Inoue , Alan Cox , linux-kernel@vger.kernel.org Subject: Re: System call interposition/unprotecting the table In-Reply-To: Message-ID: References: <20070813180535.vo36rcevi80s0c4c@www.ccsl.carleton.ca> <20070814000956.7c8929dd@the-village.bc.nu> <46C1E5F5.9050702@ccsl.carleton.ca> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 959 Lines: 27 On Aug 14 2007 21:50, Andi Kleen wrote: >Hajime Inoue writes: > >> Just protecting the table does not stop rootkits. A highly referenced >> phrack article explains how to bypass the table. > >During .23-pre for some time the kernel text was protected too (that >would have likely stopped that particular attack), but it was >removed because it caused too many problems. > >Ultimatively it is useless for security anyways because the page >tables cannot be protected (because there are valid reasons to change >them). But with DEBUG_RODATA (does that also apply to .text?) enabled, accidental writes to it should cause a fault rather than doing silent changes, would not it? Jan -- - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/