Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758775AbZFCR3b (ORCPT ); Wed, 3 Jun 2009 13:29:31 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755881AbZFCR3Y (ORCPT ); Wed, 3 Jun 2009 13:29:24 -0400 Received: from earthlight.etchedpixels.co.uk ([81.2.110.250]:54863 "EHLO www.etchedpixels.co.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1753376AbZFCR3Y (ORCPT ); Wed, 3 Jun 2009 13:29:24 -0400 Date: Wed, 3 Jun 2009 18:29:49 +0100 From: Alan Cox To: Christoph Lameter Cc: "Larry H." , Linus Torvalds , linux-mm@kvack.org, Rik van Riel , linux-kernel@vger.kernel.org, pageexec@freemail.hu Subject: Re: Security fix for remapping of page 0 (was [PATCH] Change ZERO_SIZE_PTR to point at unmapped space) Message-ID: <20090603182949.5328d411@lxorguk.ukuu.org.uk> In-Reply-To: References: <20090530192829.GK6535@oblivion.subreption.com> <20090530230022.GO6535@oblivion.subreption.com> <20090531022158.GA9033@oblivion.subreption.com> <20090602203405.GC6701@oblivion.subreption.com> X-Mailer: Claws Mail 3.7.0 (GTK+ 2.14.7; x86_64-redhat-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 705 Lines: 17 > Ok. So what we need to do is stop this toying around with remapping of > page 0. The following patch contains a fix and a test program that > demonstrates the issue. NAK - you've now broken half a dozen apps. One way you could approach this would be to write a security module for non SELINUX users - one that did one thing alone - decide whether the app being run was permitted to map the low 64K perhaps by checking the security label on the file. Alan -- 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/