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 B66325F0019 for ; Wed, 3 Jun 2009 13:28:54 -0400 (EDT) Date: Wed, 3 Jun 2009 18:29:49 +0100 From: Alan Cox 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> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org To: Christoph Lameter Cc: "Larry H." , Linus Torvalds , linux-mm@kvack.org, Rik van Riel , linux-kernel@vger.kernel.org, pageexec@freemail.hu List-ID: > 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, 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/ . Don't email: email@kvack.org