Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756315AbZFCQOa (ORCPT ); Wed, 3 Jun 2009 12:14:30 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753293AbZFCQOW (ORCPT ); Wed, 3 Jun 2009 12:14:22 -0400 Received: from earthlight.etchedpixels.co.uk ([81.2.110.250]:60862 "EHLO www.etchedpixels.co.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752581AbZFCQOW (ORCPT ); Wed, 3 Jun 2009 12:14:22 -0400 Date: Wed, 3 Jun 2009 17:14:09 +0100 From: Alan Cox To: Linus Torvalds Cc: Christoph Lameter , "Larry H." , 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: <20090603171409.5c60422c@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: 734 Lines: 17 > It defaults to 64kB in at least the x86 defconfig files, but to 0 in the > Kconfig defaults. Also, for some reason it has a "depends on SECURITY", > which means that if you just default to the old-style unix security you'll > lose it. > > So there are several ways to disable it by mistake. I don't know what > distros do. Fedora at least uses SELinux to manage it. You need some kind of security policy engine running as a few apps really need to map low space (mostly for vm86) -- 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/