Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757252AbZKJRA0 (ORCPT ); Tue, 10 Nov 2009 12:00:26 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757021AbZKJRA0 (ORCPT ); Tue, 10 Nov 2009 12:00:26 -0500 Received: from burp.tkv.asdf.org ([212.16.99.49]:45275 "EHLO cs181073102.pp.htv.fi" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1755187AbZKJRAZ (ORCPT ); Tue, 10 Nov 2009 12:00:25 -0500 X-Greylist: delayed 820 seconds by postgrey-1.27 at vger.kernel.org; Tue, 10 Nov 2009 12:00:25 EST To: linux-kernel@vger.kernel.org Subject: Re: Using x86 segments against NULL pointer deference exploit References: From: Markku Savela Date: Tue, 10 Nov 2009 18:46:49 +0200 In-Reply-To: (castet matthieu's message of "Fri\, 06 Nov 2009 14\:10\:01 +0100") Message-ID: <874op2wcna.fsf@burp.tkv.asdf.org> User-Agent: Gnus/5.11 (Gnus v5.11) Emacs/22.2 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 537 Lines: 15 I'm wondering why on architectures that actually have EXECUTE permission memory management, the user space is mapped into kernel with EXECUTE enabled!!!?? If the user space were not mapped with EXECUTE enabled, the restriction of mapping the 0-page in user space is not required anymore. -- 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/