Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756759Ab2JBWK7 (ORCPT ); Tue, 2 Oct 2012 18:10:59 -0400 Received: from mail-ie0-f174.google.com ([209.85.223.174]:52612 "EHLO mail-ie0-f174.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753527Ab2JBWK6 (ORCPT ); Tue, 2 Oct 2012 18:10:58 -0400 MIME-Version: 1.0 In-Reply-To: References: <20120820180037.GV4232@outflux.net> Date: Tue, 2 Oct 2012 15:10:56 -0700 X-Google-Sender-Auth: 5c1JydoOvL6UolxYrCK94LJSPhs Message-ID: Subject: Re: [PATCH] hardening: add PROT_FINAL prot flag to mmap/mprotect From: Kees Cook To: Ard Biesheuvel Cc: linux-kernel@vger.kernel.org, Al Viro , Andrew Morton , Ingo Molnar , Srikar Dronamraju , KOSAKI Motohiro , James Morris , Konstantin Khlebnikov , linux-mm@kvack.org Content-Type: text/plain; charset=ISO-8859-1 X-System-Of-Record: true Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1375 Lines: 40 On Tue, Oct 2, 2012 at 2:41 PM, Ard Biesheuvel wrote: > 2012/10/2 Kees Cook : >>> If desired, additional restrictions can be imposed by using the >>> security framework, e.g,, disallow non-final r-x mappings. >> >> Interesting; what kind of interface did you have in mind? > > The 'interface' we use is a LSM .ko which registers handlers for > mmap() and mprotect() that fail the respective invocations if the > passed arguments do not adhere to the policy. Seems reasonable. >>>> It seems like there needs to be a sensible way to detect that this flag is >>>> available, though. >>> >>> I am open for suggestions to address this. Our particular >>> implementation of the loader (on an embedded system) tries to set it >>> on the first mmap invocation, and stops trying if it fails. Not the >>> most elegant approach, I know ... >> >> Actually, that seems easiest. >> >> Has there been any more progress on this patch over-all? > > No progress. Al, Andrew, anyone? Thoughts on this? (First email is https://lkml.org/lkml/2012/8/14/448) -Kees -- Kees Cook Chrome OS Security -- 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/