Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752484Ab0GABjJ (ORCPT ); Wed, 30 Jun 2010 21:39:09 -0400 Received: from tundra.namei.org ([65.99.196.166]:54982 "EHLO tundra.namei.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751914Ab0GABjH (ORCPT ); Wed, 30 Jun 2010 21:39:07 -0400 Date: Thu, 1 Jul 2010 11:39:01 +1000 (EST) From: James Morris To: Christoph Hellwig cc: Kees Cook , linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 0/2] Yama: add PTRACE exception tracking In-Reply-To: <20100630073158.GA4453@infradead.org> Message-ID: References: <20100630003844.GE4837@outflux.net> <20100630073158.GA4453@infradead.org> User-Agent: Alpine 2.00 (LRH 1167 2008-08-23) 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: 1554 Lines: 38 On Wed, 30 Jun 2010, Christoph Hellwig wrote: > Err, no. This is just a very clear sign that your ptrace restrictions > were completely wrong to start with and break applications left, right > and center. Just get rid of it instead of letting workarounds for your > bad design creep into the core kernel and applications. Indeed, I wasn't aware that there were further aspects to this -- I thought it was a relatively simple case of restricting a problematic OS feature for heavily locked down systems. This is getting more complicated, with fine-grained security policy now being introduced, also with the need to modify applications. There are several existing LSMs with the ability to control ptrace, but as part of a system-wide, coherent, analyzable policy -- often in support of specific security models for which there is concrete user demand and benefit. If people won't use any of SELinux, Smack, Tomoyo or AppArmor, then I don't think providing an ad-hoc assortment of workarounds with no overall design is going to help them either. If LSMs need to call into common code in Yama, or even do lightweight chaining, that's one thing, but for Yama to evolve into yet another standalone security scheme, is something entirely different. - James -- James Morris -- 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/