Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759549Ab2EYAjK (ORCPT ); Thu, 24 May 2012 20:39:10 -0400 Received: from terminus.zytor.com ([198.137.202.10]:33318 "EHLO mail.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756146Ab2EYAjI (ORCPT ); Thu, 24 May 2012 20:39:08 -0400 Message-ID: <4FBED482.4050800@zytor.com> Date: Thu, 24 May 2012 17:38:26 -0700 From: "H. Peter Anvin" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:12.0) Gecko/20120430 Thunderbird/12.0.1 MIME-Version: 1.0 To: Andrew Lutomirski CC: James Morris , Will Drewry , linux-kernel@vger.kernel.org, mcgrathr@google.com, indan@nul.nu, netdev@parisplace.org, linux-security-module@vger.kernel.org, kernel-hardening@lists.openwall.com, mingo@redhat.com, oleg@redhat.com, peterz@infradead.org, rdunlap@xenotime.net, tglx@linutronix.de, serge.hallyn@canonical.com, pmoore@redhat.com, akpm@linux-foundation.org, corbet@lwn.net, markus@chromium.org, coreyb@linux.vnet.ibm.com, keescook@chromium.org, viro@zeniv.linux.org.uk Subject: Re: [RFC PATCH 0/3] move the secure_computing call References: <20120522173942.GJ11775@ZenIV.linux.org.uk> <1337875681-20717-1-git-send-email-wad@chromium.org> <4FBECAC2.6050303@zytor.com> In-Reply-To: X-Enigmail-Version: 1.4.1 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1196 Lines: 34 On 05/24/2012 05:26 PM, Andrew Lutomirski wrote: > > Just to clarify: are you suggesting that, for now, the traced behavior > should be: > > process -> seccomp -> ptrace -> kernel? > > If so, I think the man page or something should have a big fat warning > that seccomp filters should *never* allow ptrace (even PTRACE_TRACEME) > unless they fully understand the issue. > Yes, and yes. > In any case, I think that the UML interaction is missing the point. > UML will *emulate* the seccomp filter. If it chooses to use host > seccomp filters for some business, that's its business. I don't see why UML should have to emulate the seccomp filter. With the proposed order, then it can simply use the seccomp filter provided by the host. Furthermore, with this sequencing UML can actually *use* seccomp to provide the simulation. -hpa -- H. Peter Anvin, Intel Open Source Technology Center I work for Intel. I don't speak on their behalf. -- 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/