Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935689Ab2JaPuE (ORCPT ); Wed, 31 Oct 2012 11:50:04 -0400 Received: from lxorguk.ukuu.org.uk ([81.2.110.251]:33290 "EHLO lxorguk.ukuu.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757618Ab2JaPuB (ORCPT ); Wed, 31 Oct 2012 11:50:01 -0400 Date: Wed, 31 Oct 2012 15:55:03 +0000 From: Alan Cox To: Josh Boyer Cc: Jiri Kosina , Matthew Garrett , linux-kernel@vger.kernel.org, linux-security-module@vger.kernel.org, linux-efi@vger.kernel.org Subject: Re: [RFC] Second attempt at kernel secure boot support Message-ID: <20121031155503.1aaf4c93@pyramind.ukuu.org.uk> In-Reply-To: References: <1348152065-31353-1-git-send-email-mjg@redhat.com> <20121029174131.GC7580@srcf.ucam.org> X-Mailer: Claws Mail 3.8.1 (GTK+ 2.24.8; x86_64-redhat-linux-gnu) Face: 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 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: 1266 Lines: 31 > > is basically DMA-ing arbitrary data over the whole RAM. I am currently not > > able to imagine a scenario how this could be made "secure" (without > > storing private keys to sign the hibernation image on the machine itself > > which, well, doesn't sound secure either). That's what the TPM is for (in fact all of this stuff can be done properly with a TPM while the 'secure' boot stuff can do little if any of it. > > I have a patch that disables that. I imagine it will be included in the > next submission of the patchset. > > You can find it here in the meantime: > > http://jwboyer.fedorapeople.org/pub/0001-hibernate-Disable-in-a-Secure-Boot-environment.patch All this depends on your threat model. If I have physical access to suspend/resume your machine then you already lost. If I don't have physical access then I can't boot my unsigned OS to patch your S4 image so it doesn't matter. In fact the more I think about this the more it seems disabling hibernate is basically farting in the wind. Alan -- 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/