Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753846AbaFJVR4 (ORCPT ); Tue, 10 Jun 2014 17:17:56 -0400 Received: from mail-wi0-f175.google.com ([209.85.212.175]:57366 "EHLO mail-wi0-f175.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753510AbaFJVRz (ORCPT ); Tue, 10 Jun 2014 17:17:55 -0400 MIME-Version: 1.0 In-Reply-To: References: <1402331614.7064.60.camel@dhcp-9-2-203-236.watson.ibm.com> <20140610122008.GA31944@hansolo.jdub.homelinux.org> <20140610204021.GA8916@srcf.ucam.org> Date: Wed, 11 Jun 2014 00:17:53 +0300 Message-ID: Subject: Re: [PATCH 0/4] KEYS: validate key trust with owner and builtin keys only From: Dmitry Kasatkin To: Matthew Garrett Cc: Josh Boyer , David Howells , Mimi Zohar , Dmitry Kasatkin , keyrings , "linux-kernel@vger.kernel.org" , linux-security-module Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11 June 2014 00:00, Dmitry Kasatkin wrote: > On 10 June 2014 23:40, Matthew Garrett wrote: >> On Tue, Jun 10, 2014 at 11:34:17PM +0300, Dmitry Kasatkin wrote: >> >>> Preventing loading keys from uefi except dbx by default actually improves >>> security. Adding kernel parameter to read db we make system more >>> vulnerable. >> >> It only adds security if you're performing a measured boot and remote >> attestation. Otherwise you implicitly trust that key anyway. In almost >> all cases refusing to trust db gives you a false sense of security >> without any real improvement. I don't think it's obvious it should be >> the default. >> >> -- >> Matthew Garrett | mjg59@srcf.ucam.org > > May be you are right... "in almost all cases"... > > It does not mater if one trust DB or not... It's all about > distro/system configuration... > > Normal user even will not know what is default behavior and what > kernel parameter disables or enables... > And distro will have it by default or will use kernel parameter... It > does not change anything... > > I am just discussing kernel configuration... > Without kind of looking to it I cannot be sure if UEFI keys will > appear on system keyring or not. > Now I have to be aware how kernel is compiled... If it is compiled > with CONFIG_KEYS_UEFI or so > I need to remember may be to supply addition kernel parameters to > limit key UEFI usage... > > It is may be not a big deal... > > -- > Thanks, > Dmitry It is probably just a paranoia... Kconfig MODULE_SIG_UEFI should tell about threat of loading kernel modules from NSA or Lenovo signed by MS or Lenovo keys.. This hole is opened without warning... :) -- Thanks, Dmitry -- 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/