Received: by 10.213.65.68 with SMTP id h4csp3868182imn; Tue, 3 Apr 2018 12:04:29 -0700 (PDT) X-Google-Smtp-Source: AIpwx4/0q0zX+aWvCpL+/JraHFovpxX+xOV3t5kWVYqNvIbnfTghCqE7rhswjenqQi1p2/QoOwEK X-Received: by 10.99.54.75 with SMTP id d72mr9832329pga.96.1522782269237; Tue, 03 Apr 2018 12:04:29 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1522782269; cv=none; d=google.com; s=arc-20160816; b=Wd11p5E0AIdRQOLNumCURNoxWeADsI173FzdWndKNJgZR6KO5busaKJ4rv3jNBDJaa F0lkv0SZYT4rKvPNh0fYLmZ6Ulp4P6PIsRroL6lsUWrahmnLskFWVSsfuZn0aYmLzHja x+O9b9aSc6EkyGCA7L8wK5MbE4k++RBw2jBH/O3525/TA4UkrfTLoO0aYf0wmVKJ9mEe yf3YPvxno0V6GR8sUF/w9Gn9ZxLAkdLVCuL7SGBmMHufgulat584SlUu9C/8e+zfw6y5 wX3+PRq6MhP6Cd8g0MdOuCyatUzZFzIMCYNGKBkL7Zz9e9mBhjPamUeJsFdTBcodSbcT 1kgw== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=list-id:precedence:sender:content-transfer-encoding:cc:to:subject :message-id:date:from:references:in-reply-to:mime-version :dmarc-filter:arc-authentication-results; bh=ia/R+s6hN713qw9yeXqBDiqOEcY0R/AfSIEkwnm7VsA=; b=G1tsbeC10yiT1UYErVAgiccyrg/fYQl8wJFN/eMV9DQVxQsrPT0jZk+Up2hI3G4KG7 0craCz+pm/jq216r5W0dOy+ukPPIjpL1LOG8fBljKiqZTz4MTzTBmMd1Q3pKq/ehi51K JyrdBgBVuF5nqLikIwbdE2k7v2pR8mxRDBHzouEhKglPCspAxklspBs0gC7fNI1wEaX3 PAkHPEuMEMf6Xg87bu9CesxKr8PLi0Wp+s6z/rarAkId05jhAdlELCs7PY2w7iXYkHjF F07ZmyTk2tp0GywXzeV6tweV4LhFRJnaWiXUlWntrmkFybg8Pb2YcWRcvKofE/iTmC6v G65Q== ARC-Authentication-Results: i=1; mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Return-Path: Received: from vger.kernel.org (vger.kernel.org. [209.132.180.67]) by mx.google.com with ESMTP id q87si2677114pfj.323.2018.04.03.12.04.15; Tue, 03 Apr 2018 12:04:29 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753253AbeDCTBh convert rfc822-to-8bit (ORCPT + 99 others); Tue, 3 Apr 2018 15:01:37 -0400 Received: from mail.kernel.org ([198.145.29.99]:35254 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752881AbeDCTBa (ORCPT ); Tue, 3 Apr 2018 15:01:30 -0400 Received: from mail-io0-f169.google.com (mail-io0-f169.google.com [209.85.223.169]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 745D021837 for ; Tue, 3 Apr 2018 19:01:29 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 745D021837 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=luto@kernel.org Received: by mail-io0-f169.google.com with SMTP id 141so23268895iou.12 for ; Tue, 03 Apr 2018 12:01:29 -0700 (PDT) X-Gm-Message-State: ALQs6tAHT/u/NCmI8Th2ArybK24f7Gwqkr2fg99q0JVeNW7XVjYcJ0jf YDxlaBFKXvObIFkA5gIApNEIJeRGKg1eL7MVu6cDpA== X-Received: by 10.107.138.88 with SMTP id m85mr13360790iod.150.1522782088870; Tue, 03 Apr 2018 12:01:28 -0700 (PDT) MIME-Version: 1.0 Received: by 10.2.137.70 with HTTP; Tue, 3 Apr 2018 12:01:08 -0700 (PDT) In-Reply-To: <9758.1522775763@warthog.procyon.org.uk> References: <4136.1522452584@warthog.procyon.org.uk> <186aeb7e-1225-4bb8-3ff5-863a1cde86de@kernel.org> <30459.1522739219@warthog.procyon.org.uk> <9758.1522775763@warthog.procyon.org.uk> From: Andy Lutomirski Date: Tue, 3 Apr 2018 12:01:08 -0700 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [GIT PULL] Kernel lockdown for secure boot To: David Howells Cc: Andy Lutomirski , Matthew Garrett , Ard Biesheuvel , James Morris , Alan Cox , Linus Torvalds , Greg Kroah-Hartman , Linux Kernel Mailing List , Justin Forbes , linux-man , joeyli , LSM List , Linux API , Kees Cook , linux-efi Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > On Apr 3, 2018, at 10:16 AM, David Howells wrote: > > Andy Lutomirski wrote: > >>> A kernel that allows users arbitrary access to ring 0 is just an >>> overfeatured bootloader. Why would you want secure boot in that case? >> >> To get a chain of trust. > > You don't have a chain of trust that you can trust in that case. > Please elaborate on why I can’t trust it. Please also elaborate on how lockdown helps at all.