From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-1.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id BDC4BC4321D for ; Wed, 15 Aug 2018 21:14:41 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 31D2E208E4 for ; Wed, 15 Aug 2018 21:14:42 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="YvWp8opp" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 31D2E208E4 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727640AbeHPAIb (ORCPT ); Wed, 15 Aug 2018 20:08:31 -0400 Received: from mail-io0-f195.google.com ([209.85.223.195]:35387 "EHLO mail-io0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727427AbeHPAIb (ORCPT ); Wed, 15 Aug 2018 20:08:31 -0400 Received: by mail-io0-f195.google.com with SMTP id w11-v6so2180025iob.2 for ; Wed, 15 Aug 2018 14:14:38 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=google; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=s+HNgKzF+RElvIhHUEY/nNNqiCrgzpum4bRgrcMSR+s=; b=YvWp8oppO0sAAXG13H0Ts9P/BKqxakVRJc6G3rlc9RAO99JCc7Dup1tR+MQnp++94Z qkHQPJfR5rLkkT4tLPLJ4wVx5fxs8qPdPxrlJcUEsiFaxCpHfqJZpFSSMPy2LyvodZRl /kpaITTAWRMbc2evZD5zeopqv/rU1P6FD/dU0= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=s+HNgKzF+RElvIhHUEY/nNNqiCrgzpum4bRgrcMSR+s=; b=nYkmE/GiVZJ8c5+x3Gpc8+ZYwfOHdXrS456oEKc8ouT/kIal9HyYyLZvuxXVvs+eUW DrFdehRMrTDCypSGZaIsxuO3zJ9f1/2zaWy/ouo2Cs+FCXlyNMe9Q5adUMT5nCbruT0C E4MQxQqcJuFuBii+qlyei/EclWOSA0mEuEnBfsz+O3saqiEWNZEsVW2hYn3PMU8Tq51m Dun4tFofAe0W+UTVX9WxyqfN9Qj993unJTpC0N+l8lkC/eVWgMlSvJisRCgGDxhNypON w1RkQf+XlgCoOK4XFurnPgUXjZ6MNwtn7nJRIqy+552TIwvPmxOpwz2ds9Ps6A0OsOiN h1jQ== X-Gm-Message-State: AOUpUlF4JTFiUDl9yDpUzvF2fpKZfr44Wj4dziA+D/251zOt6fAARDnL IPL4NMZROrtDBRZnKtz8qUxGslYuaXoZjoBabI8= X-Google-Smtp-Source: AA+uWPxRWaOAxtkvgpkgfSZwPF41Izjbk5X8N2vDyoEOKO71vnVX8wUxJjK+XtxYbEOWxH64KFBEq1DSYtUSPBfkulw= X-Received: by 2002:a6b:7a08:: with SMTP id h8-v6mr19338633iom.238.1534367678212; Wed, 15 Aug 2018 14:14:38 -0700 (PDT) MIME-Version: 1.0 References: <20180815100053.13609-1-yannik@sembritzki.me> <654fbafb-69da-cd9a-b176-7b03401e71c5@sembritzki.me> <20180815174247.GB29541@redhat.com> <20180815185812.GC29541@redhat.com> <20180815194932.GD29541@redhat.com> <1ca6772b-46e0-9d93-0e15-7cf73a0b7b3f@sembritzki.me> In-Reply-To: <1ca6772b-46e0-9d93-0e15-7cf73a0b7b3f@sembritzki.me> From: Linus Torvalds Date: Wed, 15 Aug 2018 14:14:27 -0700 Message-ID: Subject: Re: [PATCH] Fix kexec forbidding kernels signed with custom platform keys to boot To: yannik@sembritzki.me Cc: Vivek Goyal , David Howells , Thomas Gleixner , Ingo Molnar , Peter Anvin , "the arch/x86 maintainers" , Linux Kernel Mailing List , Dave Young , Baoquan He , Justin Forbes , Peter Jones , James Bottomley , Matthew Garrett Content-Type: text/plain; charset="UTF-8" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Aug 15, 2018 at 2:08 PM Yannik Sembritzki wrote: > > IMO, this is not okay. The layer of trust should extend from the bottom > (user-provisioned platform key) up. Only trusting the kernel builtin key > later on (wrt. kernel modules) contradicts this principal. This module loading case is not about trusting the *key*. This is about trusting the *build system*. For example, I build my kernels with one single randomly generated key (that gets deleted afterwards). The modules get built with that key too. No amount of added keys later will make a module valid to load. Linus