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=-1.0 required=3.0 tests=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 5E8EAC4321D for ; Thu, 16 Aug 2018 12:13:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 19740208AD for ; Thu, 16 Aug 2018 12:13:38 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 19740208AD Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com 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 S2391393AbeHPPLs (ORCPT ); Thu, 16 Aug 2018 11:11:48 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:49980 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1731460AbeHPPLr (ORCPT ); Thu, 16 Aug 2018 11:11:47 -0400 Received: from smtp.corp.redhat.com (int-mx05.intmail.prod.int.rdu2.redhat.com [10.11.54.5]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id EA9794012970; Thu, 16 Aug 2018 12:13:34 +0000 (UTC) Received: from warthog.procyon.org.uk (ovpn-120-130.rdu2.redhat.com [10.10.120.130]) by smtp.corp.redhat.com (Postfix) with ESMTP id 0CB6923141; Thu, 16 Aug 2018 12:13:30 +0000 (UTC) Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 From: David Howells In-Reply-To: <20180815185812.GC29541@redhat.com> References: <20180815185812.GC29541@redhat.com> <20180815100053.13609-1-yannik@sembritzki.me> <654fbafb-69da-cd9a-b176-7b03401e71c5@sembritzki.me> <20180815174247.GB29541@redhat.com> To: Vivek Goyal Cc: dhowells@redhat.com, Yannik Sembritzki , Linus Torvalds , Thomas Gleixner , Ingo Molnar , Peter Anvin , the arch/x86 maintainers , Linux Kernel Mailing List , Dave Young , Baoquan He , "Justin M. Forbes" , Peter Jones , James Bottomley , Matthew Garrett Subject: Re: [PATCH] Fix kexec forbidding kernels signed with custom platform keys to boot MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <4910.1534421610.1@warthog.procyon.org.uk> Date: Thu, 16 Aug 2018 13:13:30 +0100 Message-ID: <4911.1534421610@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 2.79 on 10.11.54.5 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.6]); Thu, 16 Aug 2018 12:13:35 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.6]); Thu, 16 Aug 2018 12:13:35 +0000 (UTC) for IP:'10.11.54.5' DOMAIN:'int-mx05.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'dhowells@redhat.com' RCPT:'' Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Vivek Goyal wrote: > Now this patch changed it to trusting builtin_trusted_keys by default, > and all the other keys go to secondary_trusted_keys kerying. And that > probably explains why it broke. > > So checking for keys in both the keyrings makes sense to me. > > I am wondering why did we have to split this keyring to begin with. > So there are use cases where we want to trust builtin keys but > not the ones which came from other places (UEFI secure boot db, or > user loaded one)? IMA and the IMA authors. They want everything separated into separate keyrings out by source and usage as far as I can tell - though this just makes it harder to use things. One advantage of splitting things, though, is that you don't lose the built-in keys if you load a conflicting one from another source. One thing that's on my to-do list is to mark keys with the provenance, perhaps something like: enum key_source { key_added_by_user, key_built_in_for_modsign, key_added_to_image, key_from_uefi_db, key_from_uefi_dbx, key_from_tpm, }; struct key { ... enum key_source source; }; Then: (1) pass this information to LSMs to make use of (2) Make the verification code take a bitmask of what keys are permitted for the task at hand. David