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=-5.0 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE, SPF_PASS,USER_AGENT_SANE_1 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 C4D31C433E0 for ; Tue, 7 Jul 2020 19:57:53 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 8B7DC206BE for ; Tue, 7 Jul 2020 19:57:53 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="BoU1eUrW" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 8B7DC206BE Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Received: from localhost ([::1]:39058 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jstiy-0001ft-OD for qemu-devel@archiver.kernel.org; Tue, 07 Jul 2020 15:57:52 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:58048) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jstiL-00014q-PG for qemu-devel@nongnu.org; Tue, 07 Jul 2020 15:57:13 -0400 Received: from us-smtp-1.mimecast.com ([205.139.110.61]:56871 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1jstiK-0001U2-4V for qemu-devel@nongnu.org; Tue, 07 Jul 2020 15:57:13 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1594151830; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=JMpC/hLGlbH54FbCDDUDa5Gqsa0zcfzruK+j5fgi82c=; b=BoU1eUrWnVOldzBD9TUCbtzR/jmZKo+4UvtMQ01m6qmmkphLl3wvDemlQElKX2nVcryo5H uFvln5mIuSvshe+td+0EbMp4ZcWZnFs6JVyOvM+AzZosYhPEavGRcoER4i6JHJNElgLr0G Uhi5lGdRG1G4w7J8aKl9iMfZiJmsVQQ= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-390-TyfL4MohOBWbH_sAYam42w-1; Tue, 07 Jul 2020 15:57:09 -0400 X-MC-Unique: TyfL4MohOBWbH_sAYam42w-1 Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.phx2.redhat.com [10.5.11.13]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 4842A800406; Tue, 7 Jul 2020 19:57:08 +0000 (UTC) Received: from [10.3.115.46] (ovpn-115-46.phx2.redhat.com [10.3.115.46]) by smtp.corp.redhat.com (Postfix) with ESMTPS id BACE1797F1; Tue, 7 Jul 2020 19:57:04 +0000 (UTC) Subject: Re: [PATCH v6 08/10] iotests: Specify explicit backing format where sensible To: Kevin Wolf References: <20200706203954.341758-1-eblake@redhat.com> <20200706203954.341758-9-eblake@redhat.com> <20200707160701.GE7002@linux.fritz.box> From: Eric Blake Organization: Red Hat, Inc. Message-ID: <8cef9936-4373-db92-90f0-ee208b203a47@redhat.com> Date: Tue, 7 Jul 2020 14:57:04 -0500 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.9.0 MIME-Version: 1.0 In-Reply-To: <20200707160701.GE7002@linux.fritz.box> Content-Language: en-US X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=eblake@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Received-SPF: pass client-ip=205.139.110.61; envelope-from=eblake@redhat.com; helo=us-smtp-delivery-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/07/07 00:31:00 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -40 X-Spam_score: -4.1 X-Spam_bar: ---- X-Spam_report: (-4.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H2=-1, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=_AUTOLEARN X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: pkrempa@redhat.com, qemu-block@nongnu.org, kchamart@redhat.com, libvir-list@redhat.com, qemu-devel@nongnu.org, mreitz@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On 7/7/20 11:07 AM, Kevin Wolf wrote: > Am 06.07.2020 um 22:39 hat Eric Blake geschrieben: >> There are many existing qcow2 images that specify a backing file but >> no format. This has been the source of CVEs in the past, but has >> become more prominent of a problem now that libvirt has switched to >> -blockdev. With older -drive, at least the probing was always done by >> qemu (so the only risk of a changed format between successive boots of >> a guest was if qemu was upgraded and probed differently). But with >> newer -blockdev, libvirt must specify a format; if libvirt guesses raw >> where the image was formatted, this results in data corruption visible >> to the guest; conversely, if libvirt guesses qcow2 where qemu was >> using raw, this can result in potential security holes, so modern >> libvirt instead refuses to use images without explicit backing format. >> >> The change in libvirt to reject images without explicit backing format >> has pointed out that a number of tools have been far too reliant on >> probing in the past. It's time to set a better example in our own >> iotests of properly setting this parameter. >> >> iotest calls to create, rebase, and convert are all impacted to some >> degree. It's a bit annoying that we are inconsistent on command line >> - while all of those accept -o backing_file=...,backing_fmt=..., the >> shortcuts are different: create and rebase have -b and -F, while >> convert has -B but no -F. (amend has no shortcuts, but the previous >> patch just deprecated the use of amend to change backing chains). >> >> Signed-off-by: Eric Blake > > This breaks at least 024 and 043 for qed because qemu-img info can't > print the backing file format there (qed only saves a flag whether it's > raw or non-raw). Shoot. I tend to avoid tests of qed and qcow (because they take so long), so while I may have tested them around v1 or v2 of the series, all the rebasing has changed the results by now. Such is life. > > We can fix the output filtering during the freeze, though. Yes indeed, and I'll post such patches soon, now that you've pointed it out. -- Eric Blake, Principal Software Engineer Red Hat, Inc. +1-919-301-3226 Virtualization: qemu.org | libvirt.org