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=-2.4 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 E1949C35671 for ; Mon, 24 Feb 2020 11:44:49 +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 A84392072D for ; Mon, 24 Feb 2020 11:44:49 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="cV1SbPcx" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A84392072D 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]:35214 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1j6CAK-0003S6-Qd for qemu-devel@archiver.kernel.org; Mon, 24 Feb 2020 06:44:48 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:53743) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1j6C9g-000330-Ha for qemu-devel@nongnu.org; Mon, 24 Feb 2020 06:44:09 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1j6C9f-00028K-Dx for qemu-devel@nongnu.org; Mon, 24 Feb 2020 06:44:08 -0500 Received: from us-smtp-delivery-1.mimecast.com ([205.139.110.120]:46118 helo=us-smtp-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1j6C9f-00028D-9H for qemu-devel@nongnu.org; Mon, 24 Feb 2020 06:44:07 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1582544646; 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=mqjeL9elM34+DRT35i6Rrj3lAQACibs0F0yxjpbe1ng=; b=cV1SbPcxQR4b8orqupn0kq8wepZVx/nwD/OINAjqu91AZrvo7m818c7y9o+nN62IezwqCE CN6zOHhRn4FSymSr4Qq4D0j9ZSzTTOljAsoio8wcdqrsAT7S+iYK8I4Cx+J4LsI5QVape1 S7XdwAYZOnOi5FrpyoeuvoCiv8wQTrQ= 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-356-0MAFI2GsPi-tkR_vqc9N0w-1; Mon, 24 Feb 2020 06:44:04 -0500 X-MC-Unique: 0MAFI2GsPi-tkR_vqc9N0w-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id DF2361005510; Mon, 24 Feb 2020 11:44:03 +0000 (UTC) Received: from andariel.pipo.sk (ovpn-204-177.brq.redhat.com [10.40.204.177]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 5B73C60BF3; Mon, 24 Feb 2020 11:43:59 +0000 (UTC) Date: Mon, 24 Feb 2020 12:43:56 +0100 From: Peter Krempa To: Eric Blake Subject: Re: [PATCH 0/3] Tighten qemu-img rules on missing backing format Message-ID: <20200224114356.GD3296@andariel.pipo.sk> References: <20200222112341.4170045-1-eblake@redhat.com> <20200224110145.GB3296@andariel.pipo.sk> MIME-Version: 1.0 In-Reply-To: <20200224110145.GB3296@andariel.pipo.sk> X-PGP-Key-ID: 0xD018682B X-PGP-Key-Fingerprint: D294 FF38 A6A2 BF40 6C75 5DEF 36EC 16AC D018 682B User-Agent: Mutt/1.13.3 (2020-01-12) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: quoted-printable Content-Disposition: inline X-detected-operating-system: by eggs.gnu.org: Error: Can't connect to API socket. X-Received-From: 205.139.110.120 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: libvir-list@redhat.com, qemu-devel@nongnu.org, qemu-block@nongnu.org, mreitz@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Mon, Feb 24, 2020 at 12:01:45 +0100, Peter Krempa wrote: > On Sat, Feb 22, 2020 at 05:23:38 -0600, Eric Blake wrote: [...] > > libvirt HAS to use blockdev-open on the backing chain and supply a > > backing format there, and thus has to probe images. If libvirt ever > > probes differently than qemu, we are back to the potential > > guest-visible data corruption or potential host CVEs. >=20 > As I've elaborated in [1] I disagree with the host CVE part. The [1] https://www.redhat.com/archives/libvir-list/2020-February/msg00624.html > insecure part is not probing the format itself, but probing format AND > using the backing file of the image if we probed format.