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 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 smtp.lore.kernel.org (Postfix) with ESMTPS id A7CA8C433EF for ; Mon, 7 Feb 2022 13:56:38 +0000 (UTC) Received: from localhost ([::1]:48650 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nH4VR-0000wx-7n for qemu-devel@archiver.kernel.org; Mon, 07 Feb 2022 08:56:37 -0500 Received: from eggs.gnu.org ([209.51.188.92]:42232) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nH40L-0000vH-Vj for qemu-devel@nongnu.org; Mon, 07 Feb 2022 08:24:30 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]:35923) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nH40I-0002lR-08 for qemu-devel@nongnu.org; Mon, 07 Feb 2022 08:24:28 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1644240264; 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=X98rIBDPVU5c1r2w9EWfTLRfd+ulxGPrAjZIHJibUBM=; b=KTKzLlXFcYGQNZxIPl3G8gISdtlCeW+a/M2Wf3NzM8z+h/ePpdP0Qdwu9bkr88vzBBJO0h sPFA84jML3zZcbN4VG13oDjms+vc6R6YfDK69Rb5sMPLnbgr6ecgndv24akSNhsVbmNqia MWYnOHACkOjiDiaOU/1dbNZaT3JXsos= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-168-JJ-icLuoN3qmBFIgEZB1qw-1; Mon, 07 Feb 2022 08:24:18 -0500 X-MC-Unique: JJ-icLuoN3qmBFIgEZB1qw-1 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 354CB190B2AC for ; Mon, 7 Feb 2022 13:24:17 +0000 (UTC) Received: from horse.redhat.com (unknown [10.22.9.190]) by smtp.corp.redhat.com (Postfix) with ESMTP id F159A1038ACE; Mon, 7 Feb 2022 13:24:08 +0000 (UTC) Received: by horse.redhat.com (Postfix, from userid 10451) id 8149D2237EB; Mon, 7 Feb 2022 08:24:08 -0500 (EST) Date: Mon, 7 Feb 2022 08:24:08 -0500 From: Vivek Goyal To: Daniel =?iso-8859-1?Q?P=2E_Berrang=E9?= Subject: Re: [PATCH v5 0/9] virtiofsd: Add support for file security context at file creation Message-ID: References: <20220202193935.268777-1-vgoyal@redhat.com> MIME-Version: 1.0 In-Reply-To: X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=vgoyal@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=170.10.133.124; envelope-from=vgoyal@redhat.com; helo=us-smtp-delivery-124.mimecast.com X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-0.001, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_LOW=-0.7, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=ham autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: virtio-fs@redhat.com, mszeredi@redhat.com, qemu-devel@nongnu.org, dgilbert@redhat.com Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Mon, Feb 07, 2022 at 01:05:16PM +0000, Daniel P. Berrangé wrote: > On Wed, Feb 02, 2022 at 02:39:26PM -0500, Vivek Goyal wrote: > > Hi, > > > > This is V5 of the patches. I posted V4 here. > > > > https://listman.redhat.com/archives/virtio-fs/2022-January/msg00041.html > > > > These will allow us to support SELinux with virtiofs. This will send > > SELinux context at file creation to server and server can set it on > > file. > > I've not entirely figured it out from the code, so easier for me > to ask... > > How is the SELinux labelled stored on the host side ? It is stored > directly in the security.* xattr namespace, or is is subject to > xattr remapping that virtiofsd already supports. > > Storing directly means virtiofsd has to run in an essentially > unconfined context, to let it do arbitrary changes on security.* > xattrs without being blocked by SELinux) and has risk that guest > initiated changes can open holes in the host confinement if > the exported FS is generally visible to processes on the host. > > > Using remapping lets virtiofsd be strictly isolated by SELinux > policy on the host, and ensures that guest context changes > can't open up holes in the host. > > Both are valid use cases, so I'd ultimately expect us to want > to support both, but my preference for a "default" behaviour > would be remapping. I am expecting users to configure virtiofsd to remap "security.selinux" to "trusted.virtiofsd.security.selinux" and that will allow guest and host security selinux to co-exist and allow separate SELinux policies for guest and host. I agree that my preference for a default behavior is remapping as well. That makes most sense. One downside of mapping to trusted namespace is that it requires CAP_SYS_ADMIN for virtiofsd. Having said that, these patches don't enforce the remapping default. That has to come from the user because it also needs to be given CAP_SYS_ADMIN. So out of box default is no remapping and passthrough SELinux. Thanks Vivek > > Regards, > Daniel > -- > |: https://berrange.com -o- https://www.flickr.com/photos/dberrange :| > |: https://libvirt.org -o- https://fstop138.berrange.com :| > |: https://entangle-photo.org -o- https://www.instagram.com/dberrange :| >