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 A5090C433F5 for ; Tue, 8 Feb 2022 10:27:59 +0000 (UTC) Received: from localhost ([::1]:54588 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nHNj4-0007fN-Jo for qemu-devel@archiver.kernel.org; Tue, 08 Feb 2022 05:27:58 -0500 Received: from eggs.gnu.org ([209.51.188.92]:46678) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nHMLl-0008A8-Rm for qemu-devel@nongnu.org; Tue, 08 Feb 2022 03:59:52 -0500 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]:51675) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nHMLk-0007q2-2V for qemu-devel@nongnu.org; Tue, 08 Feb 2022 03:59:49 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1644310784; h=from:from:reply-to: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=HF8fMxs5opOmYeumKa7j0hei2XqIKWbQvGoblV7ENtw=; b=dTnSHR/3ldCC6LuEIBkCsEoxfB1yq2Xq2N+qTRqhU5T6xJadrSA2w55AO0E209xl4M67zd 5gsiXGWlAJ0b3Y7XT1YURRQGG0FvUhlltQBk+uAFQkoxIL2JNxA0Je+afi/UkaEIaLx2IZ Ndw0brw9kLZNNeyCX4zYC776p7B4lto= 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-453-cr21I_zJMAidW4SpeetYKg-1; Tue, 08 Feb 2022 03:59:43 -0500 X-MC-Unique: cr21I_zJMAidW4SpeetYKg-1 Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.phx2.redhat.com [10.5.11.16]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 872478143E5 for ; Tue, 8 Feb 2022 08:59:42 +0000 (UTC) Received: from redhat.com (unknown [10.33.36.138]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 205707AB7E; Tue, 8 Feb 2022 08:59:40 +0000 (UTC) Date: Tue, 8 Feb 2022 08:59:38 +0000 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Vivek Goyal 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: User-Agent: Mutt/2.1.5 (2021-12-30) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=berrange@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit Received-SPF: pass client-ip=170.10.129.124; envelope-from=berrange@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: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Cc: virtio-fs@redhat.com, mszeredi@redhat.com, Daniel J Walsh , 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 04:19:38PM -0500, Vivek Goyal wrote: > 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, > > [ CC Dan Walsh ] > > I just tried to test the mode where I don't do xattr remapping and try > to set /proc/pid/attr/fscreate with the context I want to set. It will > set security.selinux xattr on host. > > But write to /proc/pid/attr/fscreate fails if host does not recognize > the label sent by guest. I am running virtiofsd with unconfined_t but > it still fails because guest is trying to create a file with > "test_filesystem_filetranscon_t" and host does not recognize this > label. Seeing following in audit logs. > > type=SELINUX_ERR msg=audit(1644268262.666:8111): op=fscreate invalid_context="unconfined_u:object_r:test_filesystem_filetranscon_t:s0" Yes, that's to be expected if the host policy doesn't know about the label that the guest is using. IOW, non-mapping case is only useful if you have a very good match between host + guest OS policy. This could be useful for an app like Kata because their guest is not a full OS, it is something special purpose and tightly controlled. > So if we don't remap xattrs and host has SELinux enabled, then it probably > work in very limited circumstances where host and guest policies don't > conflict. I guess its like running fedora 34 guest on fedora 34 host. > I suspect that this will see very limited use. Though I have put the > code in for the sake of completeness. For general purpose guest OS virtualization remapping is going to be effectuively mandatory. The non-mapped case only usable when you tightly control the guest OS packages from the host. 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 :|