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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 37678C433F5 for ; Mon, 27 Sep 2021 13:07:38 +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 9708A60EE0 for ; Mon, 27 Sep 2021 13:07:37 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 9708A60EE0 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=nongnu.org Received: from localhost ([::1]:45534 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mUqM4-0003Co-Jo for qemu-devel@archiver.kernel.org; Mon, 27 Sep 2021 09:07:36 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:39006) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mUqAv-0003tE-Lz for qemu-devel@nongnu.org; Mon, 27 Sep 2021 08:56:06 -0400 Received: from us-smtp-delivery-124.mimecast.com ([170.10.129.124]:48770) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mUqAp-0004N9-IV for qemu-devel@nongnu.org; Mon, 27 Sep 2021 08:56:05 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1632747358; 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=4SBSDgqI5kfiFiwSa6lpk9RgVV+Mbi6ihqsITBK6h7A=; b=fzDOS9bI+IEvUKeB6MDWYWo3h9J84h+MvDfViVjk3fs+U3eDchfF+v1lwS4iGGLIWqUuKf 5AIkGBzwOHHiE1FmZl8PUjiCmMTy8rxzY0OdY/Nb2jXvqwIcqXqhPfdXy+NWZHE9+86/ps m4rmZTP3DYaOlsZq3Xw5ltbIB4h6gyc= 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-31-SPLgx9-VPyaQNtE-SqvSxw-1; Mon, 27 Sep 2021 08:55:52 -0400 X-MC-Unique: SPLgx9-VPyaQNtE-SqvSxw-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 69733802E3F; Mon, 27 Sep 2021 12:55:51 +0000 (UTC) Received: from redhat.com (unknown [10.39.194.156]) by smtp.corp.redhat.com (Postfix) with ESMTPS id 175B0100164A; Mon, 27 Sep 2021 12:55:49 +0000 (UTC) Date: Mon, 27 Sep 2021 13:55:47 +0100 From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= To: Eric Blake Subject: Re: [PATCH v2] nbd/server: Add --selinux-label option Message-ID: References: <20210723103303.1731437-1-rjones@redhat.com> <20210723103303.1731437-2-rjones@redhat.com> <20210825193504.d6ka3xzmpd54x2fq@redhat.com> MIME-Version: 1.0 In-Reply-To: <20210825193504.d6ka3xzmpd54x2fq@redhat.com> User-Agent: Mutt/2.0.7 (2021-05-04) X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 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 autolearn=unavailable autolearn_force=no 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: , Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= Cc: Kevin Wolf , vsementsov@virtuozzo.com, "Richard W.M. Jones" , qemu-block@nongnu.org, qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Wed, Aug 25, 2021 at 02:35:04PM -0500, Eric Blake wrote: > On Fri, Jul 23, 2021 at 05:38:06PM +0100, Daniel P. Berrangé wrote: > > On Fri, Jul 23, 2021 at 06:18:55PM +0200, Kevin Wolf wrote: > > > Am 23.07.2021 um 12:33 hat Richard W.M. Jones geschrieben: > > > > Under SELinux, Unix domain sockets have two labels. One is on the > > > > disk and can be set with commands such as chcon(1). There is a > > > > different label stored in memory (called the process label). This can > > > > only be set by the process creating the socket. When using SELinux + > > > > SVirt and wanting qemu to be able to connect to a qemu-nbd instance, > > > > you must set both labels correctly first. > > > > > > > > For qemu-nbd the options to set the second label are awkward. You can > > > > create the socket in a wrapper program and then exec into qemu-nbd. > > > > Or you could try something with LD_PRELOAD. > > > > > > > > This commit adds the ability to set the label straightforwardly on the > > > > command line, via the new --selinux-label flag. (The name of the flag > > > > is the same as the equivalent nbdkit option.) > > > > > > > > A worked example showing how to use the new option can be found in > > > > this bug: https://bugzilla.redhat.com/show_bug.cgi?id=1984938 > > > > > > > > Fixes: https://bugzilla.redhat.com/show_bug.cgi?id=1984938 > > > > Signed-off-by: Richard W.M. Jones > > > > > > I suppose this would also be relevant for the built-in NBD server, > > > especially in the context of qemu-storage-daemon? > > > > It depends on the usage scenario really. nbdkit / qemu-nbd are > > not commonly run under any SELinux policy, so then end up being > > unconfined_t. A QEMU NBD client can't connect to an unconfined_t > > socket, so we need to override it with this arg. > > > > In the case of qemu system emulator, under libvirt, it will > > already have a svirt_t type, so in that case there is no need > > to override the type for the socket. > > > > For qsd there's not really any strong practice established > > but i expect most current usage is unconfined_t too and > > would benefit from setting label. > > > > > If so, is this something specific to NBD sockets, or would it actually > > > make sense to have it as a generic option in UnixSocketAddress? > > > > It is applicable to inet sockets too in fact. > > So now that 6.2 is open, should I queue the patch as is, or wait for a > v3 that makes the option more generic to all socket usage? My gut feeling is that it makes sense to have a more generic option, with the selinux label specified in the "SocketAddress" QAPI type, and then have util/qemu-sockets.h be setting the context in socket_listen(). I don't think this invalidates the patch that Richard proprosed here, as we'll still need the command line argument he's added. All that will differ is that the setsockcreatecon_raw will get moved down. So from that POV, I don't think we need the general solution to be a blocker, it can be additive. 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 :|