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=-2.2 required=3.0 tests=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 4FAFEFA372A for ; Thu, 17 Oct 2019 15:30:23 +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 24D0620872 for ; Thu, 17 Oct 2019 15:30:23 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 24D0620872 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]:51048 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iL7jJ-0004bK-Qq for qemu-devel@archiver.kernel.org; Thu, 17 Oct 2019 11:30:21 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:50397) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1iL72Q-0008IW-WF for qemu-devel@nongnu.org; Thu, 17 Oct 2019 10:46:03 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1iL72P-0007ab-Ia for qemu-devel@nongnu.org; Thu, 17 Oct 2019 10:46:02 -0400 Received: from mx1.redhat.com ([209.132.183.28]:42078) by eggs.gnu.org with esmtps (TLS1.0:DHE_RSA_AES_256_CBC_SHA1:32) (Exim 4.71) (envelope-from ) id 1iL72P-0007Zh-CY for qemu-devel@nongnu.org; Thu, 17 Oct 2019 10:46:01 -0400 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 mx1.redhat.com (Postfix) with ESMTPS id 8B19781129 for ; Thu, 17 Oct 2019 14:45:59 +0000 (UTC) Received: from horse.redhat.com (unknown [10.18.25.35]) by smtp.corp.redhat.com (Postfix) with ESMTP id 5411B60852; Thu, 17 Oct 2019 14:45:54 +0000 (UTC) Received: by horse.redhat.com (Postfix, from userid 10451) id DA8A22202E5; Thu, 17 Oct 2019 10:45:53 -0400 (EDT) Date: Thu, 17 Oct 2019 10:45:53 -0400 From: Vivek Goyal To: Stefan Hajnoczi Subject: Re: [Virtio-fs] [PATCH 2/2] virtiofsd: move to a new pid namespace Message-ID: <20191017144553.GA12588@redhat.com> References: <20191016160157.12414-1-stefanha@redhat.com> <20191016160157.12414-3-stefanha@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20191016160157.12414-3-stefanha@redhat.com> User-Agent: Mutt/1.12.1 (2019-06-15) X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.27]); Thu, 17 Oct 2019 14:45:59 +0000 (UTC) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 209.132.183.28 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: virtio-fs@redhat.com, qemu-devel@nongnu.org Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Wed, Oct 16, 2019 at 05:01:57PM +0100, Stefan Hajnoczi wrote: [..] > + /* > + * If the mounts have shared propagation then we want to opt out so our > + * mount changes don't affect the parent mount namespace. > + */ > + if (mount(NULL, "/", NULL, MS_REC|MS_SLAVE, NULL) < 0) { > + fuse_log(FUSE_LOG_ERR, "mount(/, MS_REC|MS_SLAVE): %m\n"); > + exit(1); > + } So we will get mount propogation form parent but our mounts will not propagate back. Sounds reasonable. Can we take away CAP_SYS_ADMIN from virtiofsd? That way it will not be able to do mount at all. I am wondering are we dependent on daemon having CAP_SYS_ADMIN. Thanks Vivek