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=-0.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 CD023C433DF for ; Thu, 18 Jun 2020 19:09:06 +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 9BFF1207E8 for ; Thu, 18 Jun 2020 19:09:06 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="GhXWZdny" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9BFF1207E8 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]:53988 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jlzuL-0001Ke-Un for qemu-devel@archiver.kernel.org; Thu, 18 Jun 2020 15:09:05 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:37496) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jlztm-0000oI-4L for qemu-devel@nongnu.org; Thu, 18 Jun 2020 15:08:30 -0400 Received: from us-smtp-1.mimecast.com ([205.139.110.61]:51144 helo=us-smtp-delivery-1.mimecast.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_CBC_SHA1:256) (Exim 4.90_1) (envelope-from ) id 1jlztj-0007Xu-UO for qemu-devel@nongnu.org; Thu, 18 Jun 2020 15:08:29 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1592507306; 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=biL937nVRWE2AZIUC24vk6ZKO9vvm4VOV8K5gKjdplo=; b=GhXWZdnycZRssuaR+ITNUrCq2OgQouFZFXFr0aptueDE/bc5ovlLQJRIe2pMH++3BNwOBw S216Cj5c4Ga9rkyhGXh95C8VkU2r+TErala8m1cinDmGMFUFAIefKmQ2C9UgDGFDCCFR8d TZiWvnwvTgueOC/0+ewpEk9Trb2+75E= 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-234-TD5zNElmOlCmN9J_uVNaGQ-1; Thu, 18 Jun 2020 15:08:24 -0400 X-MC-Unique: TD5zNElmOlCmN9J_uVNaGQ-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 368EB84638E; Thu, 18 Jun 2020 19:08:23 +0000 (UTC) Received: from horse.redhat.com (ovpn-115-20.rdu2.redhat.com [10.10.115.20]) by smtp.corp.redhat.com (Postfix) with ESMTP id AA2795C1D0; Thu, 18 Jun 2020 19:08:16 +0000 (UTC) Received: by horse.redhat.com (Postfix, from userid 10451) id 2CD83222D7B; Thu, 18 Jun 2020 15:08:16 -0400 (EDT) Date: Thu, 18 Jun 2020 15:08:16 -0400 From: Vivek Goyal To: Stefan Hajnoczi Subject: Re: [Virtio-fs] [PATCH 0/2] virtiofsd: drop Linux capabilities(7) Message-ID: <20200618190816.GD3814@redhat.com> References: <20200416164907.244868-1-stefanha@redhat.com> MIME-Version: 1.0 In-Reply-To: <20200416164907.244868-1-stefanha@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.16 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Content-Disposition: inline Received-SPF: pass client-ip=205.139.110.61; envelope-from=vgoyal@redhat.com; helo=us-smtp-delivery-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/06/18 15:08:26 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -30 X-Spam_score: -3.1 X-Spam_bar: --- X-Spam_report: (-3.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=_AUTOLEARN 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: , Cc: virtio-fs@redhat.com, qemu-devel@nongnu.org, Miklos Szeredi Errors-To: qemu-devel-bounces+qemu-devel=archiver.kernel.org@nongnu.org Sender: "Qemu-devel" On Thu, Apr 16, 2020 at 05:49:05PM +0100, Stefan Hajnoczi wrote: > virtiofsd doesn't need of all Linux capabilities(7) available to root. Keep a > whitelisted set of capabilities that we require. This improves security in > case virtiofsd is compromised by making it hard for an attacker to gain further > access to the system. Hi Stefan, I just noticed that this patch set breaks overlayfs on top of virtiofs. overlayfs sets "trusted.overlay.*" and xattrs in trusted domain need CAP_SYS_ADMIN. man xattr says. Trusted extended attributes Trusted extended attributes are visible and accessible only to pro‐ cesses that have the CAP_SYS_ADMIN capability. Attributes in this class are used to implement mechanisms in user space (i.e., outside the kernel) which keep information in extended attributes to which ordinary processes should not have access. There is a chance that overlay moves away from trusted xattr in future. But for now we need to make it work. This is an important use case for kata docker in docker build. May be we can add an option to virtiofsd say "--add-cap " and ask user to pass in "--add-cap cap_sys_admin" if they need to run daemon with this capaibility. Thanks Vivek > > Stefan Hajnoczi (2): > virtiofsd: only retain file system capabilities > virtiofsd: drop all capabilities in the wait parent process > > tools/virtiofsd/passthrough_ll.c | 51 ++++++++++++++++++++++++++++++++ > 1 file changed, 51 insertions(+) > > -- > 2.25.1 > > _______________________________________________ > Virtio-fs mailing list > Virtio-fs@redhat.com > https://www.redhat.com/mailman/listinfo/virtio-fs