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=-3.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,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 3429AC4361B for ; Tue, 8 Dec 2020 23:42:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E62B523A5A for ; Tue, 8 Dec 2020 23:42:17 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731773AbgLHXmL (ORCPT ); Tue, 8 Dec 2020 18:42:11 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:41104 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731748AbgLHXmK (ORCPT ); Tue, 8 Dec 2020 18:42:10 -0500 Received: from mail-ed1-x530.google.com (mail-ed1-x530.google.com [IPv6:2a00:1450:4864:20::530]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9D002C06179C for ; Tue, 8 Dec 2020 15:41:30 -0800 (PST) Received: by mail-ed1-x530.google.com with SMTP id b73so6250edf.13 for ; Tue, 08 Dec 2020 15:41:30 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=paul-moore-com.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=0styejjvaAGmzemOZ5MgVk/FxItoWovN4p8t1k68Ido=; b=zQ9miL8kae4D2P0vHCXxyu6zOLNOtsMXBhVjDzSeDAgWDgQezVOte9VFwMnx0nJFF6 W2W1++Tp0cqsk14cyNspQDcpKVeuChDDiv6r6hRB53n9YF6AJWWyachsJXXvs/FmcT2d tiKKG49oNDAx3Dfd5s7Uvnrr6wrmsyRzGcgflUNMFd1NTSHrXCLBVeUSvgak8SsEY9Ms gTC/ktstcbpYkqzBLGb52MSTAOY8QY+PAmfun9yn8qyH1hFwUIoRcnHy54jMGHDemWSn oHiy3sdklNTw4k7QZEXXOhwjv5AtQZPKbp6U2H2HW0NNed2mAxUE3wkRfSFzkB0onVLQ ADqA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=0styejjvaAGmzemOZ5MgVk/FxItoWovN4p8t1k68Ido=; b=R26pwF0ARfP6n/52y68rc7NvdwQmzppinqdlqlMzUggG8gVBN1oXrLa3kAPGAnoTCw xSy3R/nkyM6Btx6X/4q/FBbwCjSxBzwh+yCj5znXHKQ0WYts28CQ25RD5yLsGBiMLNNY ga7XEzlXH7vOgKFoDUmxc4AnRuyZEHDUGQTEIV8yNywW6V5Jubyy4LY0nnKh4+Z3qpBv zt8gb67kovtWcJLBf4nx5o/G1cMegvFL7BM+WR/2WNOB1gwkKxO1FG2hICVm6Gdsxo/c vSnBM+VB3j++XC5Jshgg0lbU6WGS/doudPaEeKEgwgq3zbjZX8/IEvYLFpR0M95/aYaE Zwig== X-Gm-Message-State: AOAM530f+rQ3qV2Fjf3e93nmVAvycYIBipDd94+87miDU5Pvi1d2l/LW 2xaUhM22iP2zI+0KG+R8zZQGJHi8LYFjDmzxR27n X-Google-Smtp-Source: ABdhPJzHlU4UpwUzqg11zhEI6bUD1V1aoYiay4Hp1SkiE25rgoxmkUijslZqutsWnLJfRPm8pvRZf720v3sPEV5mje8= X-Received: by 2002:a05:6402:10ce:: with SMTP id p14mr354875edu.12.1607470889147; Tue, 08 Dec 2020 15:41:29 -0800 (PST) MIME-Version: 1.0 References: <20201207205209.GD3107@redhat.com> In-Reply-To: <20201207205209.GD3107@redhat.com> From: Paul Moore Date: Tue, 8 Dec 2020 18:41:17 -0500 Message-ID: Subject: Re: virtiofs and its optional xattr support vs. fs_use_xattr To: Vivek Goyal Cc: Ondrej Mosnacek , SElinux list , Stephen Smalley , Daniel Walsh , Zdenek Pytela , virtio-fs-list , Miklos Szeredi Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: selinux@vger.kernel.org On Mon, Dec 7, 2020 at 3:52 PM Vivek Goyal wrote: > On Mon, Dec 07, 2020 at 10:03:24AM -0500, Paul Moore wrote: > > On Mon, Dec 7, 2020 at 9:43 AM Ondrej Mosnacek wrote: > > > > > > Hi everyone, > > > > > > In [1] we ran into a problem with the current handling of filesystem > > > labeling rules. Basically, it is only possible to specify either > > > genfscon or fs_use_xattr for a given filesystem, but in the case of > > > virtiofs, certain mounts may support security xattrs, while other ones > > > may not. > > [ cc virtio-fs list and miklos ] > > Quickly skimming the linked GH issue, it appears that the problem > > really lies in the fact that virtiofs allows one to enable/disable > > xattrs at mount time. What isn't clear to me is why one would need to > > disable xattrs, can you explain that use case? Why does enabling > > xattrs in virtiofs cause problems? > > Its not exactly a mount time option. Its a virtiofs file server option. > > xattr support by default is disabled because it has performance > penalty. Users can enable it if they want to. Oh the number of sins against security that have been committed under the banner of performance! ;) Regardless, thanks for the explanation, that helps. -- paul moore www.paul-moore.com From mboxrd@z Thu Jan 1 00:00:00 1970 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=paul-moore-com.20150623.gappssmtp.com; s=20150623; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=0styejjvaAGmzemOZ5MgVk/FxItoWovN4p8t1k68Ido=; b=zQ9miL8kae4D2P0vHCXxyu6zOLNOtsMXBhVjDzSeDAgWDgQezVOte9VFwMnx0nJFF6 W2W1++Tp0cqsk14cyNspQDcpKVeuChDDiv6r6hRB53n9YF6AJWWyachsJXXvs/FmcT2d tiKKG49oNDAx3Dfd5s7Uvnrr6wrmsyRzGcgflUNMFd1NTSHrXCLBVeUSvgak8SsEY9Ms gTC/ktstcbpYkqzBLGb52MSTAOY8QY+PAmfun9yn8qyH1hFwUIoRcnHy54jMGHDemWSn oHiy3sdklNTw4k7QZEXXOhwjv5AtQZPKbp6U2H2HW0NNed2mAxUE3wkRfSFzkB0onVLQ ADqA== MIME-Version: 1.0 References: <20201207205209.GD3107@redhat.com> In-Reply-To: <20201207205209.GD3107@redhat.com> From: Paul Moore Date: Tue, 8 Dec 2020 18:41:17 -0500 Message-ID: Content-Type: text/plain; charset="UTF-8" Subject: Re: [Virtio-fs] virtiofs and its optional xattr support vs. fs_use_xattr List-Id: Development discussions about virtio-fs List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Vivek Goyal Cc: SElinux list , Stephen Smalley , Ondrej Mosnacek , virtio-fs-list , Zdenek Pytela On Mon, Dec 7, 2020 at 3:52 PM Vivek Goyal wrote: > On Mon, Dec 07, 2020 at 10:03:24AM -0500, Paul Moore wrote: > > On Mon, Dec 7, 2020 at 9:43 AM Ondrej Mosnacek wrote: > > > > > > Hi everyone, > > > > > > In [1] we ran into a problem with the current handling of filesystem > > > labeling rules. Basically, it is only possible to specify either > > > genfscon or fs_use_xattr for a given filesystem, but in the case of > > > virtiofs, certain mounts may support security xattrs, while other ones > > > may not. > > [ cc virtio-fs list and miklos ] > > Quickly skimming the linked GH issue, it appears that the problem > > really lies in the fact that virtiofs allows one to enable/disable > > xattrs at mount time. What isn't clear to me is why one would need to > > disable xattrs, can you explain that use case? Why does enabling > > xattrs in virtiofs cause problems? > > Its not exactly a mount time option. Its a virtiofs file server option. > > xattr support by default is disabled because it has performance > penalty. Users can enable it if they want to. Oh the number of sins against security that have been committed under the banner of performance! ;) Regardless, thanks for the explanation, that helps. -- paul moore www.paul-moore.com