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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 551F0C43143 for ; Mon, 1 Oct 2018 07:21:56 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 13F9F206B2 for ; Mon, 1 Oct 2018 07:21:56 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 13F9F206B2 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=xmission.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728928AbeJAN6O (ORCPT ); Mon, 1 Oct 2018 09:58:14 -0400 Received: from out03.mta.xmission.com ([166.70.13.233]:41967 "EHLO out03.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728803AbeJAN6O (ORCPT ); Mon, 1 Oct 2018 09:58:14 -0400 Received: from in02.mta.xmission.com ([166.70.13.52]) by out03.mta.xmission.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.87) (envelope-from ) id 1g6sWe-0002g3-7L; Mon, 01 Oct 2018 01:21:52 -0600 Received: from [105.184.227.67] (helo=x220.xmission.com) by in02.mta.xmission.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.87) (envelope-from ) id 1g6sWc-0003EL-V3; Mon, 01 Oct 2018 01:21:52 -0600 From: ebiederm@xmission.com (Eric W. Biederman) To: Andy Lutomirski Cc: laurent@vivier.eu, LKML , Linux FS Devel , James Bottomley , Al Viro , Linux API , Dmitry Safonov , Andrey Vagin , Linux Containers References: <20180930234628.25528-1-laurent@vivier.eu> Date: Mon, 01 Oct 2018 09:21:41 +0200 In-Reply-To: (Andy Lutomirski's message of "Sun, 30 Sep 2018 21:45:44 -0700") Message-ID: <874le63zei.fsf@xmission.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-XM-SPF: eid=1g6sWc-0003EL-V3;;;mid=<874le63zei.fsf@xmission.com>;;;hst=in02.mta.xmission.com;;;ip=105.184.227.67;;;frm=ebiederm@xmission.com;;;spf=neutral X-XM-AID: U2FsdGVkX19/H3S2D4Mi8j/zdvRM9Uz3j1kjHEMb8Ok= X-SA-Exim-Connect-IP: 105.184.227.67 X-SA-Exim-Mail-From: ebiederm@xmission.com Subject: Re: [RFC 0/2] ns: introduce binfmt_misc namespace X-SA-Exim-Version: 4.2.1 (built Thu, 05 May 2016 13:38:54 -0600) X-SA-Exim-Scanned: Yes (on in02.mta.xmission.com) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Andy Lutomirski writes: > On Sun, Sep 30, 2018 at 4:47 PM Laurent Vivier wrote: >> >> This series introduces a new namespace for binfmt_misc. >> > > This seems conceptually quite reasonable, but I'm wondering if the > number of namespace types is getting out of hand given the current > API. Should we be considering whether we need a new set of namespace > creation APIs that scale better to larger numbers of namespace types? I would rather encourage a way to make this part of an existing namespace or find a way to make a mount of binfmt_misc control this. Hmm. This looks like something that can be very straight forwardly be made part of the user namespace. If you ever mount binfmt_misc in the user namespace you get the new behavior. Otherwise you get the existing behavior. A user namespace will definitely be required, as otherwise you run the risk of confusing root (and suid root exectuables0 by being able to change the behavior of executables. What is the motivation for this? My impression is that very few people tweak binfmt_misc. I also don't think this raises to the level where it makes sense to create a new namespace for this. Eric