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=-1.0 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 7E608C10F0E for ; Mon, 15 Apr 2019 19:59:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 471FE2070D for ; Mon, 15 Apr 2019 19:59:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729105AbfDOT7n (ORCPT ); Mon, 15 Apr 2019 15:59:43 -0400 Received: from mx2.mailbox.org ([80.241.60.215]:43070 "EHLO mx2.mailbox.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728548AbfDOT7l (ORCPT ); Mon, 15 Apr 2019 15:59:41 -0400 Received: from smtp2.mailbox.org (smtp2.mailbox.org [80.241.60.241]) (using TLSv1.2 with cipher ECDHE-RSA-CHACHA20-POLY1305 (256/256 bits)) (No client certificate requested) by mx2.mailbox.org (Postfix) with ESMTPS id B6D7DA1059; Mon, 15 Apr 2019 21:59:38 +0200 (CEST) X-Virus-Scanned: amavisd-new at heinlein-support.de Received: from smtp2.mailbox.org ([80.241.60.241]) by spamfilter05.heinlein-hosting.de (spamfilter05.heinlein-hosting.de [80.241.56.123]) (amavisd-new, port 10030) with ESMTP id HDcyg6PzSmvR; Mon, 15 Apr 2019 21:59:25 +0200 (CEST) Date: Tue, 16 Apr 2019 05:59:11 +1000 From: Aleksa Sarai To: "Enrico Weigelt, metux IT consult" Cc: Christian Brauner , torvalds@linux-foundation.org, viro@zeniv.linux.org.uk, jannh@google.com, dhowells@redhat.com, linux-api@vger.kernel.org, linux-kernel@vger.kernel.org, serge@hallyn.com, luto@kernel.org, arnd@arndb.de, ebiederm@xmission.com, keescook@chromium.org, tglx@linutronix.de, mtk.manpages@gmail.com, akpm@linux-foundation.org, oleg@redhat.com, joel@joelfernandes.org, dancol@google.com Subject: Re: RFC: on adding new CLONE_* flags [WAS Re: [PATCH 0/4] clone: add CLONE_PIDFD] Message-ID: <20190415195911.z7b7miwsj67ha54y@yavin> References: <20190414201436.19502-1-christian@brauner.io> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="brclbup35wtexg3g" Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org --brclbup35wtexg3g Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On 2019-04-15, Enrico Weigelt, metux IT consult wrote: > > This patchset makes it possible to retrieve pid file descriptors at > > process creation time by introducing the new flag CLONE_PIDFD to the > > clone() system call as previously discussed. >=20 > Sorry, for highjacking this thread, but I'm curious on what things to > consider when introducing new CLONE_* flags. >=20 > The reason I'm asking is: >=20 > I'm working on implementing plan9-like fs namespaces, where unprivileged > processes can change their own namespace at will. For that, certain > traditional unix'ish things have to be disabled, most notably suid. > As forbidding suid can be helpful in other scenarios, too, I thought > about making this its own feature. Doing that switch on clone() seems > a nice place for that, IMHO. Just spit-balling -- is no_new_privs not sufficient for this usecase? Not granting privileges such as setuid during execve(2) is the main point of that flag. --=20 Aleksa Sarai Senior Software Engineer (Containers) SUSE Linux GmbH --brclbup35wtexg3g Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAABCAAdFiEEb6Gz4/mhjNy+aiz1Snvnv3Dem58FAly04o8ACgkQSnvnv3De m5+CNw//RzlU3ndiqW/T6p0030NS9m+xPmKEXXhJtL0OfrAMyZC+LPvYQP36Y39n F65TblOFVMVuCsel6+ykbkuozhlihWy/24JuP3tnQ44H6kaTH++xDjnSkxie9iHy dujGieK7T5lK0oEo/Afr3SiX9/0aTQrbrnNn6dZtwDWP6uMVldmGJGtBPMvlP9nS UYryLbHYoi7LQ6yN5O9cjrl89LC/PWdNpq1I6iv95Zm/HvrCHOxsPYZclc9Ssh9r jfiyM3tNlwqvKfWwopeQt42qjhCgZl5OKZ2ilr3ScyHFVQndIyqGWGv42Y66gnJk pytKvX9/VTUX/BqTnx7G8sIovkTYbvYwu76YGr637pT96JDzhvzCLmphu8pS8uGY 1XIo/Vpj5+HK+YOUjpe/h2R1nsooZp+HF9trhV3kLDB7dLIDBxxF563Qvra6Su/t 6mv/nOc0aqKT9ovk20xbiXZjFah1wexgQo4FwFijHpUCySHvRUgZgaBORvmG8P+g /pF+xsV5n8aizXxrr8JksLl3jNDY+Yejd9tH0nXwC6KS2J176FTVSUN3U/CZV+34 A1sdMutiEbqehRS05yVQDelMOvEogX8/aWsq+QLNFRmW1FKZuMNDXFz4u/x5JL2T pvPANIX6oGOt8VrbD6Du6xaGCD6DftobShTB1xmeZ1MmX8z6Jjs= =4433 -----END PGP SIGNATURE----- --brclbup35wtexg3g--