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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6C751C32773 for ; Wed, 17 Aug 2022 19:58:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238437AbiHQT6b (ORCPT ); Wed, 17 Aug 2022 15:58:31 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33878 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S241364AbiHQT63 (ORCPT ); Wed, 17 Aug 2022 15:58:29 -0400 Received: from out02.mta.xmission.com (out02.mta.xmission.com [166.70.13.232]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 83B30B4AA; Wed, 17 Aug 2022 12:58:18 -0700 (PDT) Received: from in01.mta.xmission.com ([166.70.13.51]:36312) by out02.mta.xmission.com with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1oOPB9-004XQI-B8; Wed, 17 Aug 2022 13:58:15 -0600 Received: from ip68-227-174-4.om.om.cox.net ([68.227.174.4]:46360 helo=email.froward.int.ebiederm.org.xmission.com) by in01.mta.xmission.com with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.93) (envelope-from ) id 1oOPB8-00F3nh-DV; Wed, 17 Aug 2022 13:58:14 -0600 From: "Eric W. Biederman" To: Paul Moore Cc: Linus Torvalds , Frederick Lawler , kpsingh@kernel.org, revest@chromium.org, jackmanb@chromium.org, ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, kafai@fb.com, songliubraving@fb.com, yhs@fb.com, john.fastabend@gmail.com, jmorris@namei.org, serge@hallyn.com, stephen.smalley.work@gmail.com, eparis@parisplace.org, shuah@kernel.org, brauner@kernel.org, casey@schaufler-ca.com, bpf@vger.kernel.org, linux-security-module@vger.kernel.org, selinux@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, netdev@vger.kernel.org, kernel-team@cloudflare.com, cgzones@googlemail.com, karl@bigbadwolfsecurity.com, tixxdz@gmail.com References: <20220815162028.926858-1-fred@cloudflare.com> <8735dux60p.fsf@email.froward.int.ebiederm.org> Date: Wed, 17 Aug 2022 14:57:40 -0500 In-Reply-To: (Paul Moore's message of "Wed, 17 Aug 2022 12:01:39 -0400") Message-ID: <871qte8wy3.fsf@email.froward.int.ebiederm.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/27.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-XM-SPF: eid=1oOPB8-00F3nh-DV;;;mid=<871qte8wy3.fsf@email.froward.int.ebiederm.org>;;;hst=in01.mta.xmission.com;;;ip=68.227.174.4;;;frm=ebiederm@xmission.com;;;spf=softfail X-XM-AID: U2FsdGVkX1/Z6TDdGlJ2fmDTXjd+QwmHz1uEXKk+3OY= X-SA-Exim-Connect-IP: 68.227.174.4 X-SA-Exim-Mail-From: ebiederm@xmission.com Subject: Re: [PATCH v5 0/4] Introduce security_create_user_ns() X-SA-Exim-Version: 4.2.1 (built Sat, 08 Feb 2020 21:53:50 +0000) X-SA-Exim-Scanned: Yes (on in01.mta.xmission.com) Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org Paul Moore writes: > At the end of the v4 patchset I suggested merging this into lsm/next > so it could get a full -rc cycle in linux-next, assuming no issues > were uncovered during testing What in the world can be uncovered in linux-next for code that has no in tree users. That is one of my largest problems. I want to talk about the users and the use cases and I don't get dialog. Nor do I get hey look back there you missed it. Since you don't want to rehash this. I will just repeat my conclusion that the patchset appears to introduce an ineffective defense that will achieve nothing in the defense of the kernel, and so all it will achieve a code maintenance burden and to occasionally break legitimate users of the user namespace. Further the process is broken. You are changing the semantics of an operation with the introduction of a security hook. That needs a man-page and discussion on linux-abi. In general of the scrutiny we give to new systems and changed system calls. As this change fundamentally changes the semantics of creating a user namespace. Skipping that part of the process is not simply disagree that is being irresponsible. Eric