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=-4.0 required=3.0 tests=BAYES_00, 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 410BCC433DF for ; Tue, 11 Aug 2020 08:51:00 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 26E9720756 for ; Tue, 11 Aug 2020 08:51:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728423AbgHKIu6 (ORCPT ); Tue, 11 Aug 2020 04:50:58 -0400 Received: from smtp-bc0e.mail.infomaniak.ch ([45.157.188.14]:57327 "EHLO smtp-bc0e.mail.infomaniak.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728346AbgHKIu6 (ORCPT ); Tue, 11 Aug 2020 04:50:58 -0400 Received: from smtp-3-0000.mail.infomaniak.ch (unknown [10.4.36.107]) by smtp-3-3000.mail.infomaniak.ch (Postfix) with ESMTPS id 4BQml41VTWzlhkjB; Tue, 11 Aug 2020 10:50:56 +0200 (CEST) Received: from ns3096276.ip-94-23-54.eu (unknown [94.23.54.103]) by smtp-3-0000.mail.infomaniak.ch (Postfix) with ESMTPA id 4BQml140TQzlh8Tv; Tue, 11 Aug 2020 10:50:53 +0200 (CEST) Subject: Re: [PATCH v7 0/7] Add support for O_MAYEXEC To: David Laight , Al Viro Cc: Kees Cook , Andrew Morton , "linux-kernel@vger.kernel.org" , Aleksa Sarai , Alexei Starovoitov , Andy Lutomirski , Christian Brauner , Christian Heimes , Daniel Borkmann , Deven Bowers , Dmitry Vyukov , Eric Biggers , Eric Chiang , Florian Weimer , James Morris , Jan Kara , Jann Horn , Jonathan Corbet , Lakshmi Ramasubramanian , Matthew Garrett , Matthew Wilcox , Michael Kerrisk , Mimi Zohar , =?UTF-8?Q?Philippe_Tr=c3=a9buchet?= , Scott Shell , Sean Christopherson , Shuah Khan , Steve Dower , Steve Grubb , Tetsuo Handa , Thibaut Sautereau , Vincent Strubel , "kernel-hardening@lists.openwall.com" , "linux-api@vger.kernel.org" , "linux-integrity@vger.kernel.org" , "linux-security-module@vger.kernel.org" , "linux-fsdevel@vger.kernel.org" References: <20200723171227.446711-1-mic@digikod.net> <202007241205.751EBE7@keescook> <0733fbed-cc73-027b-13c7-c368c2d67fb3@digikod.net> <20200810202123.GC1236603@ZenIV.linux.org.uk> <30b8c003f49d4280be5215f634ca2c06@AcuMS.aculab.com> <20200810222838.GF1236603@ZenIV.linux.org.uk> <2531a0e8-5122-867c-ba06-5d2e623a3834@digikod.net> <26a4a8378f3b4ad28eaa476853092716@AcuMS.aculab.com> From: =?UTF-8?Q?Micka=c3=abl_Sala=c3=bcn?= Message-ID: Date: Tue, 11 Aug 2020 10:50:53 +0200 User-Agent: MIME-Version: 1.0 In-Reply-To: <26a4a8378f3b4ad28eaa476853092716@AcuMS.aculab.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit X-Antivirus: Dr.Web (R) for Unix mail servers drweb plugin ver.6.0.2.8 X-Antivirus-Code: 0x100000 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/08/2020 10:09, David Laight wrote: >> On 11/08/2020 00:28, Al Viro wrote: >>> On Mon, Aug 10, 2020 at 10:09:09PM +0000, David Laight wrote: >>>>> On Mon, Aug 10, 2020 at 10:11:53PM +0200, Mickaël Salaün wrote: >>>>>> It seems that there is no more complains nor questions. Do you want me >>>>>> to send another series to fix the order of the S-o-b in patch 7? >>>>> >>>>> There is a major question regarding the API design and the choice of >>>>> hooking that stuff on open(). And I have not heard anything resembling >>>>> a coherent answer. >>>> >>>> To me O_MAYEXEC is just the wrong name. >>>> The bit would be (something like) O_INTERPRET to indicate >>>> what you want to do with the contents. >> >> The properties is "execute permission". This can then be checked by >> interpreters or other applications, then the generic O_MAYEXEC name. > > The english sense of MAYEXEC is just wrong for what you are trying > to check. We think it reflects exactly what it's purpose is. > >>> ... which does not answer the question - name of constant is the least of >>> the worries here. Why the hell is "apply some unspecified checks to >>> file" combined with opening it, rather than being an independent primitive >>> you apply to an already opened file? Just in case - "'cuz that's how we'd >>> done it" does not make a good answer... > > Maybe an access_ok() that acts on an open fd would be more > appropriate. > Which might end up being an fcntrl() action. > That would give you a full 32bit mask of options. I previously talk about fcntl(2): https://lore.kernel.org/lkml/eaf5bc42-e086-740b-a90c-93e67c535eee@digikod.net/