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, 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 C3912C43461 for ; Wed, 9 Sep 2020 17:55:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8C1442076C for ; Wed, 9 Sep 2020 17:55:51 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726605AbgIIRzu (ORCPT ); Wed, 9 Sep 2020 13:55:50 -0400 Received: from smtp-8fac.mail.infomaniak.ch ([83.166.143.172]:49245 "EHLO smtp-8fac.mail.infomaniak.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726408AbgIIRzu (ORCPT ); Wed, 9 Sep 2020 13:55:50 -0400 Received: from smtp-3-0001.mail.infomaniak.ch (unknown [10.4.36.108]) by smtp-3-3000.mail.infomaniak.ch (Postfix) with ESMTPS id 4BmqSL5vl0zlhLB1; Wed, 9 Sep 2020 19:55:46 +0200 (CEST) Received: from ns3096276.ip-94-23-54.eu (unknown [94.23.54.103]) by smtp-3-0001.mail.infomaniak.ch (Postfix) with ESMTPA id 4BmqSH5cwXzlh8TF; Wed, 9 Sep 2020 19:55:43 +0200 (CEST) Subject: Re: [RFC PATCH v8 0/3] Add support for AT_INTERPRETED (was O_MAYEXEC) To: Matthew Wilcox Cc: Al Viro , linux-kernel@vger.kernel.org, Aleksa Sarai , Alexei Starovoitov , Andrew Morton , 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 , Kees Cook , Lakshmi Ramasubramanian , Matthew Garrett , Michael Kerrisk , Miklos Szeredi , 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: <20200908075956.1069018-1-mic@digikod.net> <20200908185026.GU1236603@ZenIV.linux.org.uk> <20200909170851.GL6583@casper.infradead.org> From: =?UTF-8?Q?Micka=c3=abl_Sala=c3=bcn?= Message-ID: <3e83b98e-a99d-2e7d-a205-aa83ce94f3fe@digikod.net> Date: Wed, 9 Sep 2020 19:55:48 +0200 User-Agent: MIME-Version: 1.0 In-Reply-To: <20200909170851.GL6583@casper.infradead.org> Content-Type: text/plain; charset=iso-8859-15 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On 09/09/2020 19:08, Matthew Wilcox wrote: > On Wed, Sep 09, 2020 at 09:19:11AM +0200, Mickaël Salaün wrote: >> >> On 08/09/2020 20:50, Al Viro wrote: >>> On Tue, Sep 08, 2020 at 09:59:53AM +0200, Mickaël Salaün wrote: >>>> Hi, >>>> >>>> This height patch series rework the previous O_MAYEXEC series by not >>>> adding a new flag to openat2(2) but to faccessat2(2) instead. As >>>> suggested, this enables to perform the access check on a file descriptor >>>> instead of on a file path (while opening it). This may require two >>>> checks (one on open and then with faccessat2) but it is a more generic >>>> approach [8]. >>> >>> Again, why is that folded into lookup/open/whatnot, rather than being >>> an operation applied to a file (e.g. O_PATH one)? >> >> I don't understand your question. AT_INTERPRETED can and should be used >> with AT_EMPTY_PATH. The two checks I wrote about was for IMA. > > Al is saying you should add a new syscall, not try to fold it into > some existing syscall. > > I agree with him. Add a new syscall, just like you were told to do it > last time. > OK, but I didn't receive a response for my proposition to extend faccessat2(2).