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 948C5C43461 for ; Tue, 8 Sep 2020 18:52:01 +0000 (UTC) Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.kernel.org (Postfix) with SMTP id 74A762080A for ; Tue, 8 Sep 2020 18:52:00 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 74A762080A Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=zeniv.linux.org.uk Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kernel-hardening-return-19824-kernel-hardening=archiver.kernel.org@lists.openwall.com Received: (qmail 22101 invoked by uid 550); 8 Sep 2020 18:51:53 -0000 Mailing-List: contact kernel-hardening-help@lists.openwall.com; run by ezmlm Precedence: bulk List-Post: List-Help: List-Unsubscribe: List-Subscribe: List-ID: Received: (qmail 22081 invoked from network); 8 Sep 2020 18:51:52 -0000 Date: Tue, 8 Sep 2020 19:50:26 +0100 From: Al Viro To: =?iso-8859-1?Q?Micka=EBl_Sala=FCn?= Cc: 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 , Matthew Wilcox , Michael Kerrisk , Miklos Szeredi , Mimi Zohar , Philippe =?iso-8859-1?Q?Tr=E9buchet?= , 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 Subject: Re: [RFC PATCH v8 0/3] Add support for AT_INTERPRETED (was O_MAYEXEC) Message-ID: <20200908185026.GU1236603@ZenIV.linux.org.uk> References: <20200908075956.1069018-1-mic@digikod.net> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20200908075956.1069018-1-mic@digikod.net> Sender: Al Viro 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)?