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 C3D61C433E2 for ; Thu, 10 Sep 2020 20:01:35 +0000 (UTC) Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.kernel.org (Postfix) with SMTP id A6572221E3 for ; Thu, 10 Sep 2020 20:01:34 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A6572221E3 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-19856-kernel-hardening=archiver.kernel.org@lists.openwall.com Received: (qmail 8038 invoked by uid 550); 10 Sep 2020 20:01:27 -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 8018 invoked from network); 10 Sep 2020 20:01:27 -0000 Date: Thu, 10 Sep 2020 21:00:10 +0100 From: Al Viro To: Matthew Wilcox Cc: =?iso-8859-1?Q?Micka=EBl_Sala=FCn?= , Mimi Zohar , linux-kernel@vger.kernel.org, Aleksa Sarai , Alexei Starovoitov , Andrew Morton , Andy Lutomirski , Arnd Bergmann , Casey Schaufler , 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 , 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 v9 0/3] Add introspect_access(2) (was O_MAYEXEC) Message-ID: <20200910200010.GF1236603@ZenIV.linux.org.uk> References: <20200910164612.114215-1-mic@digikod.net> <20200910170424.GU6583@casper.infradead.org> <880bb4ee-89a2-b9b0-747b-0f779ceda995@digikod.net> <20200910184033.GX6583@casper.infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20200910184033.GX6583@casper.infradead.org> Sender: Al Viro On Thu, Sep 10, 2020 at 07:40:33PM +0100, Matthew Wilcox wrote: > On Thu, Sep 10, 2020 at 08:38:21PM +0200, Mickaël Salaün wrote: > > There is also the use case of noexec mounts and file permissions. From > > user space point of view, it doesn't matter which kernel component is in > > charge of defining the policy. The syscall should then not be tied with > > a verification/integrity/signature/appraisal vocabulary, but simply an > > access control one. > > permission()? int lsm(int fd, const char *how, char *error, int size); Seriously, this is "ask LSM to apply special policy to file"; let's _not_ mess with flags, etc. for that; give it decent bandwidth and since it's completely opaque for the rest of the kernel, just a pass a string to be parsed by LSM as it sees fit.