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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 70177C433DB for ; Wed, 10 Feb 2021 19:36:46 +0000 (UTC) Received: from mother.openwall.net (mother.openwall.net [195.42.179.200]) by mail.kernel.org (Postfix) with SMTP id 7B66664DAE for ; Wed, 10 Feb 2021 19:36:45 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7B66664DAE Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=hallyn.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kernel-hardening-return-20750-kernel-hardening=archiver.kernel.org@lists.openwall.com Received: (qmail 30323 invoked by uid 550); 10 Feb 2021 19:36:36 -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 30291 invoked from network); 10 Feb 2021 19:36:36 -0000 Date: Wed, 10 Feb 2021 13:36:24 -0600 From: "Serge E. Hallyn" To: =?iso-8859-1?Q?Micka=EBl_Sala=FCn?= Cc: James Morris , Jann Horn , "Serge E . Hallyn" , Al Viro , Andrew Morton , Andy Lutomirski , Anton Ivanov , Arnd Bergmann , Casey Schaufler , Jeff Dike , Jonathan Corbet , Kees Cook , Michael Kerrisk , Richard Weinberger , Shuah Khan , Vincent Dagonneau , kernel-hardening@lists.openwall.com, linux-api@vger.kernel.org, linux-arch@vger.kernel.org, linux-doc@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-security-module@vger.kernel.org, x86@kernel.org, =?iso-8859-1?Q?Micka=EBl_Sala=FCn?= Subject: Re: [PATCH v28 07/12] landlock: Support filesystem access-control Message-ID: <20210210193624.GA29893@mail.hallyn.com> References: <20210202162710.657398-1-mic@digikod.net> <20210202162710.657398-8-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: <20210202162710.657398-8-mic@digikod.net> User-Agent: Mutt/1.9.4 (2018-02-28) On Tue, Feb 02, 2021 at 05:27:05PM +0100, Mickaël Salaün wrote: > From: Mickaël Salaün > > Thanks to the Landlock objects and ruleset, it is possible to identify > inodes according to a process's domain. To enable an unprivileged This throws me off a bit. "identify inodes according to a process's domain". What exactly does it mean? "identify" how ? > process to express a file hierarchy, it first needs to open a directory > (or a file) and pass this file descriptor to the kernel through > landlock_add_rule(2). When checking if a file access request is > allowed, we walk from the requested dentry to the real root, following > the different mount layers. The access to each "tagged" inodes are > collected according to their rule layer level, and ANDed to create > access to the requested file hierarchy. This makes possible to identify > a lot of files without tagging every inodes nor modifying the > filesystem, while still following the view and understanding the user > has from the filesystem. > > Add a new ARCH_EPHEMERAL_INODES for UML because it currently does not > keep the same struct inodes for the same inodes whereas these inodes are > in use. -serge