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 BFA90C433E0 for ; Fri, 19 Feb 2021 15:35:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 864E864E92 for ; Fri, 19 Feb 2021 15:35:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229886AbhBSPfM (ORCPT ); Fri, 19 Feb 2021 10:35:12 -0500 Received: from mail.hallyn.com ([178.63.66.53]:51598 "EHLO mail.hallyn.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229824AbhBSPfE (ORCPT ); Fri, 19 Feb 2021 10:35:04 -0500 Received: by mail.hallyn.com (Postfix, from userid 1001) id 679722BF; Fri, 19 Feb 2021 09:34:14 -0600 (CST) Date: Fri, 19 Feb 2021 09:34:14 -0600 From: "Serge E. Hallyn" To: =?iso-8859-1?Q?Micka=EBl_Sala=FCn?= Cc: "Serge E. Hallyn" , James Morris , Jann Horn , 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: <20210219153414.GA18061@mail.hallyn.com> References: <20210202162710.657398-1-mic@digikod.net> <20210202162710.657398-8-mic@digikod.net> <20210210193624.GA29893@mail.hallyn.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.9.4 (2018-02-28) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Feb 10, 2021 at 09:17:25PM +0100, Mickaël Salaün wrote: > > On 10/02/2021 20:36, Serge E. Hallyn wrote: > > 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 ? > > A domain is a set of rules (i.e. layers of rulesets) enforced on a set > of threads. Inodes are tagged per domain (i.e. not system-wide) and > actions are restricted thanks to these tags, which form rules. It means > that the created access-controls are scoped to a set of threads. Thanks, that's helpful. To me it would be much clearer if you used the word 'tagged' : Using the Landlock objects and ruleset, it is possible to tag inodes according to a process's domain. > >> 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 > >