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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS autolearn=ham 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 174C7C282C2 for ; Wed, 13 Feb 2019 08:05:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D8D27222B5 for ; Wed, 13 Feb 2019 08:05:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388590AbfBMIFq (ORCPT ); Wed, 13 Feb 2019 03:05:46 -0500 Received: from mx2.suse.de ([195.135.220.15]:55964 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1729612AbfBMIFq (ORCPT ); Wed, 13 Feb 2019 03:05:46 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id 1521BAD4C; Wed, 13 Feb 2019 08:05:45 +0000 (UTC) From: Fabian Vogt To: Mimi Zohar Cc: Amir Goldstein , linux-integrity , Miklos Szeredi , overlayfs , Ignaz Forster Subject: Re: [RFC PATCH 0/5] Fix overlayfs on EVM Date: Wed, 13 Feb 2019 09:05:44 +0100 Message-ID: <4472439.nvz8ndpTJa@linux-e202.suse.de> In-Reply-To: <1550011897.12743.310.camel@linux.ibm.com> References: <20190211165323.9369-1-iforster@suse.com> <1550011897.12743.310.camel@linux.ibm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 7Bit Content-Type: text/plain; charset="us-ascii" Sender: linux-integrity-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-integrity@vger.kernel.org Hi, Am Dienstag, 12. Februar 2019, 23:51:37 CET schrieb Mimi Zohar: > > > > > If my assumptions so far are correct, then the effort for making > > > > IMA/EVM work with overlayfs should focus around finding the > > > > places where overlayfs uses lower level vfs interface (often > > > > vfs_xxx helpers) and make sure that the IMA hooks are place > > > > in those lower vfs interfaces, just like vfs_create() patch does > > > > and like vfs_tmpfile() patch did before it. > > > > > > So basically turning on NOIMA for overlayfs while ensuring that integrity > > > checks and operations still perform as expected? > > > > Yes. > > As far as IMA is concerned, Overlayfs is like a filesystem user from kernel. > > Very similar to knfsd in that respect. > > Fabian, if you're thinking of disabling IMA-appraisal on overlay filesystems, > have you tried defining an appraise policy rule based on the overlayfs > magic number (eg. dont_appraise fsmagic=0x794c7630)? Yes, that was one of the first approaches we tested - basically switching from a) to b) using configuration. It didn't work: Then IMA was completely circumvented and neither were hashes updated for changed files nor were they checked on access. That was a few months ago though, so it might have changed. Cheers, Fabian > Mimi