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 EC797C43381 for ; Wed, 13 Mar 2019 15:30:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BC3E820651 for ; Wed, 13 Mar 2019 15:30:18 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726670AbfCMPaR convert rfc822-to-8bit (ORCPT ); Wed, 13 Mar 2019 11:30:17 -0400 Received: from lithops.sigma-star.at ([195.201.40.130]:44490 "EHLO lithops.sigma-star.at" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725870AbfCMPaM (ORCPT ); Wed, 13 Mar 2019 11:30:12 -0400 Received: from localhost (localhost [127.0.0.1]) by lithops.sigma-star.at (Postfix) with ESMTP id DF0F96091877; Wed, 13 Mar 2019 16:30:08 +0100 (CET) Received: from lithops.sigma-star.at ([127.0.0.1]) by localhost (lithops.sigma-star.at [127.0.0.1]) (amavisd-new, port 10032) with ESMTP id 8kml4iUHCbwV; Wed, 13 Mar 2019 16:30:08 +0100 (CET) Received: from localhost (localhost [127.0.0.1]) by lithops.sigma-star.at (Postfix) with ESMTP id 87935609187F; Wed, 13 Mar 2019 16:30:08 +0100 (CET) Received: from lithops.sigma-star.at ([127.0.0.1]) by localhost (lithops.sigma-star.at [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id 60h5QYQyybex; Wed, 13 Mar 2019 16:30:08 +0100 (CET) Received: from blindfold.localnet (089144193070.atnat0002.highway.a1.net [89.144.193.70]) by lithops.sigma-star.at (Postfix) with ESMTPSA id 84ABD6091877; Wed, 13 Mar 2019 16:30:05 +0100 (CET) From: Richard Weinberger To: Theodore Ts'o Cc: Amir Goldstein , Miklos Szeredi , linux-fsdevel , linux-fscrypt@vger.kernel.org, overlayfs , linux-kernel , Paul Lawrence , david@sigma-star.at Subject: Re: overlayfs vs. fscrypt Date: Wed, 13 Mar 2019 16:30:03 +0100 Message-ID: <3369831.hnip8tpcNh@blindfold> In-Reply-To: <20190313151633.GA672@mit.edu> References: <4603533.ZIfxmiEf7K@blindfold> <20190313151633.GA672@mit.edu> MIME-Version: 1.0 Content-Transfer-Encoding: 8BIT Content-Type: text/plain; charset="iso-8859-1" Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Am Mittwoch, 13. März 2019, 16:16:33 CET schrieb Theodore Ts'o: > So before we talk about how to make things work from a technical > perspective, we should consider what the use case happens to be, and > what are the security requirements. *Why* are we trying to use the > combination of overlayfs and fscrypt, and what are the security > properties we are trying to provide to someone who is relying on this > combination? Well, as stated, on (deeply) embedded systems overlayfs is common. You have a lowerdir with read-only files and an read-write upper dir. Of course both lower and upper directory need to be encrypted. In my case ubifs+fscrypt, sometimes also combined with an encrypted+authenticated squashfs. Thanks, //richard