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=-0.8 required=3.0 tests=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 D9BECC3A5A9 for ; Mon, 4 May 2020 21:59:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B2F6B206A4 for ; Mon, 4 May 2020 21:59:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728141AbgEDV7U convert rfc822-to-8bit (ORCPT ); Mon, 4 May 2020 17:59:20 -0400 Received: from lithops.sigma-star.at ([195.201.40.130]:52546 "EHLO lithops.sigma-star.at" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727855AbgEDV7T (ORCPT ); Mon, 4 May 2020 17:59:19 -0400 Received: from localhost (localhost [127.0.0.1]) by lithops.sigma-star.at (Postfix) with ESMTP id 82AEB6071A61; Mon, 4 May 2020 23:59:17 +0200 (CEST) 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 ORmgk83AKakw; Mon, 4 May 2020 23:59:16 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by lithops.sigma-star.at (Postfix) with ESMTP id A74316071A7C; Mon, 4 May 2020 23:59:16 +0200 (CEST) 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 YuWijWMN5XAw; Mon, 4 May 2020 23:59:16 +0200 (CEST) Received: from lithops.sigma-star.at (lithops.sigma-star.at [195.201.40.130]) by lithops.sigma-star.at (Postfix) with ESMTP id 7DAC86071A61; Mon, 4 May 2020 23:59:16 +0200 (CEST) Date: Mon, 4 May 2020 23:59:16 +0200 (CEST) From: Richard Weinberger To: Johannes Thumshirn Cc: David Sterba , linux-fsdevel , linux-btrfs , Eric Biggers , Johannes Thumshirn , Johannes Thumshirn , david , Sascha Hauer Message-ID: <164471725.184338.1588629556400.JavaMail.zimbra@nod.at> In-Reply-To: <20200428105859.4719-2-jth@kernel.org> References: <20200428105859.4719-1-jth@kernel.org> <20200428105859.4719-2-jth@kernel.org> Subject: Re: [PATCH v2 1/2] btrfs: add authentication support MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8BIT X-Originating-IP: [195.201.40.130] X-Mailer: Zimbra 8.8.12_GA_3807 (ZimbraWebClient - FF68 (Linux)/8.8.12_GA_3809) Thread-Topic: btrfs: add authentication support Thread-Index: Z3MnT0+k8n5OYo6is7pXVDYH2KOhKQ== Sender: linux-btrfs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-btrfs@vger.kernel.org ----- Ursprüngliche Mail ----- > Von: "Johannes Thumshirn" > An: "David Sterba" > CC: "linux-fsdevel" , "linux-btrfs" , "Eric Biggers" > , "richard" , "Johannes Thumshirn" , "Johannes > Thumshirn" > Gesendet: Dienstag, 28. April 2020 12:58:58 > Betreff: [PATCH v2 1/2] btrfs: add authentication support > From: Johannes Thumshirn > > Add authentication support for a BTRFS file-system. > > This works, because in BTRFS every meta-data block as well as every > data-block has a own checksum. For meta-data the checksum is in the > meta-data node itself. For data blocks, the checksums are stored in the > checksum tree. Eric already raised doubts, let me ask more directly. Does the checksum tree really cover all moving parts of BTRFS? I'm a little surprised how small your patch is. Getting all this done for UBIFS was not easy and given that UBIFS is truly copy-on-write it was still less work than it would be for other filesystems. If I understand the checksum tree correctly, the main purpose is protecting you from flipping bits. An attacker will perform much more sophisticated attacks. Thanks, //richard