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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 30174C433F5 for ; Thu, 21 Oct 2021 14:02:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0515660F46 for ; Thu, 21 Oct 2021 14:02:46 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230072AbhJUOFB (ORCPT ); Thu, 21 Oct 2021 10:05:01 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33188 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229878AbhJUOFB (ORCPT ); Thu, 21 Oct 2021 10:05:01 -0400 Received: from fieldses.org (fieldses.org [IPv6:2600:3c00:e000:2f7::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E53D5C0613B9 for ; Thu, 21 Oct 2021 07:02:43 -0700 (PDT) Received: by fieldses.org (Postfix, from userid 2815) id 57D5E647C; Thu, 21 Oct 2021 10:02:43 -0400 (EDT) DKIM-Filter: OpenDKIM Filter v2.11.0 fieldses.org 57D5E647C DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=fieldses.org; s=default; t=1634824963; bh=s3dy4Ehxo8S4MO7AqhWht9Cy3DylkZkhu0SEN5aynSw=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=y42Iu/O5T1L4jUd9IHveATzXP7ppE/FksMuGjNLS6ruMN4ag9FIuPrN8YWiLmyxPP 4lBNsWVZ1DPdnm1wOXTRTSlEEGBoDlJHTVFYDt5C4xcAybwvv0Jq2amF/gZKOI/A9u 6IMT8nYs93fk1v1ChyMxvcxO/EX9IDuxBLICIKhE= Date: Thu, 21 Oct 2021 10:02:43 -0400 From: Bruce Fields To: dai.ngo@oracle.com Cc: Linux NFS Mailing List , Steve Dickson , Olga Kornievskaia , Chuck Lever Subject: Re: server-to-server copy by default Message-ID: <20211021140243.GB25711@fieldses.org> References: <20211020155421.GC597@fieldses.org> <18E32DF5-3F1D-4C23-8C2F-A7963103CF8C@oracle.com> <8b1eb564-974d-00b6-397a-d92f301df7d8@oracle.com> <20211020202907.GF597@fieldses.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2010-09-15) Precedence: bulk List-ID: X-Mailing-List: linux-nfs@vger.kernel.org Thanks for the persistence: On Wed, Oct 20, 2021 at 10:00:41PM -0700, dai.ngo@oracle.com wrote: > The attack can come from the replies of the source server or requests > from the source server to the destination server via the back channel. > One of possible attack in the reply is BAD_STATEID which was handled > by the client code as mentioned by Olga. > > Here is the list of NFS requests made from the destination to the > source server: > > EXCHANGE_ID > CREATE_SESSION > RECLAIM_COMLETE > SEQUENCE > PUTROOTFH > PUTHF > GETFH > GETATTR > READ/READ_PLUS > DESTROY_SESSION > DESTROY_CLIENTID > > Do you think we should review all replies from these requests to make > sure error replies do not cause problems for the destination server? That's the exactly the sort of analysis I was curious to see, yes. (I doubt the PUTROOTFH, PUTFH, GETFH, and GETATTR are really necessary, I wonder if there's any way we could just bypass them in our case. I don't know, maybe that's more trouble than it's worth.) > same for the back channel ops: > > OP_CB_GETATTR > OP_CB_RECALL > OP_CB_LAYOUTRECALL > OP_CB_NOTIFY > OP_CB_PUSH_DELEG > OP_CB_RECALL_ANY > OP_CB_RECALLABLE_OBJ_AVAIL > OP_CB_RECALL_SLOT > OP_CB_SEQUENCE > OP_CB_WANTS_CANCELLED > OP_CB_NOTIFY_LOCK > OP_CB_NOTIFY_DEVICEID > OP_CB_OFFLOAD There shouldn't be any need for callbacks at all. We might be able to get away without even setting up a backchannel. But, yes, if the server tries to send one anyway, it'd be good to know we do something reasonable. --b.