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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id EAD9DC6FD1C for ; Sun, 26 Mar 2023 00:11:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229564AbjCZALK (ORCPT ); Sat, 25 Mar 2023 20:11:10 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60118 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229446AbjCZALJ (ORCPT ); Sat, 25 Mar 2023 20:11:09 -0400 Received: from out30-113.freemail.mail.aliyun.com (out30-113.freemail.mail.aliyun.com [115.124.30.113]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B3A34AF31 for ; Sat, 25 Mar 2023 17:11:05 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R161e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018045168;MF=chengyou@linux.alibaba.com;NM=1;PH=DS;RN=6;SR=0;TI=SMTPD_---0Vebos7F_1679789461; Received: from 30.15.194.245(mailfrom:chengyou@linux.alibaba.com fp:SMTPD_---0Vebos7F_1679789461) by smtp.aliyun-inc.com; Sun, 26 Mar 2023 08:11:02 +0800 Message-ID: <5823ff9c-eef9-f834-9e54-421b3d04bee0@linux.alibaba.com> Date: Sun, 26 Mar 2023 08:10:57 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:102.0) Gecko/20100101 Thunderbird/102.9.0 Subject: Re: [PATCH for-next v2 2/2] RDMA/erdma: Support non-4K page size in doorbell allocation Content-Language: en-US To: Jason Gunthorpe Cc: Leon Romanovsky , linux-rdma@vger.kernel.org, KaiShen@linux.alibaba.com, Yossi Leybovich , Gal Pressman References: <2c82439c-15d0-d5dd-b1c5-46053d3dd202@linux.alibaba.com> <6c982b76-61b2-7317-ab76-8ff0b4fb4471@linux.alibaba.com> <8c446431-9f86-7267-6051-9c016e23215e@linux.alibaba.com> <243f9c6f-72ab-c503-33be-24e58e1d4ddf@linux.alibaba.com> <8677b42c-3f61-b83d-cd97-68591778944d@linux.alibaba.com> From: Cheng Xu In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org On 3/23/23 10:18 PM, Jason Gunthorpe wrote: > On Thu, Mar 23, 2023 at 10:10:25PM +0800, Cheng Xu wrote: >> >> <...> >> >> Malicious doorbell will corrupt the head pointer in QPC, and then invalid WQEs >> will be processed. My point is that WQE validation can correct the head pointer >> carried in malicious doorbell, and can prevent such attack. > > No, if the head pointer is incorrect an attack can stall the QP by > guessing a head pointer that is valid but before already submitted > WQEs. You are right. Thanks very much for this discussion and your advisement. Cheng Xu > > There is no WQE based recovery for such a thing. > > Jason