From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from lindbergh.monkeyblade.net (lindbergh.monkeyblade.net [23.128.96.19]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 29A003D8A for ; Tue, 6 Jun 2023 08:58:01 +0000 (UTC) Received: from NAM12-MW2-obe.outbound.protection.outlook.com (mail-mw2nam12on2111.outbound.protection.outlook.com [40.107.244.111]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 415A1E8; Tue, 6 Jun 2023 01:57:59 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=BAg4/ksm0/dH8qy8uANhYvhDBn7EnKhzNKbb5stKZLiQq0IOwzQiyzurZschj/gOJoiFSIZ1Qhh84xGIGZCmwrXqijEnpiBTTxCMii9lCw68XHfVxYu3GNyTefr7q2wQBuVsbS7AWP1YDATlaGY4uxg070MRj/DDG3CzwnC0gmBR4qXJ3iAfSS0xC0/I5IjWGVkubw3o7KOTvSHAE8UR32lNuIt3p1ouQbVdeMHmyeeYQdYXwD+bLxIK3P7flathFMaCQseQTlc2jA86G0ZSDYXq+5ONAzyBEJATcHmQKlNRdBZ+97XkGJcCTKIWWCcvbEn2n83h4rHeBDANsSE5TQ== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-AntiSpam-MessageData-ChunkCount:X-MS-Exchange-AntiSpam-MessageData-0:X-MS-Exchange-AntiSpam-MessageData-1; bh=86WoxlMEncMyYRHb9J3Hwt/gPDJLV3PLH+4XNI1VUlA=; b=Q9jCp/YHeAeEb+oAAnkJDBBR/t34yMPwAc8omTJjsojB1ZPTuTHxUA5ALXwjrq2CuC6juYaOMFqm0cs8lsQlAM9buOoYt973OAMbObLPmuYlgxVerkJpCLXULzaDY1U7xsbK//ZI2281kuMd46tC3PvCkERkfBbcu+125QGEToGhdMxiVJxhODYYQYTlk5PotQaRJNygy/JVTU96YraBQCLX4u+csG3Mu9SBbIcwg4CDXRDEIpeoPSjYvoNeoznC0Ncfj7vN8VYe2vjLQdU4/dDUthRaKxU0DQI1xZjWCZc/N4SLxN2wgVW+lC0fkGH4NMcE6Dxxja/uKYusLID5bA== ARC-Authentication-Results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=corigine.com; dmarc=pass action=none header.from=corigine.com; dkim=pass header.d=corigine.com; arc=none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=corigine.onmicrosoft.com; s=selector2-corigine-onmicrosoft-com; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=86WoxlMEncMyYRHb9J3Hwt/gPDJLV3PLH+4XNI1VUlA=; b=vcfL5UzmTeLt+fHbMZaY/m87YQreu/8m1lLcICNtTIb8rXoP3Mi9sZYDv7Wh6dHXa4DNv40y4zrSyalYuhl5FgJ6hRcXz7UxTetuRvIzEV+DFLZTziz5mqHvua8rRbBu9CPRQpSLuyt+6UYDLlNUjc7GPUvLDrd1DFcOPFY0r20= Authentication-Results: dkim=none (message not signed) header.d=none;dmarc=none action=none header.from=corigine.com; Received: from PH0PR13MB4842.namprd13.prod.outlook.com (2603:10b6:510:78::6) by SA1PR13MB4813.namprd13.prod.outlook.com (2603:10b6:806:1a5::5) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.20.6455.32; Tue, 6 Jun 2023 08:57:57 +0000 Received: from PH0PR13MB4842.namprd13.prod.outlook.com ([fe80::eb8f:e482:76e0:fe6e]) by PH0PR13MB4842.namprd13.prod.outlook.com ([fe80::eb8f:e482:76e0:fe6e%4]) with mapi id 15.20.6455.030; Tue, 6 Jun 2023 08:57:57 +0000 Date: Tue, 6 Jun 2023 10:57:50 +0200 From: Simon Horman To: Duan Muquan Cc: davem@davemloft.net, dsahern@kernel.org, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v1] tcp: fix connection reset due to tw hashdance race. Message-ID: References: <20230605035140.89106-1-duanmuquan@baidu.com> Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20230605035140.89106-1-duanmuquan@baidu.com> X-ClientProxiedBy: AM8P189CA0019.EURP189.PROD.OUTLOOK.COM (2603:10a6:20b:218::24) To PH0PR13MB4842.namprd13.prod.outlook.com (2603:10b6:510:78::6) Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-MS-PublicTrafficType: Email X-MS-TrafficTypeDiagnostic: PH0PR13MB4842:EE_|SA1PR13MB4813:EE_ X-MS-Office365-Filtering-Correlation-Id: dd1bade0-412b-413e-250a-08db666c1f2b X-MS-Exchange-SenderADCheck: 1 X-MS-Exchange-AntiSpam-Relay: 0 X-Microsoft-Antispam: BCL:0; X-Microsoft-Antispam-Message-Info: a2/bdMxFOEFIp8mdIv/7vNjV1tzDsypei7/EW8vtujRxcxRqk5TyFRrxdSwFl7rEDIHDCZF0HV8qXw/AYt0JA8NDrUe4slW0I2tTwsZkFLir7+SMQ+CUc9c+8P0vMXYjyzbehOT7ODXK+bXmvXZZv/nAHwxIby1b+JGBNPvKRhphkhAHZwvT17GCQLyO0L1omBwgaSlDYM5PKYbW2vee75dkOzf9rC3QxiIFotN9dEzlp6QZ29namDar5B/4Br48HCKG0OG9BYoe8mLrvFltHCCYPp1MqZ46akd6cFx1nuXlFWw6n9zQBzZj0R+ZoDswUX9Jp/L5Z470Ia8rI0EhaMpAbswRymE0pEC91mEJ8/mbdMINu8RbVbP3nHUr8/pWHw++fhaVeT+vTnQC4gJksqUrfYoL0E7bWES6JNGntuzxLcOfSvyMlIEa4M31b1Y4suFVyj4lqTOpfDtRax8QEZrZFxrjDev7yYGBT0bGvn5r2HXi5+Wnliyjvc1DnPF/QvqKYUbPw6HVMUADfJsacaVxfAvRYZbr7OqlRv6H+aN4uZ7wj8GXEhkVKPoOtL8O X-Forefront-Antispam-Report: CIP:255.255.255.255;CTRY:;LANG:en;SCL:1;SRV:;IPV:NLI;SFV:NSPM;H:PH0PR13MB4842.namprd13.prod.outlook.com;PTR:;CAT:NONE;SFS:(13230028)(4636009)(39840400004)(366004)(376002)(396003)(136003)(346002)(451199021)(2906002)(478600001)(66946007)(6916009)(8936002)(316002)(4744005)(4326008)(8676002)(41300700001)(5660300002)(44832011)(66556008)(6666004)(6486002)(66476007)(6512007)(6506007)(38100700002)(2616005)(186003)(83380400001)(36756003)(86362001);DIR:OUT;SFP:1102; X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?ud08E3tZ0dAccYGGPs89DKdPlD8ykfXB5zkUeSgiK429do3ifjp7IBRDgGOn?= =?us-ascii?Q?KXMisZfMY6LLzSYzCiL056g1zT+YHDmBFUQA+AUlpWxcVFs07nivk/RgZtTd?= =?us-ascii?Q?/jCV7JqoxRyq8Ri2WciKf99tU5xvAH18O33OO4QqFV2wY5CZe5HQ1F08bs7i?= =?us-ascii?Q?YhJlpTOHRYclDY8XhGY6pPKyv5rnL7C9ctym6eEMxEeXNIW0gJhfkTdyz0aL?= =?us-ascii?Q?dsFazmpgDfOXsLrzbOfHNr09nSZeV7uiq4+H+qDp3VZoDCITHVPSe7lotKKA?= =?us-ascii?Q?AsDG3nnUczaXTVBB4cmcBOTZ97DTubtJPfH19DX4qLbSsHW2IzXmxMcTVRWM?= =?us-ascii?Q?0beWEZ+WgrpkfXRppX0YFMQtSowrdPGtMQ1EF947lZxPuNRnUjztQgOPWHF0?= =?us-ascii?Q?jV5XqVLFn/Ya0D56szxhMT7+Lq/QdBW6klwhuvBJUdKIw7HxoQTD6zTBCIHq?= =?us-ascii?Q?BzXvUOMib+jhopFBjt3jD6uZhEO0OzMnHkb+Ees7z1/i2jwz3uh2lkcizpsp?= =?us-ascii?Q?PK8/2p+1dQyQjG3lt/DhPffHBxuvnlqnE0GapEevaIZjCesUSqE8X1C+FMLD?= =?us-ascii?Q?3HfsSKX59RwxWcD3Lq6JjNf4jsDGyPZTv71/gl2CoaZ7uaWuNKBUeq/hLHC+?= =?us-ascii?Q?TF5V8U+dKqL/AG78hlgJ8LfqKw8B/7DN81krkcudGr4Lf0FIlLskAQXGSGGF?= =?us-ascii?Q?Cv61+aWUOaipaZOWhDJH0/9VlFqX68ELU0F/o4SBtkcIL1jGTqz6yDH23Qwh?= =?us-ascii?Q?c4bm7aSXhtceb07avcP5GC4urdVqKfmuKkk+/cDzx92/YySLCQPFgdHbv2pj?= =?us-ascii?Q?wY14eHN8N1Kl7Pysl0zDDMtl7rAMPPsWG1VBJBWdMzCO8Gh2le7bkRYYg4oq?= =?us-ascii?Q?geKn/BbLd32QADNcFldHUkwjRBZov8ufPnM7hPztXtXWigZKc54GTGYdqHVt?= =?us-ascii?Q?nY0ys3ZetFA09xHgeshOcyl8BojdVSDykFu+Vcl8Vxqaz/9El+OZARbU4gE6?= =?us-ascii?Q?jDMu8lT3DBBrk2jpQ0UyE3KtlWi8ooxN5klnk0NMJFAVWLr0t0lPKKtPRYvf?= =?us-ascii?Q?V/fntIXUuwfTDvO6ToweX0Si7M2Xc+LIn6D/1Hg0YHo1n5qBiQyfRdkj5rJG?= =?us-ascii?Q?d+A7/sjT99YvE7kTyX+hWSzyiOwhkp+oPpMqf6ttHW/BR+U3PvGD9qHccxIt?= =?us-ascii?Q?osF7naLrd6w0qy9Rt7u2f1yznjMBEoif15rlKZgnBJSHI3Vgm+N8ziqwOwNh?= =?us-ascii?Q?cBFDqomBg23Nb/yGDahVM7ue2eY+ELEDc6g1o0uo/C7cOMvRGq25RoB9iOeV?= =?us-ascii?Q?ed28usBb2h4xbdOnAePBJzRh5oI3e1VUY/NWFqHS40VXzbu1/TQ6tofzJ7FC?= =?us-ascii?Q?LRmN5kYoHhZATwKvXlGqCqLW/F5ASQPMHdd4sFLVvNfpbTcY1xgBU/fvFBmS?= =?us-ascii?Q?p5XwNxgfxZ7UQiUz1wwG1eEPQcDLvwrGi+bXeYvUvx2U4egS6rFje4+SNEvE?= =?us-ascii?Q?RoxVInKSO5AkiHGw5XQAWCGMN2oVLCZnPG5/dHODLFMmkZwPambVPiuCult4?= =?us-ascii?Q?d877fDxwUTPWrc7pBY726GaOQFC23PKULk/V4usnN9wZCfN/gPeCRPYUvbVW?= =?us-ascii?Q?Nbx3grT2wO/O2CCinV3WU0mJmddoRoTJQwg+5/haSMcnTbJwmra3kEvmFAON?= =?us-ascii?Q?XS/BIg=3D=3D?= X-OriginatorOrg: corigine.com X-MS-Exchange-CrossTenant-Network-Message-Id: dd1bade0-412b-413e-250a-08db666c1f2b X-MS-Exchange-CrossTenant-AuthSource: PH0PR13MB4842.namprd13.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 06 Jun 2023 08:57:57.0436 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: fe128f2c-073b-4c20-818e-7246a585940c X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: BIzAhANTTjMgwWgvuNK0MA5MRxOTH8VQlvWrp+vysS8QTbHMDu8OXAnUWeNpzzzZZuftxNllC+lp4JEU3JzT2kz4L4Y+tDsaUI8iVLoVDOI= X-MS-Exchange-Transport-CrossTenantHeadersStamped: SA1PR13MB4813 X-Spam-Status: No, score=-1.9 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,RCVD_IN_DNSWL_NONE,RCVD_IN_MSPIKE_H2,SPF_HELO_PASS,SPF_PASS, T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net On Mon, Jun 05, 2023 at 11:51:40AM +0800, Duan Muquan wrote: ... > Brief of the scenario: > > 1. Server runs on CPU 0 and Client runs on CPU 1. Server closes > connection actively and sends a FIN to client. The lookback's driver > enqueues the FIN segment to backlog queue of CPU 0 via > loopback_xmit()->netif_rx(), one of the conditions for non-delay ack > meets in __tcp_ack_snd_check(), and the ACK is sent immediately. > > 2. On loopback interface, the ACK is received and processed on CPU 0, > the 'dance' from original sock to tw sock will perfrom, tw sock will Hi Duan Muquan, a minor nit from my side: perfrom -> perform > be inserted to ehash table, then the original sock will be removed. ...