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 7E1E7C433F5 for ; Sat, 5 Mar 2022 12:28:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230424AbiCEM27 (ORCPT ); Sat, 5 Mar 2022 07:28:59 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55170 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231178AbiCEM25 (ORCPT ); Sat, 5 Mar 2022 07:28:57 -0500 Received: from ams.source.kernel.org (ams.source.kernel.org [IPv6:2604:1380:4601:e00::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7BDE940929 for ; Sat, 5 Mar 2022 04:28:06 -0800 (PST) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 271A2B80BE8 for ; Sat, 5 Mar 2022 12:28:05 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4FF3BC004E1; Sat, 5 Mar 2022 12:28:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1646483283; bh=BiN4nJmlies1YbnRHKlq/lKJlSL71H2p55v5w+ez0wY=; h=Subject:To:Cc:From:Date:From; b=mLh9gT7556IbcUYdTjwt7cmUSKnYPdEQ9pkeL0ws3Kmwixh17NND5JupLN8Fse61g V7i/TyrWi9BjFfm2Zxf9qyc89lC1zz5SGOytaIfL8ApG//T1I/bIWzmqCLBIkxw3tP 3TpSSfwIioHkFnrReSq3KMG976MzIwMEQn5VntxI= Subject: FAILED: patch "[PATCH] net/smc: fix connection leak" failed to apply to 5.4-stable tree To: alibuda@linux.alibaba.com, davem@davemloft.net, kgraul@linux.ibm.com Cc: From: Date: Sat, 05 Mar 2022 13:28:00 +0100 Message-ID: <16464832802030@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 9f1c50cf39167ff71dc5953a3234f3f6eeb8fcb5 Mon Sep 17 00:00:00 2001 From: "D. Wythe" Date: Thu, 24 Feb 2022 23:26:19 +0800 Subject: [PATCH] net/smc: fix connection leak There's a potential leak issue under following execution sequence : smc_release smc_connect_work if (sk->sk_state == SMC_INIT) send_clc_confirim tcp_abort(); ... sk.sk_state = SMC_ACTIVE smc_close_active switch(sk->sk_state) { ... case SMC_ACTIVE: smc_close_final() // then wait peer closed Unfortunately, tcp_abort() may discard CLC CONFIRM messages that are still in the tcp send buffer, in which case our connection token cannot be delivered to the server side, which means that we cannot get a passive close message at all. Therefore, it is impossible for the to be disconnected at all. This patch tries a very simple way to avoid this issue, once the state has changed to SMC_ACTIVE after tcp_abort(), we can actively abort the smc connection, considering that the state is SMC_INIT before tcp_abort(), abandoning the complete disconnection process should not cause too much problem. In fact, this problem may exist as long as the CLC CONFIRM message is not received by the server. Whether a timer should be added after smc_close_final() needs to be discussed in the future. But even so, this patch provides a faster release for connection in above case, it should also be valuable. Fixes: 39f41f367b08 ("net/smc: common release code for non-accepted sockets") Signed-off-by: D. Wythe Acked-by: Karsten Graul Signed-off-by: David S. Miller diff --git a/net/smc/af_smc.c b/net/smc/af_smc.c index 306d9e8cd1dd..81984c1c0e78 100644 --- a/net/smc/af_smc.c +++ b/net/smc/af_smc.c @@ -183,7 +183,7 @@ static int smc_release(struct socket *sock) { struct sock *sk = sock->sk; struct smc_sock *smc; - int rc = 0; + int old_state, rc = 0; if (!sk) goto out; @@ -191,8 +191,10 @@ static int smc_release(struct socket *sock) sock_hold(sk); /* sock_put below */ smc = smc_sk(sk); + old_state = sk->sk_state; + /* cleanup for a dangling non-blocking connect */ - if (smc->connect_nonblock && sk->sk_state == SMC_INIT) + if (smc->connect_nonblock && old_state == SMC_INIT) tcp_abort(smc->clcsock->sk, ECONNABORTED); if (cancel_work_sync(&smc->connect_work)) @@ -206,6 +208,10 @@ static int smc_release(struct socket *sock) else lock_sock(sk); + if (old_state == SMC_INIT && sk->sk_state == SMC_ACTIVE && + !smc->use_fallback) + smc_close_active_abort(smc); + rc = __smc_release(smc); /* detach socket */