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 AE73AC43217 for ; Mon, 7 Mar 2022 09:29:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S237092AbiCGJah (ORCPT ); Mon, 7 Mar 2022 04:30:37 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36330 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238508AbiCGJ3Q (ORCPT ); Mon, 7 Mar 2022 04:29:16 -0500 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6786717AA5; Mon, 7 Mar 2022 01:27:32 -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 dfw.source.kernel.org (Postfix) with ESMTPS id 7662260C00; Mon, 7 Mar 2022 09:27:09 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6E14AC340E9; Mon, 7 Mar 2022 09:27:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1646645228; bh=0lXCyqnVDK3iXuwhZvDdIYlZi31kNqZ7P7LDbjNY0qk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ApZft9KpK/i37bEDISXO9iGwOW4eLJb0mQ79lBzHCScqWfxApZ5bKbsEi/CbFZckq G0ZYuVrHQ0/W8SiLAdrfWiZReShVXh+2CIK4D3bQUcB5RLV2Um2sgxNYUzmiICT7mM s088C4wW6jE3/mKozSPqeJdzMPF/2m8JDvJTUS6M= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, "D. Wythe" , "David S. Miller" Subject: [PATCH 5.4 27/64] net/smc: fix unexpected SMC_CLC_DECL_ERR_REGRMB error generated by client Date: Mon, 7 Mar 2022 10:19:00 +0100 Message-Id: <20220307091639.916023970@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220307091639.136830784@linuxfoundation.org> References: <20220307091639.136830784@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: D. Wythe commit 0537f0a2151375dcf90c1bbfda6a0aaf57164e89 upstream. The main reason for this unexpected SMC_CLC_DECL_ERR_REGRMB in client dues to following execution sequence: Server Conn A: Server Conn B: Client Conn B: smc_lgr_unregister_conn smc_lgr_register_conn smc_clc_send_accept -> smc_rtoken_add smcr_buf_unuse -> Client Conn A: smc_rtoken_delete smc_lgr_unregister_conn() makes current link available to assigned to new incoming connection, while smcr_buf_unuse() has not executed yet, which means that smc_rtoken_add may fail because of insufficient rtoken_entry, reversing their execution order will avoid this problem. Fixes: 3e034725c0d8 ("net/smc: common functions for RMBs and send buffers") Signed-off-by: D. Wythe Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/smc/smc_core.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/net/smc/smc_core.c +++ b/net/smc/smc_core.c @@ -342,8 +342,8 @@ void smc_conn_free(struct smc_connection } else { smc_cdc_tx_dismiss_slots(conn); } - smc_lgr_unregister_conn(conn); smc_buf_unuse(conn, lgr); /* allow buffer reuse */ + smc_lgr_unregister_conn(conn); conn->lgr = NULL; if (!lgr->conns_num)