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 X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id DEE37C33CAF for ; Thu, 16 Jan 2020 19:18:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id BA0B22077C for ; Thu, 16 Jan 2020 19:18:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579202302; bh=XQKsPWErsPgbw5v5Rfqyy6rs8flD5VJUc1xLev5jRyE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=kXiKK5xeNTOPeOK+Ql6FK5Pn8EclNbP/fk77rLTIk0yr6E9rEV6Og7TDVlATUIeFU Et3sB82VBjhiND6guWFwxvgQpCGZU7tEcYBz74kohgUBQFcVzOWrBZqOeKYOpBK5LV icDic2zubypGJDTPzjNKJcT2eAP+O7QqfUw5gQGM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2393315AbgAPTSV (ORCPT ); Thu, 16 Jan 2020 14:18:21 -0500 Received: from mail.kernel.org ([198.145.29.99]:39306 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729903AbgAPQyj (ORCPT ); Thu, 16 Jan 2020 11:54:39 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 696D220730; Thu, 16 Jan 2020 16:54:37 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579193678; bh=XQKsPWErsPgbw5v5Rfqyy6rs8flD5VJUc1xLev5jRyE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=YPPiu1fopwVhd3gvBYMlc1XvcK9J0TjuRsv6Q0tJOFPqTe0T26chZ4Abg7F3Rnj90 9cNc2SkkkY6Y8ejhdwEGHQ/5p1hTNyxdYXaNgB8U9fcWIPEB9RwNJD4YDlJGmhNFzR q2Uuy2NDU8MdntCzUpVCViK57/ibrUQHbV0JPzRU= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Tuong Lien , Jon Maloy , "David S . Miller" , Sasha Levin , netdev@vger.kernel.org, tipc-discussion@lists.sourceforge.net Subject: [PATCH AUTOSEL 5.4 202/205] tipc: fix retrans failure due to wrong destination Date: Thu, 16 Jan 2020 11:42:57 -0500 Message-Id: <20200116164300.6705-202-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200116164300.6705-1-sashal@kernel.org> References: <20200116164300.6705-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Tuong Lien [ Upstream commit abc9b4e0549b93fdaff56e9532bc49a2d7b04955 ] When a user message is sent, TIPC will check if the socket has faced a congestion at link layer. If that happens, it will make a sleep to wait for the congestion to disappear. This leaves a gap for other users to take over the socket (e.g. multi threads) since the socket is released as well. Also, in case of connectionless (e.g. SOCK_RDM), user is free to send messages to various destinations (e.g. via 'sendto()'), then the socket's preformatted header has to be updated correspondingly prior to the actual payload message building. Unfortunately, the latter action is done before the first action which causes a condition issue that the destination of a certain message can be modified incorrectly in the middle, leading to wrong destination when that message is built. Consequently, when the message is sent to the link layer, it gets stuck there forever because the peer node will simply reject it. After a number of retransmission attempts, the link is eventually taken down and the retransmission failure is reported. This commit fixes the problem by rearranging the order of actions to prevent the race condition from occurring, so the message building is 'atomic' and its header will not be modified by anyone. Fixes: 365ad353c256 ("tipc: reduce risk of user starvation during link congestion") Acked-by: Jon Maloy Signed-off-by: Tuong Lien Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/tipc/socket.c | 32 ++++++++++++++++++-------------- 1 file changed, 18 insertions(+), 14 deletions(-) diff --git a/net/tipc/socket.c b/net/tipc/socket.c index 90ace35dbf0f..aea951a1f805 100644 --- a/net/tipc/socket.c +++ b/net/tipc/socket.c @@ -1306,8 +1306,8 @@ static int __tipc_sendmsg(struct socket *sock, struct msghdr *m, size_t dlen) struct tipc_msg *hdr = &tsk->phdr; struct tipc_name_seq *seq; struct sk_buff_head pkts; - u32 dport, dnode = 0; - u32 type, inst; + u32 dport = 0, dnode = 0; + u32 type = 0, inst = 0; int mtu, rc; if (unlikely(dlen > TIPC_MAX_USER_MSG_SIZE)) @@ -1360,23 +1360,11 @@ static int __tipc_sendmsg(struct socket *sock, struct msghdr *m, size_t dlen) type = dest->addr.name.name.type; inst = dest->addr.name.name.instance; dnode = dest->addr.name.domain; - msg_set_type(hdr, TIPC_NAMED_MSG); - msg_set_hdr_sz(hdr, NAMED_H_SIZE); - msg_set_nametype(hdr, type); - msg_set_nameinst(hdr, inst); - msg_set_lookup_scope(hdr, tipc_node2scope(dnode)); dport = tipc_nametbl_translate(net, type, inst, &dnode); - msg_set_destnode(hdr, dnode); - msg_set_destport(hdr, dport); if (unlikely(!dport && !dnode)) return -EHOSTUNREACH; } else if (dest->addrtype == TIPC_ADDR_ID) { dnode = dest->addr.id.node; - msg_set_type(hdr, TIPC_DIRECT_MSG); - msg_set_lookup_scope(hdr, 0); - msg_set_destnode(hdr, dnode); - msg_set_destport(hdr, dest->addr.id.ref); - msg_set_hdr_sz(hdr, BASIC_H_SIZE); } else { return -EINVAL; } @@ -1387,6 +1375,22 @@ static int __tipc_sendmsg(struct socket *sock, struct msghdr *m, size_t dlen) if (unlikely(rc)) return rc; + if (dest->addrtype == TIPC_ADDR_NAME) { + msg_set_type(hdr, TIPC_NAMED_MSG); + msg_set_hdr_sz(hdr, NAMED_H_SIZE); + msg_set_nametype(hdr, type); + msg_set_nameinst(hdr, inst); + msg_set_lookup_scope(hdr, tipc_node2scope(dnode)); + msg_set_destnode(hdr, dnode); + msg_set_destport(hdr, dport); + } else { /* TIPC_ADDR_ID */ + msg_set_type(hdr, TIPC_DIRECT_MSG); + msg_set_lookup_scope(hdr, 0); + msg_set_destnode(hdr, dnode); + msg_set_destport(hdr, dest->addr.id.ref); + msg_set_hdr_sz(hdr, BASIC_H_SIZE); + } + __skb_queue_head_init(&pkts); mtu = tipc_node_get_mtu(net, dnode, tsk->portid); rc = tipc_msg_build(hdr, m, 0, dlen, mtu, &pkts); -- 2.20.1