From patchwork Tue Sep 29 10:56:46 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 263063 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=-13.5 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, 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 94FA8C4727F for ; Tue, 29 Sep 2020 12:14:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3F3422076A for ; Tue, 29 Sep 2020 12:14:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601381649; bh=6RUKgCHvA2eA0aAlNvnq6xNbribKN+2EF/kr+A51ois=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=fh17OnvBIUBnT9jwMUICH3rL/S+36Y76UxtjahG6INJZBXrTvVN3qSqQsIXG6wz1D PpqE5Zjuma3Vicf6aDg4v9+BaiffEdQRKqVzeQzEx9yRJKn51rMj7fIuLBZNYXV490 1a3jJcC8AEtFHQ5ikLatuVv/ZWeWuh1UcPAvigpw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732039AbgI2MOI (ORCPT ); Tue, 29 Sep 2020 08:14:08 -0400 Received: from mail.kernel.org ([198.145.29.99]:53440 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1730117AbgI2Lh3 (ORCPT ); Tue, 29 Sep 2020 07:37:29 -0400 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 45FF223B32; Tue, 29 Sep 2020 11:34:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1601379241; bh=6RUKgCHvA2eA0aAlNvnq6xNbribKN+2EF/kr+A51ois=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bhwj9KFitTyHu+kUhAJzt8OzRvuFLSxqmYPJIBNXsB85ypnFovjdIXUJD8/nzUsoV 82XilqsGIsHC7sbrPytftx8FuSt2d49yIoTGFnoqu0khjpu0Sr2KvxUKh7TLS2qHvC Qnp639u/tkdwU+v7t2pCNMRX5qjeg59U4AwD8VxY= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ying Xue , Jon Maloy , Tuong Lien , "David S. Miller" , Sasha Levin Subject: [PATCH 5.4 075/388] tipc: fix link overflow issue at socket shutdown Date: Tue, 29 Sep 2020 12:56:46 +0200 Message-Id: <20200929110014.125708026@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200929110010.467764689@linuxfoundation.org> References: <20200929110010.467764689@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Tuong Lien [ Upstream commit 49afb806cb650dd1f06f191994f3aa657d264009 ] When a socket is suddenly shutdown or released, it will reject all the unreceived messages in its receive queue. This applies to a connected socket too, whereas there is only one 'FIN' message required to be sent back to its peer in this case. In case there are many messages in the queue and/or some connections with such messages are shutdown at the same time, the link layer will easily get overflowed at the 'TIPC_SYSTEM_IMPORTANCE' backlog level because of the message rejections. As a result, the link will be taken down. Moreover, immediately when the link is re-established, the socket layer can continue to reject the messages and the same issue happens... The commit refactors the '__tipc_shutdown()' function to only send one 'FIN' in the situation mentioned above. For the connectionless case, it is unavoidable but usually there is no rejections for such socket messages because they are 'dest-droppable' by default. In addition, the new code makes the other socket states clear (e.g.'TIPC_LISTEN') and treats as a separate case to avoid misbehaving. Acked-by: Ying Xue Acked-by: Jon Maloy Signed-off-by: Tuong Lien Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/tipc/socket.c | 53 ++++++++++++++++++++++++++++------------------- 1 file changed, 32 insertions(+), 21 deletions(-) diff --git a/net/tipc/socket.c b/net/tipc/socket.c index 959155c3a1608..66e8f89bce534 100644 --- a/net/tipc/socket.c +++ b/net/tipc/socket.c @@ -260,12 +260,12 @@ static void tipc_sk_respond(struct sock *sk, struct sk_buff *skb, int err) * * Caller must hold socket lock */ -static void tsk_rej_rx_queue(struct sock *sk) +static void tsk_rej_rx_queue(struct sock *sk, int error) { struct sk_buff *skb; while ((skb = __skb_dequeue(&sk->sk_receive_queue))) - tipc_sk_respond(sk, skb, TIPC_ERR_NO_PORT); + tipc_sk_respond(sk, skb, error); } static bool tipc_sk_connected(struct sock *sk) @@ -515,34 +515,45 @@ static void __tipc_shutdown(struct socket *sock, int error) /* Remove any pending SYN message */ __skb_queue_purge(&sk->sk_write_queue); - /* Reject all unreceived messages, except on an active connection - * (which disconnects locally & sends a 'FIN+' to peer). - */ - while ((skb = __skb_dequeue(&sk->sk_receive_queue)) != NULL) { - if (TIPC_SKB_CB(skb)->bytes_read) { - kfree_skb(skb); - continue; - } - if (!tipc_sk_type_connectionless(sk) && - sk->sk_state != TIPC_DISCONNECTING) { - tipc_set_sk_state(sk, TIPC_DISCONNECTING); - tipc_node_remove_conn(net, dnode, tsk->portid); - } - tipc_sk_respond(sk, skb, error); + /* Remove partially received buffer if any */ + skb = skb_peek(&sk->sk_receive_queue); + if (skb && TIPC_SKB_CB(skb)->bytes_read) { + __skb_unlink(skb, &sk->sk_receive_queue); + kfree_skb(skb); } - if (tipc_sk_type_connectionless(sk)) + /* Reject all unreceived messages if connectionless */ + if (tipc_sk_type_connectionless(sk)) { + tsk_rej_rx_queue(sk, error); return; + } - if (sk->sk_state != TIPC_DISCONNECTING) { + switch (sk->sk_state) { + case TIPC_CONNECTING: + case TIPC_ESTABLISHED: + tipc_set_sk_state(sk, TIPC_DISCONNECTING); + tipc_node_remove_conn(net, dnode, tsk->portid); + /* Send a FIN+/- to its peer */ + skb = __skb_dequeue(&sk->sk_receive_queue); + if (skb) { + __skb_queue_purge(&sk->sk_receive_queue); + tipc_sk_respond(sk, skb, error); + break; + } skb = tipc_msg_create(TIPC_CRITICAL_IMPORTANCE, TIPC_CONN_MSG, SHORT_H_SIZE, 0, dnode, tsk_own_node(tsk), tsk_peer_port(tsk), tsk->portid, error); if (skb) tipc_node_xmit_skb(net, skb, dnode, tsk->portid); - tipc_node_remove_conn(net, dnode, tsk->portid); - tipc_set_sk_state(sk, TIPC_DISCONNECTING); + break; + case TIPC_LISTEN: + /* Reject all SYN messages */ + tsk_rej_rx_queue(sk, error); + break; + default: + __skb_queue_purge(&sk->sk_receive_queue); + break; } } @@ -2564,7 +2575,7 @@ static int tipc_accept(struct socket *sock, struct socket *new_sock, int flags, * Reject any stray messages received by new socket * before the socket lock was taken (very, very unlikely) */ - tsk_rej_rx_queue(new_sk); + tsk_rej_rx_queue(new_sk, TIPC_ERR_NO_PORT); /* Connect new socket to it's peer */ tipc_sk_finish_conn(new_tsock, msg_origport(msg), msg_orignode(msg));