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 ACA31C4167B for ; Tue, 5 Apr 2022 13:23:19 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1381055AbiDENOc (ORCPT ); Tue, 5 Apr 2022 09:14:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45120 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344219AbiDEJSs (ORCPT ); Tue, 5 Apr 2022 05:18:48 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 8A0D349683; Tue, 5 Apr 2022 02:05:42 -0700 (PDT) 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 0017161564; Tue, 5 Apr 2022 09:05:42 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 099D7C385A0; Tue, 5 Apr 2022 09:05:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1649149541; bh=+HmpgAwitYAtX3vItdMTFYGz4EiR3MK7TjuXfzAqvNc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=0yhMO/z87z2wOuAzM4GVYh5juh+h1TNvqIGfx7SSM4gUpiAPgJqzhHdfGzvTQJV1A dhq/LkbAkyI4dJa80xvAdp6mjdfKhPWPRNuE3Yh3vfN7/haMvBfPAxh3ayriyr9NsR BttgPdH0fa94zxLk42Ing/kahpY138Q020jOgefM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Enrico Scholz , Trond Myklebust , Sasha Levin Subject: [PATCH 5.16 0715/1017] SUNRPC: Dont call connect() more than once on a TCP socket Date: Tue, 5 Apr 2022 09:27:08 +0200 Message-Id: <20220405070415.493509770@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220405070354.155796697@linuxfoundation.org> References: <20220405070354.155796697@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: linux-kernel@vger.kernel.org From: Trond Myklebust [ Upstream commit 89f42494f92f448747bd8a7ab1ae8b5d5520577d ] Avoid socket state races due to repeated calls to ->connect() using the same socket. If connect() returns 0 due to the connection having completed, but we are in fact in a closing state, then we may leave the XPRT_CONNECTING flag set on the transport. Reported-by: Enrico Scholz Fixes: 3be232f11a3c ("SUNRPC: Prevent immediate close+reconnect") Signed-off-by: Trond Myklebust Signed-off-by: Sasha Levin --- include/linux/sunrpc/xprtsock.h | 1 + net/sunrpc/xprtsock.c | 22 ++++++++++++---------- 2 files changed, 13 insertions(+), 10 deletions(-) diff --git a/include/linux/sunrpc/xprtsock.h b/include/linux/sunrpc/xprtsock.h index 3c1423ee74b4..fed813ffe7db 100644 --- a/include/linux/sunrpc/xprtsock.h +++ b/include/linux/sunrpc/xprtsock.h @@ -88,5 +88,6 @@ struct sock_xprt { #define XPRT_SOCK_WAKE_WRITE (5) #define XPRT_SOCK_WAKE_PENDING (6) #define XPRT_SOCK_WAKE_DISCONNECT (7) +#define XPRT_SOCK_CONNECT_SENT (8) #endif /* _LINUX_SUNRPC_XPRTSOCK_H */ diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c index 821eeea1c83b..37d961c1a5c9 100644 --- a/net/sunrpc/xprtsock.c +++ b/net/sunrpc/xprtsock.c @@ -2257,10 +2257,15 @@ static void xs_tcp_setup_socket(struct work_struct *work) if (atomic_read(&xprt->swapper)) current->flags |= PF_MEMALLOC; - if (!sock) { - sock = xs_create_sock(xprt, transport, - xs_addr(xprt)->sa_family, SOCK_STREAM, - IPPROTO_TCP, true); + + if (xprt_connected(xprt)) + goto out; + if (test_and_clear_bit(XPRT_SOCK_CONNECT_SENT, + &transport->sock_state) || + !sock) { + xs_reset_transport(transport); + sock = xs_create_sock(xprt, transport, xs_addr(xprt)->sa_family, + SOCK_STREAM, IPPROTO_TCP, true); if (IS_ERR(sock)) { xprt_wake_pending_tasks(xprt, PTR_ERR(sock)); goto out; @@ -2284,6 +2289,7 @@ static void xs_tcp_setup_socket(struct work_struct *work) fallthrough; case -EINPROGRESS: /* SYN_SENT! */ + set_bit(XPRT_SOCK_CONNECT_SENT, &transport->sock_state); if (xprt->reestablish_timeout < XS_TCP_INIT_REEST_TO) xprt->reestablish_timeout = XS_TCP_INIT_REEST_TO; fallthrough; @@ -2345,13 +2351,9 @@ static void xs_connect(struct rpc_xprt *xprt, struct rpc_task *task) WARN_ON_ONCE(!xprt_lock_connect(xprt, task, transport)); - if (transport->sock != NULL && !xprt_connecting(xprt)) { + if (transport->sock != NULL) { dprintk("RPC: xs_connect delayed xprt %p for %lu " - "seconds\n", - xprt, xprt->reestablish_timeout / HZ); - - /* Start by resetting any existing state */ - xs_reset_transport(transport); + "seconds\n", xprt, xprt->reestablish_timeout / HZ); delay = xprt_reconnect_delay(xprt); xprt_reconnect_backoff(xprt, XS_TCP_INIT_REEST_TO); -- 2.34.1