From patchwork Mon Aug 10 15:21:36 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 266628 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=-10.0 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, USER_AGENT_GIT autolearn=unavailable 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 1FDE8C433DF for ; Mon, 10 Aug 2020 15:38:30 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id ED2EF22EBE for ; Mon, 10 Aug 2020 15:38:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597073910; bh=LoCBf9smeqKX90IxjUKH7UtGhuBKcdKjGFseDosWpvs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=RsU9RhRV44Fe84Zy1ajLsqMa2IFAjgdC8HtjjMtY0DuwHwLvf6vzQW1E9tCW4GKzI 80ic0qlFZGxhApf0hh9KBstKE+AAh2ZrskhVUEUr0eo3Q/OkR64UpYUNj7+Wi2Nj2k 2dTx4zwckbPPb2GIJ/m+9WvR0X/jUd9lI7RqsWVA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728952AbgHJPiS (ORCPT ); Mon, 10 Aug 2020 11:38:18 -0400 Received: from mail.kernel.org ([198.145.29.99]:59930 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728613AbgHJPZ6 (ORCPT ); Mon, 10 Aug 2020 11:25:58 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 E01DA20658; Mon, 10 Aug 2020 15:25:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1597073157; bh=LoCBf9smeqKX90IxjUKH7UtGhuBKcdKjGFseDosWpvs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=RdCZFuWycpAmThkbxzZE4jOO3I8WqZXDjRRdZW7OL7+3Q6rptxFyrBSi5Z7JMER9I dJwykivaK8xiwr4DLcbnwuAuSJcpKTlIHYRrr/Guzv2t+vp+jK7VP3ZTE5QMNIfh5X F9W5GHmBZzq/7TGp2PK3+6XeYM8gYXlbEb4XYr3Q= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Matthieu Baerts , Paolo Abeni , "David S. Miller" Subject: [PATCH 5.7 77/79] mptcp: fix bogus sendmsg() return code under pressure Date: Mon, 10 Aug 2020 17:21:36 +0200 Message-Id: <20200810151816.018579465@linuxfoundation.org> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200810151812.114485777@linuxfoundation.org> References: <20200810151812.114485777@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Paolo Abeni [ Upstream commit 8555c6bfd5fddb1cf363d3cd157d70a1bb27f718 ] In case of memory pressure, mptcp_sendmsg() may call sk_stream_wait_memory() after succesfully xmitting some bytes. If the latter fails we currently return to the user-space the error code, ignoring the succeful xmit. Address the issue always checking for the xmitted bytes before mptcp_sendmsg() completes. Fixes: f296234c98a8 ("mptcp: Add handling of incoming MP_JOIN requests") Reviewed-by: Matthieu Baerts Signed-off-by: Paolo Abeni Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/mptcp/protocol.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -802,7 +802,6 @@ fallback: mptcp_set_timeout(sk, ssk); if (copied) { - ret = copied; tcp_push(ssk, msg->msg_flags, mss_now, tcp_sk(ssk)->nonagle, size_goal); @@ -815,7 +814,7 @@ fallback: release_sock(ssk); out: release_sock(sk); - return ret; + return copied ? : ret; } static void mptcp_wait_data(struct sock *sk, long *timeo)