From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Google-Smtp-Source: AIpwx49zLHo6UkeB/z75tbmd/UGpS0GjLJv663f0r6oHI+oUmkvXkXRTtRqTRB9vZ8x4bPXLVxHt ARC-Seal: i=1; a=rsa-sha256; t=1523981027; cv=none; d=google.com; s=arc-20160816; b=uJv5w9zLtBeG5gLE+Ly2O25x0aSM+OIMjaZGtuhlQwvmGJP9lBsFRYD7U/hawnzvG2 83SZKFglZUl3DfkyyO24KM1Uw/bBST63MLHC24gkY0YRk8FFGp48yjRoE91DRgexXADD GFXeDqiGmcFa6Ck69rI4EWFjBPokokO/+xPvWCKzrMssyJjHePvMkCY0lMifq+n1pvI0 /9KDUzgp4/Ox1bkSLXQcPTmLwGfOLTO4jCoJKHB7NHxD7C5Hv15zSnzKim6/hXJ28bUO c/6AjKPMGjqpEarEzpXo0jmOG32xna3hJw5S251opJj3Fxv7dVsEURJh0ab/8BnXOL0D xe8g== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=mime-version:user-agent:references:in-reply-to:message-id:date :subject:cc:to:from:arc-authentication-results; bh=ikgZ0cY0NMuM46nA78rD8mvBFv/hI2sO3b4XgvUfetY=; b=ZX2vwWFDGVNX7CsDCxp2J6M7UlKb5Sgcm369FIDqTnwoeTfRN1CJlnRRNueDRRhew2 jPT65grPuUl3wF0Gr2eh1wozXQ7mmbGx6ZeWrjqK/6H32BWF+8JhfL8cGYvQzNQE0oa0 OoYZtCMspGJZTZl/jEDK+JZTxWUCyRiLRY3ppNdJ35odNdTRZGTaVuprwx/0pAd2RSb9 TxDxMIUTATscfsV7wzRuZuJvl8jYHLzp265MqaPdHPTru2ivBIEzSNfUWzhLGF2bpEKK qc5YuDH8+lEbpSs4k2Pza1YtU9bD3060cIEhrCw19EJcblnrxsc3BBPxVonXkWdhPxel HwnQ== ARC-Authentication-Results: i=1; mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 46.44.180.42 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org Authentication-Results: mx.google.com; spf=softfail (google.com: domain of transitioning gregkh@linuxfoundation.org does not designate 46.44.180.42 as permitted sender) smtp.mailfrom=gregkh@linuxfoundation.org From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Ka-Cheong Poon , Santosh Shilimkar , "David S. Miller" Subject: [PATCH 4.15 04/53] rds: MP-RDS may use an invalid c_path Date: Tue, 17 Apr 2018 17:58:29 +0200 Message-Id: <20180417155723.273438512@linuxfoundation.org> X-Mailer: git-send-email 2.17.0 In-Reply-To: <20180417155723.091120060@linuxfoundation.org> References: <20180417155723.091120060@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 X-getmail-retrieved-from-mailbox: INBOX X-GMAIL-LABELS: =?utf-8?b?IlxcU2VudCI=?= X-GMAIL-THRID: =?utf-8?q?1598009722009378488?= X-GMAIL-MSGID: =?utf-8?q?1598009930517686851?= X-Mailing-List: linux-kernel@vger.kernel.org List-ID: 4.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ka-Cheong Poon [ Upstream commit a43cced9a348901f9015f4730b70b69e7c41a9c9 ] rds_sendmsg() calls rds_send_mprds_hash() to find a c_path to use to send a message. Suppose the RDS connection is not yet up. In rds_send_mprds_hash(), it does if (conn->c_npaths == 0) wait_event_interruptible(conn->c_hs_waitq, (conn->c_npaths != 0)); If it is interrupted before the connection is set up, rds_send_mprds_hash() will return a non-zero hash value. Hence rds_sendmsg() will use a non-zero c_path to send the message. But if the RDS connection ends up to be non-MP capable, the message will be lost as only the zero c_path can be used. Signed-off-by: Ka-Cheong Poon Acked-by: Santosh Shilimkar Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/rds/send.c | 15 ++++++++++----- 1 file changed, 10 insertions(+), 5 deletions(-) --- a/net/rds/send.c +++ b/net/rds/send.c @@ -1,5 +1,5 @@ /* - * Copyright (c) 2006 Oracle. All rights reserved. + * Copyright (c) 2006, 2018 Oracle and/or its affiliates. All rights reserved. * * This software is available to you under a choice of one of two * licenses. You may choose to be licensed under the terms of the GNU @@ -986,10 +986,15 @@ static int rds_send_mprds_hash(struct rd if (conn->c_npaths == 0 && hash != 0) { rds_send_ping(conn, 0); - if (conn->c_npaths == 0) { - wait_event_interruptible(conn->c_hs_waitq, - (conn->c_npaths != 0)); - } + /* The underlying connection is not up yet. Need to wait + * until it is up to be sure that the non-zero c_path can be + * used. But if we are interrupted, we have to use the zero + * c_path in case the connection ends up being non-MP capable. + */ + if (conn->c_npaths == 0) + if (wait_event_interruptible(conn->c_hs_waitq, + conn->c_npaths != 0)) + hash = 0; if (conn->c_npaths == 1) hash = 0; }