From mboxrd@z Thu Jan  1 00:00:00 1970
From: David Miller <davem@davemloft.net>
Subject: Re: [PATCH net] rds: MP-RDS may use an invalid c_path
Date: Wed, 11 Apr 2018 10:24:28 -0400 (EDT)
Message-ID: <20180411.102428.2000222108532218799.davem@davemloft.net>
References: <1523433445-7596-1-git-send-email-ka-cheong.poon@oracle.com>
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Cc: netdev@vger.kernel.org, santosh.shilimkar@oracle.com,
        rds-devel@oss.oracle.com
To: ka-cheong.poon@oracle.com
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From: Ka-Cheong Poon <ka-cheong.poon@oracle.com>
Date: Wed, 11 Apr 2018 00:57:25 -0700

> 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 <ka-cheong.poon@oracle.com>

Applied and queued up for -stable, thanks.