Patch "iw_cxgb4: stop MPA_REPLY timer when disconnecting" has been added to the 4.7-stable tree

This is a note to let you know that I've just added the patch titled

iw_cxgb4: stop MPA_REPLY timer when disconnecting

to the 4.7-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
iw_cxgb4-stop-mpa_reply-timer-when-disconnecting.patch
and it can be found in the queue-4.7 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Steve Wise <[email protected]>
Date: Fri, 29 Jul 2016 08:38:44 -0700
Subject: iw_cxgb4: stop MPA_REPLY timer when disconnecting

From: Steve Wise <[email protected]>

commit 12eb5137edecfd8fb6d23dacec2a3630e729736f upstream.

There exists a race where the application can setup a connection and then disconnect it before iw_cxgb4 processes the fw4_ack message. For passive side connections, the fw4_ack message is used to know when to stop the ep timer for MPA_REPLY messages.

If the application disconnects before the fw4_ack is handled then c4iw_ep_disconnect() needs to clean up the timer state and stop the timer before restarting it for the disconnect timer. Failure to do this results in a "timer already started" message and a premature stopping of the disconnect timer.

---
 drivers/infiniband/hw/cxgb4/cm.c |   12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

@@ -3011,9 +3011,9 @@ static int fw4_ack(struct c4iw_dev *dev,
 		PDBG("%s last streaming msg ack ep %p tid %u state %u "
 		     "initiator %u freeing skb\n", __func__, ep, ep->hwtid,
 		     state_read(&ep->com), ep->mpa_attr.initiator ? 1 : 0);
+		mutex_lock(&ep->com.mutex);
 		kfree_skb(ep->mpa_skb);
 		ep->mpa_skb = NULL;
-		mutex_lock(&ep->com.mutex);
 		if (test_bit(STOP_MPA_TIMER, &ep->com.flags))
 			stop_ep_timer(ep);
 		mutex_unlock(&ep->com.mutex);

@@ -3582,6 +3582,16 @@ int c4iw_ep_disconnect(struct c4iw_ep *e
 			ep->com.state = ABORTING;
 		else {
 			ep->com.state = CLOSING;
+
+			/*
+			 * if we close before we see the fw4_ack() then we fix
+			 * up the timer state since we're reusing it.
+			 */
+			if (ep->mpa_skb &&
+			    test_bit(STOP_MPA_TIMER, &ep->com.flags)) {
+				clear_bit(STOP_MPA_TIMER, &ep->com.flags);
+				stop_ep_timer(ep);
+			}
 			start_ep_timer(ep);
 		}
 		set_bit(CLOSE_SENT, &ep->com.flags);

Patches currently in stable-queue which might be from [email protected] are

queue-4.7/iw_cxgb4-stop-mpa_reply-timer-when-disconnecting.patch