Patch "IB/ipoib: Grab rtnl lock on heavy flush when calling ndo_open/stop" has been added to the 4.4-stable tree

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

IB/ipoib: Grab rtnl lock on heavy flush when calling ndo_open/stop

to the 4.4-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:
ib-ipoib-grab-rtnl-lock-on-heavy-flush-when-calling-ndo_open-stop.patch
and it can be found in the queue-4.4 subdirectory.

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

From: Alex Vesker <[email protected]>
Date: Tue, 10 Oct 2017 10:36:41 +0300
Subject: IB/ipoib: Grab rtnl lock on heavy flush when calling ndo_open/stop

From: Alex Vesker <[email protected]>

[ Upstream commit b4b678b06f6eef18bff44a338c01870234db0bc9 ]

When ndo_open and ndo_stop are called RTNL lock should be held. In this specific case ipoib_ib_dev_open calls the offloaded ndo_open which re-sets the number of TX queue assuming RTNL lock is held. Since RTNL lock is not held, RTNL assert will fail.

---
 drivers/infiniband/ulp/ipoib/ipoib_ib.c |    7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

@@ -1044,10 +1044,15 @@ static void __ipoib_ib_dev_flush(struct
 		ipoib_ib_dev_down(dev);
 
 	if (level == IPOIB_FLUSH_HEAVY) {
+		rtnl_lock();
 		if (test_bit(IPOIB_FLAG_INITIALIZED, &priv->flags))
 			ipoib_ib_dev_stop(dev);
-		if (ipoib_ib_dev_open(dev) != 0)
+
+		result = ipoib_ib_dev_open(dev);
+		rtnl_unlock();
+		if (result)
 			return;
+
 		if (netif_queue_stopped(dev))
 			netif_start_queue(dev);
 	}

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

queue-4.4/ib-ipoib-grab-rtnl-lock-on-heavy-flush-when-calling-ndo_open-stop.patch