Patch "IB/mlx4: Fix out-of-range array index in destroy qp flow" has been added to the 4.9-stable tree

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

IB/mlx4: Fix out-of-range array index in destroy qp flow

to the 4.9-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-mlx4-fix-out-of-range-array-index-in-destroy-qp-flow.patch
and it can be found in the queue-4.9 subdirectory.

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

From: Jack Morgenstein <[email protected]>
Date: Sun, 27 Nov 2016 15:18:19 +0200
Subject: IB/mlx4: Fix out-of-range array index in destroy qp flow

From: Jack Morgenstein <[email protected]>

commit c482af646d0809a8d5e1b7f4398cce3592589b98 upstream.

For non-special QPs, the port value becomes non-zero only at the RESET-to-INIT transition. If the QP has not undergone that transition, its port number value is still zero.

If such a QP is destroyed before being moved out of the RESET state, subtracting one from the qp port number results in a negative value. Using that negative value as an index into the qp1_proxy array results in an out-of-bounds array reference.

Fix this by testing that the QP type is one that uses qp1_proxy before using the port number. For special QPs of all types, the port number is specified at QP creation time.

---
 drivers/infiniband/hw/mlx4/qp.c |    3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

@@ -1280,7 +1280,8 @@ static int _mlx4_ib_destroy_qp(struct ib
 	if (is_qp0(dev, mqp))
 		mlx4_CLOSE_PORT(dev->dev, mqp->port);
 
-	if (dev->qp1_proxy[mqp->port - 1] == mqp) {
+	if (mqp->mlx4_ib_qp_type == MLX4_IB_QPT_PROXY_GSI &&
+	    dev->qp1_proxy[mqp->port - 1] == mqp) {
 		mutex_lock(&dev->qp1_proxy_lock[mqp->port - 1]);
 		dev->qp1_proxy[mqp->port - 1] = NULL;
 		mutex_unlock(&dev->qp1_proxy_lock[mqp->port - 1]);

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

queue-4.9/ib-mlx4-handle-well-known-gid-in-mad_demux-processing.patch queue-4.9/ib-mlx4-fix-out-of-range-array-index-in-destroy-qp-flow.patch