[PATCH 4.9 001/117] rapidio: fix a NULL pointer dereference when create_workqueue() fails

[Greg Kroah-Hartman]

[ Upstream commit 23015b22e47c5409620b1726a677d69e5cd032ba ]

In case create_workqueue fails, the fix releases resources and returns
-ENOMEM to avoid NULL pointer dereference.

Signed-off-by: Kangjie Lu <kjlu@xxxxxxx>
Acked-by: Alexandre Bounine <alex.bou9@xxxxxxxxx>
Cc: Matt Porter <mporter@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/rapidio/rio_cm.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/rapidio/rio_cm.c b/drivers/rapidio/rio_cm.c
index bad0e0ea4f30..ef989a15aefc 100644
--- a/drivers/rapidio/rio_cm.c
+++ b/drivers/rapidio/rio_cm.c
@@ -2145,6 +2145,14 @@ static int riocm_add_mport(struct device *dev,
 	mutex_init(&cm->rx_lock);
 	riocm_rx_fill(cm, RIOCM_RX_RING_SIZE);
 	cm->rx_wq = create_workqueue(DRV_NAME "/rxq");
+	if (!cm->rx_wq) {
+		riocm_error("failed to allocate IBMBOX_%d on %s",
+			    cmbox, mport->name);
+		rio_release_outb_mbox(mport, cmbox);
+		kfree(cm);
+		return -ENOMEM;
+	}
+
 	INIT_WORK(&cm->rx_work, rio_ibmsg_handler);
 
 	cm->tx_slot = 0;
-- 
2.20.1