RE: [PATCH] rapidio: fix a NULL pointer derefenrece when create_workqueue fails

[alex.bou9]

Please correct spelling in the subject line: "dereference"

-----Original Message-----
From: Kangjie Lu <kjlu@xxxxxxx> 
Sent: Thursday, March 14, 2019 2:10 AM
To: kjlu@xxxxxxx
Cc: pakki001@xxxxxxx; Matt Porter <mporter@xxxxxxxxxxxxxxxxxxx>; Alexandre
Bounine <alex.bou9@xxxxxxxxx>; linux-kernel@xxxxxxxxxxxxxxx
Subject: [PATCH] rapidio: fix a NULL pointer derefenrece when
create_workqueue fails

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

Signed-off-by: Kangjie Lu <kjlu@xxxxxxx>
---
 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 cf45829585cb..b29fc258eeba 100644
--- a/drivers/rapidio/rio_cm.c
+++ b/drivers/rapidio/rio_cm.c
@@ -2147,6 +2147,14 @@ 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;
-- 
2.17.1