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From:   <alex.bou9@gmail.com>
To:     "'Kangjie Lu'" <kjlu@umn.edu>
Cc:     <pakki001@umn.edu>, "'Matt Porter'" <mporter@kernel.crashing.org>,
        <linux-kernel@vger.kernel.org>, <akpm@linux-foundation.org>
References: <20190314061015.11291-1-kjlu@umn.edu>
In-Reply-To: <20190314061015.11291-1-kjlu@umn.edu>
Subject: RE: [PATCH] rapidio: fix a NULL pointer derefenrece when create_workqueue fails
Date:   Mon, 18 Mar 2019 18:44:05 -0400
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Acked-by: Alexandre Bounine <alex.bou9@gmail.com>  

-----Original Message-----
From: Kangjie Lu <kjlu@umn.edu> 
Sent: Thursday, March 14, 2019 2:10 AM
To: kjlu@umn.edu
Cc: pakki001@umn.edu; Matt Porter <mporter@kernel.crashing.org>; Alexandre
Bounine <alex.bou9@gmail.com>; linux-kernel@vger.kernel.org
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@umn.edu>
---
 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