[PATCH] net: spi: fix a potential NULL pointer dereference

[Kangjie Lu]

In case alloc_workqueue fails to allocate the work queue and
returns NULL, the fix releases the resources and returns
-ENOMEM.

Signed-off-by: Kangjie Lu <k...@umn.edu>
---
 drivers/net/can/spi/mcp251x.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/net/can/spi/mcp251x.c b/drivers/net/can/spi/mcp251x.c
index e90817608645..2737b9a20dfe 100644
--- a/drivers/net/can/spi/mcp251x.c
+++ b/drivers/net/can/spi/mcp251x.c
@@ -962,6 +962,14 @@ static int mcp251x_open(struct net_device *net)
 
        priv->wq = alloc_workqueue("mcp251x_wq", WQ_FREEZABLE | WQ_MEM_RECLAIM,
                                   0);
+       if (unlikely(!priv->wq)) {
+               dev_err(&spi->dev, "failed to allocate work queue\n");
+               mcp251x_power_enable(priv->transceiver, 0);
+               close_candev(net);
+               ret = -ENOMEM;
+               goto open_unlock;
+       }
+
        INIT_WORK(&priv->tx_work, mcp251x_tx_work_handler);
        INIT_WORK(&priv->restart_work, mcp251x_restart_work_handler);
 
-- 
2.17.1