[PATCH AUTOSEL 5.0 003/173] rapidio: fix a NULL pointer dereference when create_workqueue() fails

[Sasha Levin]

From: Kangjie Lu <k...@umn.edu>

[ 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 <k...@umn.edu>
Acked-by: Alexandre Bounine <alex.b...@gmail.com>
Cc: Matt Porter <mpor...@kernel.crashing.org>
Signed-off-by: Andrew Morton <a...@linux-foundation.org>
Signed-off-by: Linus Torvalds <torva...@linux-foundation.org>
Signed-off-by: Sasha Levin <sas...@kernel.org>
---
 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 bad0e0ea4f305..ef989a15aefc4 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