[PATCH 4.19 20/49] rapidio: handle create_workqueue() failure

[Greg Kroah-Hartman]

From: Anirudh Rayabharam <mail@xxxxxxxxxxxxx>

commit 69ce3ae36dcb03cdf416b0862a45369ddbf50fdf upstream.

In case create_workqueue() fails, release all resources and return -ENOMEM
to caller to avoid potential NULL pointer deref later. Move up the
create_workequeue() call to return early and avoid unwinding the call to
riocm_rx_fill().

Cc: Alexandre Bounine <alex.bou9@xxxxxxxxx>
Cc: Matt Porter <mporter@xxxxxxxxxxxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: stable <stable@xxxxxxxxxxxxxxx>
Signed-off-by: Anirudh Rayabharam <mail@xxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20210503115736.2104747-46-gregkh@xxxxxxxxxxxxxxxxxxx
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/rapidio/rio_cm.c |    9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

--- a/drivers/rapidio/rio_cm.c
+++ b/drivers/rapidio/rio_cm.c
@@ -2136,6 +2136,14 @@ static int riocm_add_mport(struct device
 		return -ENODEV;
 	}
 
+	cm->rx_wq = create_workqueue(DRV_NAME "/rxq");
+	if (!cm->rx_wq) {
+		rio_release_inb_mbox(mport, cmbox);
+		rio_release_outb_mbox(mport, cmbox);
+		kfree(cm);
+		return -ENOMEM;
+	}
+
 	/*
 	 * Allocate and register inbound messaging buffers to be ready
 	 * to receive channel and system management requests
@@ -2146,7 +2154,6 @@ static int riocm_add_mport(struct device
 	cm->rx_slots = RIOCM_RX_RING_SIZE;
 	mutex_init(&cm->rx_lock);
 	riocm_rx_fill(cm, RIOCM_RX_RING_SIZE);
-	cm->rx_wq = create_workqueue(DRV_NAME "/rxq");
 	INIT_WORK(&cm->rx_work, rio_ibmsg_handler);
 
 	cm->tx_slot = 0;