[PATCH 3.16 021/136] USB: serial: metro-usb: stop I/O after failed open

[Ben Hutchings]

3.16.54-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Johan Hovold <johan@xxxxxxxxxx>

commit 2339536d229df25c71c0900fc619289229bfecf6 upstream.

Make sure to kill the interrupt-in URB after a failed open request.
Apart from saving power (and avoiding stale input after a later
successful open), this also prevents a NULL-deref in the completion
handler if the port is manually unbound.

Reviewed-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Fixes: 704577861d5e ("USB: serial: metro-usb: get data from device in Uni-Directional mode.")
Signed-off-by: Johan Hovold <johan@xxxxxxxxxx>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@xxxxxxxxxxxxxxx>
---
 drivers/usb/serial/metro-usb.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

--- a/drivers/usb/serial/metro-usb.c
+++ b/drivers/usb/serial/metro-usb.c
@@ -217,7 +217,7 @@ static int metrousb_open(struct tty_stru
 		dev_err(&port->dev,
 			"%s - failed submitting interrupt in urb, error code=%d\n",
 			__func__, result);
-		goto exit;
+		return result;
 	}
 
 	/* Send activate cmd to device */
@@ -226,11 +226,16 @@ static int metrousb_open(struct tty_stru
 		dev_err(&port->dev,
 			"%s - failed to configure device, error code=%d\n",
 			__func__, result);
-		goto exit;
+		goto err_kill_urb;
 	}
 
 	dev_dbg(&port->dev, "%s - port open\n", __func__);
-exit:
+
+	return 0;
+
+err_kill_urb:
+	usb_kill_urb(port->interrupt_in_urb);
+
 	return result;
 }