FAILED: patch "[PATCH] USB: serial: keyspan: handle unbound ports" failed to apply to 4.4-stable tree

The patch below does not apply to the 4.4-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 3018dd3fa114b13261e9599ddb5656ef97a1fa17 Mon Sep 17 00:00:00 2001
From: Johan Hovold <[email protected]>
Date: Fri, 17 Jan 2020 10:50:25 +0100
Subject: [PATCH] USB: serial: keyspan: handle unbound ports

Check for NULL port data in the control URB completion handlers to avoid dereferencing a NULL pointer in the unlikely case where a port device isn't bound to a driver (e.g. after an allocation failure on port probe()).

index e66a59ef43a1..aa3dbce22cfb 100644
@@ -1058,6 +1058,8 @@ static void	usa49_glocont_callback(struct urb *urb)
 	for (i = 0; i < serial->num_ports; ++i) {
 		port = serial->port[i];
 		p_priv = usb_get_serial_port_data(port);
+		if (!p_priv)
+			continue;
 
 		if (p_priv->resend_cont) {
 			dev_dbg(&port->dev, "%s - sending setup\n", __func__);

@@ -1459,6 +1461,8 @@ static void usa67_glocont_callback(struct urb *urb)
 	for (i = 0; i < serial->num_ports; ++i) {
 		port = serial->port[i];
 		p_priv = usb_get_serial_port_data(port);
+		if (!p_priv)
+			continue;
 
 		if (p_priv->resend_cont) {
 			dev_dbg(&port->dev, "%s - sending setup\n", __func__);