USB: keyspan: fix null-deref at probe

commit b5122236 upstream.

Fix null-pointer dereference during probe if the interface-status
completion handler is called before the individual ports have been set
up.

Fixes: f79b2d0f ("USB: keyspan: fix NULL-pointer dereferences and
memory leaks")
Reported-by: Richard <richjunk@pacbell.net>
Tested-by: Richard <richjunk@pacbell.net>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>

drivers/usb/serial/keyspan.c

@@ -410,6 +410,8 @@ static void	usa26_instat_callback(struct urb *urb)
 	}
 	port = serial->port[msg->port];
 	p_priv = usb_get_serial_port_data(port);
+	if (!p_priv)
+		goto resubmit;
 
 	/* Update handshaking pin state information */
 	old_dcd_state = p_priv->dcd_state;
@@ -420,7 +422,7 @@ static void	usa26_instat_callback(struct urb *urb)
 
 	if (old_dcd_state != p_priv->dcd_state)
 		tty_port_tty_hangup(&port->port, true);
-
+resubmit:
 	/* Resubmit urb so we continue receiving */
 	err = usb_submit_urb(urb, GFP_ATOMIC);
 	if (err != 0)
@@ -527,6 +529,8 @@ static void	usa28_instat_callback(struct urb *urb)
 	}
 	port = serial->port[msg->port];
 	p_priv = usb_get_serial_port_data(port);
+	if (!p_priv)
+		goto resubmit;
 
 	/* Update handshaking pin state information */
 	old_dcd_state = p_priv->dcd_state;
@@ -537,7 +541,7 @@ static void	usa28_instat_callback(struct urb *urb)
 
 	if (old_dcd_state != p_priv->dcd_state && old_dcd_state)
 		tty_port_tty_hangup(&port->port, true);
-
+resubmit:
 		/* Resubmit urb so we continue receiving */
 	err = usb_submit_urb(urb, GFP_ATOMIC);
 	if (err != 0)
@@ -607,6 +611,8 @@ static void	usa49_instat_callback(struct urb *urb)
 	}
 	port = serial->port[msg->portNumber];
 	p_priv = usb_get_serial_port_data(port);
+	if (!p_priv)
+		goto resubmit;
 
 	/* Update handshaking pin state information */
 	old_dcd_state = p_priv->dcd_state;
@@ -617,7 +623,7 @@ static void	usa49_instat_callback(struct urb *urb)
 
 	if (old_dcd_state != p_priv->dcd_state && old_dcd_state)
 		tty_port_tty_hangup(&port->port, true);
-
+resubmit:
 	/* Resubmit urb so we continue receiving */
 	err = usb_submit_urb(urb, GFP_ATOMIC);
 	if (err != 0)
@@ -855,6 +861,8 @@ static void	usa90_instat_callback(struct urb *urb)
 
 	port = serial->port[0];
 	p_priv = usb_get_serial_port_data(port);
+	if (!p_priv)
+		goto resubmit;
 
 	/* Update handshaking pin state information */
 	old_dcd_state = p_priv->dcd_state;
@@ -865,7 +873,7 @@ static void	usa90_instat_callback(struct urb *urb)
 
 	if (old_dcd_state != p_priv->dcd_state && old_dcd_state)
 		tty_port_tty_hangup(&port->port, true);
-
+resubmit:
 	/* Resubmit urb so we continue receiving */
 	err = usb_submit_urb(urb, GFP_ATOMIC);
 	if (err != 0)
@@ -926,6 +934,8 @@ static void	usa67_instat_callback(struct urb *urb)
 
 	port = serial->port[msg->port];
 	p_priv = usb_get_serial_port_data(port);
+	if (!p_priv)
+		goto resubmit;
 
 	/* Update handshaking pin state information */
 	old_dcd_state = p_priv->dcd_state;
@@ -934,7 +944,7 @@ static void	usa67_instat_callback(struct urb *urb)
 
 	if (old_dcd_state != p_priv->dcd_state && old_dcd_state)
 		tty_port_tty_hangup(&port->port, true);
-
+resubmit:
 	/* Resubmit urb so we continue receiving */
 	err = usb_submit_urb(urb, GFP_ATOMIC);
 	if (err != 0)