USB: serial: io_edgeport: handle unbound ports on URB completion

BugLink: https://bugs.launchpad.net/bugs/1860681

[ Upstream commit e37d1aed ]

Check for NULL port data in the shared interrupt and bulk completion
callbacks to avoid dereferencing a NULL pointer in case a device sends
data for a port device which isn't bound to a driver (e.g. due to a
malicious device having unexpected endpoints or after an allocation
failure on port probe).

Fixes: 1da177e4 ("Linux-2.6.12-rc2")
Cc: stable <stable@vger.kernel.org>
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Connor Kuehl <connor.kuehl@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

drivers/usb/serial/io_edgeport.c

@@ -640,7 +640,7 @@ static void edge_interrupt_callback(struct urb *urb)
 			if (txCredits) {
 				port = edge_serial->serial->port[portNumber];
 				edge_port = usb_get_serial_port_data(port);
-				if (edge_port->open) {
+				if (edge_port && edge_port->open) {
 					spin_lock_irqsave(&edge_port->ep_lock,
 							  flags);
 					edge_port->txCredits += txCredits;
@@ -1780,7 +1780,7 @@ static void process_rcvd_data(struct edgeport_serial *edge_serial,
 			if (rxLen && edge_serial->rxPort < serial->num_ports) {
 				port = serial->port[edge_serial->rxPort];
 				edge_port = usb_get_serial_port_data(port);
-				if (edge_port->open) {
+				if (edge_port && edge_port->open) {
 					dev_dbg(dev, "%s - Sending %d bytes to TTY for port %d\n",
 						__func__, rxLen,
 						edge_serial->rxPort);