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

commit e37d1aeda737a20b1846a91a3da3f8b0f00cf690 upstream.

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: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
[bwh: Backported to 3.16: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/drivers/usb/serial/io_edgeport.c b/drivers/usb/serial/io_edgeport.c
index 0de11898fee7a8764f9de2824bd909fb49b428d7..f98c622baae247e45300a2962aa2ce6294807c8e 100644 (file)
--- a/drivers/usb/serial/io_edgeport.c
+++ b/drivers/usb/serial/io_edgeport.c
@@ -638,7 +638,7 @@ 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(&edge_port->ep_lock);
                                        edge_port->txCredits += txCredits;
                                        spin_unlock(&edge_port->ep_lock);
@@ -1775,7 +1775,7 @@ static void process_rcvd_data(struct edgeport_serial *edge_serial,
                                port = edge_serial->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);