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

BugLink: https://bugs.launchpad.net/bugs/1862259
[ Upstream commit e37d1aeda737a20b1846a91a3da3f8b0f00cf690 ]

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")
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: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>

diff --git a/drivers/usb/serial/io_edgeport.c b/drivers/usb/serial/io_edgeport.c
index 9551c1774f1305132eee70c66d79b9f56991e7aa..5d101b022e713950576d815bbef0add84966ae9e 100644 (file)
--- a/drivers/usb/serial/io_edgeport.c
+++ b/drivers/usb/serial/io_edgeport.c
@@ -716,7 +716,7 @@ 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;
@@ -1843,7 +1843,7 @@ 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);