[PATCH 4.19 014/103] USB: serial: io_edgeport: handle unbound ports on URB completion

Greg Kroah-Hartman
2020-01-22T09:40:41Z

From: Johan Hovold <johan@kernel.org>

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")
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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/usb/serial/io_edgeport.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)

--- a/drivers/usb/serial/io_edgeport.c
+++ b/drivers/usb/serial/io_edgeport.c
@@ -716,7 +716,7 @@ static void edge_interrupt_callback(stru
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 edg
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);