Add a sanity check on the device id-table driver_info field to make sure
we never access a type structure (and function pointers) outside of the
device info array (e.g. if someone fails to ifdef a device-id entry).

Signed-off-by: Johan Hovold <johan@kernel.org>
---
 drivers/input/touchscreen/usbtouchscreen.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/input/touchscreen/usbtouchscreen.c b/drivers/input/touchscreen/usbtouchscreen.c
index 6683554f0e92..f90acbeea74f 100644
--- a/drivers/input/touchscreen/usbtouchscreen.c
+++ b/drivers/input/touchscreen/usbtouchscreen.c

@@ -1656,6 +1656,9 @@ static int usbtouch_probe(struct usb_interface *intf,
 	if (id->driver_info == DEVTYPE_IGNORE)
 		return -ENODEV;
 
+	if (id->driver_info >= DEVTYPE_COUNT)
+		return -EINVAL;
+
 	endpoint = usbtouch_get_input_endpoint(intf->cur_altsetting);
 	if (!endpoint)
 		return -ENXIO;

-- 
2.35.1