Input: kbtab - sanity check for endpoint type

The driver should check whether the endpoint it uses has the correct
type.

Reported-by: syzbot+c7df50363aaff50aa363@syzkaller.appspotmail.com
Signed-off-by: Oliver Neukum <oneukum@suse.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

diff --git a/drivers/input/tablet/kbtab.c b/drivers/input/tablet/kbtab.c
index 04b8557..aa57789 100644 (file)
--- a/drivers/input/tablet/kbtab.c
+++ b/drivers/input/tablet/kbtab.c
@@ -117,6 +117,10 @@ static int kbtab_probe(struct usb_interface *intf, const struct usb_device_id *i
        if (intf->cur_altsetting->desc.bNumEndpoints < 1)
                return -ENODEV;
 
+       endpoint = &intf->cur_altsetting->endpoint[0].desc;
+       if (!usb_endpoint_is_int_in(endpoint))
+               return -ENODEV;
+
        kbtab = kzalloc(sizeof(struct kbtab), GFP_KERNEL);
        input_dev = input_allocate_device();
        if (!kbtab || !input_dev)
@@ -155,8 +159,6 @@ static int kbtab_probe(struct usb_interface *intf, const struct usb_device_id *i
        input_set_abs_params(input_dev, ABS_Y, 0, 0x1750, 4, 0);
        input_set_abs_params(input_dev, ABS_PRESSURE, 0, 0xff, 0, 0);
 
-       endpoint = &intf->cur_altsetting->endpoint[0].desc;
-
        usb_fill_int_urb(kbtab->irq, dev,
                         usb_rcvintpipe(dev, endpoint->bEndpointAddress),
                         kbtab->data, 8,