Input: kbtab - validate number of endpoints before using them

commit cb1b494663e037253337623bf1ef2df727883cb7 upstream.

Make sure to check the number of endpoints to avoid dereferencing a
NULL-pointer should a malicious device lack endpoints.

Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>

diff --git a/drivers/input/tablet/kbtab.c b/drivers/input/tablet/kbtab.c
index 290f4e57b589a18f440d9d41f01f9c42e7798670..3b67fb865346ac6867722523716046c93cb72043 100644 (file)
--- a/drivers/input/tablet/kbtab.c
+++ b/drivers/input/tablet/kbtab.c
@@ -117,6 +117,9 @@ static int kbtab_probe(struct usb_interface *intf, const struct usb_device_id *i
        struct input_dev *input_dev;
        int error = -ENOMEM;
 
+       if (intf->cur_altsetting->desc.bNumEndpoints < 1)
+               return -ENODEV;
+
        kbtab = kzalloc(sizeof(struct kbtab), GFP_KERNEL);
        input_dev = input_allocate_device();
        if (!kbtab || !input_dev)