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

1 files changed, 3 insertions, 0 deletions

diff --git a/drivers/input/tablet/kbtab.c b/drivers/input/tablet/kbtab.c
index e850d7e8afbc..4d9d64908b59 100644
--- a/drivers/input/tablet/kbtab.c
+++ b/drivers/input/tablet/kbtab.c
@@ -122,6 +122,9 @@ 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)