Input: hanwang - validate number of endpoints before using them

commit ba340d7b83703768ce566f53f857543359aa1b98 upstream.

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

Fixes: bba5394ad3bd ("Input: add support for Hanwang tablets")
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>

diff --git a/drivers/input/tablet/hanwang.c b/drivers/input/tablet/hanwang.c
index cd852059b99e81899f8436f31071c929eb470b83..df4bea96d7ed7d10e66478c929feb1094ff5f09c 100644 (file)
--- a/drivers/input/tablet/hanwang.c
+++ b/drivers/input/tablet/hanwang.c
@@ -340,6 +340,9 @@ static int hanwang_probe(struct usb_interface *intf, const struct usb_device_id
        int error;
        int i;
 
+       if (intf->cur_altsetting->desc.bNumEndpoints < 1)
+               return -ENODEV;
+
        hanwang = kzalloc(sizeof(struct hanwang), GFP_KERNEL);
        input_dev = input_allocate_device();
        if (!hanwang || !input_dev) {