Input: ims-pcu - validate number of endpoints before using them

commit 1916d319271664241b7aa0cd2b05e32bdb310ce9 upstream.

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

Fixes: 628329d52474 ("Input: add IMS Passenger Control Unit driver")
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>
This commit is contained in:
Johan Hovold 2017-03-16 11:36:13 -07:00 committed by Greg Kroah-Hartman
parent 0afac79f66
commit 1f5a512844

View File

@ -1667,6 +1667,10 @@ static int ims_pcu_parse_cdc_data(struct usb_interface *intf, struct ims_pcu *pc
return -EINVAL;
alt = pcu->ctrl_intf->cur_altsetting;
if (alt->desc.bNumEndpoints < 1)
return -ENODEV;
pcu->ep_ctrl = &alt->endpoint[0].desc;
pcu->max_ctrl_size = usb_endpoint_maxp(pcu->ep_ctrl);