On Sat, Aug 03, 2019 at 08:29:04PM -0400, Hui Peng wrote:
> The `ar_usb` field of `ath6kl_usb_pipe_usb_pipe` objects
> are initialized to point to the containing `ath6kl_usb` object
> according to endpoint descriptors read from the device side, as shown
> below in `ath6kl_usb_setup_pipe_resources`:
>
> for (i = 0; i < iface_desc->desc.bNumEndpoints; ++i) {
> endpoint = &iface_desc->endpoint[i].desc;
>
> // get the address from endpoint descriptor
> pipe_num = ath6kl_usb_get_logical_pipe_num(ar_usb,
> endpoint->bEndpointAddress,
> &urbcount);
> ......
> // select the pipe object
> pipe = &ar_usb->pipes[pipe_num];
>
> // initialize the ar_usb field
> pipe->ar_usb = ar_usb;
> }
>
> The driver assumes that the addresses reported in endpoint
> descriptors from device side to be complete. If a device is
> malicious and does not report complete addresses, it may trigger
> NULL-ptr-deref `ath6kl_usb_alloc_urb_from_pipe` and
> `ath6kl_usb_free_urb_to_pipe`.
>
> This patch fixes the bug by preventing potential NULL-ptr-deref.
>
> Signed-off-by: Hui Peng <benqu...@gmail.com>
> Reported-by: Hui Peng <benqu...@gmail.com>
> Reported-by: Mathias Payer <mathias.pa...@nebelwelt.net>
Reviewed-by: Greg Kroah-Hartman <gre...@linuxfoundation.org>
