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 <benquike@xxxxxxxxx>
> Reported-by: Hui Peng <benquike@xxxxxxxxx>
> Reported-by: Mathias Payer <mathias.payer@xxxxxxxxxxxxx>
I don't see this patch in the upstream kernel or in -next.
At the same time, it is supposed to fix CVE-2019-15098, which has
a CVSS v2.0 score of 7.8 (high).
Is this patch going to be applied to the upstream kernel ? If not,
are there reasons to believe that the vulnerability is not as severe
as its CVSS score indicates ?
Thanks,
Guenter
> ---
> drivers/net/wireless/ath/ath6kl/usb.c | 8 ++++++++
> 1 file changed, 8 insertions(+)
>
> diff --git a/drivers/net/wireless/ath/ath6kl/usb.c b/drivers/net/wireless/ath/ath6kl/usb.c
> index 4defb7a0330f..53b66e9434c9 100644
> --- a/drivers/net/wireless/ath/ath6kl/usb.c
> +++ b/drivers/net/wireless/ath/ath6kl/usb.c
> @@ -132,6 +132,10 @@ ath6kl_usb_alloc_urb_from_pipe(struct ath6kl_usb_pipe *pipe)
> struct ath6kl_urb_context *urb_context = NULL;
> unsigned long flags;
>
> + /* bail if this pipe is not initialized */
> + if (!pipe->ar_usb)
> + return NULL;
> +
> spin_lock_irqsave(&pipe->ar_usb->cs_lock, flags);
> if (!list_empty(&pipe->urb_list_head)) {
> urb_context =
> @@ -150,6 +154,10 @@ static void ath6kl_usb_free_urb_to_pipe(struct ath6kl_usb_pipe *pipe,
> {
> unsigned long flags;
>
> + /* bail if this pipe is not initialized */
> + if (!pipe->ar_usb)
> + return;
> +
> spin_lock_irqsave(&pipe->ar_usb->cs_lock, flags);
> pipe->urb_cnt++;
>
> --
> 2.22.0
>
