On Sat, Aug 03, 2019 at 08:31:01PM -0400, Hui Peng wrote: > The `ar_usb` field of `ath10k_usb_pipe_usb_pipe` objects > are initialized to point to the containing `ath10k_usb` object > according to endpoint descriptors read from the device side, as shown > below in `ath10k_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 = ath10k_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 `ath10k_usb_alloc_urb_from_pipe` and > `ath10k_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> Reviewed-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>