USB: serial: io_edgeport: fix epic endpoint lookup

commit 7c5a2df3367a2c4984f1300261345817d95b71f8 upstream.

Make sure to use the current alternate setting when looking up the
endpoints on epic devices to avoid binding to an invalid interface.

Failing to do so could cause the driver to misbehave or trigger a WARN()
in usb_submit_urb() that kernels with panic_on_warn set would choke on.

Fixes: 6e8cf7751f9f ("USB: add EPIC support to the io_edgeport driver")
Cc: stable <stable@vger.kernel.org>     # 2.6.21
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20191210112601.3561-5-johan@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Johan Hovold 2019-12-10 12:26:01 +01:00 committed by Greg Kroah-Hartman
parent 6ca5c81b0a
commit 1e63d9a793

View File

@ -2852,16 +2852,18 @@ static int edge_startup(struct usb_serial *serial)
response = 0;
if (edge_serial->is_epic) {
struct usb_host_interface *alt;
alt = serial->interface->cur_altsetting;
/* EPIC thing, set up our interrupt polling now and our read
* urb, so that the device knows it really is connected. */
interrupt_in_found = bulk_in_found = bulk_out_found = false;
for (i = 0; i < serial->interface->altsetting[0]
.desc.bNumEndpoints; ++i) {
for (i = 0; i < alt->desc.bNumEndpoints; ++i) {
struct usb_endpoint_descriptor *endpoint;
int buffer_size;
endpoint = &serial->interface->altsetting[0].
endpoint[i].desc;
endpoint = &alt->endpoint[i].desc;
buffer_size = usb_endpoint_maxp(endpoint);
if (!interrupt_in_found &&
(usb_endpoint_is_int_in(endpoint))) {