From: Johan Hovold johan@kernel.org
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
--- drivers/usb/serial/io_edgeport.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-)
--- a/drivers/usb/serial/io_edgeport.c +++ b/drivers/usb/serial/io_edgeport.c @@ -2852,16 +2852,18 @@ static int edge_startup(struct usb_seria 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))) {