@@ -1240,9 +1240,21 @@ static int acm_probe(struct usb_interface *intf,
}
}
} else {
+ int class = -1;
+
data_intf_num = union_header->bSlaveInterface0;
control_interface = usb_ifnum_to_if(usb_dev, union_header->bMasterInterface0);
data_interface = usb_ifnum_to_if(usb_dev, data_intf_num);
+
+ if (control_interface)
+ class = control_interface->cur_altsetting->desc.bInterfaceClass;
+
+ if (class != USB_CLASS_COMM && class != USB_CLASS_CDC_DATA) {
+ dev_dbg(&intf->dev, "Broken union descriptor, assuming single interface\n");
+ combined_interfaces = 1;
+ control_interface = data_interface = intf;
+ goto look_for_collapsed_interface;
+ }
}
if (!control_interface || !data_interface) {
Handle broken union functional descriptors where the master-interface doesn't exist or where its class is of neither Communication or Data type (as required by the specification) by falling back to "combined-interface" probing. Note that this still allows for handling union descriptors with switched interfaces. This specifically makes the Whistler radio scanners TRX series devices work with the driver without adding further quirks to the device-id table. Link: https://lore.kernel.org/r/5f4ca4f8.1c69fb81.a4487.0f5f@mx.google.com Reported-by: Daniel Caujolle-Bert <f1rmb.daniel@gmail.com> Cc: stable@vger.kernel.org Signed-off-by: Johan Hovold <johan@kernel.org> --- drivers/usb/class/cdc-acm.c | 12 ++++++++++++ 1 file changed, 12 insertions(+)