USB: cdc-acm: always claim data interface

Make sure to always claim the data interface and bail out if binding
fails.

Note that the driver had a check to verify that the data interface was
not already bound to a driver but would not detect other failures (e.g.
if the interface was not authorised).
Signed-off-by: Johan Hovold <johan@kernel.org>
Link: https://lore.kernel.org/r/20210322155318.9837-8-johan@kernel.orgSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/usb/class/cdc-acm.c

@@ -1309,13 +1309,6 @@ static int acm_probe(struct usb_interface *intf,
 	if (!combined_interfaces && intf != control_interface)
 		return -ENODEV;
 
-	if (!combined_interfaces && usb_interface_claimed(data_interface)) {
-		/* valid in this context */
-		dev_dbg(&intf->dev, "The data interface isn't available\n");
-		return -EBUSY;
-	}
-
-
 	if (data_interface->cur_altsetting->desc.bNumEndpoints < 2 ||
 	    control_interface->cur_altsetting->desc.bNumEndpoints == 0)
 		return -EINVAL;
@@ -1499,7 +1492,11 @@ static int acm_probe(struct usb_interface *intf,
 	acm->line.bDataBits = 8;
 	acm_set_line(acm, &acm->line);
 
-	usb_driver_claim_interface(&acm_driver, data_interface, acm);
+	if (!acm->combined_interfaces) {
+		rv = usb_driver_claim_interface(&acm_driver, data_interface, acm);
+		if (rv)
+			goto err_remove_files;
+	}
 
 	tty_dev = tty_port_register_device(&acm->port, acm_tty_driver, minor,
 			&control_interface->dev);
@@ -1521,6 +1518,7 @@ static int acm_probe(struct usb_interface *intf,
 		usb_set_intfdata(data_interface, NULL);
 		usb_driver_release_interface(&acm_driver, data_interface);
 	}
+err_remove_files:
 	if (acm->country_codes) {
 		device_remove_file(&acm->control->dev,
 				&dev_attr_wCountryCodes);