most: usb: fix double free on late probe failure

The MOST subsystem has a non-standard registration function which frees
the interface on registration failures and on deregistration.

This unsurprisingly leads to bugs in the MOST drivers, and a couple of
recent changes turned a reference underflow and use-after-free in the
USB driver into several double free and a use-after-free on late probe
failures.

Fixes: 723de0f9171e ("staging: most: remove device from interface structure")
Fixes: 4b1270902609 ("most: usb: Fix use-after-free in hdm_disconnect")
Fixes: a8cc9e5fcb0e ("most: usb: hdm_probe: Fix calling put_device() before device initialization")
Cc: [e-mail]
Cc: Christian Gromm <[e-mail]>
Cc: Victoria Votokina <[e-mail]>
Signed-off-by: Johan Hovold <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/most/most_usb.c

···
 
 	ret = most_register_interface(&mdev->iface);
 	if (ret)
-		goto err_free_busy_urbs;
+		return ret;
 
 	mutex_lock(&mdev->io_mutex);
 	if (le16_to_cpu(usb_dev->descriptor.idProduct) == USB_DEV_ID_OS81118 ||
···
 		if (!mdev->dci) {
 			mutex_unlock(&mdev->io_mutex);
 			most_deregister_interface(&mdev->iface);
-			ret = -ENOMEM;
-			goto err_free_busy_urbs;
+			return -ENOMEM;
 		}
 
 		mdev->dci->dev.init_name = "dci";
···
 		mdev->dci->dev.release = release_dci;
 		if (device_register(&mdev->dci->dev)) {
 			mutex_unlock(&mdev->io_mutex);
+			put_device(&mdev->dci->dev);
 			most_deregister_interface(&mdev->iface);
-			ret = -ENOMEM;
-			goto err_free_dci;
+			return -ENOMEM;
 		}
 		mdev->dci->usb_device = mdev->usb_device;
 	}
 	mutex_unlock(&mdev->io_mutex);
 	return 0;
-err_free_dci:
-	put_device(&mdev->dci->dev);
-err_free_busy_urbs:
-	kfree(mdev->busy_urbs);
+
 err_free_ep_address:
 	kfree(mdev->ep_address);
 err_free_cap: