diff --git a/net/core/dev.c b/net/core/dev.c index a9fe14908b44038deb28936c652dfeea34f5ace6..c6bbf310d4071140091afad4d455cd0acc12421d 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -5219,6 +5219,20 @@ struct net_device *netdev_master_upper_dev_get(struct net_device *dev) } EXPORT_SYMBOL(netdev_master_upper_dev_get); +/** + * netdev_has_any_lower_dev - Check if device is linked to some device + * @dev: device + * + * Find out if a device is linked to a lower device and return true in case + * it is. The caller must hold the RTNL lock. + */ +static bool netdev_has_any_lower_dev(struct net_device *dev) +{ + ASSERT_RTNL(); + + return !list_empty(&dev->adj_list.lower); +} + void *netdev_adjacent_get_private(struct list_head *adj_list) { struct netdev_adjacent *adj; @@ -6616,6 +6630,7 @@ static void rollback_registered_many(struct list_head *head) /* Notifier chain MUST detach us all upper devices. */ WARN_ON(netdev_has_any_upper_dev(dev)); + WARN_ON(netdev_has_any_lower_dev(dev)); /* Remove entries from kobject tree */ netdev_unregister_kobject(dev);