diff --git a/net/core/dev.c b/net/core/dev.c index 6591440cc03d..13e6447f0398 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -3313,6 +3313,7 @@ int netdev_rx_handler_register(struct net_device *dev, if (dev->rx_handler) return -EBUSY; + /* Note: rx_handler_data must be set before rx_handler */ rcu_assign_pointer(dev->rx_handler_data, rx_handler_data); rcu_assign_pointer(dev->rx_handler, rx_handler); @@ -3333,6 +3334,11 @@ void netdev_rx_handler_unregister(struct net_device *dev) ASSERT_RTNL(); RCU_INIT_POINTER(dev->rx_handler, NULL); + /* a reader seeing a non NULL rx_handler in a rcu_read_lock() + * section has a guarantee to see a non NULL rx_handler_data + * as well. + */ + synchronize_net(); RCU_INIT_POINTER(dev->rx_handler_data, NULL); } EXPORT_SYMBOL_GPL(netdev_rx_handler_unregister);