--- x/net/smc/smc_core.c
+++ y/net/smc/smc_core.c
@@ -1896,7 +1896,9 @@ int smc_vlan_by_tcpsk(struct socket *clc
 
 	priv.data = (void *)&ini->vlan_id;
 	rtnl_lock();
+	rcu_read_lock();
 	netdev_walk_all_lower_dev(ndev, smc_vlan_by_tcpsk_walk, &priv);
+	rcu_read_unlock();
 	rtnl_unlock();
 
 out_rel: