udp_tunnel: remove rtnl_lock dependency

Drivers that are using ops lock and don't depend on RTNL lock
still need to manage it because udp_tunnel's RTNL dependency.
Introduce new udp_tunnel_nic_lock and use it instead of
rtnl_lock. Drop non-UDP_TUNNEL_NIC_INFO_MAY_SLEEP mode from
udp_tunnel infra (udp_tunnel_nic_device_sync_work needs to
grab udp_tunnel_nic_lock mutex and might sleep).

Cover more places in v4:

- netlink
  - udp_tunnel_notify_add_rx_port (ndo_open)
    - triggers udp_tunnel_nic_device_sync_work
  - udp_tunnel_notify_del_rx_port (ndo_stop)
    - triggers udp_tunnel_nic_device_sync_work
  - udp_tunnel_get_rx_info (__netdev_update_features)
    - triggers NETDEV_UDP_TUNNEL_PUSH_INFO
  - udp_tunnel_drop_rx_info (__netdev_update_features)
    - triggers NETDEV_UDP_TUNNEL_DROP_INFO
  - udp_tunnel_nic_reset_ntf (ndo_open)

- notifiers
  - udp_tunnel_nic_netdevice_event, depending on the event:
    - triggers NETDEV_UDP_TUNNEL_PUSH_INFO
    - triggers NETDEV_UDP_TUNNEL_DROP_INFO

- ethnl_tunnel_info_reply_size
- udp_tunnel_nic_set_port_priv (two intel drivers)

Cc: Michael Chan <michael.chan@broadcom.com>
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Stanislav Fomichev <stfomichev@gmail.com>
Link: https://patch.msgid.link/20250616162117.287806-4-stfomichev@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c

@@ -10219,8 +10219,7 @@ static int bnx2x_udp_tunnel_sync(struct net_device *netdev, unsigned int table)
 
 static const struct udp_tunnel_nic_info bnx2x_udp_tunnels = {
 	.sync_table	= bnx2x_udp_tunnel_sync,
-	.flags		= UDP_TUNNEL_NIC_INFO_MAY_SLEEP |
+	.flags		= UDP_TUNNEL_NIC_INFO_OPEN_ONLY,
-			  UDP_TUNNEL_NIC_INFO_OPEN_ONLY,
 	.tables		= {
 		{ .n_entries = 1, .tunnel_types = UDP_TUNNEL_TYPE_VXLAN,  },
 		{ .n_entries = 1, .tunnel_types = UDP_TUNNEL_TYPE_GENEVE, },

drivers/net/ethernet/broadcom/bnxt/bnxt.c

@@ -15573,8 +15573,7 @@ static int bnxt_udp_tunnel_unset_port(struct net_device *netdev, unsigned int ta
 static const struct udp_tunnel_nic_info bnxt_udp_tunnels = {
 	.set_port	= bnxt_udp_tunnel_set_port,
 	.unset_port	= bnxt_udp_tunnel_unset_port,
-	.flags		= UDP_TUNNEL_NIC_INFO_MAY_SLEEP |
+	.flags		= UDP_TUNNEL_NIC_INFO_OPEN_ONLY,
-			  UDP_TUNNEL_NIC_INFO_OPEN_ONLY,
 	.tables		= {
 		{ .n_entries = 1, .tunnel_types = UDP_TUNNEL_TYPE_VXLAN,  },
 		{ .n_entries = 1, .tunnel_types = UDP_TUNNEL_TYPE_GENEVE, },
@@ -15582,8 +15581,7 @@ static const struct udp_tunnel_nic_info bnxt_udp_tunnels = {
 }, bnxt_udp_tunnels_p7 = {
 	.set_port	= bnxt_udp_tunnel_set_port,
 	.unset_port	= bnxt_udp_tunnel_unset_port,
-	.flags		= UDP_TUNNEL_NIC_INFO_MAY_SLEEP |
+	.flags		= UDP_TUNNEL_NIC_INFO_OPEN_ONLY,
-			  UDP_TUNNEL_NIC_INFO_OPEN_ONLY,
 	.tables		= {
 		{ .n_entries = 1, .tunnel_types = UDP_TUNNEL_TYPE_VXLAN,  },
 		{ .n_entries = 1, .tunnel_types = UDP_TUNNEL_TYPE_GENEVE, },

drivers/net/ethernet/emulex/benet/be_main.c

@@ -4031,8 +4031,7 @@ static int be_vxlan_unset_port(struct net_device *netdev, unsigned int table,
 static const struct udp_tunnel_nic_info be_udp_tunnels = {
 	.set_port	= be_vxlan_set_port,
 	.unset_port	= be_vxlan_unset_port,
-	.flags		= UDP_TUNNEL_NIC_INFO_MAY_SLEEP |
+	.flags		= UDP_TUNNEL_NIC_INFO_OPEN_ONLY,
-			  UDP_TUNNEL_NIC_INFO_OPEN_ONLY,
 	.tables		= {
 		{ .n_entries = 1, .tunnel_types = UDP_TUNNEL_TYPE_VXLAN, },
 	},

drivers/net/ethernet/intel/i40e/i40e_main.c

@@ -15895,7 +15895,6 @@ static int i40e_probe(struct pci_dev *pdev, const struct pci_device_id *ent)
 
 	pf->udp_tunnel_nic.set_port = i40e_udp_tunnel_set_port;
 	pf->udp_tunnel_nic.unset_port = i40e_udp_tunnel_unset_port;
-	pf->udp_tunnel_nic.flags = UDP_TUNNEL_NIC_INFO_MAY_SLEEP;
 	pf->udp_tunnel_nic.shared = &pf->udp_tunnel_shared;
 	pf->udp_tunnel_nic.tables[0].n_entries = I40E_MAX_PF_UDP_OFFLOAD_PORTS;
 	pf->udp_tunnel_nic.tables[0].tunnel_types = UDP_TUNNEL_TYPE_VXLAN |

drivers/net/ethernet/intel/ice/ice_main.c

@@ -4767,7 +4767,6 @@ int ice_init_dev(struct ice_pf *pf)
 
 	pf->hw.udp_tunnel_nic.set_port = ice_udp_tunnel_set_port;
 	pf->hw.udp_tunnel_nic.unset_port = ice_udp_tunnel_unset_port;
-	pf->hw.udp_tunnel_nic.flags = UDP_TUNNEL_NIC_INFO_MAY_SLEEP;
 	pf->hw.udp_tunnel_nic.shared = &pf->hw.udp_tunnel_shared;
 	if (pf->hw.tnl.valid_count[TNL_VXLAN]) {
 		pf->hw.udp_tunnel_nic.tables[0].n_entries =

drivers/net/ethernet/mellanox/mlx4/en_netdev.c

@@ -2670,8 +2670,7 @@ static int mlx4_udp_tunnel_sync(struct net_device *dev, unsigned int table)
 
 static const struct udp_tunnel_nic_info mlx4_udp_tunnels = {
 	.sync_table	= mlx4_udp_tunnel_sync,
-	.flags		= UDP_TUNNEL_NIC_INFO_MAY_SLEEP |
+	.flags		= UDP_TUNNEL_NIC_INFO_IPV4_ONLY,
-			  UDP_TUNNEL_NIC_INFO_IPV4_ONLY,
 	.tables		= {
 		{ .n_entries = 1, .tunnel_types = UDP_TUNNEL_TYPE_VXLAN, },
 	},

drivers/net/ethernet/mellanox/mlx5/core/en_main.c

@@ -5351,8 +5351,7 @@ void mlx5e_vxlan_set_netdev_info(struct mlx5e_priv *priv)
 
 	priv->nic_info.set_port = mlx5e_vxlan_set_port;
 	priv->nic_info.unset_port = mlx5e_vxlan_unset_port;
-	priv->nic_info.flags = UDP_TUNNEL_NIC_INFO_MAY_SLEEP |
+	priv->nic_info.flags = UDP_TUNNEL_NIC_INFO_STATIC_IANA_VXLAN;
-				UDP_TUNNEL_NIC_INFO_STATIC_IANA_VXLAN;
 	priv->nic_info.tables[0].tunnel_types = UDP_TUNNEL_TYPE_VXLAN;
 	/* Don't count the space hard-coded to the IANA port */
 	priv->nic_info.tables[0].n_entries =

drivers/net/ethernet/netronome/nfp/nfp_net_common.c

@@ -2394,8 +2394,7 @@ static int nfp_udp_tunnel_sync(struct net_device *netdev, unsigned int table)
 
 static const struct udp_tunnel_nic_info nfp_udp_tunnels = {
 	.sync_table     = nfp_udp_tunnel_sync,
-	.flags          = UDP_TUNNEL_NIC_INFO_MAY_SLEEP |
+	.flags          = UDP_TUNNEL_NIC_INFO_OPEN_ONLY,
-			  UDP_TUNNEL_NIC_INFO_OPEN_ONLY,
 	.tables         = {
 		{
 			.n_entries      = NFP_NET_N_VXLAN_PORTS,

drivers/net/ethernet/qlogic/qede/qede_filter.c

@@ -987,20 +987,17 @@ static int qede_udp_tunnel_sync(struct net_device *dev, unsigned int table)
 
 static const struct udp_tunnel_nic_info qede_udp_tunnels_both = {
 	.sync_table	= qede_udp_tunnel_sync,
-	.flags		= UDP_TUNNEL_NIC_INFO_MAY_SLEEP,
 	.tables		= {
 		{ .n_entries = 1, .tunnel_types = UDP_TUNNEL_TYPE_VXLAN,  },
 		{ .n_entries = 1, .tunnel_types = UDP_TUNNEL_TYPE_GENEVE, },
 	},
 }, qede_udp_tunnels_vxlan = {
 	.sync_table	= qede_udp_tunnel_sync,
-	.flags		= UDP_TUNNEL_NIC_INFO_MAY_SLEEP,
 	.tables		= {
 		{ .n_entries = 1, .tunnel_types = UDP_TUNNEL_TYPE_VXLAN,  },
 	},
 }, qede_udp_tunnels_geneve = {
 	.sync_table	= qede_udp_tunnel_sync,
-	.flags		= UDP_TUNNEL_NIC_INFO_MAY_SLEEP,
 	.tables		= {
 		{ .n_entries = 1, .tunnel_types = UDP_TUNNEL_TYPE_GENEVE, },
 	},

drivers/net/ethernet/qlogic/qlcnic/qlcnic_main.c

@@ -486,7 +486,6 @@ static int qlcnic_udp_tunnel_sync(struct net_device *dev, unsigned int table)
 
 static const struct udp_tunnel_nic_info qlcnic_udp_tunnels = {
 	.sync_table	= qlcnic_udp_tunnel_sync,
-	.flags		= UDP_TUNNEL_NIC_INFO_MAY_SLEEP,
 	.tables		= {
 		{ .n_entries = 1, .tunnel_types = UDP_TUNNEL_TYPE_VXLAN, },
 	},

drivers/net/ethernet/sfc/ef10.c

@@ -3985,7 +3985,6 @@ static int efx_ef10_udp_tnl_unset_port(struct net_device *dev,
 static const struct udp_tunnel_nic_info efx_ef10_udp_tunnels = {
 	.set_port	= efx_ef10_udp_tnl_set_port,
 	.unset_port	= efx_ef10_udp_tnl_unset_port,
-	.flags          = UDP_TUNNEL_NIC_INFO_MAY_SLEEP,
 	.tables         = {
 		{
 			.n_entries = 16,

drivers/net/netdevsim/udp_tunnels.c

@@ -112,12 +112,10 @@ nsim_udp_tunnels_info_reset_write(struct file *file, const char __user *data,
 	struct net_device *dev = file->private_data;
 	struct netdevsim *ns = netdev_priv(dev);
 
-	rtnl_lock();
 	if (dev->reg_state == NETREG_REGISTERED) {
 		memset(ns->udp_ports.ports, 0, sizeof(ns->udp_ports.__ports));
 		udp_tunnel_nic_reset_ntf(dev);
 	}
-	rtnl_unlock();
 
 	return count;
 }
@@ -181,8 +179,6 @@ int nsim_udp_tunnels_info_create(struct nsim_dev *nsim_dev,
 		info->sync_table = NULL;
 	}
 
-	if (ns->udp_ports.sleep)
-		info->flags |= UDP_TUNNEL_NIC_INFO_MAY_SLEEP;
 	if (nsim_dev->udp_ports.open_only)
 		info->flags |= UDP_TUNNEL_NIC_INFO_OPEN_ONLY;
 	if (nsim_dev->udp_ports.ipv4_only)

include/net/udp_tunnel.h

@@ -130,22 +130,6 @@ void udp_tunnel_drop_rx_port(struct net_device *dev, struct socket *sock,
 void udp_tunnel_notify_add_rx_port(struct socket *sock, unsigned short type);
 void udp_tunnel_notify_del_rx_port(struct socket *sock, unsigned short type);
 
-static inline void udp_tunnel_get_rx_info(struct net_device *dev)
-{
-	ASSERT_RTNL();
-	if (!(dev->features & NETIF_F_RX_UDP_TUNNEL_PORT))
-		return;
-	call_netdevice_notifiers(NETDEV_UDP_TUNNEL_PUSH_INFO, dev);
-}
-
-static inline void udp_tunnel_drop_rx_info(struct net_device *dev)
-{
-	ASSERT_RTNL();
-	if (!(dev->features & NETIF_F_RX_UDP_TUNNEL_PORT))
-		return;
-	call_netdevice_notifiers(NETDEV_UDP_TUNNEL_DROP_INFO, dev);
-}
-
 /* Transmit the skb using UDP encapsulation. */
 void udp_tunnel_xmit_skb(struct rtable *rt, struct sock *sk, struct sk_buff *skb,
 			 __be32 src, __be32 dst, __u8 tos, __u8 ttl,
@@ -222,19 +206,17 @@ static inline void udp_tunnel_encap_enable(struct sock *sk)
 #define UDP_TUNNEL_NIC_MAX_TABLES	4
 
 enum udp_tunnel_nic_info_flags {
-	/* Device callbacks may sleep */
-	UDP_TUNNEL_NIC_INFO_MAY_SLEEP	= BIT(0),
 	/* Device only supports offloads when it's open, all ports
 	 * will be removed before close and re-added after open.
 	 */
-	UDP_TUNNEL_NIC_INFO_OPEN_ONLY	= BIT(1),
+	UDP_TUNNEL_NIC_INFO_OPEN_ONLY	= BIT(0),
 	/* Device supports only IPv4 tunnels */
-	UDP_TUNNEL_NIC_INFO_IPV4_ONLY	= BIT(2),
+	UDP_TUNNEL_NIC_INFO_IPV4_ONLY	= BIT(1),
 	/* Device has hard-coded the IANA VXLAN port (4789) as VXLAN.
 	 * This port must not be counted towards n_entries of any table.
 	 * Driver will not receive any callback associated with port 4789.
 	 */
-	UDP_TUNNEL_NIC_INFO_STATIC_IANA_VXLAN	= BIT(3),
+	UDP_TUNNEL_NIC_INFO_STATIC_IANA_VXLAN	= BIT(2),
 };
 
 struct udp_tunnel_nic;
@@ -325,6 +307,9 @@ struct udp_tunnel_nic_ops {
 	size_t (*dump_size)(struct net_device *dev, unsigned int table);
 	int (*dump_write)(struct net_device *dev, unsigned int table,
 			  struct sk_buff *skb);
+	void (*assert_locked)(struct net_device *dev);
+	void (*lock)(struct net_device *dev);
+	void (*unlock)(struct net_device *dev);
 };
 
 #ifdef CONFIG_INET
@@ -353,8 +338,29 @@ static inline void
 udp_tunnel_nic_set_port_priv(struct net_device *dev, unsigned int table,
 			     unsigned int idx, u8 priv)
 {
-	if (udp_tunnel_nic_ops)
+	if (udp_tunnel_nic_ops) {
+		udp_tunnel_nic_ops->lock(dev);
 		udp_tunnel_nic_ops->set_port_priv(dev, table, idx, priv);
+		udp_tunnel_nic_ops->unlock(dev);
+	}
+}
+
+static inline void udp_tunnel_nic_assert_locked(struct net_device *dev)
+{
+	if (udp_tunnel_nic_ops)
+		udp_tunnel_nic_ops->assert_locked(dev);
+}
+
+static inline void udp_tunnel_nic_lock(struct net_device *dev)
+{
+	if (udp_tunnel_nic_ops)
+		udp_tunnel_nic_ops->lock(dev);
+}
+
+static inline void udp_tunnel_nic_unlock(struct net_device *dev)
+{
+	if (udp_tunnel_nic_ops)
+		udp_tunnel_nic_ops->unlock(dev);
 }
 
 static inline void
@@ -396,17 +402,50 @@ static inline void udp_tunnel_nic_reset_ntf(struct net_device *dev)
 static inline size_t
 udp_tunnel_nic_dump_size(struct net_device *dev, unsigned int table)
 {
+	size_t ret;
+
 	if (!udp_tunnel_nic_ops)
 		return 0;
-	return udp_tunnel_nic_ops->dump_size(dev, table);
+
+	udp_tunnel_nic_ops->lock(dev);
+	ret = udp_tunnel_nic_ops->dump_size(dev, table);
+	udp_tunnel_nic_ops->unlock(dev);
+
+	return ret;
 }
 
 static inline int
 udp_tunnel_nic_dump_write(struct net_device *dev, unsigned int table,
 			  struct sk_buff *skb)
 {
+	int ret;
+
 	if (!udp_tunnel_nic_ops)
 		return 0;
-	return udp_tunnel_nic_ops->dump_write(dev, table, skb);
+
+	udp_tunnel_nic_ops->lock(dev);
+	ret = udp_tunnel_nic_ops->dump_write(dev, table, skb);
+	udp_tunnel_nic_ops->unlock(dev);
+
+	return ret;
 }
+
+static inline void udp_tunnel_get_rx_info(struct net_device *dev)
+{
+	ASSERT_RTNL();
+	if (!(dev->features & NETIF_F_RX_UDP_TUNNEL_PORT))
+		return;
+	udp_tunnel_nic_assert_locked(dev);
+	call_netdevice_notifiers(NETDEV_UDP_TUNNEL_PUSH_INFO, dev);
+}
+
+static inline void udp_tunnel_drop_rx_info(struct net_device *dev)
+{
+	ASSERT_RTNL();
+	if (!(dev->features & NETIF_F_RX_UDP_TUNNEL_PORT))
+		return;
+	udp_tunnel_nic_assert_locked(dev);
+	call_netdevice_notifiers(NETDEV_UDP_TUNNEL_DROP_INFO, dev);
+}
+
 #endif

net/core/dev.c

@@ -10771,12 +10771,14 @@ sync_lower:
 			 * *before* calling udp_tunnel_get_rx_info,
 			 * but *after* calling udp_tunnel_drop_rx_info.
 			 */
+			udp_tunnel_nic_lock(dev);
 			if (features & NETIF_F_RX_UDP_TUNNEL_PORT) {
 				dev->features = features;
 				udp_tunnel_get_rx_info(dev);
 			} else {
 				udp_tunnel_drop_rx_info(dev);
 			}
+			udp_tunnel_nic_unlock(dev);
 		}
 
 		if (diff & NETIF_F_HW_VLAN_CTAG_FILTER) {

net/ipv4/udp_tunnel_core.c

@@ -134,15 +134,17 @@ void udp_tunnel_notify_add_rx_port(struct socket *sock, unsigned short type)
 	struct udp_tunnel_info ti;
 	struct net_device *dev;
 
+	ASSERT_RTNL();
+
 	ti.type = type;
 	ti.sa_family = sk->sk_family;
 	ti.port = inet_sk(sk)->inet_sport;
 
-	rcu_read_lock();
+	for_each_netdev(net, dev) {
-	for_each_netdev_rcu(net, dev) {
+		udp_tunnel_nic_lock(dev);
 		udp_tunnel_nic_add_port(dev, &ti);
+		udp_tunnel_nic_unlock(dev);
 	}
-	rcu_read_unlock();
 }
 EXPORT_SYMBOL_GPL(udp_tunnel_notify_add_rx_port);
 
@@ -154,15 +156,17 @@ void udp_tunnel_notify_del_rx_port(struct socket *sock, unsigned short type)
 	struct udp_tunnel_info ti;
 	struct net_device *dev;
 
+	ASSERT_RTNL();
+
 	ti.type = type;
 	ti.sa_family = sk->sk_family;
 	ti.port = inet_sk(sk)->inet_sport;
 
-	rcu_read_lock();
+	for_each_netdev(net, dev) {
-	for_each_netdev_rcu(net, dev) {
+		udp_tunnel_nic_lock(dev);
 		udp_tunnel_nic_del_port(dev, &ti);
+		udp_tunnel_nic_unlock(dev);
 	}
-	rcu_read_unlock();
 }
 EXPORT_SYMBOL_GPL(udp_tunnel_notify_del_rx_port);
 

net/ipv4/udp_tunnel_nic.c

@@ -29,6 +29,7 @@ struct udp_tunnel_nic_table_entry {
  * struct udp_tunnel_nic - UDP tunnel port offload state
  * @work:	async work for talking to hardware from process context
  * @dev:	netdev pointer
+ * @lock:	protects all fields
  * @need_sync:	at least one port start changed
  * @need_replay: space was freed, we need a replay of all ports
  * @work_pending: @work is currently scheduled
@@ -41,6 +42,8 @@ struct udp_tunnel_nic {
 
 	struct net_device *dev;
 
+	struct mutex lock;
+
 	u8 need_sync:1;
 	u8 need_replay:1;
 	u8 work_pending:1;
@@ -298,22 +301,11 @@ __udp_tunnel_nic_device_sync(struct net_device *dev, struct udp_tunnel_nic *utn)
 static void
 udp_tunnel_nic_device_sync(struct net_device *dev, struct udp_tunnel_nic *utn)
 {
-	const struct udp_tunnel_nic_info *info = dev->udp_tunnel_nic_info;
-	bool may_sleep;
-
 	if (!utn->need_sync)
 		return;
 
-	/* Drivers which sleep in the callback need to update from
+	queue_work(udp_tunnel_nic_workqueue, &utn->work);
-	 * the workqueue, if we come from the tunnel driver's notification.
+	utn->work_pending = 1;
-	 */
-	may_sleep = info->flags & UDP_TUNNEL_NIC_INFO_MAY_SLEEP;
-	if (!may_sleep)
-		__udp_tunnel_nic_device_sync(dev, utn);
-	if (may_sleep || utn->need_replay) {
-		queue_work(udp_tunnel_nic_workqueue, &utn->work);
-		utn->work_pending = 1;
-	}
 }
 
 static bool
@@ -554,12 +546,12 @@ static void __udp_tunnel_nic_reset_ntf(struct net_device *dev)
 	struct udp_tunnel_nic *utn;
 	unsigned int i, j;
 
-	ASSERT_RTNL();
-
 	utn = dev->udp_tunnel_nic;
 	if (!utn)
 		return;
 
+	mutex_lock(&utn->lock);
+
 	utn->need_sync = false;
 	for (i = 0; i < utn->n_tables; i++)
 		for (j = 0; j < info->tables[i].n_entries; j++) {
@@ -569,7 +561,7 @@ static void __udp_tunnel_nic_reset_ntf(struct net_device *dev)
 
 			entry->flags &= ~(UDP_TUNNEL_NIC_ENTRY_DEL |
 					  UDP_TUNNEL_NIC_ENTRY_OP_FAIL);
-			/* We don't release rtnl across ops */
+			/* We don't release utn lock across ops */
 			WARN_ON(entry->flags & UDP_TUNNEL_NIC_ENTRY_FROZEN);
 			if (!entry->use_cnt)
 				continue;
@@ -579,6 +571,8 @@ static void __udp_tunnel_nic_reset_ntf(struct net_device *dev)
 		}
 
 	__udp_tunnel_nic_device_sync(dev, utn);
+
+	mutex_unlock(&utn->lock);
 }
 
 static size_t
@@ -643,6 +637,33 @@ err_cancel:
 	return -EMSGSIZE;
 }
 
+static void __udp_tunnel_nic_assert_locked(struct net_device *dev)
+{
+	struct udp_tunnel_nic *utn;
+
+	utn = dev->udp_tunnel_nic;
+	if (utn)
+		lockdep_assert_held(&utn->lock);
+}
+
+static void __udp_tunnel_nic_lock(struct net_device *dev)
+{
+	struct udp_tunnel_nic *utn;
+
+	utn = dev->udp_tunnel_nic;
+	if (utn)
+		mutex_lock(&utn->lock);
+}
+
+static void __udp_tunnel_nic_unlock(struct net_device *dev)
+{
+	struct udp_tunnel_nic *utn;
+
+	utn = dev->udp_tunnel_nic;
+	if (utn)
+		mutex_unlock(&utn->lock);
+}
+
 static const struct udp_tunnel_nic_ops __udp_tunnel_nic_ops = {
 	.get_port	= __udp_tunnel_nic_get_port,
 	.set_port_priv	= __udp_tunnel_nic_set_port_priv,
@@ -651,6 +672,9 @@ static const struct udp_tunnel_nic_ops __udp_tunnel_nic_ops = {
 	.reset_ntf	= __udp_tunnel_nic_reset_ntf,
 	.dump_size	= __udp_tunnel_nic_dump_size,
 	.dump_write	= __udp_tunnel_nic_dump_write,
+	.assert_locked	= __udp_tunnel_nic_assert_locked,
+	.lock		= __udp_tunnel_nic_lock,
+	.unlock		= __udp_tunnel_nic_unlock,
 };
 
 static void
@@ -710,11 +734,15 @@ static void udp_tunnel_nic_device_sync_work(struct work_struct *work)
 		container_of(work, struct udp_tunnel_nic, work);
 
 	rtnl_lock();
+	mutex_lock(&utn->lock);
+
 	utn->work_pending = 0;
 	__udp_tunnel_nic_device_sync(utn->dev, utn);
 
 	if (utn->need_replay)
 		udp_tunnel_nic_replay(utn->dev, utn);
+
+	mutex_unlock(&utn->lock);
 	rtnl_unlock();
 }
 
@@ -730,6 +758,7 @@ udp_tunnel_nic_alloc(const struct udp_tunnel_nic_info *info,
 		return NULL;
 	utn->n_tables = n_tables;
 	INIT_WORK(&utn->work, udp_tunnel_nic_device_sync_work);
+	mutex_init(&utn->lock);
 
 	for (i = 0; i < n_tables; i++) {
 		utn->entries[i] = kcalloc(info->tables[i].n_entries,
@@ -821,8 +850,11 @@ static int udp_tunnel_nic_register(struct net_device *dev)
 	dev_hold(dev);
 	dev->udp_tunnel_nic = utn;
 
-	if (!(info->flags & UDP_TUNNEL_NIC_INFO_OPEN_ONLY))
+	if (!(info->flags & UDP_TUNNEL_NIC_INFO_OPEN_ONLY)) {
+		udp_tunnel_nic_lock(dev);
 		udp_tunnel_get_rx_info(dev);
+		udp_tunnel_nic_unlock(dev);
+	}
 
 	return 0;
 }
@@ -832,6 +864,8 @@ udp_tunnel_nic_unregister(struct net_device *dev, struct udp_tunnel_nic *utn)
 {
 	const struct udp_tunnel_nic_info *info = dev->udp_tunnel_nic_info;
 
+	udp_tunnel_nic_lock(dev);
+
 	/* For a shared table remove this dev from the list of sharing devices
 	 * and if there are other devices just detach.
 	 */
@@ -841,8 +875,10 @@ udp_tunnel_nic_unregister(struct net_device *dev, struct udp_tunnel_nic *utn)
 		list_for_each_entry(node, &info->shared->devices, list)
 			if (node->dev == dev)
 				break;
-		if (list_entry_is_head(node, &info->shared->devices, list))
+		if (list_entry_is_head(node, &info->shared->devices, list)) {
+			udp_tunnel_nic_unlock(dev);
 			return;
+		}
 
 		list_del(&node->list);
 		kfree(node);
@@ -852,6 +888,7 @@ udp_tunnel_nic_unregister(struct net_device *dev, struct udp_tunnel_nic *utn)
 		if (first) {
 			udp_tunnel_drop_rx_info(dev);
 			utn->dev = first->dev;
+			udp_tunnel_nic_unlock(dev);
 			goto release_dev;
 		}
 
@@ -862,6 +899,7 @@ udp_tunnel_nic_unregister(struct net_device *dev, struct udp_tunnel_nic *utn)
 	 * from the work which we will boot immediately.
 	 */
 	udp_tunnel_nic_flush(dev, utn);
+	udp_tunnel_nic_unlock(dev);
 
 	/* Wait for the work to be done using the state, netdev core will
 	 * retry unregister until we give up our reference on this device.
@@ -910,12 +948,16 @@ udp_tunnel_nic_netdevice_event(struct notifier_block *unused,
 		return NOTIFY_DONE;
 
 	if (event == NETDEV_UP) {
+		udp_tunnel_nic_lock(dev);
 		WARN_ON(!udp_tunnel_nic_is_empty(dev, utn));
 		udp_tunnel_get_rx_info(dev);
+		udp_tunnel_nic_unlock(dev);
 		return NOTIFY_OK;
 	}
 	if (event == NETDEV_GOING_DOWN) {
+		udp_tunnel_nic_lock(dev);
 		udp_tunnel_nic_flush(dev, utn);
+		udp_tunnel_nic_unlock(dev);
 		return NOTIFY_OK;
 	}