bonding: Don't allow bond devices to change network namespaces.

Like bridge, bonding as netdevice doesn't cross netns boundaries.

Bonding ports and bonding itself live in same netns.

Signed-off-by: Weilong Chen <chenweilong@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/bonding/bond_main.c b/drivers/net/bonding/bond_main.c
index 4a8ccce..f9e0c8b 100644
--- a/drivers/net/bonding/bond_main.c
+++ b/drivers/net/bonding/bond_main.c
@@ -3884,6 +3884,9 @@
 	 * capable
 	 */
 
+	/* Don't allow bond devices to change network namespaces. */
+	bond_dev->features |= NETIF_F_NETNS_LOCAL;
+
 	bond_dev->hw_features = BOND_VLAN_FEATURES |
 				NETIF_F_HW_VLAN_CTAG_TX |
 				NETIF_F_HW_VLAN_CTAG_RX |