3 files changed, 7 insertions, 0 deletions

diff --git a/drivers/net/vxlan.c b/drivers/net/vxlan.c
index 0346eaa6d236..19d3664ab9dd 100644
--- a/drivers/net/vxlan.c
+++ b/drivers/net/vxlan.c
@@ -339,6 +339,11 @@ static int vxlan_fdb_info(struct sk_buff *skb, struct vxlan_dev *vxlan,
         ndm->ndm_flags = fdb->flags;
         ndm->ndm_type = RTN_UNICAST;
 
+        if (!net_eq(dev_net(vxlan->dev), vxlan->net) &&
+            nla_put_s32(skb, NDA_NDM_IFINDEX_NETNSID,
+                        peernet2id(vxlan->net, dev_net(vxlan->dev))))
+                goto nla_put_failure;
+
         if (send_eth && nla_put(skb, NDA_LLADDR, ETH_ALEN, &fdb->eth_addr))
                 goto nla_put_failure;
 
diff --git a/include/uapi/linux/neighbour.h b/include/uapi/linux/neighbour.h
index f3d77f9f1e0b..38f236853cc0 100644
--- a/include/uapi/linux/neighbour.h
+++ b/include/uapi/linux/neighbour.h
@@ -25,6 +25,7 @@ enum {
         NDA_VNI,
         NDA_IFINDEX,
         NDA_MASTER,
+        NDA_NDM_IFINDEX_NETNSID,
         __NDA_MAX
 };
 
diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
index 9d1a4cac83b6..b7bde551ef76 100644
--- a/net/core/net_namespace.c
+++ b/net/core/net_namespace.c
@@ -202,6 +202,7 @@ int peernet2id(struct net *net, struct net *peer)
 
         return id >= 0 ? id : NETNSA_NSID_NOT_ASSIGNED;
 }
+EXPORT_SYMBOL(peernet2id);
 
 struct net *get_net_ns_by_id(struct net *net, int id)
 {