diff --git a/fs/namespace.c b/fs/namespace.c
index 85b5f7bea82e..88ebde39959f 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -31,6 +31,10 @@
 #include <linux/fs_context.h>
 #include <linux/shmem_fs.h>

+#ifdef CONFIG_NET_NS
+#include <net/net_namespace.h>
+#endif
+
 #include "pnode.h"
 #include "internal.h"

@@ -1013,12 +1017,25 @@ vfs_submount(const struct dentry *mountpoint, struct file_system_type *type,
 }
 EXPORT_SYMBOL_GPL(vfs_submount);

+#ifdef CONFIG_NET_NS
+static bool is_net_ns_file(struct dentry *dentry)
+{
+	/* Is this a proxy for a mount namespace? */
+	return dentry->d_op == &ns_dentry_operations &&
+	       dentry->d_fsdata == &netns_operations;
+}
+#endif
+
 static struct mount *clone_mnt(struct mount *old, struct dentry *root,
 					int flag)
 {
 	struct super_block *sb = old->mnt.mnt_sb;
 	struct mount *mnt;
 	int err;
+#ifdef CONFIG_NET_NS
+	struct ns_common *ns = NULL;
+	struct net *net = NULL;
+#endif

 	mnt = alloc_vfsmnt(old->mnt_devname);
 	if (!mnt)
@@ -1035,6 +1052,20 @@ static struct mount *clone_mnt(struct mount *old, struct dentry *root,
 			goto out_free;
 	}

+#ifdef CONFIG_NET_NS
+	if (!(flag & CL_COPY_MNT_NS_FILE) && is_net_ns_file(root)) {
+		ns = get_proc_ns(d_inode(root));
+		if (ns == NULL || ns->ops->type != CLONE_NEWNET) {
+			err = -EINVAL;
+
+			goto out_free;
+		}
+
+		net = to_net_ns(ns);
+		net = get_net(net);
+	}
+#endif
+
 	mnt->mnt.mnt_flags = old->mnt.mnt_flags;
 	mnt->mnt.mnt_flags &= ~(MNT_WRITE_HOLD|MNT_MARKED|MNT_INTERNAL);

diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h
index 854d39ef1ca3..df3fb066a002 100644
--- a/include/net/net_namespace.h
+++ b/include/net/net_namespace.h
@@ -469,4 +469,11 @@ static inline void fnhe_genid_bump(struct net *net)
 	atomic_inc(&net->fnhe_genid);
 }

+#ifdef CONFIG_NET_NS
+static inline struct net *to_net_ns(struct ns_common *ns)
+{
+	return container_of(ns, struct net, ns);
+}
+#endif
+
 #endif /* __NET_NET_NAMESPACE_H */
diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
index 757cc1d084e7..b6771c201805 100644
--- a/net/core/net_namespace.c
+++ b/net/core/net_namespace.c
@@ -1328,11 +1328,6 @@ static struct ns_common *netns_get(struct task_struct *task)
 	return net ? &net->ns : NULL;
 }

-static inline struct net *to_net_ns(struct ns_common *ns)
-{
-	return container_of(ns, struct net, ns);
-}
-
 static void netns_put(struct ns_common *ns)
 {
 	put_net(to_net_ns(ns));