X-Git-Url: http://git.cascardo.info/?a=blobdiff_plain;f=kernel%2Fuser_namespace.c;h=86b7854fec8ee0df88e3bf7d499859993915b8c0;hb=2eee010d092903ee95716b6c2fbd9d3289839aa4;hp=f2c5ba5505f14cac479d0f0658ed71d472f042b3;hpb=df75e7748bae1c7098bfa358485389b897f71305;p=cascardo%2Flinux.git

diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c
index f2c5ba5505f1..86b7854fec8e 100644
--- a/kernel/user_namespace.c
+++ b/kernel/user_namespace.c
@@ -1050,12 +1050,37 @@ static int userns_install(struct nsproxy *nsproxy, struct ns_common *ns)
 	return commit_creds(cred);
 }
 
+struct ns_common *ns_get_owner(struct ns_common *ns)
+{
+	struct user_namespace *my_user_ns = current_user_ns();
+	struct user_namespace *owner, *p;
+
+	/* See if the owner is in the current user namespace */
+	owner = p = ns->ops->owner(ns);
+	for (;;) {
+		if (!p)
+			return ERR_PTR(-EPERM);
+		if (p == my_user_ns)
+			break;
+		p = p->parent;
+	}
+
+	return &get_user_ns(owner)->ns;
+}
+
+static struct user_namespace *userns_owner(struct ns_common *ns)
+{
+	return to_user_ns(ns)->parent;
+}
+
 const struct proc_ns_operations userns_operations = {
 	.name		= "user",
 	.type		= CLONE_NEWUSER,
 	.get		= userns_get,
 	.put		= userns_put,
 	.install	= userns_install,
+	.owner		= userns_owner,
+	.get_parent	= ns_get_owner,
 };
 
 static __init int user_namespaces_init(void)