--- x/kernel/nsproxy.c~	2008-07-27 17:28:21.000000000 +0400
+++ x/kernel/nsproxy.c	2008-08-21 21:17:43.000000000 +0400
@@ -225,7 +225,8 @@ void switch_task_namespaces(struct task_
 
 	ns = p->nsproxy;
 
-	rcu_assign_pointer(p->nsproxy, new);
+	if (new)
+		rcu_assign_pointer(p->nsproxy, new);
 
 	if (ns && atomic_dec_and_test(&ns->count)) {
 		/*