x86: don't return invalid pointers from node_to_cpumask()

Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c
index dd12c1c..df49ce8 100644
--- a/arch/x86/kernel/setup.c
+++ b/arch/x86/kernel/setup.c
@@ -350,6 +350,7 @@
 		dump_stack();
 		return &cpu_online_map;
 	}
+	BUG_ON(node >= nr_node_ids);
 	return &node_to_cpumask_map[node];
 }
 EXPORT_SYMBOL(_node_to_cpumask_ptr);
@@ -365,6 +366,7 @@
 		dump_stack();
 		return cpu_online_map;
 	}
+	BUG_ON(node >= nr_node_ids);
 	return node_to_cpumask_map[node];
 }
 EXPORT_SYMBOL(node_to_cpumask);