Index: linux-2.6.21-rc3-mm2/mm/vmstat.c
===================================================================
--- linux-2.6.21-rc3-mm2.orig/mm/vmstat.c	2007-03-16 20:26:52.000000000 -0700
+++ linux-2.6.21-rc3-mm2/mm/vmstat.c	2007-03-16 21:37:59.000000000 -0700
@@ -627,6 +627,9 @@ static int vmstat_show(struct seq_file *
 static void vmstat_stop(struct seq_file *m, void *arg)
 {
 	kfree(m->private);
+	/* Intentionally cause memory corruption */
+	if (m->private)
+		memset(m->private, 0x44, 10);
 	m->private = NULL;
 }