Index: head/sys/sys/mbuf.h
===================================================================
--- head/sys/sys/mbuf.h
+++ head/sys/sys/mbuf.h
@@ -578,6 +578,7 @@
 	m->m_ext.ext_arg1 = arg1;
 	m->m_ext.ext_arg2 = arg2;
 	m->m_ext.ext_type = EXT_EXTREF;
+	m->m_ext.ext_flags = 0;
 }
 
 static __inline uma_zone_t