--- a/src/hotspot/share/jfr/recorder/repository/jfrEmergencyDump.cpp	Fri Aug 31 12:41:00 2018 +0200
+++ b/src/hotspot/share/jfr/recorder/repository/jfrEmergencyDump.cpp	Fri Aug 31 07:03:46 2018 -0400
@@ -74,6 +74,10 @@
     Module_lock->unlock();
   }
 
+  if (ClassLoaderDataGraph_lock->owned_by_self()) {
+    ClassLoaderDataGraph_lock->unlock();
+  }
+
   if (Heap_lock->owned_by_self()) {
     Heap_lock->unlock();
   }