--- old/src/hotspot/share/gc/parallel/psCardTable.cpp	2020-01-22 10:29:43.023694849 +0100
+++ new/src/hotspot/share/gc/parallel/psCardTable.cpp	2020-01-22 10:29:42.487686077 +0100
@@ -46,6 +46,8 @@
  protected:
   template <class T> void do_oop_work(T* p) {
     oop obj = RawAccess<>::oop_load(p);
+    assert_object_is_in_heap_or_null(p, obj);
+
     if (_young_gen->is_in_reserved(obj) &&
         !_card_table->addr_is_marked_imprecise(p)) {
       // Don't overwrite the first missing card mark
@@ -103,6 +105,8 @@
  protected:
   template <class T> void do_oop_work(T* p) {
     oop obj = RawAccess<IS_NOT_NULL>::oop_load(p);
+    assert_object_is_in_heap_or_null(p, obj);
+
     if (_young_gen->is_in_reserved(obj)) {
       assert(_card_table->addr_is_marked_precise(p), "Found unmarked precise oop");
       _card_table->set_card_newgen(p);