This crash seems to be caused by bad race in ClassLoaderDataGraph::add_to_graph().
ClassLoaderData* cld = new ClassLoaderData(loader, is_anonymous);
if (!is_anonymous) {
// First, Atomically set it
ClassLoaderData* old = java_lang_ClassLoader::cmpxchg_loader_data(cld, loader(), NULL);
if (old != NULL) {
delete cld;
// Returns the data.
return old;
}
}
unnamed_module entry is set to java_lang_module in ClassLoaderData constructor, if it loses race, the class_loader_data is deleted, that leaves java_lang_module points to stalled module_entry.