Ladybird: FinalizationRegistry::cleanup() heap use-after-free via reentrant unregister()
Ladybird is a truly independent web browser. Prior to 209579c96473c75bd5eba9701fcadb841a045964, FinalizationRegistry::cleanup() in Libraries/LibJS/Runtime/FinalizationRegistry.cpp removed a dead record from m_records, retained an iterator to the next Finaliza…