JNI global references leak when native method registration fails

[QiuYucheng2003]

Summary

Java_com_sun_jna_Native_registerMethod creates persistent JNI references before several fallible FFI initialization steps.

Affected code:

jna/native/dispatch.c

Lines 3553 to 3587 in d036ad9

	data->closure_method = (*env)->NewGlobalRef(env, closure_method);
	status = ffi_prep_cif(closure_cif, abi, argc+2, closure_rtype, data->closure_arg_types);
	if (ffi_error(env, "Native method mapping", status)) {
	goto cleanup;
	}
	status = ffi_prep_cif(&data->cif, abi, argc, rtype, data->arg_types);
	if (ffi_error(env, "Native method setup", status)) {
	goto cleanup;
	}
	closure = ffi_closure_alloc(sizeof(ffi_closure), &code);
	if (closure == NULL) {
	throwByName(env, EUnsupportedOperation, "Failed to allocate closure");
	status = FFI_BAD_ABI;
	goto cleanup;
	}
	status = ffi_prep_closure_loc(closure, closure_cif, dispatch_direct, data, code);
	if (status != FFI_OK) {
	throwByName(env, EError, "Native method linkage failed");
	goto cleanup;
	}
	{
	JNINativeMethod m = { (char*)cname, (char*)sig, code };
	(*env)->RegisterNatives(env, cls, &m, 1);
	}
	cleanup:
	if (status != FFI_OK) {
	free(data->arg_types);
	free(data->flags);
	free(data);
	data = NULL;

If ffi_prep_cif, ffi_closure_alloc, or ffi_prep_closure_loc fails, execution jumps to cleanup. That path frees data without calling DeleteGlobalRef for data->closure_method.

Because registration did not complete, Native_unregister cannot release this reference later.

Impact

Each failed registration permanently retains the reflected Java Method and potentially its class-loader object graph until JVM shutdown. Repeated failures may cause persistent memory growth.

The same cleanup path also omits some related resources, including weak global references, closure_arg_types, encoding, and an allocated FFI closure.

Suggested fix

Before freeing data on failure:

• Delete closure_method with DeleteGlobalRef.
• Delete any from_native and to_native weak global references.
• Free all allocated arrays, encoding data, and FFI closure memory.

Successful registrations should continue to transfer ownership to Native_unregister.