kernel/vm: Set CLONEABLE_AREA before cloning areas for transfer.

src/system/kernel/vm/vm.cpp

@@ -5992,6 +5992,11 @@ transfer_area(area_id id, void** _address, uint32 addressSpec, team_id target,
 	if (info.team != thread_get_current_thread()->team->id)
 		return B_PERMISSION_DENIED;
 
+	// We need to mark the area cloneable so the following operations work.
+	status = set_area_protection(id, info.protection | B_CLONEABLE_AREA);
+	if (status != B_OK)
+		return status;
+
 	area_id clonedArea = vm_clone_area(target, info.name, _address,
 		addressSpec, info.protection, REGION_NO_PRIVATE_MAP, id, kernel);
 	if (clonedArea < 0)
@@ -6003,6 +6008,9 @@ transfer_area(area_id id, void** _address, uint32 addressSpec, team_id target,
 		return status;
 	}
 
+	// Now we can reset the protection to whatever it was before.
+	set_area_protection(clonedArea, info.protection);
+
 	// TODO: The clonedArea is B_SHARED_AREA, which is not really desired.
 
 	return clonedArea;