Debugged a fun crash today. I had some driver code that was enumerating all the child streams of a file. Because of a bug it ended up calling the code for a directory rather than a file. What I would have expected to see is that a call to ZwQueryInformationFile for the FileStreamInformation class would have returned at least one FILE_STREAM_INFORMATION structure, or an error code such as a not found. Instead it seems that the call returns STATUS_SUCCESS, and the IoStatusBlock.Information contains zero bytes returned. From what I can tell this only happens on a directory.