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The (most) correct way of telling if closing a file handle is required?

Dejan_MaksimovicDejan_Maksimovic Member - All Emails Posts: 430

Sounds like a newbie question, but it is not..
After a call to APIs like ZwOpenFile/FltCreateFile/ZwCreateKey/etc., what is the most correct way to tell if I need to close a handle?
One would think it is

if(NT_SUCCESS(ntRes))
    ZwClose(hHandle);

But... I have often seen cases where this is not the way to tell if the call to the open API succeeded, as sometimes the return value is a success code, but IoStatus.Status is not, and the actual status is there. This is kinda rare, but often enough that it is not uncatchable.

So... is it:
if(NT_SUCCESS(ntRes) && NT_SUCCESS(IoStatus.Status))
or simply
if(hHandle) // kernel handles are all NULL if invalid, for the above API

?

Regards, Dejan.

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