Permission checks are done when you open[1] a file, not when you otherwise operate on it. So yes, you could access "unauthorized" files. It's up to the sending

Permission checks are done when you open[1] a file, not when you otherwise operate on it. So yes, you could access "unauthorized" files. It's up to the sending process whether it wants to share particular filedescriptor to someone else, so you can't gain access to something you're not supposed to though. [1] I'm not sure about security frameworks, it may be e.g. SELinux provides more granular checks.