Re: bin/55815: tar opens device files

[Christos Zoulas <christos%zoulas.com@localhost>]

The following reply was made to PR bin/55815; it has been noted by GNATS.

From: Christos Zoulas <christos%zoulas.com@localhost>
To: gnats-bugs%netbsd.org@localhost
Cc: gnats-admin%netbsd.org@localhost,
 netbsd-bugs%netbsd.org@localhost,
 "martin%netbsd.org@localhost" <martin%NetBSD.org@localhost>
Subject: Re: bin/55815: tar opens device files
Date: Wed, 25 Nov 2020 13:20:28 -0500

 > I don't know what's available for fetching extattrs, but if that requires
 > an open, we should fix that, and make them available without opening.
 > But surely there is already a way, I can't believe that ls attempts to
 > open files, yet it shows (when asked) extattrs, right?
 
 There are methods by pathname and by fd. By pathname suffer from
 TOCTOU, so we need to do by fd. To get an fd we need open. So the
 only reasonable solution seems to be to provide an open flag that does
 not have side effects on devices.
 
 christos