Re: bin/55815: tar opens device files

[Jason Thorpe <thorpej%me.com@localhost>]

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

From: Jason Thorpe <thorpej%me.com@localhost>
To: Christos Zoulas <christos%zoulas.com@localhost>
Cc: gnats-bugs%netbsd.org@localhost,
 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: Sat, 5 Jun 2021 07:27:06 -0700

 > On Jun 5, 2021, at 7:18 AM, Christos Zoulas <christos%zoulas.com@localhost> =
 wrote:
 >=20
 >=20
 >>=20
 >> If we=E2=80=99re talking about =E2=80=9Censure the file we=E2=80=99re =
 opening is a regular file=E2=80=9D, won=E2=80=99t O_REGULAR do that you =
 want?
 >=20
 > Yes, but that suffers from TOCTOA too:
 >=20
 > if (open(path, O_REGULAR) =3D=3D -1)
 > 	fstat(path, &st);
 >=20
 > But that's probably good enough.
 
 Sorry, I was looking at your example of:
 
 	fd =3D open(...);
 	fstat(...);
 	if (device)
 		bail;
 
 What's the point if stat'ing the path if opening with O_REGULAR fails?  =
 Isn't the point here to prevent tar from opening device files?
 
 -- thorpej