Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!uunet!mcsun!unido!tub!net
From: net@tub.UUCP (Oliver Laumann)
Newsgroups: comp.unix.wizards
Subject: Re: SUID directories -- security concern?
Message-ID: <1183@tub.UUCP>
Date: 20 Feb 90 09:40:18 GMT
References: <14198@s.ms.uky.edu> <12157@smoke.BRL.MIL> <2946@auspex.auspex.com> <13946@phoenix.Princeton.EDU>
Reply-To: net@tub.UUCP (Oliver Laumann)
Organization: Technical University of Berlin, Germany
Lines: 10

The set-UID bit on directories is ignored (at least in all version of UNIX
that I'm familiar with).  However, in SunOS the set-GID (GID, not UID) bit
controls the group-ID of newly created sub-directories.  If it is set, a
sub-directory inherits the parent directory's group-ID (i.e. the standard
BSD semantics), otherwise it is set to the process's current group-ID.
Sub-directories inherit the parent directory's set-GID bit (see mkdir(2)).

Regards,
--
Oliver Laumann     net@TUB.BITNET     net@tub.cs.tu-berlin.de     net@tub.UUCP