From owner-freebsd-current Fri Jul 19 20:11:30 2002 Delivered-To: freebsd-current@freebsd.org Received: from mx1.FreeBSD.org (mx1.FreeBSD.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id A1C7F37B405 for ; Fri, 19 Jul 2002 20:11:27 -0700 (PDT) Received: from mailman.zeta.org.au (mailman.zeta.org.au [203.26.10.16]) by mx1.FreeBSD.org (Postfix) with ESMTP id 551ED43E6E for ; Fri, 19 Jul 2002 20:11:26 -0700 (PDT) (envelope-from bde@zeta.org.au) Received: from bde.zeta.org.au (bde.zeta.org.au [203.2.228.102]) by mailman.zeta.org.au (8.9.3/8.8.7) with ESMTP id NAA27145; Sat, 20 Jul 2002 13:11:13 +1000 Date: Sat, 20 Jul 2002 13:15:11 +1000 (EST) From: Bruce Evans X-X-Sender: bde@gamplex.bde.org To: Julian Elischer Cc: current@freebsd.org Subject: Re: [Fwd: FreeBSD/Linux kernel setgid implementation] In-Reply-To: <20020720130233.Y15254-100000@gamplex.bde.org> Message-ID: <20020720131426.T15254-100000@gamplex.bde.org> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.ORG On Fri, 19 Jul 2002, Julian Elischer wrote: > forwarded from bugtraq.. > Indeed, with their rigourous methodology, the authors did detect this error in the setgid linux manpage on Red Hat 7.2. I just wonder if they reported it (the manpage on www.linux.org is still inaccurate at the moment). > This paper also reports a real example of a program with the setgid flag only, that thinks it can drop all privileges by calling setgid(getgid()). It is OK on FreeBSD, but not on Linux... This point will have to be revisited son, since POSIX-1.2001 requires _POSIX_SAVED_IDS. I think the full brokenness of _POSIX_SAVED_IDS can be avoided using a suitably weaselish definition of "appropriate" privilege (give everyone that can do set[ug]id() appropriate privilege, so that doing it drops the extra saved [ug]id privilege). Bruce To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message