Date: Mon, 8 Mar 2004 11:43:05 +0100 From: Pawel Jakub Dawidek <pjd@FreeBSD.org> To: Tim Robbins <tjr@freebsd.org> Cc: freebsd-security@freebsd.org Subject: Re: Call for review: restricted hardlinks. Message-ID: <20040308104305.GJ10864@darkness.comp.waw.pl> In-Reply-To: <20040308102555.GA85110@cat.robbins.dropbear.id.au> References: <20040308093642.GI10864@darkness.comp.waw.pl> <20040308102555.GA85110@cat.robbins.dropbear.id.au>
next in thread | previous in thread | raw e-mail | index | archive | help
--acY8GN8fvSPNWryy Content-Type: text/plain; charset=iso-8859-2 Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Mar 08, 2004 at 09:25:55PM +1100, Tim Robbins wrote: +> > It adds two new sysctls: +> >=20 +> > security.bsd.hardlink_check_uid +> > security.bsd.hardlink_check_gid +> >=20 +> > If sysctl security.bsd.hardlink_check_uid is set to 1, unprivileged us= ers +> > are not permitted to create hard links to files not owned by them. +> > If sysctl security.bsd.hardlink_check_gid is set to 1, unprivileged us= ers +> > are not permitted to create hard links to files if they are not member +> > of file's group. +> >=20 +> > For now user is able to create hardlinks to any files. +>=20 +> It might be more consistent with other UNIX access checks (e.g. vaccess(= )) +> if having the same uid as the file was sufficient to link to it, +> without having to be a group member. I can't convince myself either way +> on this, but it's worth thinking about. So you need to set security.bsd.hardlink_check_uid and don't touch security.bsd.hardlink_check_gid. +> Also be aware that as a side effect of this patch, old applications that= use +> the unlink()/link()/unlink() sequence instead of the rename() system call +> may not be able to rename files they don't own. Default values for those sysctls is 0, so system behaviour will change only on administrator request. --=20 Pawel Jakub Dawidek http://www.FreeBSD.org pjd@FreeBSD.org http://garage.freebsd.pl FreeBSD committer Am I Evil? Yes, I Am! --acY8GN8fvSPNWryy Content-Type: application/pgp-signature Content-Disposition: inline -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.2.4 (FreeBSD) iD8DBQFATE45ForvXbEpPzQRAktnAKCozr3T4aVZ/YedQe3eVJLjnLjyBQCeMxXU m6uCZnHVrBYZPWqFpq4V2t8= =P19i -----END PGP SIGNATURE----- --acY8GN8fvSPNWryy--
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20040308104305.GJ10864>