From: Eric Lammerts <eric@lammerts.org>
To: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Marc Ballarin <Ballarin.Marc@gmx.de>, Greg KH <greg@kroah.com>,
albert@users.sourceforge.net,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: dynamic /dev security hole?
Date: Mon, 9 Aug 2004 12:17:10 -0400 (EDT) [thread overview]
Message-ID: <Pine.LNX.4.58.0408091203160.8353@vivaldi.madbase.net> (raw)
In-Reply-To: <1092062974.14153.26.camel@localhost.localdomain>
On Mon, 9 Aug 2004, Alan Cox wrote:
> On Llu, 2004-08-09 at 05:40, Eric Lammerts wrote:
> > Just an idea for a fix for this problem: If udev would change the
> > permissions to 000 and ownership to root.root just before it unlinks
> > the device node, the copy would become useless.
>
> Unfortunately not the whole story. The permissions are checked at open
> time not on read/write/ioctl so once I have the device opened you
> lose.
It's only meant as a fix for the hardlink trick, not against the open
file descriptor trick. About the latter, if someone still has the
device opened, how can it go away? And if it doesn't go away, how can
udev create a new node with the same major/minor?
Eric
next prev parent reply other threads:[~2004-08-09 16:17 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-08-08 12:47 Albert Cahalan
2004-08-08 15:58 ` Marc Ballarin
2004-08-08 15:04 ` Albert Cahalan
2004-08-08 20:42 ` Greg KH
2004-08-08 16:21 ` Greg KH
2004-08-08 21:43 ` Marc Ballarin
2004-08-08 22:07 ` Marc Ballarin
2004-08-09 4:40 ` Eric Lammerts
2004-08-09 13:30 ` Michael Buesch
2004-08-09 13:19 ` Albert Cahalan
2004-08-09 16:54 ` Michael Buesch
2004-08-09 17:04 ` Eric Lammerts
2004-08-09 17:14 ` Michael Buesch
2004-08-10 0:21 ` Greg KH
2004-08-11 17:12 ` [RFC, PATCH] sys_revoke(), just a try. (was: Re: dynamic /dev security hole?) Michael Buesch
2004-08-12 16:49 ` Michael Buesch
2004-08-12 19:51 ` Alan Cox
2004-08-12 19:39 ` Albert Cahalan
2004-08-13 12:39 ` Michael Buesch
2004-08-09 14:49 ` dynamic /dev security hole? Alan Cox
2004-08-09 16:17 ` Eric Lammerts [this message]
2004-08-09 15:33 ` Alan Cox
2004-08-09 16:47 ` Eric Lammerts
2004-08-09 17:54 ` Alan Cox
2004-08-10 0:21 ` Greg KH
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