From: Pavel Machek <pavel@ucw.cz>
To: Casey Schaufler <casey@schaufler-ca.com>
Cc: David Wagner <daw-news@cs.berkeley.edu>, linux-kernel@vger.kernel.org
Subject: Re: symlinks with permissions
Date: Fri, 30 Oct 2009 15:07:45 +0100 [thread overview]
Message-ID: <20091030140745.GC1481@ucw.cz> (raw)
In-Reply-To: <4AE91658.9090105@schaufler-ca.com>
Hi!
> > Perhaps take a look at Pavel's post describing the attack again?
>
> Yeah, I did that. It still looks like the complaint is that
> /proc/8675309/fd/3 gives you the ability to gain RW access to
> an object for which you have RW access.
>
> Look, with hard links and the various mount options available
> today you just can't count on setting the mode on a directory
> to completely protect the files that it references. Look carefully
Look again. I can count on paths if I can prevent mounts and
hardlinks. Mounts are irrelevant as they are root-only, and I was
checking for hardlinks.
> Now, ask me if I think that /proc/8675309/fd/3 is a good idea,
> and we'll have a different discussion, but from an old school
Cool, so we actually agree, and can drop this thread?
Pavel
--
(english) http://www.livejournal.com/~pavelmachek
(cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html
next prev parent reply other threads:[~2009-10-30 14:07 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-10-25 6:29 symlinks with permissions Pavel Machek
2009-10-26 16:31 ` Jan Kara
2009-10-26 16:57 ` Serge E. Hallyn
2009-10-26 17:36 ` J. Bruce Fields
2009-10-26 17:46 ` Jan Kara
2009-10-26 17:57 ` Trond Myklebust
2009-10-25 9:36 ` Pavel Machek
2009-10-26 18:22 ` Trond Myklebust
2009-10-27 8:11 ` Pavel Machek
2009-10-27 10:27 ` Jamie Lokier
2009-10-26 18:35 ` J. Bruce Fields
2009-10-28 4:15 ` Eric W. Biederman
2009-10-28 8:16 ` Pavel Machek
2009-10-28 11:25 ` Eric W. Biederman
2009-10-28 21:03 ` Pavel Machek
2009-10-29 2:20 ` Eric W. Biederman
2009-10-29 11:03 ` Pavel Machek
2009-10-29 16:23 ` Eric W. Biederman
2009-10-30 18:35 ` Pavel Machek
2009-10-30 20:37 ` Nick Bowler
2009-10-30 23:03 ` Eric W. Biederman
2009-10-31 2:30 ` Jamie Lokier
2009-10-28 16:34 ` Casey Schaufler
2009-10-28 19:44 ` Jamie Lokier
2009-10-28 21:06 ` Pavel Machek
2009-10-28 22:48 ` David Wagner
2009-10-29 4:13 ` Casey Schaufler
2009-10-29 7:53 ` David Wagner
2009-10-30 14:07 ` Pavel Machek [this message]
2009-10-31 4:09 ` Casey Schaufler
2009-11-01 9:23 ` David Wagner
2009-11-01 17:43 ` Casey Schaufler
2009-11-01 20:39 ` David Wagner
2009-11-01 22:05 ` Casey Schaufler
2009-10-26 18:02 ` J. Bruce Fields
2009-10-26 17:57 ` Serge E. Hallyn
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