From: Kees Cook <kees.cook@canonical.com>
To: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Greg KH <gregkh@suse.de>, David Daney <ddaney@caviumnetworks.com>,
linux-kernel@vger.kernel.org, Eugene Teo <eugeneteo@kernel.sg>,
Ralph Campbell <infinipath@qlogic.com>,
Roland Dreier <roland@kernel.org>,
Sean Hefty <sean.hefty@intel.com>,
Hal Rosenstock <hal.rosenstock@gmail.com>,
Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>,
Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
Alexander Viro <viro@zeniv.linux.org.uk>,
Miklos Szeredi <miklos@szeredi.hu>,
"J. Bruce Fields" <bfields@fieldses.org>,
Neil Brown <neilb@suse.de>, Matthew Wilcox <matthew@wil.cx>,
James Morris <jmorris@namei.org>,
Stephen Smalley <sds@tycho.nsa.gov>,
Eric Paris <eparis@parisplace.org>,
Nick Piggin <npiggin@kernel.dk>, Arnd Bergmann <arnd@arndb.de>,
Ian Campbell <ian.campbell@citrix.com>,
Jarkko Sakkinen <ext-jarkko.2.sakkinen@nokia.com>,
Tejun Heo <tj@kernel.org>,
Casey Schaufler <casey@schaufler-ca.com>
Subject: Re: [PATCH 2/2] debugfs: only allow root access to debugging interfaces
Date: Tue, 22 Feb 2011 11:50:18 -0800 [thread overview]
Message-ID: <20110222195018.GA4000@outflux.net> (raw)
In-Reply-To: <20110222193418.773ccd4b@lxorguk.ukuu.org.uk>
On Tue, Feb 22, 2011 at 07:34:18PM +0000, Alan Cox wrote:
> > What system do you proposed to keep these "stupid mistakes" from
> > continuing to happen? If debugfs had already been mode 0700, we could have
> > avoided all of these CVEs, including the full-blown local root escalation.
>
> And all sorts of features would have put themselves in sysfs instead and
> broken no doubt.
>
> > The "no rules" approach to debugfs is not a good idea, IMO.
>
> It's a debugging fs, it needs to be "no rules" other than the obvious
> "don't mount it on production systems"
Okay, so the debugfs is not supposed to be mounted on a production system.
This seems to be news to a lot of developers trying to use the interfaces
exposed there. It would be nice to say this more loudly. Basically,
a normal system should not depend on anything in the debugfs. I can get
behind that.
> Or of course you could just chmod it 0700 in the distro !
I'm trying to, but that involves a race condition since I can't control it
during the mount (nor set the default mode like I was trying to with the
patchset). tmpfs allows "mode=", but debugfs does not...
-Kees
--
Kees Cook
Ubuntu Security Team
next prev parent reply other threads:[~2011-02-22 19:50 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-02-22 18:09 [PATCH 1/2] fs: pass root inode mode to simple_fill_super Kees Cook
2011-02-22 18:09 ` [PATCH 2/2] debugfs: only allow root access to debugging interfaces Kees Cook
2011-02-22 18:16 ` Kees Cook
2011-02-22 18:32 ` David Daney
2011-02-22 18:47 ` Kees Cook
2011-02-22 19:14 ` Greg KH
2011-02-22 19:25 ` Kees Cook
2011-02-22 19:34 ` Alan Cox
2011-02-22 19:50 ` Kees Cook [this message]
2011-02-22 19:53 ` David Daney
2011-02-22 20:16 ` Greg KH
2011-02-22 20:28 ` Kees Cook
2011-02-22 20:37 ` Greg KH
2011-02-22 20:54 ` Kees Cook
2011-02-25 0:22 ` Kees Cook
2011-02-25 0:35 ` Greg KH
2011-02-25 1:12 ` Kees Cook
2011-02-25 3:31 ` Greg KH
2011-02-25 3:39 ` Al Viro
2011-02-22 19:54 ` Kees Cook
2011-02-22 19:43 ` Greg KH
2011-02-22 19:13 ` Greg KH
2011-02-22 19:22 ` Kees Cook
2011-02-22 19:33 ` Greg KH
2011-02-22 20:29 ` Dan Carpenter
2011-02-22 20:33 ` Kees Cook
2011-02-22 20:58 ` Henrique de Moraes Holschuh
2011-02-24 16:38 ` Steven Rostedt
2011-02-24 17:34 ` Henrique de Moraes Holschuh
2011-02-26 11:50 ` Arnd Bergmann
2011-02-25 19:56 ` Greg KH
2011-02-25 20:40 ` Hugh Dickins
2011-02-25 20:57 ` Greg KH
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