linux-kernel - Re: [rfc] fcntl: Add F_GETOWNER

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20120327223420.GB9669@moon>
Date:	Wed, 28 Mar 2012 02:34:20 +0400
From:	Cyrill Gorcunov <gorcunov@...nvz.org>
To:	"Serge E. Hallyn" <serge@...lyn.com>
Cc:	Oleg Nesterov <oleg@...hat.com>,
	LKML <linux-kernel@...r.kernel.org>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Pavel Emelyanov <xemul@...allels.com>,
	"Eric W. Biederman" <ebiederm@...ssion.com>,
	"Serge E. Hallyn" <serge.hallyn@...onical.com>
Subject: Re: [rfc] fcntl: Add F_GETOWNER_UIDS option

On Tue, Mar 27, 2012 at 10:29:23PM +0000, Serge E. Hallyn wrote:
> Quoting Cyrill Gorcunov (gorcunov@...nvz.org):
> > On Tue, Mar 27, 2012 at 05:25:34PM +0200, Oleg Nesterov wrote:
> > > user_ns_map_uid() should translate uid_t from one namespace to another,
> > > in this case the namespace is the same.
> > > 
> > > user_ns_map_uid(cred->user_ns, cred) must be the identical mapping,
> > > no matter how we change the implementation.
> > > 
> > > What I think you need is
> > > user_ns_map_uid(current_user_ns(), filp->f_owner.cred), the only
> > > problem is that f_owner.cred doesn't exist.
> > > 
> > 
> > Hmm, I was confused by likely() in user_ns_map_uid. But indeed, I think
> > you're so right. Is there some reason why we can't carry f_owner.cred
> > pointer?
> 
> We would need that for this, yes.  However, Eric is working on a new
> patchset which changes the cross-userns uid mappings.  I think it's
> worth simply leaving a comment that this will need to be addressed,
> and leave in the unconverted uid.

Hi Serge, thanks for info. But if it will be unconverted uid, can't
be there some security problem with that which I missed?

	Cyrill
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/