linux-kernel - Re: [RFC][PATCH 2/4] sunrpc: Use utsnamespaces

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: <20090107002024.GJ13785@fieldses.org>
Date:	Tue, 6 Jan 2009 19:20:24 -0500
From:	"J. Bruce Fields" <bfields@...ldses.org>
To:	Matt Helsley <matthltc@...ibm.com>
Cc:	Trond Myklebust <trond.myklebust@....uio.no>,
	"Serge E. Hallyn" <serue@...ibm.com>,
	Linux Containers <containers@...ts.linux-foundation.org>,
	linux-nfs@...r.kernel.org,
	Linux Kernel Mailing List <linux-kernel@...r.kernel.org>,
	Chuck Lever <chuck.lever@...cle.com>,
	"Eric W. Biederman" <ebiederm@...ssion.com>,
	Linux Containers <containers@...ts.osdl.org>,
	Cedric Le Goater <clg@...ibm.com>
Subject: Re: [RFC][PATCH 2/4] sunrpc: Use utsnamespaces

On Tue, Jan 06, 2009 at 04:08:50PM -0800, Matt Helsley wrote:
> On Tue, 2009-01-06 at 17:42 -0500, Trond Myklebust wrote:
> > On Tue, 2009-01-06 at 15:58 -0600, Serge E. Hallyn wrote:
> > 
> > > So should we use patch 2/4, plus (as someone - was it you? - suggested)
> > > using a DEFAULT instead of init_utsname()->nodename when
> > > current->utsname() == NULL?
> > 
> > No. I'm don't think that 2/4 is correct either. Basically, 2/4 is saying
> > that the container that first mounts the filesystem 'owns' it. However
> > at the same time we know that the lifetime of the filesystem is in no
> > way bounded by the lifetime of the container, and that's what gets you
> > into trouble with 'umount' in the first place.
> >
> > IMO, the current code is the most correct approach, in that it assumes
> > that the filesystems are owned by the 'init' namespace.
> 
> IMHO This seems more incorrect than trying to use a more proximal
> namespace.

If it would be possible, for example, for the 'init' namespace to have
no network interfaces at all, then it would be nicer to use a name
that's at least been used with nfs at *some* point--just on the general
principle of not leaking information to a domain that the user wouldn't
expect it to.

(Assuming it's unlikely anyone would consider init's utsname to be
sensitive information, that's a minor point.)

--b.
--
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/