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From: "Serge E. Hallyn" <serge@hallyn.com>
To: Casey Schaufler <casey@schaufler-ca.com>
Cc: Sungbae Yoo <sungbae.yoo@samsung.com>,
	"'Lukasz Pawelczyk'" <l.pawelczyk@samsung.com>,
	"'James Morris'" <james.l.morris@oracle.com>,
	"'Serge E. Hallyn'" <serge@hallyn.com>,
	linux-security-module@vger.kernel.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] Smack: replace capable() with ns_capable()
Date: Tue, 28 Jul 2015 10:06:36 -0500	[thread overview]
Message-ID: <20150728150636.GA1656@mail.hallyn.com> (raw)
In-Reply-To: <55B7936E.2080007@schaufler-ca.com>

On Tue, Jul 28, 2015 at 07:36:30AM -0700, Casey Schaufler wrote:
> On 7/26/2015 6:27 PM, Sungbae Yoo wrote:
> > So, Do you agree to allow the process to change its own labels?
> 
> No. This requires CAP_MAC_ADMIN. Smack is mandatory access control.
> Being in a namespace (as they are implemented today) is not sufficient.

"requires CAP_MAC_ADMIN" should probably read "requires
CAP_MAC_ADMIN against initial user namespace."  Any unprivileged
user can unshare a user_ns and get CAP_MAC_ADMIN.

I'm terribly sorry I'm not yet caught up on the smack-lsm thread.
But intuitively I'd think that you'd want a way for smack policy
to say "this label is allowed to create a user-ns which will be
allowed to CAP_MAC_ADMIN", so then smack_capable() can use that
information to cleanly deny CAP_MAC_ADMIN in namespaces.

-serge

  reply	other threads:[~2015-07-28 15:06 UTC|newest]

Thread overview: 8+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-07-24 11:26 [PATCH] Smack: replace capable() with ns_capable() Sungbae Yoo
2015-07-24 11:40 ` Lukasz Pawelczyk
2015-07-25 16:59   ` Casey Schaufler
2015-07-27  1:27   ` Sungbae Yoo
2015-07-27  8:52     ` Lukasz Pawelczyk
2015-07-28 14:36     ` Casey Schaufler
2015-07-28 15:06       ` Serge E. Hallyn [this message]
2015-07-28 16:11         ` Casey Schaufler

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