From: "Serge E. Hallyn" <serge@hallyn.com>
To: Stefan Berger <stefanb@linux.vnet.ibm.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>,
"Theodore Ts'o" <tytso@mit.edu>,
"Serge E. Hallyn" <serge@hallyn.com>,
containers@lists.linux-foundation.org, lkp@01.org,
linux-kernel@vger.kernel.org, zohar@linux.vnet.ibm.com,
tycho@docker.com, James.Bottomley@HansenPartnership.com,
vgoyal@redhat.com, christian.brauner@mailbox.org,
amir73il@gmail.com, linux-security-module@vger.kernel.org,
casey@schaufler-ca.com
Subject: Re: [PATCH v2] xattr: Enable security.capability in user namespaces
Date: Fri, 14 Jul 2017 08:34:37 -0500 [thread overview]
Message-ID: <20170714133437.GA16737@mail.hallyn.com> (raw)
In-Reply-To: <65dbe654-0d99-03fa-c838-5a726b462826@linux.vnet.ibm.com>
Quoting Stefan Berger (stefanb@linux.vnet.ibm.com):
> On 07/13/2017 08:38 PM, Eric W. Biederman wrote:
> >Stefan Berger <stefanb@linux.vnet.ibm.com> writes:
> >
> >>On 07/13/2017 01:49 PM, Eric W. Biederman wrote:
> >>
> >>>My big question right now is can you implement Ted's suggested
> >>>restriction. Only one security.foo or secuirty.foo@... attribute ?
> >>We need to raw-list the xattrs and do the check before writing them. I am fairly sure this can be done.
> >>
> >>So now you want to allow security.foo and one security.foo@uid=<> or just a single one security.foo(@[[:print:]]*)?
> >>
> >The latter.
>
> That case would prevent a container user from overriding the xattr
> on the host. Is that what we want? For limiting the number of xattrs
Not really. If the file is owned by a uid mapped into the container,
then the container root can chown the file which will clear the file
capability, after which he can set a new one. If the file is not
owned by a uid mapped into the container, then container root could
not set a filecap anyway.
-serge
next prev parent reply other threads:[~2017-07-14 13:34 UTC|newest]
Thread overview: 76+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-07-11 15:05 [PATCH v2] Enable namespaced file capabilities Stefan Berger
2017-07-11 15:05 ` [PATCH v2] xattr: Enable security.capability in user namespaces Stefan Berger
2017-07-11 17:12 ` Serge E. Hallyn
2017-07-12 0:15 ` Stefan Berger
2017-07-12 0:47 ` Serge E. Hallyn
2017-07-12 3:45 ` Serge E. Hallyn
2017-07-12 11:35 ` Stefan Berger
2017-07-12 17:32 ` Serge E. Hallyn
2017-07-12 7:59 ` James Morris
2017-07-12 13:25 ` Eric W. Biederman
2017-07-12 17:03 ` Serge E. Hallyn
2017-07-12 22:20 ` James Morris
2017-07-13 0:33 ` Eric W. Biederman
2017-07-13 1:01 ` Serge E. Hallyn
2017-07-12 23:13 ` Eric W. Biederman
2017-07-13 0:43 ` Serge E. Hallyn
2017-07-13 0:44 ` Stefan Berger
2017-07-13 1:15 ` Theodore Ts'o
2017-07-13 2:34 ` Serge E. Hallyn
2017-07-13 12:11 ` Eric W. Biederman
2017-07-13 16:40 ` Theodore Ts'o
2017-07-13 17:05 ` Stefan Berger
2017-07-13 17:39 ` Eric W. Biederman
2017-07-13 19:14 ` Theodore Ts'o
2017-07-13 19:41 ` Serge E. Hallyn
2017-07-13 21:17 ` Serge E. Hallyn
2017-07-18 7:01 ` James Morris
2017-07-18 12:12 ` Stefan Berger
2017-07-18 13:26 ` Eric W. Biederman
2017-07-18 23:13 ` Serge E. Hallyn
2017-07-13 17:14 ` Eric W. Biederman
2017-07-13 17:33 ` Stefan Berger
2017-07-13 17:49 ` Eric W. Biederman
2017-07-13 19:48 ` Serge E. Hallyn
2017-07-13 21:12 ` Eric W. Biederman
[not found] ` <9a3010e5-ca2b-5e7a-656b-fcc14f7bec4e@linux.vnet.ibm.com>
2017-07-14 0:38 ` Eric W. Biederman
2017-07-14 11:32 ` Stefan Berger
2017-07-14 12:04 ` Eric W. Biederman
2017-07-14 12:39 ` Stefan Berger
2017-07-14 13:34 ` Serge E. Hallyn [this message]
2017-07-14 15:22 ` Stefan Berger
2017-07-14 17:35 ` Serge E. Hallyn
2017-07-14 18:17 ` Eric W. Biederman
2017-07-14 18:48 ` Mimi Zohar
2017-07-14 18:52 ` James Bottomley
2017-07-14 20:03 ` Mimi Zohar
2017-07-14 20:39 ` James Bottomley
2017-07-14 21:34 ` Theodore Ts'o
2017-07-14 23:22 ` Eric W. Biederman
2017-07-14 23:29 ` Mimi Zohar
2017-07-14 23:53 ` Eric W. Biederman
2017-07-14 19:29 ` Theodore Ts'o
2017-07-14 19:43 ` Mimi Zohar
[not found] ` <xagsmtp2.20170714182525.6604@vmsdvm4.vnet.ibm.com>
2017-07-14 19:26 ` Mimi Zohar
2017-07-15 0:02 ` Eric W. Biederman
[not found] ` <xagsmtp3.20170715001054.9173@uk1vsc.vnet.ibm.com>
2017-07-16 11:25 ` Mimi Zohar
2017-07-26 3:00 ` Serge E. Hallyn
2017-07-26 13:57 ` Mimi Zohar
2017-07-14 17:36 ` Eric W. Biederman
2017-07-14 19:22 ` Stefan Berger
2017-07-13 21:21 ` Serge E. Hallyn
2017-07-13 21:13 ` Serge E. Hallyn
2017-07-12 17:53 ` Vivek Goyal
2017-07-12 19:19 ` Stefan Berger
2017-07-14 23:41 ` Eric W. Biederman
2017-07-15 21:27 ` Stefan Berger
2017-07-17 18:58 ` Vivek Goyal
2017-07-17 20:50 ` Stefan Berger
2017-07-18 11:48 ` Vivek Goyal
2017-07-18 12:05 ` Stefan Berger
2017-07-18 12:30 ` Vivek Goyal
2017-07-18 12:36 ` Vivek Goyal
2017-07-18 13:29 ` Eric W. Biederman
2017-07-18 13:21 ` Stefan Berger
2017-07-18 14:57 ` Vivek Goyal
2017-07-18 16:11 ` Stefan Berger
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