From: Richard Guy Briggs <rgb@redhat.com>
To: Paul Moore <paul@paul-moore.com>
Cc: Tycho Andersen <tycho@tycho.ws>,
containers@lists.linux-foundation.org, linux-api@vger.kernel.org,
Linux-Audit Mailing List <linux-audit@redhat.com>,
linux-fsdevel@vger.kernel.org,
LKML <linux-kernel@vger.kernel.org>,
netdev@vger.kernel.org, netfilter-devel@vger.kernel.org,
sgrubb@redhat.com, omosnace@redhat.com, dhowells@redhat.com,
simo@redhat.com, Eric Paris <eparis@parisplace.org>,
Serge Hallyn <serge@hallyn.com>,
ebiederm@xmission.com, nhorman@tuxdriver.com
Subject: Re: [PATCH ghak90 V6 02/10] audit: add container id
Date: Mon, 8 Jul 2019 13:51:05 -0400 [thread overview]
Message-ID: <20190708175105.7zb6mikjw2wmnwln@madcap2.tricolour.ca> (raw)
In-Reply-To: <CAHC9VhR4fudQanvZGYWMvCf7k2CU3q7e7n1Pi7hzC3v_zpVEdw@mail.gmail.com>
On 2019-05-29 11:29, Paul Moore wrote:
> On Wed, May 29, 2019 at 10:57 AM Tycho Andersen <tycho@tycho.ws> wrote:
> >
> > On Mon, Apr 08, 2019 at 11:39:09PM -0400, Richard Guy Briggs wrote:
> > > It is not permitted to unset the audit container identifier.
> > > A child inherits its parent's audit container identifier.
> >
> > ...
> >
> > > /**
> > > + * audit_set_contid - set current task's audit contid
> > > + * @contid: contid value
> > > + *
> > > + * Returns 0 on success, -EPERM on permission failure.
> > > + *
> > > + * Called (set) from fs/proc/base.c::proc_contid_write().
> > > + */
> > > +int audit_set_contid(struct task_struct *task, u64 contid)
> > > +{
> > > + u64 oldcontid;
> > > + int rc = 0;
> > > + struct audit_buffer *ab;
> > > + uid_t uid;
> > > + struct tty_struct *tty;
> > > + char comm[sizeof(current->comm)];
> > > +
> > > + task_lock(task);
> > > + /* Can't set if audit disabled */
> > > + if (!task->audit) {
> > > + task_unlock(task);
> > > + return -ENOPROTOOPT;
> > > + }
> > > + oldcontid = audit_get_contid(task);
> > > + read_lock(&tasklist_lock);
> > > + /* Don't allow the audit containerid to be unset */
> > > + if (!audit_contid_valid(contid))
> > > + rc = -EINVAL;
> > > + /* if we don't have caps, reject */
> > > + else if (!capable(CAP_AUDIT_CONTROL))
> > > + rc = -EPERM;
> > > + /* if task has children or is not single-threaded, deny */
> > > + else if (!list_empty(&task->children))
> > > + rc = -EBUSY;
> > > + else if (!(thread_group_leader(task) && thread_group_empty(task)))
> > > + rc = -EALREADY;
> > > + read_unlock(&tasklist_lock);
> > > + if (!rc)
> > > + task->audit->contid = contid;
> > > + task_unlock(task);
> > > +
> > > + if (!audit_enabled)
> > > + return rc;
> >
> > ...but it is allowed to change it (assuming
> > capable(CAP_AUDIT_CONTROL), of course)? Seems like this might be more
> > immediately useful since we still live in the world of majority
> > privileged containers if we didn't allow changing it, in addition to
> > un-setting it.
>
> The idea is that only container orchestrators should be able to
> set/modify the audit container ID, and since setting the audit
> container ID can have a significant effect on the records captured
> (and their routing to multiple daemons when we get there) modifying
> the audit container ID is akin to modifying the audit configuration
> which is why it is gated by CAP_AUDIT_CONTROL. The current thinking
> is that you would only change the audit container ID from one
> set/inherited value to another if you were nesting containers, in
> which case the nested container orchestrator would need to be granted
> CAP_AUDIT_CONTROL (which everyone to date seems to agree is a workable
> compromise). We did consider allowing for a chain of nested audit
> container IDs, but the implications of doing so are significant
> (implementation mess, runtime cost, etc.) so we are leaving that out
> of this effort.
We had previously discussed the idea of restricting
orchestrators/engines from only being able to set the audit container
identifier on their own descendants, but it was discarded. I've added a
check to ensure this is now enforced.
I've also added a check to ensure that a process can't set its own audit
container identifier and that if the identifier is already set, then the
orchestrator/engine must be in a descendant user namespace from the
orchestrator that set the previously inherited audit container
identifier.
> From a practical perspective, un-setting the audit container ID is
> pretty much the same as changing it from one set value to another so
> most of the above applies to that case as well.
>
> --
> paul moore
> www.paul-moore.com
- RGB
--
Richard Guy Briggs <rgb@redhat.com>
Sr. S/W Engineer, Kernel Security, Base Operating Systems
Remote, Ottawa, Red Hat Canada
IRC: rgb, SunRaycer
Voice: +1.647.777.2635, Internal: (81) 32635
next prev parent reply other threads:[~2019-07-08 17:51 UTC|newest]
Thread overview: 87+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-04-09 3:39 [PATCH ghak90 V6 00/10] audit: implement container identifier Richard Guy Briggs
2019-04-09 3:39 ` [PATCH ghak90 V6 01/10] audit: collect audit task parameters Richard Guy Briggs
2019-04-09 3:39 ` [PATCH ghak90 V6 02/10] audit: add container id Richard Guy Briggs
2019-05-29 14:57 ` Tycho Andersen
2019-05-29 15:29 ` Paul Moore
2019-05-29 15:34 ` Tycho Andersen
2019-05-29 16:03 ` Paul Moore
2019-05-29 22:28 ` Tycho Andersen
2019-05-29 22:39 ` Paul Moore
2019-05-30 17:09 ` Serge E. Hallyn
2019-05-30 19:29 ` Paul Moore
2019-05-30 21:29 ` Tycho Andersen
2019-05-30 23:26 ` Paul Moore
2019-05-31 0:20 ` Richard Guy Briggs
2019-05-31 12:44 ` Paul Moore
2019-06-03 20:24 ` Steve Grubb
2019-06-18 22:12 ` Paul Moore
2019-06-18 22:46 ` Richard Guy Briggs
2019-07-08 18:12 ` Richard Guy Briggs
2019-07-08 20:43 ` Paul Moore
2019-07-15 21:09 ` Paul Moore
2019-07-16 15:37 ` Richard Guy Briggs
2019-07-16 16:08 ` Paul Moore
2019-07-16 16:26 ` Richard Guy Briggs
2019-07-08 18:05 ` Richard Guy Briggs
2019-07-15 21:04 ` Paul Moore
2019-07-16 22:03 ` Richard Guy Briggs
2019-07-16 23:30 ` Paul Moore
2019-07-18 0:51 ` Richard Guy Briggs
2019-07-18 21:52 ` Paul Moore
2019-07-19 16:00 ` Eric W. Biederman
2019-07-20 2:19 ` James Bottomley
2019-07-19 15:32 ` Eric W. Biederman
2019-07-08 17:51 ` Richard Guy Briggs [this message]
2019-07-15 20:38 ` Paul Moore
2019-07-16 19:38 ` Richard Guy Briggs
2019-07-16 21:39 ` Paul Moore
2019-07-19 16:07 ` Eric W. Biederman
2019-04-09 3:39 ` [PATCH ghak90 V6 03/10] audit: read container ID of a process Richard Guy Briggs
2019-07-19 16:03 ` Eric W. Biederman
2019-07-19 17:05 ` Richard Guy Briggs
2019-04-09 3:39 ` [PATCH ghak90 V6 04/10] audit: log container info of syscalls Richard Guy Briggs
2019-05-29 22:15 ` Paul Moore
2019-05-30 13:08 ` Ondrej Mosnacek
2019-05-30 14:08 ` Richard Guy Briggs
2019-05-30 14:34 ` Paul Moore
2019-04-09 3:39 ` [PATCH ghak90 V6 05/10] audit: add contid support for signalling the audit daemon Richard Guy Briggs
2019-04-09 12:57 ` Ondrej Mosnacek
2019-04-09 13:40 ` Paul Moore
2019-04-09 13:48 ` Neil Horman
2019-04-09 14:00 ` Ondrej Mosnacek
2019-04-09 14:07 ` Paul Moore
2019-04-09 13:53 ` Richard Guy Briggs
2019-04-09 14:08 ` Paul Moore
2019-04-09 13:46 ` Neil Horman
2019-04-09 3:39 ` [PATCH ghak90 V6 06/10] audit: add support for non-syscall auxiliary records Richard Guy Briggs
2019-04-09 3:39 ` [PATCH ghak90 V6 07/10] audit: add containerid support for user records Richard Guy Briggs
2019-04-09 3:39 ` [PATCH ghak90 V6 08/10] audit: add containerid filtering Richard Guy Briggs
2019-05-29 22:16 ` Paul Moore
2019-05-30 14:19 ` Richard Guy Briggs
2019-05-30 14:34 ` Paul Moore
2019-05-30 20:37 ` Richard Guy Briggs
2019-05-30 20:45 ` Paul Moore
2019-05-30 21:10 ` Richard Guy Briggs
2019-04-09 3:39 ` [PATCH ghak90 V6 09/10] audit: add support for containerid to network namespaces Richard Guy Briggs
2019-05-29 22:17 ` Paul Moore
2019-05-30 14:15 ` Richard Guy Briggs
2019-05-30 14:32 ` Paul Moore
2019-04-09 3:39 ` [PATCH ghak90 V6 10/10] audit: NETFILTER_PKT: record each container ID associated with a netNS Richard Guy Briggs
2019-04-11 11:31 ` [PATCH ghak90 V6 00/10] audit: implement container identifier Richard Guy Briggs
2019-04-22 11:38 ` Neil Horman
2019-04-22 13:49 ` Paul Moore
2019-04-23 10:28 ` Neil Horman
2019-05-28 21:53 ` Daniel Walsh
2019-05-28 22:25 ` Richard Guy Briggs
2019-05-28 22:26 ` Paul Moore
2019-05-28 23:00 ` Steve Grubb
2019-05-29 0:43 ` Richard Guy Briggs
2019-05-29 12:02 ` Daniel Walsh
2019-05-29 13:17 ` Paul Moore
2019-05-29 14:07 ` Daniel Walsh
2019-05-29 14:33 ` Paul Moore
2019-05-29 13:14 ` Paul Moore
2019-05-29 22:26 ` Paul Moore
2019-05-30 13:08 ` Steve Grubb
2019-05-30 13:35 ` Paul Moore
2019-05-30 14:08 ` Richard Guy Briggs
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