Re: [PATCH ghak90 V6 09/10] audit: add support for containerid to network namespaces

[Richard Guy Briggs]

On 2019-05-29 18:17, Paul Moore wrote:
> On Mon, Apr 8, 2019 at 11:41 PM Richard Guy Briggs <rgb@xxxxxxxxxx> wrote:
> >
> > Audit events could happen in a network namespace outside of a task
> > context due to packets received from the net that trigger an auditing
> > rule prior to being associated with a running task.  The network
> > namespace could be in use by multiple containers by association to the
> > tasks in that network namespace.  We still want a way to attribute
> > these events to any potential containers.  Keep a list per network
> > namespace to track these audit container identifiiers.
> >
> > Add/increment the audit container identifier on:
> > - initial setting of the audit container identifier via /proc
> > - clone/fork call that inherits an audit container identifier
> > - unshare call that inherits an audit container identifier
> > - setns call that inherits an audit container identifier
> > Delete/decrement the audit container identifier on:
> > - an inherited audit container identifier dropped when child set
> > - process exit
> > - unshare call that drops a net namespace
> > - setns call that drops a net namespace
> >
> > Please see the github audit kernel issue for contid net support:
> >   https://github.com/linux-audit/audit-kernel/issues/92
> > Please see the github audit testsuiite issue for the test case:
> >   https://github.com/linux-audit/audit-testsuite/issues/64
> > Please see the github audit wiki for the feature overview:
> >   https://github.com/linux-audit/audit-kernel/wiki/RFE-Audit-Container-ID
> > Signed-off-by: Richard Guy Briggs <rgb@xxxxxxxxxx>
> > Acked-by: Neil Horman <nhorman@xxxxxxxxxxxxx>
> > Reviewed-by: Ondrej Mosnacek <omosnace@xxxxxxxxxx>
> > ---
> >  include/linux/audit.h | 19 +++++++++++
> >  kernel/audit.c        | 88 +++++++++++++++++++++++++++++++++++++++++++++++++--
> >  kernel/nsproxy.c      |  4 +++
> >  3 files changed, 108 insertions(+), 3 deletions(-)
> 
> ...
> 
> > diff --git a/kernel/audit.c b/kernel/audit.c
> > index 6c742da66b32..996213591617 100644
> > --- a/kernel/audit.c
> > +++ b/kernel/audit.c
> > @@ -376,6 +384,75 @@ static struct sock *audit_get_sk(const struct net *net)
> >         return aunet->sk;
> >  }
> >
> > +void audit_netns_contid_add(struct net *net, u64 contid)
> > +{
> > +       struct audit_net *aunet;
> > +       struct list_head *contid_list;
> > +       struct audit_contid *cont;
> > +
> > +       if (!net)
> > +               return;
> > +       if (!audit_contid_valid(contid))
> > +               return;
> > +       aunet = net_generic(net, audit_net_id);
> > +       if (!aunet)
> > +               return;
> > +       contid_list = &aunet->contid_list;
> > +       spin_lock(&aunet->contid_list_lock);
> > +       list_for_each_entry_rcu(cont, contid_list, list)
> > +               if (cont->id == contid) {
> > +                       refcount_inc(&cont->refcount);
> > +                       goto out;
> > +               }
> > +       cont = kmalloc(sizeof(struct audit_contid), GFP_ATOMIC);
> > +       if (cont) {
> > +               INIT_LIST_HEAD(&cont->list);
> 
> I thought you were going to get rid of this INIT_LIST_HEAD() call?

I was intending to, and then Neil weighed in with this opinion:

	https://www.redhat.com/archives/linux-audit/2019-April/msg00014.html

If you feel that isn't important, please remove it.

> > +               cont->id = contid;
> > +               refcount_set(&cont->refcount, 1);
> > +               list_add_rcu(&cont->list, contid_list);
> > +       }
> > +out:
> > +       spin_unlock(&aunet->contid_list_lock);
> > +}
> 
> --
> paul moore
> www.paul-moore.com

- RGB

--
Richard Guy Briggs <rgb@xxxxxxxxxx>
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