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

[Paul Moore <paul@paul-moore.com>]

On Thu, May 30, 2019 at 10:16 AM Richard Guy Briggs <rgb@redhat.com> wrote:
>
> On 2019-05-29 18:17, Paul Moore wrote:
> > On Mon, Apr 8, 2019 at 11:41 PM Richard Guy Briggs <rgb@redhat.com> 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@redhat.com>
> > > Acked-by: Neil Horman <nhorman@tuxdriver.com>
> > > Reviewed-by: Ondrej Mosnacek <omosnace@redhat.com>
> > > ---
> > >  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.

Okay, I missed/forgot that, it seems like the right thing to do is to
leave it as-is.

-- 
paul moore
www.paul-moore.com