On Sat, Jun 27, 2020 at 9:23 AM Richard Guy Briggs <rgb@xxxxxxxxxx> wrote: > > This also adds support to qualify NETFILTER_PKT records. > > 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 > > Add audit container identifier auxiliary record(s) to NETFILTER_PKT > event standalone records. Iterate through all potential audit container > identifiers associated with a network 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 | 20 ++++++ > kernel/audit.c | 156 ++++++++++++++++++++++++++++++++++++++++++++++- > kernel/nsproxy.c | 4 ++ > net/netfilter/nft_log.c | 11 +++- > net/netfilter/xt_AUDIT.c | 11 +++- > 5 files changed, 195 insertions(+), 7 deletions(-) > > diff --git a/include/linux/audit.h b/include/linux/audit.h > index c4a755ae0d61..304fbb7c3c5b 100644 > --- a/include/linux/audit.h > +++ b/include/linux/audit.h > @@ -128,6 +128,13 @@ struct audit_task_info { > > extern struct audit_task_info init_struct_audit; > > +struct audit_contobj_netns { > + struct list_head list; > + struct audit_contobj *obj; > + int count; This seems like it might be a good candidate for refcount_t, yes? > + struct rcu_head rcu; > +}; ... > diff --git a/kernel/audit.c b/kernel/audit.c > index 997c34178ee8..a862721dfd9b 100644 > --- a/kernel/audit.c > +++ b/kernel/audit.c > @@ -437,6 +452,136 @@ static struct sock *audit_get_sk(const struct net *net) > return aunet->sk; > } > > +void audit_netns_contid_add(struct net *net, struct audit_contobj *cont) > +{ > + struct audit_net *aunet; > + struct list_head *contobj_list; > + struct audit_contobj_netns *contns; > + > + if (!net) > + return; > + if (!cont) > + return; > + aunet = net_generic(net, audit_net_id); > + if (!aunet) > + return; > + contobj_list = &aunet->contobj_list; > + rcu_read_lock(); > + spin_lock(&aunet->contobj_list_lock); > + list_for_each_entry_rcu(contns, contobj_list, list) > + if (contns->obj == cont) { > + contns->count++; > + goto out; > + } > + contns = kmalloc(sizeof(*contns), GFP_ATOMIC); > + if (contns) { > + INIT_LIST_HEAD(&contns->list); > + contns->obj = cont; > + contns->count = 1; > + list_add_rcu(&contns->list, contobj_list); > + } > +out: > + spin_unlock(&aunet->contobj_list_lock); > + rcu_read_unlock(); > +} > + > +void audit_netns_contid_del(struct net *net, struct audit_contobj *cont) > +{ > + struct audit_net *aunet; > + struct list_head *contobj_list; > + struct audit_contobj_netns *contns = NULL; > + > + if (!net) > + return; > + if (!cont) > + return; > + aunet = net_generic(net, audit_net_id); > + if (!aunet) > + return; > + contobj_list = &aunet->contobj_list; > + rcu_read_lock(); > + spin_lock(&aunet->contobj_list_lock); > + list_for_each_entry_rcu(contns, contobj_list, list) > + if (contns->obj == cont) { > + contns->count--; > + if (contns->count < 1) { One could simplify this with "(--countns->count) < 1", although if it is changed to a refcount_t (which seems like a smart thing), the normal decrement/test would be the best choice. > + list_del_rcu(&contns->list); > + kfree_rcu(contns, rcu); > + } > + break; > + } > + spin_unlock(&aunet->contobj_list_lock); > + rcu_read_unlock(); > +} -- paul moore www.paul-moore.com
