Re: [PATCH ghak90 V7 13/21] audit: NETFILTER_PKT: record each container ID associated with a netNS

[Paul Moore]

On Wed, Sep 18, 2019 at 9:26 PM Richard Guy Briggs <rgb@xxxxxxxxxx> wrote:
> 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.
>
> Signed-off-by: Richard Guy Briggs <rgb@xxxxxxxxxx>
> Acked-by: Neil Horman <nhorman@xxxxxxxxxxxxx>
> Reviewed-by: Ondrej Mosnacek <omosnace@xxxxxxxxxx>
> ---
>  include/linux/audit.h    |  5 +++++
>  kernel/audit.c           | 39 +++++++++++++++++++++++++++++++++++++++
>  net/netfilter/nft_log.c  | 11 +++++++++--
>  net/netfilter/xt_AUDIT.c | 11 +++++++++--
>  4 files changed, 62 insertions(+), 4 deletions(-)

This should be squashed together with patch 12/21; neither patch makes
sense by themselves.

> diff --git a/include/linux/audit.h b/include/linux/audit.h
> index 73e3ab38e3e0..dcd92f964120 100644
> --- a/include/linux/audit.h
> +++ b/include/linux/audit.h
> @@ -241,6 +241,8 @@ static inline u64 audit_get_contid(struct task_struct *tsk)
>  extern void audit_netns_contid_del(struct net *net, u64 contid);
>  extern void audit_switch_task_namespaces(struct nsproxy *ns,
>                                          struct task_struct *p);
> +extern void audit_log_netns_contid_list(struct net *net,
> +                                       struct audit_context *context);
>
>  extern u32 audit_enabled;
>
> @@ -328,6 +330,9 @@ static inline void audit_netns_contid_del(struct net *net, u64 contid)
>  static inline void audit_switch_task_namespaces(struct nsproxy *ns,
>                                                 struct task_struct *p)
>  { }
> +static inline void audit_log_netns_contid_list(struct net *net,
> +                                              struct audit_context *context)
> +{ }
>
>  #define audit_enabled AUDIT_OFF
>
> diff --git a/kernel/audit.c b/kernel/audit.c
> index e0c27bc39925..9ce7a1ec7a92 100644
> --- a/kernel/audit.c
> +++ b/kernel/audit.c
> @@ -450,6 +450,45 @@ void audit_switch_task_namespaces(struct nsproxy *ns, struct task_struct *p)
>                 audit_netns_contid_add(new->net_ns, contid);
>  }
>
> +/**
> + * audit_log_netns_contid_list - List contids for the given network namespace
> + * @net: the network namespace of interest
> + * @context: the audit context to use
> + *
> + * Description:
> + * Issues a CONTAINER_ID record with a CSV list of contids associated
> + * with a network namespace to accompany a NETFILTER_PKT record.
> + */
> +void audit_log_netns_contid_list(struct net *net, struct audit_context *context)
> +{
> +       struct audit_buffer *ab = NULL;
> +       struct audit_contid *cont;
> +       struct audit_net *aunet;
> +
> +       /* Generate AUDIT_CONTAINER_ID record with container ID CSV list */
> +       rcu_read_lock();
> +       aunet = net_generic(net, audit_net_id);
> +       if (!aunet)
> +               goto out;
> +       list_for_each_entry_rcu(cont, &aunet->contid_list, list) {
> +               if (!ab) {
> +                       ab = audit_log_start(context, GFP_ATOMIC,
> +                                            AUDIT_CONTAINER_ID);
> +                       if (!ab) {
> +                               audit_log_lost("out of memory in audit_log_netns_contid_list");
> +                               goto out;
> +                       }
> +                       audit_log_format(ab, "contid=");
> +               } else
> +                       audit_log_format(ab, ",");
> +               audit_log_format(ab, "%llu", cont->id);
> +       }
> +       audit_log_end(ab);
> +out:
> +       rcu_read_unlock();
> +}
> +EXPORT_SYMBOL(audit_log_netns_contid_list);
> +
>  void audit_panic(const char *message)
>  {
>         switch (audit_failure) {
> diff --git a/net/netfilter/nft_log.c b/net/netfilter/nft_log.c
> index fe4831f2258f..98d1e7e1a83c 100644
> --- a/net/netfilter/nft_log.c
> +++ b/net/netfilter/nft_log.c
> @@ -66,13 +66,16 @@ static void nft_log_eval_audit(const struct nft_pktinfo *pkt)
>         struct sk_buff *skb = pkt->skb;
>         struct audit_buffer *ab;
>         int fam = -1;
> +       struct audit_context *context;
> +       struct net *net;
>
>         if (!audit_enabled)
>                 return;
>
> -       ab = audit_log_start(NULL, GFP_ATOMIC, AUDIT_NETFILTER_PKT);
> +       context = audit_alloc_local(GFP_ATOMIC);
> +       ab = audit_log_start(context, GFP_ATOMIC, AUDIT_NETFILTER_PKT);
>         if (!ab)
> -               return;
> +               goto errout;
>
>         audit_log_format(ab, "mark=%#x", skb->mark);
>
> @@ -99,6 +102,10 @@ static void nft_log_eval_audit(const struct nft_pktinfo *pkt)
>                 audit_log_format(ab, " saddr=? daddr=? proto=-1");
>
>         audit_log_end(ab);
> +       net = xt_net(&pkt->xt);
> +       audit_log_netns_contid_list(net, context);
> +errout:
> +       audit_free_context(context);
>  }
>
>  static void nft_log_eval(const struct nft_expr *expr,
> diff --git a/net/netfilter/xt_AUDIT.c b/net/netfilter/xt_AUDIT.c
> index 9cdc16b0d0d8..ecf868a1abde 100644
> --- a/net/netfilter/xt_AUDIT.c
> +++ b/net/netfilter/xt_AUDIT.c
> @@ -68,10 +68,13 @@ static bool audit_ip6(struct audit_buffer *ab, struct sk_buff *skb)
>  {
>         struct audit_buffer *ab;
>         int fam = -1;
> +       struct audit_context *context;
> +       struct net *net;
>
>         if (audit_enabled == AUDIT_OFF)
> -               goto errout;
> -       ab = audit_log_start(NULL, GFP_ATOMIC, AUDIT_NETFILTER_PKT);
> +               goto out;
> +       context = audit_alloc_local(GFP_ATOMIC);
> +       ab = audit_log_start(context, GFP_ATOMIC, AUDIT_NETFILTER_PKT);
>         if (ab == NULL)
>                 goto errout;
>
> @@ -101,7 +104,11 @@ static bool audit_ip6(struct audit_buffer *ab, struct sk_buff *skb)
>
>         audit_log_end(ab);
>
> +       net = xt_net(par);
> +       audit_log_netns_contid_list(net, context);
>  errout:
> +       audit_free_context(context);
> +out:
>         return XT_CONTINUE;
>  }
>

--
paul moore
www.paul-moore.com