[RFC PATCH ghak90 (was ghak32) V3 08/10] audit: NETFILTER_PKT: record each container ID associated with a netNS

[Laura Garcia]

CC'ing Netfilter.

On Wed, Jun 6, 2018 at 6:58 PM, Richard Guy Briggs <rgb at redhat.com> 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 at redhat.com>
> ---
>  include/linux/audit.h    |  5 +++++
>  kernel/audit.c           | 20 +++++++++++++++++++-
>  kernel/auditsc.c         |  2 ++
>  net/netfilter/xt_AUDIT.c | 12 ++++++++++--
>  4 files changed, 36 insertions(+), 3 deletions(-)
>
> diff --git a/include/linux/audit.h b/include/linux/audit.h
> index 7e2e51c..4560a4e 100644
> --- a/include/linux/audit.h
> +++ b/include/linux/audit.h
> @@ -167,6 +167,8 @@ extern int audit_log_contid(struct audit_context *context,
>  extern void audit_contid_add(struct net *net, u64 contid);
>  extern void audit_contid_del(struct net *net, u64 contid);
>  extern void audit_switch_task_namespaces(struct nsproxy *ns, struct task_struct *p);
> +extern void audit_log_contid_list(struct net *net,
> +                                struct audit_context *context);
>
>  extern int                 audit_update_lsm_rules(void);
>
> @@ -231,6 +233,9 @@ static inline void audit_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_contid_list(struct net *net,
> +                                       struct audit_context *context)
> +{ }
>
>  #define audit_enabled 0
>  #endif /* CONFIG_AUDIT */
> diff --git a/kernel/audit.c b/kernel/audit.c
> index ecd2de4..8cca41a 100644
> --- a/kernel/audit.c
> +++ b/kernel/audit.c
> @@ -382,6 +382,20 @@ void audit_switch_task_namespaces(struct nsproxy *ns, struct task_struct *p)
>                 audit_contid_add(new->net_ns, contid);
>  }
>
> +void audit_log_contid_list(struct net *net, struct audit_context *context)
> +{
> +       struct audit_contid *cont;
> +       int i = 0;
> +
> +       list_for_each_entry(cont, audit_get_contid_list(net), list) {
> +               char buf[14];
> +
> +               sprintf(buf, "net%u", i++);
> +               audit_log_contid(context, buf, cont->id);
> +       }
> +}
> +EXPORT_SYMBOL(audit_log_contid_list);
> +
>  void audit_panic(const char *message)
>  {
>         switch (audit_failure) {
> @@ -2132,17 +2146,21 @@ int audit_log_contid(struct audit_context *context,
>                               char *op, u64 contid)
>  {
>         struct audit_buffer *ab;
> +       gfp_t gfpflags;
>
>         if (!cid_valid(contid))
>                 return 0;
> +       /* We can be called in atomic context via audit_tg() */
> +       gfpflags = (in_atomic() || irqs_disabled()) ? GFP_ATOMIC : GFP_KERNEL;
>         /* Generate AUDIT_CONTAINER record with container ID */
> -       ab = audit_log_start(context, GFP_KERNEL, AUDIT_CONTAINER);
> +       ab = audit_log_start(context, gfpflags, AUDIT_CONTAINER);
>         if (!ab)
>                 return -ENOMEM;
>         audit_log_format(ab, "op=%s contid=%llu", op, contid);
>         audit_log_end(ab);
>         return 0;
>  }
> +EXPORT_SYMBOL(audit_log_contid);
>
>  void audit_log_key(struct audit_buffer *ab, char *key)
>  {
> diff --git a/kernel/auditsc.c b/kernel/auditsc.c
> index 6ab5e5e..e2a16d2 100644
> --- a/kernel/auditsc.c
> +++ b/kernel/auditsc.c
> @@ -1015,6 +1015,7 @@ struct audit_context *audit_alloc_local(void)
>         context->in_syscall = 1;
>         return context;
>  }
> +EXPORT_SYMBOL(audit_alloc_local);
>
>  void audit_free_context(struct audit_context *context)
>  {
> @@ -1029,6 +1030,7 @@ void audit_free_context(struct audit_context *context)
>         audit_proctitle_free(context);
>         kfree(context);
>  }
> +EXPORT_SYMBOL(audit_free_context);
>
>  static int audit_log_pid_context(struct audit_context *context, pid_t pid,
>                                  kuid_t auid, kuid_t uid, unsigned int sessionid,
> diff --git a/net/netfilter/xt_AUDIT.c b/net/netfilter/xt_AUDIT.c
> index f368ee6..10d2707 100644
> --- a/net/netfilter/xt_AUDIT.c
> +++ b/net/netfilter/xt_AUDIT.c
> @@ -71,10 +71,13 @@ 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 == 0)
> -               goto errout;
> -       ab = audit_log_start(NULL, GFP_ATOMIC, AUDIT_NETFILTER_PKT);
> +               goto out;
> +       context = audit_alloc_local();
> +       ab = audit_log_start(context, GFP_ATOMIC, AUDIT_NETFILTER_PKT);
>         if (ab == NULL)
>                 goto errout;
>
> @@ -104,7 +107,12 @@ static bool audit_ip6(struct audit_buffer *ab, struct sk_buff *skb)
>
>         audit_log_end(ab);
>
> +       net = xt_net(par);
> +       audit_log_contid_list(net, context);
> +
>  errout:
> +       audit_free_context(context);
> +out:
>         return XT_CONTINUE;
>  }
>
> --
> 1.8.3.1
>