Re: [PATCH ghak90 V8 11/16] audit: add support for containerid to network namespaces

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(a)redhat.com&gt; Acked-by: Neil Horman <nhorman(a)tuxdriver.com&gt; Reviewed-by: Ondrej Mosnacek <omosnace(a)redhat.com&gt; --- include/linux/audit.h | 24 +++++++++ kernel/audit.c | 132 ++++++++++++++++++++++++++++++++++++++++++++++- kernel/nsproxy.c | 4 ++ net/netfilter/nft_log.c | 11 +++- net/netfilter/xt_AUDIT.c | 11 +++- 5 files changed, 176 insertions(+), 6 deletions(-)

diff --git a/include/linux/audit.h b/include/linux/audit.h index 5531d37a4226..ed8d5b74758d 100644 --- a/include/linux/audit.h +++ b/include/linux/audit.h @@ -12,6 +12,7 @@ #include <linux/sched.h> #include <linux/ptrace.h> #include <uapi/linux/audit.h> +#include <linux/refcount.h> #define AUDIT_INO_UNSET ((unsigned long)-1) #define AUDIT_DEV_UNSET ((dev_t)-1) @@ -121,6 +122,13 @@ struct audit_task_info { extern struct audit_task_info init_struct_audit; +struct audit_contobj_netns { + struct list_head list; + u64 id;

+ refcount_t refcount; + struct rcu_head rcu; +}; + extern int is_audit_feature_set(int which); extern int __init audit_register_class(int class, unsigned *list); @@ -225,6 +233,12 @@ static inline u64 audit_get_contid(struct task_struct *tsk) } extern void audit_log_container_id(struct audit_context *context, u64 contid); +extern void audit_netns_contid_add(struct net *net, u64 contid); +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; @@ -297,6 +311,16 @@ static inline u64 audit_get_contid(struct task_struct *tsk) static inline void audit_log_container_id(struct audit_context *context, u64 contid) { } +static inline void audit_netns_contid_add(struct net *net, u64 contid) +{ } +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 d4e6eafe5644..f7a8d3288ca0 100644 --- a/kernel/audit.c +++ b/kernel/audit.c @@ -59,6 +59,7 @@ #include <linux/freezer.h> #include <linux/pid_namespace.h> #include <net/netns/generic.h> +#include <net/net_namespace.h> #include "audit.h" @@ -86,9 +87,13 @@ /** * struct audit_net - audit private network namespace data * @sk: communication socket + * @contid_list: audit container identifier list + * @contid_list_lock audit container identifier list lock */ struct audit_net { struct sock *sk; + struct list_head contid_list; + spinlock_t contid_list_lock; }; /** @@ -305,8 +310,11 @@ struct audit_task_info init_struct_audit = { void audit_free(struct task_struct *tsk) { struct audit_task_info *info = tsk->audit; + struct nsproxy *ns = tsk->nsproxy; audit_free_syscall(tsk); + if (ns) + audit_netns_contid_del(ns->net_ns, audit_get_contid(tsk)); /* Freeing the audit_task_info struct must be performed after * audit_log_exit() due to need for loginuid and sessionid. */ @@ -409,6 +417,120 @@ 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_contobj_netns *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; + rcu_read_lock(); + list_for_each_entry_rcu(cont, contid_list, list) + if (cont->id == contid) { + spin_lock(&aunet->contid_list_lock); + refcount_inc(&cont->refcount); + spin_unlock(&aunet->contid_list_lock); + goto out; + } + cont = kmalloc(sizeof(*cont), GFP_ATOMIC); + if (cont) { + INIT_LIST_HEAD(&cont->list); + cont->id = contid; + refcount_set(&cont->refcount, 1); + spin_lock(&aunet->contid_list_lock); + list_add_rcu(&cont->list, contid_list); + spin_unlock(&aunet->contid_list_lock); + } +out: + rcu_read_unlock(); +}