Re: [PATCH ghak90 V5 09/10] audit: add support for containerid to network namespaces

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 See: https://github.com/linux-audit/audit-kernel/issues/92 See: https://github.com/linux-audit/audit-testsuite/issues/64 See: https://github.com/linux-audit/audit-kernel/wiki/RFE-Audit-Container-ID Signed-off-by: Richard Guy Briggs <rgb(a)redhat.com&gt; --- include/linux/audit.h | 19 ++++++++++++ kernel/audit.c | 86 +++++++++++++++++++++++++++++++++++++++++++++++++-- kernel/nsproxy.c | 4 +++ 3 files changed, 106 insertions(+), 3 deletions(-)

diff --git a/kernel/audit.c b/kernel/audit.c index cf448599ef34..7fa3194f5342 100644 --- a/kernel/audit.c +++ b/kernel/audit.c @@ -72,6 +72,7 @@ #include <linux/freezer.h> #include <linux/pid_namespace.h> #include <net/netns/generic.h> +#include <net/net_namespace.h> #include "audit.h" @@ -99,9 +100,13 @@ /** * 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; }; /** @@ -275,8 +280,11 @@ 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. */ @@ -376,6 +384,73 @@ 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 = net_generic(net, audit_net_id); + struct list_head *contid_list = &aunet->contid_list; + struct audit_contid *cont; + + if (!audit_contid_valid(contid)) + return; + if (!aunet) + return;

+ spin_lock(&aunet->contid_list_lock); + if (!list_empty(contid_list))

+ 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);

+ cont->id = contid; + refcount_set(&cont->refcount, 1); + list_add_rcu(&cont->list, contid_list); + } +out: + spin_unlock(&aunet->contid_list_lock); +}