configurations:
	auditctl -b 64
	auditctl --backlog_wait_time 60000
	auditctl -r 0
	auditctl -w /root/aaa  -p wrx
shell scripts：
	#!/bin/bash
	i=0
	while [ $i -le 66 ]
	do
	    touch /root/aaa
	    let i++
	done
mandatory conditions:

add "audit=1" to the cmdline, and kill -19 pid_number(for /sbin/auditd).

 As long as we keep the audit_hold_queue non-empty, flush the hold queue will fall into
 an infinite loop.

713 static int kauditd_send_queue(struct sock *sk, u32 portid,
714                               struct sk_buff_head *queue,
715                               unsigned int retry_limit,
716                               void (*skb_hook)(struct sk_buff *skb),
717                               void (*err_hook)(struct sk_buff *skb))
718 {
719         int rc = 0;
720         struct sk_buff *skb;
721         unsigned int failed = 0;
722
723         /* NOTE: kauditd_thread takes care of all our locking, we just use
724          *       the netlink info passed to us (e.g. sk and portid) */
725
726         while ((skb = skb_dequeue(queue))) {
727                 /* call the skb_hook for each skb we touch */
728                 if (skb_hook)
729                         (*skb_hook)(skb);
730
731                 /* can we send to anyone via unicast? */
732                 if (!sk) {
733                         if (err_hook)
734                                 (*err_hook)(skb);
735                         continue;
736                 }
737
738 retry:
739                 /* grab an extra skb reference in case of error */
740                 skb_get(skb);
741                 rc = netlink_unicast(sk, skb, portid, 0);
742                 if (rc < 0) {
743                         /* send failed - try a few times unless fatal error */
744                         if (++failed >= retry_limit ||
745                             rc == -ECONNREFUSED || rc == -EPERM) {
746                                 sk = NULL;
747                                 if (err_hook)
748                                         (*err_hook)(skb);
749                                 if (rc == -EAGAIN)
750                                         rc = 0;
751                                 /* continue to drain the queue */
752                                 continue;
753                         } else
754                                 goto retry;
755                 } else {
756                         /* skb sent - drop the extra reference and continue */
757                         consume_skb(skb);
758                         failed = 0;
759                 }
760         }
761
762         return (rc >= 0 ? 0 : rc);
763 }

When kauditd attempt to flush the hold queue, the queue parameter is &audit_hold_queue,
and if netlink_unicast(line 741 ) return -EAGAIN, sk will be NULL(line 746), so err_hook(kauditd_rehold_skb)
will be call. Then continue, skb_dequeue(line 726) and err_hook(kauditd_rehold_skb,line 733) will
fall into an infinite loop. 
I don't really understand the value of audit_hold_queue, can we remove it, or stop droping the logs
into kauditd_rehold_skb when the auditd is abnormal?

Look forward your reply. Thank you very much.

Gaosheng.