[AUDIT] Requeue messages at head of queue, up to audit_backlog

If netlink_unicast() fails, requeue the skb back at the head of the queue
it just came from, instead of the tail. And do so unless we've exceeded
the audit_backlog limit; not according to some other arbitrary limit.

From: Chris Wright <chrisw@osdl.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>

1 files changed, 3 insertions, 5 deletions

diff --git a/kernel/audit.c b/kernel/audit.c
index 587d3b2eba7f..4a697c73faec 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -142,7 +142,6 @@ struct audit_buffer {
         int                  total;
         int                  type;
         int                  pid;
-        int                  count; /* Times requeued */
 };
 
 void audit_set_type(struct audit_buffer *ab, int type)
@@ -526,9 +525,9 @@ static inline int audit_log_drain(struct audit_buffer *ab)
                         retval = netlink_unicast(audit_sock, skb, audit_pid,
                                                  MSG_DONTWAIT);
                 }
-                if (retval == -EAGAIN && ab->count < 5) {
-                        ++ab->count;
-                        skb_queue_tail(&ab->sklist, skb);
+                if (retval == -EAGAIN &&
+                    (atomic_read(&audit_backlog)) < audit_backlog_limit) {
+                        skb_queue_head(&ab->sklist, skb);
                         audit_log_end_irq(ab);
                         return 1;
                 }
@@ -666,7 +665,6 @@ struct audit_buffer *audit_log_start(struct audit_context *ctx)
         ab->total = 0;
         ab->type  = AUDIT_KERNEL;
         ab->pid   = 0;
-        ab->count = 0;
 
 #ifdef CONFIG_AUDITSYSCALL
         if (ab->ctx)