audit: don't reset working wait time accidentally with auditd

During a queue overflow condition while we are waiting for auditd to drain the
queue to make room for regular messages, we don't want a successful auditd that
has bypassed the queue check to reset the backlog wait time.
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Paul Moore <pmoore@redhat.com>

kernel/audit.c

@@ -1395,7 +1395,8 @@ struct audit_buffer *audit_log_start(struct audit_context *ctx, gfp_t gfp_mask,
 		return NULL;
 	}
 
-	audit_backlog_wait_time = audit_backlog_wait_time_master;
+	if (!reserve)
+		audit_backlog_wait_time = audit_backlog_wait_time_master;
 
 	ab = audit_buffer_alloc(ctx, gfp_mask, type);
 	if (!ab) {