From bfd6fe8246f7d63e074aab6b738fa9886ed548f3 Mon Sep 17 00:00:00 2001
From: Daniel Borkmann <borkmann@iogearbox.net>
Date: Sun, 1 May 2011 21:56:00 +0200
Subject: [PATCH] prevent adding fb it already exists

---
 src/xt_user.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/src/xt_user.c b/src/xt_user.c
index f37634c..df47d38 100644
--- a/src/xt_user.c
+++ b/src/xt_user.c
@@ -14,6 +14,7 @@
 #include <linux/socket.h>
 #include <linux/net.h>
 #include <linux/skbuff.h>
+#include <linux/rcupdate.h>
 #include <net/netlink.h>
 #include <net/sock.h>
 
@@ -40,6 +41,11 @@ static int __userctl_rcv(struct sk_buff *skb, struct nlmsghdr *nlh)
 		struct fblock *fb;
 		struct lananlmsg_add *msg =
 			(struct lananlmsg_add *) lmsg->buff;
+		fb = search_fblock_n(msg->name);
+		if (fb) {
+			put_fblock(fb);
+			return -EINVAL;
+		}
 		fb = build_fblock_object(msg->type, msg->name);
 		if (!fb)
 			return -ENOMEM;
-- 
2.11.4.GIT