[Feature][ZXW-88]merge P50 version

Only Configure: No
Affected branch: master
Affected module: unknown
Is it affected on both ZXIC and MTK: only ZXIC
Self-test: Yes
Doc Update: No

Change-Id: I34667719d9e0e7e29e8e4368848601cde0a48408
diff --git a/ap/os/linux/linux-3.4.x/net/ipv4/ping.c b/ap/os/linux/linux-3.4.x/net/ipv4/ping.c
old mode 100644
new mode 100755
index 5ff3ed1..0d2f13a
--- a/ap/os/linux/linux-3.4.x/net/ipv4/ping.c
+++ b/ap/os/linux/linux-3.4.x/net/ipv4/ping.c
@@ -135,16 +135,17 @@
 {
 	struct inet_sock *isk = inet_sk(sk);
 	pr_debug("ping_v4_unhash(isk=%p,isk->num=%u)\n", isk, isk->inet_num);
+	//BDSA-2017-0084(CVE-2017-2671)
+	write_lock_bh(&ping_table.lock);
 	if (sk_hashed(sk)) {
-		write_lock_bh(&ping_table.lock);
 		hlist_nulls_del(&sk->sk_nulls_node);
 		sk_nulls_node_init(&sk->sk_nulls_node);
 		sock_put(sk);
 		isk->inet_num = 0;
 		isk->inet_sport = 0;
 		sock_prot_inuse_add(sock_net(sk), sk->sk_prot, -1);
-		write_unlock_bh(&ping_table.lock);
 	}
+	write_unlock_bh(&ping_table.lock);
 }
 
 static struct sock *ping_v4_lookup(struct net *net, __be32 saddr, __be32 daddr,