net: af_key: add check for pfkey_broadcast in function pfkey_process

If skb_clone() returns null pointer, pfkey_broadcast() will
return error.
Therefore, it should be better to check the return value of
pfkey_broadcast() and return error if fails.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Jiasheng Jiang <jiasheng@iscas.ac.cn>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
diff --git a/net/key/af_key.c b/net/key/af_key.c
index fd51db3..92e9d75 100644
--- a/net/key/af_key.c
+++ b/net/key/af_key.c
@@ -2826,8 +2826,10 @@
 	void *ext_hdrs[SADB_EXT_MAX];
 	int err;
 
-	pfkey_broadcast(skb_clone(skb, GFP_KERNEL), GFP_KERNEL,
-			BROADCAST_PROMISC_ONLY, NULL, sock_net(sk));
+	err = pfkey_broadcast(skb_clone(skb, GFP_KERNEL), GFP_KERNEL,
+			      BROADCAST_PROMISC_ONLY, NULL, sock_net(sk));
+	if (err)
+		return err;
 
 	memset(ext_hdrs, 0, sizeof(ext_hdrs));
 	err = parse_exthdrs(skb, hdr, ext_hdrs);