sctp: Fix a big endian bug in sctp_diag_dump()

The sctp_for_each_transport() function takes an pointer to int.  The
cb->args[] array holds longs so it's only using the high 32 bits.  It
works on little endian system but will break on big endian 64 bit
machines.

Fixes: d25adbeb ("sctp: fix an use-after-free issue in sctp_sock_dump")
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Acked-by: NNeil Horman <nhorman@tuxdriver.com>
Reviewed-by: NXin Long <lucien.xin@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

net/sctp/sctp_diag.c

@@ -463,6 +463,7 @@ static void sctp_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
 		.r = r,
 		.net_admin = netlink_net_capable(cb->skb, CAP_NET_ADMIN),
 	};
+	int pos = cb->args[2];
 
 	/* eps hashtable dumps
 	 * args:
@@ -493,7 +494,8 @@ static void sctp_diag_dump(struct sk_buff *skb, struct netlink_callback *cb,
 		goto done;
 
 	sctp_for_each_transport(sctp_sock_filter, sctp_sock_dump,
-				net, (int *)&cb->args[2], &commp);
+				net, &pos, &commp);
+	cb->args[2] = pos;
 
 done:
 	cb->args[1] = cb->args[4];