sock_diag: align nlattr properly when needed

I also fix the value of INET_DIAG_MAX. It's wrong since commit 8f840e47f190
which is only in net-next right now, thus I didn't make a separate patch.

Fixes: 8f840e47f190 ("sctp: add the sctp_diag.c file")
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/inet_diag.c b/net/ipv4/inet_diag.c
index ad7956f..25af124 100644
--- a/net/ipv4/inet_diag.c
+++ b/net/ipv4/inet_diag.c
@@ -220,8 +220,9 @@
 	}
 
 	if ((ext & (1 << (INET_DIAG_INFO - 1))) && handler->idiag_info_size) {
-		attr = nla_reserve(skb, INET_DIAG_INFO,
-				   handler->idiag_info_size);
+		attr = nla_reserve_64bit(skb, INET_DIAG_INFO,
+					 handler->idiag_info_size,
+					 INET_DIAG_PAD);
 		if (!attr)
 			goto errout;
 
@@ -1078,7 +1079,9 @@
 	}
 
 	attr = handler->idiag_info_size
-		? nla_reserve(skb, INET_DIAG_INFO, handler->idiag_info_size)
+		? nla_reserve_64bit(skb, INET_DIAG_INFO,
+				    handler->idiag_info_size,
+				    INET_DIAG_PAD)
 		: NULL;
 	if (attr)
 		info = nla_data(attr);