From: Dan Carpenter <dan.carpenter@oracle.com>
Date: Mon, 25 Sep 2017 13:19:26 +0300
Subject: sctp: Fix a big endian bug in sctp_diag_dump()
Patch-mainline: v4.14-rc4
Git-commit: c2cc187e53011c1c4931055984657da9085c763b
References: bsc#1076830

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: d25adbeb0cdb ("sctp: fix an use-after-free issue in sctp_sock_dump")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Reviewed-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Michal Kubecek <mkubecek@suse.cz>

---
 net/sctp/sctp_diag.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/net/sctp/sctp_diag.c b/net/sctp/sctp_diag.c
index 7008a992749b..83b04d73f1fa 100644
--- a/net/sctp/sctp_diag.c
+++ b/net/sctp/sctp_diag.c
@@ -464,6 +464,7 @@ 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:
@@ -494,7 +495,8 @@ 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];
-- 
2.16.0