From 2f0e6d80e8b570aeb7e6eb6db2e2dd9fdbb6236c Mon Sep 17 00:00:00 2001
From: Antony Antony <antony.antony@secunet.com>
Date: Tue, 1 Feb 2022 07:51:57 +0100
Subject: [PATCH] xfrm: fix the if_id check in changelink

commit 6d0d95a1c2b07270870e7be16575c513c29af3f1 upstream.

if_id will be always 0, because it was not yet initialized.

Fixes: 8dce43919566 ("xfrm: interface with if_id 0 should return error")
Reported-by: Pavel Machek <pavel@denx.de>
Signed-off-by: Antony Antony <antony.antony@secunet.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/xfrm/xfrm_interface.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/xfrm/xfrm_interface.c b/net/xfrm/xfrm_interface.c
index e1fae61a5bb9..4420c8fd318a 100644
--- a/net/xfrm/xfrm_interface.c
+++ b/net/xfrm/xfrm_interface.c
@@ -679,12 +679,12 @@ static int xfrmi_changelink(struct net_device *dev, struct nlattr *tb[],
 	struct net *net = xi->net;
 	struct xfrm_if_parms p = {};
 
+	xfrmi_netlink_parms(data, &p);
 	if (!p.if_id) {
 		NL_SET_ERR_MSG(extack, "if_id must be non zero");
 		return -EINVAL;
 	}
 
-	xfrmi_netlink_parms(data, &p);
 	xi = xfrmi_locate(net, &p);
 	if (!xi) {
 		xi = netdev_priv(dev);