From: Xin Long <lucien.xin@gmail.com>
Date: Sun, 13 Sep 2020 19:51:51 +0800
Subject: lwtunnel: only keep the available bits when setting vxlan md->gbp
Patch-mainline: v5.9-rc7
Git-commit: 681d2cfb790339a3e95b98bc140baf1f816a896a
References: bsc#1176447

As we can see from vxlan_build/parse_gbp_hdr(), when processing metadata
on vxlan rx/tx path, only dont_learn/policy_applied/policy_id fields can
be set to or parse from the packet for vxlan gbp option.

So do the mask when set it in lwtunnel, as it does in act_tunnel_key and
cls_flower.

Signed-off-by: Xin Long <lucien.xin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Acked-by: Thomas Bogendoerfer <tbogendoerfer@suse.de>
---
 net/ipv4/ip_tunnel_core.c |    1 +
 1 file changed, 1 insertion(+)

--- a/net/ipv4/ip_tunnel_core.c
+++ b/net/ipv4/ip_tunnel_core.c
@@ -554,6 +554,7 @@ static int ip_tun_parse_opts_vxlan(struc
 
 		attr = tb[LWTUNNEL_IP_OPT_VXLAN_GBP];
 		md->gbp = nla_get_u32(attr);
+		md->gbp &= VXLAN_GBP_MASK;
 		info->key.tun_flags |= TUNNEL_VXLAN_OPT;
 	}