4.20-stable review patch. If anyone has any objections, please let me know.
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From: Lorenzo Bianconi lorenzo.bianconi@redhat.com
[ Upstream commit c706863bc8902d0c2d1a5a27ac8e1ead5d06b79d ]
As Erspan_v4, Erspan_v6 protocol relies on o_key to configure session id header field. However TUNNEL_KEY bit is cleared in ip6erspan_tunnel_xmit since ERSPAN protocol does not set the key field of the external GRE header and so the configured o_key is not reported to userspace. The issue can be triggered with the following reproducer:
$ip link add ip6erspan1 type ip6erspan local 2000::1 remote 2000::2 \ key 1 seq erspan_ver 1 $ip link set ip6erspan1 up ip -d link sh ip6erspan1
ip6erspan1@NONE: <BROADCAST,MULTICAST> mtu 1422 qdisc noop state DOWN mode DEFAULT link/ether ba:ff:09:24:c3:0e brd ff:ff:ff:ff:ff:ff promiscuity 0 minmtu 68 maxmtu 1500 ip6erspan remote 2000::2 local 2000::1 encaplimit 4 flowlabel 0x00000 ikey 0.0.0.1 iseq oseq
Fix the issue adding TUNNEL_KEY bit to the o_flags parameter in ip6gre_fill_info
Fixes: 5a963eb61b7c ("ip6_gre: Add ERSPAN native tunnel support") Signed-off-by: Lorenzo Bianconi lorenzo.bianconi@redhat.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/ipv6/ip6_gre.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
--- a/net/ipv6/ip6_gre.c +++ b/net/ipv6/ip6_gre.c @@ -2102,12 +2102,17 @@ static int ip6gre_fill_info(struct sk_bu { struct ip6_tnl *t = netdev_priv(dev); struct __ip6_tnl_parm *p = &t->parms; + __be16 o_flags = p->o_flags; + + if ((p->erspan_ver == 1 || p->erspan_ver == 2) && + !p->collect_md) + o_flags |= TUNNEL_KEY;
if (nla_put_u32(skb, IFLA_GRE_LINK, p->link) || nla_put_be16(skb, IFLA_GRE_IFLAGS, gre_tnl_flags_to_gre_flags(p->i_flags)) || nla_put_be16(skb, IFLA_GRE_OFLAGS, - gre_tnl_flags_to_gre_flags(p->o_flags)) || + gre_tnl_flags_to_gre_flags(o_flags)) || nla_put_be32(skb, IFLA_GRE_IKEY, p->i_key) || nla_put_be32(skb, IFLA_GRE_OKEY, p->o_key) || nla_put_in6_addr(skb, IFLA_GRE_LOCAL, &p->laddr) ||