From: Hangbin Liu liuhangbin@gmail.com
[ Upstream commit 675d76ad0ad5bf41c9a129772ef0aba8f57ea9a7 ]
When we do ipv6 gre pmtu update, we will also do neigh confirm currently. This will cause the neigh cache be refreshed and set to REACHABLE before xmit.
But if the remote mac address changed, e.g. device is deleted and recreated, we will not able to notice this and still use the old mac address as the neigh cache is REACHABLE.
Fix this by disable neigh confirm when do pmtu update
v5: No change. v4: No change. v3: Do not remove dst_confirm_neigh, but add a new bool parameter in dst_ops.update_pmtu to control whether we should do neighbor confirm. Also split the big patch to small ones for each area. v2: Remove dst_confirm_neigh in __ip6_rt_update_pmtu.
Reported-by: Jianlin Shi jishi@redhat.com Reviewed-by: Guillaume Nault gnault@redhat.com Acked-by: David Ahern dsahern@gmail.com Signed-off-by: Hangbin Liu liuhangbin@gmail.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/ipv6/ip6_gre.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)
--- a/net/ipv6/ip6_gre.c +++ b/net/ipv6/ip6_gre.c @@ -1040,7 +1040,7 @@ static netdev_tx_t ip6erspan_tunnel_xmit
/* TooBig packet may have updated dst->dev's mtu */ if (!t->parms.collect_md && dst && dst_mtu(dst) > dst->dev->mtu) - dst->ops->update_pmtu(dst, NULL, skb, dst->dev->mtu, true); + dst->ops->update_pmtu(dst, NULL, skb, dst->dev->mtu, false);
err = ip6_tnl_xmit(skb, dev, dsfield, &fl6, encap_limit, &mtu, NEXTHDR_GRE);