From 4e3c0a8d0f85422a9ea23bb64e26b4288f6632c6 Mon Sep 17 00:00:00 2001 From: Hangbin Liu Date: Sun, 22 Dec 2019 10:51:10 +0800 Subject: [PATCH] ip6_gre: do not confirm neighbor when do pmtu update [ 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 Reviewed-by: Guillaume Nault Acked-by: David Ahern Signed-off-by: Hangbin Liu Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- net/ipv6/ip6_gre.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/ipv6/ip6_gre.c b/net/ipv6/ip6_gre.c index 38a9c10b351e..726ba41133a3 100644 --- a/net/ipv6/ip6_gre.c +++ b/net/ipv6/ip6_gre.c @@ -527,7 +527,7 @@ static netdev_tx_t __gre6_xmit(struct sk_buff *skb, /* TooBig packet may have updated dst->dev's mtu */ if (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); return ip6_tnl_xmit(skb, dev, dsfield, fl6, encap_limit, pmtu, NEXTHDR_GRE); -- 2.20.1