This is a note to let you know that I've just added the patch titled net/dst: do not confirm neighbor for vxlan and geneve pmtu update to the 4.19-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: net-dst-do-not-confirm-neighbor-for-vxlan-and-geneve-pmtu-update.patch and it can be found in the queue-4.19 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From foo@baz Wed 01 Jan 2020 10:36:29 PM CET From: Hangbin Liu <liuhangbin@xxxxxxxxx> Date: Sun, 22 Dec 2019 10:51:16 +0800 Subject: net/dst: do not confirm neighbor for vxlan and geneve pmtu update From: Hangbin Liu <liuhangbin@xxxxxxxxx> [ Upstream commit f081042d128a0c7acbd67611def62e1b52e2d294 ] When do IPv6 tunnel PMTU update and calls __ip6_rt_update_pmtu() in the end, we should not call dst_confirm_neigh() as there is no two-way communication. So disable the neigh confirm for vxlan and geneve 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. Fixes: a93bf0ff4490 ("vxlan: update skb dst pmtu on tx path") Fixes: 52a589d51f10 ("geneve: update skb dst pmtu on tx path") Reviewed-by: Guillaume Nault <gnault@xxxxxxxxxx> Tested-by: Guillaume Nault <gnault@xxxxxxxxxx> Acked-by: David Ahern <dsahern@xxxxxxxxx> Signed-off-by: Hangbin Liu <liuhangbin@xxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- include/net/dst.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/include/net/dst.h +++ b/include/net/dst.h @@ -546,7 +546,7 @@ static inline void skb_tunnel_check_pmtu u32 encap_mtu = dst_mtu(encap_dst); if (skb->len > encap_mtu - headroom) - skb_dst_update_pmtu(skb, encap_mtu - headroom); + skb_dst_update_pmtu_no_confirm(skb, encap_mtu - headroom); } #endif /* _NET_DST_H */ Patches currently in stable-queue which might be from liuhangbin@xxxxxxxxx are queue-4.19/sit-do-not-confirm-neighbor-when-do-pmtu-update.patch queue-4.19/net-dst-add-new-function-skb_dst_update_pmtu_no_confirm.patch queue-4.19/vti-do-not-confirm-neighbor-when-do-pmtu-update.patch queue-4.19/net-dst-do-not-confirm-neighbor-for-vxlan-and-geneve-pmtu-update.patch queue-4.19/gtp-do-not-confirm-neighbor-when-do-pmtu-update.patch queue-4.19/ip6_gre-do-not-confirm-neighbor-when-do-pmtu-update.patch queue-4.19/net-add-bool-confirm_neigh-parameter-for-dst_ops.update_pmtu.patch queue-4.19/tunnel-do-not-confirm-neighbor-when-do-pmtu-update.patch