4.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Xin Long <lucien.xin@xxxxxxxxx> [ Upstream commit ffc2b6ee417435605ee8bb1eb4c8f02e9ff4b4a5 ] It's safe to remove the setting of dev's needed_headroom and mtu in __gre_tunnel_init, as discussed in [1], ip_tunnel_newlink can do it properly. Now Eric noticed that it could cover the mtu value set in do_setlink when creating a ip_gre dev. It makes IFLA_MTU param not take effect. So this patch is to remove them to make IFLA_MTU work, as in other ipv4 tunnels. [1]: https://patchwork.ozlabs.org/patch/823504/ Fixes: c54419321455 ("GRE: Refactor GRE tunneling code.") Reported-by: Eric Garver <e@xxxxxxx> Signed-off-by: Xin Long <lucien.xin@xxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/ipv4/ip_gre.c | 5 ----- 1 file changed, 5 deletions(-) --- a/net/ipv4/ip_gre.c +++ b/net/ipv4/ip_gre.c @@ -951,9 +951,6 @@ static void __gre_tunnel_init(struct net t_hlen = tunnel->hlen + sizeof(struct iphdr); - dev->needed_headroom = LL_MAX_HEADER + t_hlen + 4; - dev->mtu = ETH_DATA_LEN - t_hlen - 4; - dev->features |= GRE_FEATURES; dev->hw_features |= GRE_FEATURES; @@ -1253,8 +1250,6 @@ static int erspan_tunnel_init(struct net sizeof(struct erspanhdr); t_hlen = tunnel->hlen + sizeof(struct iphdr); - dev->needed_headroom = LL_MAX_HEADER + t_hlen + 4; - dev->mtu = ETH_DATA_LEN - t_hlen - 4; dev->features |= GRE_FEATURES; dev->hw_features |= GRE_FEATURES; dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;