4.14-stable review patch. If anyone has any objections, please let me know.
------------------ From: Nicolas Dichtel <nicolas.dich...@6wind.com> [ Upstream commit f7ff1fde9441b4fcc8ffb6e66e6e5a00d008937e ] I don't know where this value comes from (probably a copy and paste and paste and paste ...). Let's use standard values which are a bit greater. Link: https://git.kernel.org/pub/scm/linux/kernel/git/davem/netdev-vger-cvs.git/commit/?id=e5afd356a411a Signed-off-by: Nicolas Dichtel <nicolas.dich...@6wind.com> Signed-off-by: David S. Miller <da...@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gre...@linuxfoundation.org> --- net/ipv6/ip6_tunnel.c | 11 ++++++++--- net/ipv6/sit.c | 5 +++-- 2 files changed, 11 insertions(+), 5 deletions(-) --- a/net/ipv6/ip6_tunnel.c +++ b/net/ipv6/ip6_tunnel.c @@ -1693,8 +1693,13 @@ int ip6_tnl_change_mtu(struct net_device if (new_mtu < ETH_MIN_MTU) return -EINVAL; } - if (new_mtu > 0xFFF8 - dev->hard_header_len) - return -EINVAL; + if (tnl->parms.proto == IPPROTO_IPV6 || tnl->parms.proto == 0) { + if (new_mtu > IP6_MAX_MTU - dev->hard_header_len) + return -EINVAL; + } else { + if (new_mtu > IP_MAX_MTU - dev->hard_header_len) + return -EINVAL; + } dev->mtu = new_mtu; return 0; } @@ -1842,7 +1847,7 @@ ip6_tnl_dev_init_gen(struct net_device * if (!(t->parms.flags & IP6_TNL_F_IGN_ENCAP_LIMIT)) dev->mtu -= 8; dev->min_mtu = ETH_MIN_MTU; - dev->max_mtu = 0xFFF8 - dev->hard_header_len; + dev->max_mtu = IP6_MAX_MTU - dev->hard_header_len; return 0; --- a/net/ipv6/sit.c +++ b/net/ipv6/sit.c @@ -1360,7 +1360,7 @@ static void ipip6_tunnel_setup(struct ne dev->hard_header_len = LL_MAX_HEADER + t_hlen; dev->mtu = ETH_DATA_LEN - t_hlen; dev->min_mtu = IPV6_MIN_MTU; - dev->max_mtu = 0xFFF8 - t_hlen; + dev->max_mtu = IP6_MAX_MTU - t_hlen; dev->flags = IFF_NOARP; netif_keep_dst(dev); dev->addr_len = 4; @@ -1572,7 +1572,8 @@ static int ipip6_newlink(struct net *src if (tb[IFLA_MTU]) { u32 mtu = nla_get_u32(tb[IFLA_MTU]); - if (mtu >= IPV6_MIN_MTU && mtu <= 0xFFF8 - dev->hard_header_len) + if (mtu >= IPV6_MIN_MTU && + mtu <= IP6_MAX_MTU - dev->hard_header_len) dev->mtu = mtu; }
