4.14-stable review patch. If anyone has any objections, please let me know.
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From: Alexey Kodanev alexey.kodanev@oracle.com
[ Upstream commit 128bb975dc3c25d00de04e503e2fe0a780d04459 ]
Commit b05229f44228 ("gre6: Cleanup GREv6 transmit path, call common GRE functions") moved dev->mtu initialization from ip6gre_tunnel_setup() to ip6gre_tunnel_init(), as a result, the previously set values, before ndo_init(), are reset in the following cases:
* rtnl_create_link() can update dev->mtu from IFLA_MTU parameter.
* ip6gre_tnl_link_config() is invoked before ndo_init() in netlink and ioctl setup, so ndo_init() can reset MTU adjustments with the lower device MTU as well, dev->mtu and dev->hard_header_len.
Not applicable for ip6gretap because it has one more call to ip6gre_tnl_link_config(tunnel, 1) in ip6gre_tap_init().
Fix the first case by updating dev->mtu with 'tb[IFLA_MTU]' parameter if a user sets it manually on a device creation, and fix the second one by moving ip6gre_tnl_link_config() call after register_netdevice().
Fixes: b05229f44228 ("gre6: Cleanup GREv6 transmit path, call common GRE functions") Fixes: db2ec95d1ba4 ("ip6_gre: Fix MTU setting") Signed-off-by: Alexey Kodanev alexey.kodanev@oracle.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/ipv6/ip6_gre.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-)
--- a/net/ipv6/ip6_gre.c +++ b/net/ipv6/ip6_gre.c @@ -337,11 +337,12 @@ static struct ip6_tnl *ip6gre_tunnel_loc
nt->dev = dev; nt->net = dev_net(dev); - ip6gre_tnl_link_config(nt, 1);
if (register_netdevice(dev) < 0) goto failed_free;
+ ip6gre_tnl_link_config(nt, 1); + /* Can use a lockless transmit, unless we generate output sequences */ if (!(nt->parms.o_flags & TUNNEL_SEQ)) dev->features |= NETIF_F_LLTX; @@ -1307,7 +1308,6 @@ static void ip6gre_netlink_parms(struct
static int ip6gre_tap_init(struct net_device *dev) { - struct ip6_tnl *tunnel; int ret;
ret = ip6gre_tunnel_init_common(dev); @@ -1316,10 +1316,6 @@ static int ip6gre_tap_init(struct net_de
dev->priv_flags |= IFF_LIVE_ADDR_CHANGE;
- tunnel = netdev_priv(dev); - - ip6gre_tnl_link_config(tunnel, 1); - return 0; }
@@ -1411,12 +1407,16 @@ static int ip6gre_newlink(struct net *sr
nt->dev = dev; nt->net = dev_net(dev); - ip6gre_tnl_link_config(nt, !tb[IFLA_MTU]);
err = register_netdevice(dev); if (err) goto out;
+ ip6gre_tnl_link_config(nt, !tb[IFLA_MTU]); + + if (tb[IFLA_MTU]) + ip6_tnl_change_mtu(dev, nla_get_u32(tb[IFLA_MTU])); + dev_hold(dev); ip6gre_tunnel_link(ign, nt);