4.14-stable review patch. If anyone has any objections, please let me know.
------------------
From: Alexey Kodanev <alexey.kodanev@xxxxxxxxxx>
[ 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@xxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
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);