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Patch "ip_gre: remove the incorrect mtu limit for ipgre tap" has been added to the 4.14-stable tree

PATCH [email protected] 1 participant 1 message Feb 28, 2018

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This is a note to let you know that I've just added the patch titled

ip_gre: remove the incorrect mtu limit for ipgre tap

to the 4.14-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:
ip_gre-remove-the-incorrect-mtu-limit-for-ipgre-tap.patch
and it can be found in the queue-4.14 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

Quoted 1 line

From foo@baz Wed Feb 28 16:23:28 CET 2018

From: Xin Long <[email protected]>
Date: Mon, 18 Dec 2017 14:24:35 +0800
Subject: ip_gre: remove the incorrect mtu limit for ipgre tap

From: Xin Long <[email protected]>

[ Upstream commit cfddd4c33c254954927942599d299b3865743146 ]

ipgre tap driver calls ether_setup(), after commit 61e84623ace3 ("net: centralize net_device min/max MTU checking"), the range of mtu is [min_mtu, max_mtu], which is [68, 1500] by default.

It causes the dev mtu of the ipgre tap device to not be greater than 1500, this limit value is not correct for ipgre tap device.

Besides, it's .change_mtu already does the right check. So this patch is just to set max_mtu as 0, and leave the check to it's .change_mtu.

Fixes 61e84623ace3 ("net: centralize net_device min/max MTU checking")
---
 net/ipv4/ip_gre.c |    1 +
 1 file changed, 1 insertion(+)
net/ipv4/ip_gre.c +1 -0
@@ -1274,6 +1274,7 @@ static const struct net_device_ops erspa
 static void ipgre_tap_setup(struct net_device *dev)
 {
 	ether_setup(dev);
+	dev->max_mtu = 0;
 	dev->netdev_ops	= &gre_tap_netdev_ops;
 	dev->priv_flags &= ~IFF_TX_SKB_SHARING;
 	dev->priv_flags	|= IFF_LIVE_ADDR_CHANGE;

Patches currently in stable-queue which might be from [email protected] are

queue-4.14/ip_gre-remove-the-incorrect-mtu-limit-for-ipgre-tap.patch queue-4.14/ip6_gre-remove-the-incorrect-mtu-limit-for-ipgre-tap.patch queue-4.14/ip6_tunnel-allow-ip6gre-dev-mtu-to-be-set-below-1280.patch queue-4.14/vxlan-update-skb-dst-pmtu-on-tx-path.patch queue-4.14/ip6_tunnel-get-the-min-mtu-properly-in-ip6_tnl_xmit.patch queue-4.14/sctp-fix-the-issue-that-a-__u16-variable-may-overflow-in-sctp_ulpq_renege.patch