ACK: [SRU][Artful][Bionic][PATCH 0/1] ip_gre: remove the incorrect mtu limit for ipgre tap

[Kleber Souza]

On 01/19/18 16:54, Joseph Salisbury wrote:
> BugLink: http://bugs.launchpad.net/bugs/1743746
> 
> == SRU Justification ==
> The following mainline commit introduced a regression in v4.10-rc1:
> 61e84623ace3 ("net: centralize net_device min/max MTU checking")
> 
> In Artful and Bionic, it is not possible to configure GRE tunnel devices 
> with a MTU larger than 1500; this impacts on Open vSwitch (which creates 
> tunnel devices for GRE overlay networking) and the ip tools.
> 
> The kernel will error with:
>   "gre_sys: Invalid MTU 65000 requested, hw max 1500"
> 
> The side effect of this is that if overlay networks are configured with 
> high MTUs, the gre devices fragment the packets and networking is generally 
> slow/broken.
>    
> This regression is now fixed by mainline commit cfddd4c33c25, which was 
> added in v4.15-rc5.
>  
> 
> == Fix ==
> commit cfddd4c33c254954927942599d299b3865743146
> Author: Xin Long <lucien.xin at gmail.com>
> Date:   Mon Dec 18 14:24:35 2017 +0800
> 
>     ip_gre: remove the incorrect mtu limit for ipgre tap
> 
> 
> == Regression Potential ==
> Low.  This patch fixes a current regression.  It was cc'd to upstream stable
> so had additional upstream review.
> 
> == Test Case ==
> A test kernel was built with this patch and tested by the original bug reporter.
> The bug reporter states the test kernel resolved the bug.
> 
> Xin Long (1):
>   ip_gre: remove the incorrect mtu limit for ipgre tap
> 
>  net/ipv4/ip_gre.c | 1 +
>  1 file changed, 1 insertion(+)
> 

Acked-by: Kleber Sacilotto de Souza <kleber.souza at canonical.com>