Re: [PATCH net] ipv6: un-do: defrag: drop non-last frags smaller than min mtu

[Sasha Levin <sashal@kernel.org>]

On Mon, Apr 08, 2019 at 08:49:52AM -0600, Captain Wiggum wrote:
>Hi Sasha,
>
>This patch cannot be applied to upstream, the code is significantly different.
>Therefore, this un-do patch would not be seen in the upstream git log.
>It was solved there by coding a better solution, not by the un-do patch.

Okay, so this is effectively a request to diverge the -stable tree from
upstream in a non-trivial way, which is why I asked David Miller to ack
this act explcitly (or to send me patches, or whatever else he thinks is
appropriate here).

>Please consider this:
>Upstream passes the TAHI IPv6 protocol tests. All the LTS kernels do NOT.
>This is the patch that causes the failure in 4.9, 4.14, 4.19 LTS kernels.

I very much agree that this should get fixed. My concerns are not with
the bug but are with the proposed fix as it applies to -stable trees.

>And this patch has been in place with 4.9.134, a long time.
>It is not right that "Linux" can not pass the IPv6 protocol test.
>My executive are asking me why "Linux" is not fit for IPv6 deployments.

Arguments such as this carry no weight in a more technical discussion
such as this. Yes, some tests are currently broken, but we will not take
shortcuts just because "executives are unhappy".

--
Thanks,
Sasha