Re: Patch "selftests: mptcp: join: validate C-flag + def limit" has been added to the 5.10-stable tree

Re: Patch "selftests: mptcp: join: validate C-flag + def limit" has been added to the 5.10-stable tree

[Matthieu Baerts]

Hi Greg,

On 16/10/2025 15:25, gregkh@linuxfoundation.org wrote:
> 
> This is a note to let you know that I've just added the patch titled
> 
>     selftests: mptcp: join: validate C-flag + def limit
> 
> to the 5.10-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:
>      selftests-mptcp-join-validate-c-flag-def-limit.patch
> and it can be found in the queue-5.10 subdirectory.
> 
> If you, or anyone else, feels it should not be added to the stable tree,
> please let <stable@vger.kernel.org> know about it.

I do! :)
> From 008385efd05e04d8dff299382df2e8be0f91d8a0 Mon Sep 17 00:00:00 2001
> From: "Matthieu Baerts (NGI0)" <matttbe@kernel.org>
> Date: Thu, 25 Sep 2025 12:32:37 +0200
> Subject: selftests: mptcp: join: validate C-flag + def limit
> 
> From: Matthieu Baerts (NGI0) <matttbe@kernel.org>
> 
> commit 008385efd05e04d8dff299382df2e8be0f91d8a0 upstream.
> 
> The previous commit adds an exception for the C-flag case. The
> 'mptcp_join.sh' selftest is extended to validate this case.
> 
> In this subtest, there is a typical CDN deployment with a client where
> MPTCP endpoints have been 'automatically' configured:
> 
> - the server set net.mptcp.allow_join_initial_addr_port=0
> 
> - the client has multiple 'subflow' endpoints, and the default limits:
>   not accepting ADD_ADDRs.
> 
> Without the parent patch, the client is not able to establish new
> subflows using its 'subflow' endpoints. The parent commit fixes that.
> 
> The 'Fixes' tag here below is the same as the one from the previous
> commit: this patch here is not fixing anything wrong in the selftests,
> but it validates the previous fix for an issue introduced by this commit
> ID.
> 
> Fixes: df377be38725 ("mptcp: add deny_join_id0 in mptcp_options_received")

This commit has been introduced in v5.14, and not backported before. Do
you mind dropping it from v5.10 please? :)

Cheers,
Matt
-- 
Sponsored by the NGI0 Core fund.