Re: FAILED: patch "[PATCH] mptcp: pm: re-using ID of unused removed ADD_ADDR" failed to apply to 5.15-stable tree

[Matthieu Baerts <matttbe@kernel.org>]

Hi Greg,

On 26/08/2024 15:37, gregkh@linuxfoundation.org wrote:
> 
> The patch below does not apply to the 5.15-stable tree.
> If someone wants it applied there, or to any other stable or longterm
> tree, then please email the backport, including the original git commit
> id to <stable@vger.kernel.org>.

Thank you for the notification!

(...)

> ------------------ original commit in Linus's tree ------------------
> 
> From e255683c06df572ead96db5efb5d21be30c0efaa Mon Sep 17 00:00:00 2001
> From: "Matthieu Baerts (NGI0)" <matttbe@kernel.org>
> Date: Mon, 19 Aug 2024 21:45:19 +0200
> Subject: [PATCH] mptcp: pm: re-using ID of unused removed ADD_ADDR
> 
> If no subflow is attached to the 'signal' endpoint that is being
> removed, the addr ID will not be marked as available again.
> 
> Mark the linked ID as available when removing the address entry from the
> list to cover this case.
> 
> Fixes: b6c08380860b ("mptcp: remove addr and subflow in PM netlink")

FYI, I think it is best not to backport this patch to v5.15: to fix the
issue, we need commit 86e39e04482b ("mptcp: keep track of local endpoint
still available for each msk") as well. This other commit is modifying
quite a bit of code, it depends on other ones, and it was seen as a new
feature at that time. Even if it improves the user experience, I think
it is best to consider this as an improvement, and keep the "annoying
behaviours", including the one being fixed here, as "known issues" in
this version.

In other words, I don't think we need to backport this patch to v5.15.

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