Re: [PATCH net v2 2/6] mptcp: pm: fix ADD_ADDR timer infinite retry on option space insufficient

[Matthieu Baerts <matttbe@kernel.org>]

Hello,

On 15/05/2026 06:27, Matthieu Baerts (NGI0) wrote:
> From: Li Xiasong <lixiasong1@huawei.com>
> 
> When TCP option space is insufficient (e.g., when sending ADD_ADDR with an
> IPv6 address and port while tcp_timestamps is enabled), the original code
> jumped to out_unlock without clearing the addr_signal flag. This caused
> mptcp_pm_add_timer to keep rescheduling indefinitely, not sending ADD_ADDR,
> preventing subsequent addresses in the endpoint list from being announced.

(...)

> diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
> index 3c152bf66cd5..3e770c7407e1 100644
> --- a/net/mptcp/pm.c
> +++ b/net/mptcp/pm.c

(...)

> @@ -414,8 +420,12 @@ mptcp_pm_del_add_timer(struct mptcp_sock *msk,
>  	/* Note: entry might have been removed by another thread.
>  	 * We hold rcu_read_lock() to ensure it is not freed under us.
>  	 */
> -	if (stop_timer)
> -		sk_stop_timer_sync(sk, &entry->add_timer);
FYI, sashiko found a pre-existing issue here, but I guess that's not
blocking this series.

https://sashiko.dev/#/patchset/20260515-net-mptcp-misc-fixes-7-1-rc4-v2-0-701e96419f2f%40kernel.org

@Li: just to know what I do with this pre-existing issue, do you plan to
look at it?

Just in case, I just opened:

  https://github.com/multipath-tcp/mptcp_net-next/issues/623

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