From: Matthieu Baerts <matttbe@kernel.org>
To: Tao Cui <cuitao@kylinos.cn>, geliang@kernel.org
Cc: mptcp@lists.linux.dev
Subject: Re: [PATCH mptcp-next] mptcp: pm: add WARN_ON_ONCE guards on extra_subflows underflow
Date: Wed, 27 May 2026 21:40:48 +1000 [thread overview]
Message-ID: <4e5575e3-038b-43eb-9d63-9fcbd5116fcd@kernel.org> (raw)
In-Reply-To: <20260522085049.1896537-1-cuitao@kylinos.cn>
Hi Tao,
On 22/05/2026 18:50, Tao Cui wrote:
> extra_subflows is a u8 counter that can underflow if a decrement races
> with or precedes an increment. While the recently fixed userspace PM
> subflow creation path eliminated the primary cause, add defensive
> WARN_ON_ONCE guards at both decrement sites to catch any remaining edge
> cases rather than silently wrapping to 255.
Thank you for the patch:
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
New patches for t/upstream:
- abefe4ecdb46: mptcp: pm: add WARN_ON_ONCE guards on extra_subflows
underflow
- Results: c40ac68d9bc2..cde220b5fe28 (export)
Tests are now in progress:
- export:
https://github.com/multipath-tcp/mptcp_net-next/commit/02fc64d2cebb020984c74fb4950be7a46909b4d9/checks
Cheers,
Matt
--
Sponsored by the NGI0 Core fund.
prev parent reply other threads:[~2026-05-27 11:40 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-22 8:50 [PATCH mptcp-next] mptcp: pm: add WARN_ON_ONCE guards on extra_subflows underflow Tao Cui
2026-05-22 10:31 ` MPTCP CI
2026-05-27 11:40 ` Matthieu Baerts [this message]
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