Re: [PATCH net v2 05/15] mptcp: options: handle MPC data + csum reqd + no csum

[Matthieu Baerts <matttbe@kernel.org>]

Hello,

On 09/09/2026 16:49, netdev-bot+sashiko@kernel.org wrote:
> Thank you for your contribution! Sashiko AI review found 1 potential
> issue(s) to consider:
> 
> Critical: 0 · High: 0 · Medium: 0 · Low: 1 (1)
> 
> - [Low] Residual uninitialised read of `mp_opt->csum`: the patch closes
>   the functional consumer of the uninitialised checksum…

There is a pr_debug() reading mp_opt->csum. Harmless, but should be
fixed to silence such report. A follow-up patch will follow:

https://lore.kernel.org/20260908-mptcp-opt-read-debug-v1-2-b3e74549b6f6@kernel.org

> Pre-existing issues:
> - [Low] Reported concern (assessed as an intentional, documented
>   behaviour change): a passive endpoint whose local checksum sysctl is…

(...)

> The commit message already
> covers that trade-off.  The gap where the peer's SYN A bit is never
> stored in subflow_req is pre-existing and unchanged here.

Indeed ...

> Would it be worth a short note in the commit message that the passive
> side's only source for the peer's A bit is the third ACK, so the new
> condition also drops that signal for a data-bearing third ACK?

... but there is already a note about that. Maybe the note is not clear
enough, or my English is not good enough, but I don't think we need to
add an even longer text.

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