Re: [PATCH mptcp-net v2 1/2] mptcp: reset msk state on early connect failure

[Matthieu Baerts <matttbe@kernel.org>]

On 06/10/2026 19:36, Matthieu Baerts wrote:
> Hi Quanye,
> 
> On 11/09/2026 17:42, Quanye Yang via B4 Relay wrote:
>> From: Quanye Yang <quanyeyang@proton.me>
>>
>> mptcp_connect() can fall back before the subflow SYN is sent, for
>> example when the netns is in an MPTCP blackhole, token allocation
>> fails, or MD5SIG is in use. If the subsequent subflow connect()
>> fails immediately (EAFNOSUPPORT, ENETUNREACH, ...),
>> __inet_stream_connect() returns while the socket is still
>> SS_UNCONNECTED and never calls ->disconnect().
>>
>> The error path only dropped the token and moved the msk back to
>> TCP_CLOSE. MPTCP_FALLBACK_DONE, allow_subflows and
>> request_mptcp were left as after early fallback, so a later
>> connect() on the same fd stayed TCP-only.
> 
> Thank you for the new version, and for your patience! This patch looks
> good to me:
> 
> Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>

Now in our tree:

New patches for t/upstream-net and t/upstream:
- 070796c3cfb9: mptcp: reset msk state on early connect failure
- Results: 55d917c22cff..a89bac927400 (export-net)
- Results: 3f56793da91f..3ec672648191 (export)

Tests are now in progress:

- export-net:
https://github.com/multipath-tcp/mptcp_net-next/commit/fe786c67a826c2b32c8a2882858ab9ab45b7cfe0/checks
- export:
https://github.com/multipath-tcp/mptcp_net-next/commit/bd2d51a45268c4bc02f5bdf66c5605ff6de59afd/checks

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