Re: [PATCH mptcp-net v2] mptcp: fix extra_subflows leak on failed passive join

Hi Chenguang,

On 01/07/2026 05:20, Chenguang Zhao wrote:
> From: Chenguang Zhao <[email protected]>
> 
> mptcp_pm_allow_new_subflow() increments extra_subflows
> before __mptcp_finish_join() on the passive MP_JOIN path.
> On synchronous join failure the subflow is dropped without
> calling mptcp_close_ssk(), so the counter is not rolled back.
> 
> Call mptcp_pm_close_subflow() when the join completion fails.
> 
> Fixes: 3e5014909b56 ("mptcp: cleanup MPJ subflow list handling")
> Signed-off-by: Chenguang Zhao <[email protected]>
> Reviewed-by: Matthieu Baerts (NGI0) <[email protected]>

Thank you for the patch. Now in our tree (with small adaptations in the
commit message):

New patches for t/upstream-net and t/upstream:
- 5cc023a79ad5: mptcp: decrement subflows counter on failed passive join
- Results: 6e75226ac108..4c2362a7db02 (export-net)
- Results: 4c2752580a3e..4285a4fe811b (export)

Tests are now in progress:

- export-net:
https://github.com/multipath-tcp/mptcp_net-next/commit/bc033e934bd44ead5a065f26cb78af76769e90de/checks
- export:
https://github.com/multipath-tcp/mptcp_net-next/commit/254350c480d5cc9124500ba3588f2d24a1905608/checks

Cheers,
Matt
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