Re: [PATCH mptcp-next 0/2] mptcp: pm: net-next port of the alloc-during-teardown leak fix

Matthieu Baerts <[email protected]> Fri, 31 Jul 2026 17:49:42 +0200
Newsgroups dev.linux.lists.mptcp
Organization NGI0 Core
Message-ID <[email protected]>
Hi Shardul,

On 20/06/2026 10:44, Shardul Bankar wrote:
> This is the net-next counterpart of the net fix "mptcp: pm: fix memory
> leak from alloc-during-teardown race" (v3):
> https://lore.kernel.org/all/[email protected]/
> 
> v3 remains the canonical fix for net; it applies as-is on export-net. It
> does not apply on export, because the userspace local address list free
> moved into the userspace path manager .release callback in "mptcp: pm:
> init and release mptcp_pm_ops". This series ports the fix to net-next:
> 
>   1/2 squashes the unconditional free into that refactor commit (covering
>       the disconnect/reuse path).
>   2/2 is the MPTCP_PM_DESTROYING fence (the alloc-during-teardown race),
>       rebased onto the renamed mptcp_pm_announced_alloc() /
>       mptcp_pm_destroy().
> 
> The net fix was validated with an MPTCP protocol-flow harness (BRF) over
> multi-hour runs with zero kmemleak reports (reported on the v3 thread).
> This port is structurally equivalent and is sent so the CI can exercise
> it on net-next.
Thank you for the v3, the reply to Sashiko's comment, and sorry for the
delay.

Note that I applied the patch from the v2 on top of net, and used the
message that was on the v3. I also reduced the comments in the code.

I got a bunch of conflicts, but that was expected.

Now in our tree:

New patches for t/upstream-net and t/upstream:
- 2b2f15275853: mptcp: pm: fix memory leak from alloc-during-teardown race
- f53bd07233a6: conflict in t/mptcp-pm-init-and-release-mptcp_pm_ops
- 919a44ee381d: "squashed" (with conflicts) in "mptcp: pm: init and
release mptcp_pm_ops"
- c7d92e52241a: conflict in t/mptcp-pm-add-get_local_id-interface
- 58c196b64826: conflict in t/mptcp-pm-add-get_priority-interface
- Results: 8fa2ab05d71f..a811f9685bfd (export-net)
- Results: 588708fb07a7..4cc6862c4795 (export)

Tests are now in progress:

- export-net:
https://github.com/multipath-tcp/mptcp_net-next/commit/a1feb73d0d2bb6aa9873ac55926f920e6d1209ba/checks
- export:
https://github.com/multipath-tcp/mptcp_net-next/commit/ca43dbbb8a8abda8ead4866bfd62b06bdf1c7d08/checks

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