Hi Greg,
On 19/02/2024 17:04, gregkh@linuxfoundation.org wrote:
The patch below does not apply to the 6.1-stable tree.
(...)
From 013e3179dbd2bc756ce1dd90354abac62f65b739 Mon Sep 17 00:00:00 2001 From: Paolo Abeni pabeni@redhat.com Date: Thu, 8 Feb 2024 19:03:50 +0100 Subject: [PATCH] mptcp: fix rcv space initialization
mptcp_rcv_space_init() is supposed to happen under the msk socket lock, but active msk socket does that without such protection.
Leverage the existing mptcp_propagate_state() helper to that extent. We need to ensure mptcp_rcv_space_init will happen before mptcp_rcv_space_adjust(), and the release_cb does not assure that: explicitly check for such condition.
While at it, move the wnd_end initialization out of mptcp_rcv_space_init(), it never belonged there.
Note that the race does not produce ill effect in practice, but change allows cleaning-up and defying better the locking model.
FYI, because of the various conflicts, and because the race explained here "does not produce ill effects in practice", with Paolo, we think it is best not to backport this patch to v6.1 and older.
Cheers, Matt