FAILED: patch "[PATCH] mptcp: pm: prio: skip closed subflows" failed to apply to 6.6-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 6.6-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@vger.kernel.org>.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y
git checkout FETCH_HEAD
git cherry-pick -x 166b78344031bf7ac9f55cb5282776cfd85f220e
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026051229-encounter-relish-ce49@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..

Possible dependencies:



thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 166b78344031bf7ac9f55cb5282776cfd85f220e Mon Sep 17 00:00:00 2001
From: "Matthieu Baerts (NGI0)" <matttbe@kernel.org>
Date: Tue, 5 May 2026 17:00:57 +0200
Subject: [PATCH] mptcp: pm: prio: skip closed subflows

When sending an MP_PRIO, closed subflows need to be skipped.

This fixes the case where the initial subflow got closed, re-opened
later, then an MP_PRIO is needed for the same local address.

Note that explicit MP_PRIO cannot be sent during the 3WHS, so it is fine
to use __mptcp_subflow_active().

Fixes: 067065422fcd ("mptcp: add the outgoing MP_PRIO support")
Cc: stable@vger.kernel.org
Fixes: b29fcfb54cd7 ("mptcp: full disconnect implementation")
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20260505-net-mptcp-pm-fixes-7-1-rc3-v1-9-fca8091060a4@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/mptcp/pm.c b/net/mptcp/pm.c
index 4a6e5ab30d80..3c152bf66cd5 100644
--- a/net/mptcp/pm.c
+++ b/net/mptcp/pm.c
@@ -284,6 +284,9 @@ int mptcp_pm_mp_prio_send_ack(struct mptcp_sock *msk,
 		struct sock *ssk = mptcp_subflow_tcp_sock(subflow);
 		struct mptcp_addr_info local, remote;
 
+		if (!__mptcp_subflow_active(subflow))
+			continue;
+
 		mptcp_local_address((struct sock_common *)ssk, &local);
 		if (!mptcp_addresses_equal(&local, addr, addr->port))
 			continue;