FAILED: patch "[PATCH] sctp: close UDP tunnel sockets during netns teardown" failed to apply to 5.10-stable tree

[<gregkh@linuxfoundation.org>]

The patch below does not apply to the 5.10-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-5.10.y
git checkout FETCH_HEAD
git cherry-pick -x ffb2bd7ade36ec4da32c46a6eddbf4515316d08c
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2026072947-cried-undermost-ddcd@gregkh' --subject-prefix 'PATCH 5.10.y' 'HEAD^..'

Possible dependencies:



thanks,

greg k-h

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

From ffb2bd7ade36ec4da32c46a6eddbf4515316d08c Mon Sep 17 00:00:00 2001
From: Zhiling Zou <roxy520tt@gmail.com>
Date: Wed, 15 Jul 2026 09:50:11 +0800
Subject: [PATCH] sctp: close UDP tunnel sockets during netns teardown

proc_sctp_do_udp_port() starts per-net SCTP UDP tunneling sockets when
net.sctp.udp_port is set, and stops/restarts them when the sysctl value
changes. The netns exit path does not stop these sockets, so a namespace
can be torn down while its SCTP UDP tunnel sockets are still installed.

Close the UDP tunnel sockets from sctp_ctrlsock_exit() after unregistering
the per-net sysctl table. This prevents new sysctl writes from racing in
while the sockets are being released, and closes the sockets before the
control socket is destroyed.

Fixes: 046c052b475e ("sctp: enable udp tunneling socks")
Cc: stable@vger.kernel.org
Reported-by: Sashiko <sashiko-bot@kernel.org>
Closes: https://sashiko.dev/#/patchset/b9f1f02b0780ad6a719e2413f5f0bb8eb7702d94.1782585631.git.roxy520tt%40gmail.com
Signed-off-by: Zhiling Zou <roxy520tt@gmail.com>
Signed-off-by: Ren Wei <n05ec@lzu.edu.cn>
Acked-by: Xin Long <lucien.xin@gmail.com>
Link: https://patch.msgid.link/6dab75f22855cb219e2e30a5497cab03b970ab91.1784033357.git.roxy520tt@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/sctp/protocol.c b/net/sctp/protocol.c
index 49d9740b1e0f..27c26e12f95d 100644
--- a/net/sctp/protocol.c
+++ b/net/sctp/protocol.c
@@ -1460,6 +1460,7 @@ static int __net_init sctp_ctrlsock_init(struct net *net)
 static void __net_exit sctp_ctrlsock_exit(struct net *net)
 {
 	sctp_sysctl_net_unregister(net);
+	sctp_udp_sock_stop(net);
 
 	/* Free the control endpoint.  */
 	inet_ctl_sock_destroy(net->sctp.ctl_sock);