FAILED: patch "[PATCH] mptcp: ensure subflow is unhashed before cleaning the backlog" failed to apply to 6.1-stable tree

FAILED: patch "[PATCH] mptcp: ensure subflow is unhashed before cleaning the backlog" failed to apply to 6.1-stable tree

[gregkh]

The patch below does not apply to the 6.1-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-6.1.y
git checkout FETCH_HEAD
git cherry-pick -x 3fffa15bfef48b0ad6424779c03e68ae8ace5acb
# <resolve conflicts, build, test, etc.>
git commit -s
git send-email --to '<stable@vger.kernel.org>' --in-reply-to '2023072102-finicky-everyday-cce4@gregkh' --subject-prefix 'PATCH 6.1.y' HEAD^..

Possible dependencies:

3fffa15bfef4 ("mptcp: ensure subflow is unhashed before cleaning the backlog")
57fc0f1ceaa4 ("mptcp: ensure listener is unhashed before updating the sk status")
2a6a870e44dd ("mptcp: stops worker on unaccepted sockets at listener close")
0a3f4f1f9c27 ("mptcp: fix UaF in listener shutdown")
b6985b9b8295 ("mptcp: use the workqueue to destroy unaccepted sockets")
c558246ee73e ("mptcp: add statistics for mptcp socket in use")
cfdcfeed6449 ("mptcp: introduce 'sk' to replace 'sock->sk' in mptcp_listen()")
fec3adfd754c ("mptcp: fix lockdep false positive")
7d803344fdc3 ("mptcp: fix deadlock in fastopen error path")
f8c9dfbd875b ("mptcp: add pm listener events")
f2bb566f5c97 ("Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net")

thanks,

greg k-h

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

From 3fffa15bfef48b0ad6424779c03e68ae8ace5acb Mon Sep 17 00:00:00 2001
From: Paolo Abeni <pabeni@redhat.com>
Date: Tue, 4 Jul 2023 22:44:33 +0200
Subject: [PATCH] mptcp: ensure subflow is unhashed before cleaning the backlog

While tacking care of the mptcp-level listener I unintentionally
moved the subflow level unhash after the subflow listener backlog
cleanup.

That could cause some nasty race and makes the code harder to read.

Address the issue restoring the proper order of operations.

Fixes: 57fc0f1ceaa4 ("mptcp: ensure listener is unhashed before updating the sk status")
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index e892673deb73..489a3defdde5 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -2909,10 +2909,10 @@ static void mptcp_check_listen_stop(struct sock *sk)
 		return;
 
 	lock_sock_nested(ssk, SINGLE_DEPTH_NESTING);
+	tcp_set_state(ssk, TCP_CLOSE);
 	mptcp_subflow_queue_clean(sk, ssk);
 	inet_csk_listen_stop(ssk);
 	mptcp_event_pm_listener(ssk, MPTCP_EVENT_LISTENER_CLOSED);
-	tcp_set_state(ssk, TCP_CLOSE);
 	release_sock(ssk);
 }
 

[PATCH 6.1.y] mptcp: ensure subflow is unhashed before cleaning the backlog

[Matthieu Baerts]

From: Paolo Abeni <pabeni@redhat.com>

commit 3fffa15bfef48b0ad6424779c03e68ae8ace5acb upstream.

While tacking care of the mptcp-level listener I unintentionally
moved the subflow level unhash after the subflow listener backlog
cleanup.

That could cause some nasty race and makes the code harder to read.

Address the issue restoring the proper order of operations.

Fixes: 57fc0f1ceaa4 ("mptcp: ensure listener is unhashed before updating the sk status")
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Matthieu Baerts <matthieu.baerts@tessares.net>
---
Backport notes:
  - it was conflicting with a new feature not present in v6.1, see
    commit f8c9dfbd875b ("mptcp: add pm listener events"): the call to
    mptcp_event_pm_listener() has not been taken, only tcp_set_state()
    has been moved here.
---
 net/mptcp/protocol.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c
index 4ca61e80f4bb..a6a5c16f2a49 100644
--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -2945,9 +2945,9 @@ static void mptcp_check_listen_stop(struct sock *sk)
 		return;
 
 	lock_sock_nested(ssk, SINGLE_DEPTH_NESTING);
+	tcp_set_state(ssk, TCP_CLOSE);
 	mptcp_subflow_queue_clean(sk, ssk);
 	inet_csk_listen_stop(ssk);
-	tcp_set_state(ssk, TCP_CLOSE);
 	release_sock(ssk);
 }
 
-- 
2.40.1