This is a note to let you know that I've just added the patch titled

    mptcp: ensure snd_una is properly initialized on connect

to the 5.10-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     mptcp-ensure-snd_una-is-properly-initialized-on-connect.patch
and it can be found in the queue-5.10 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


From stable+bounces-52669-greg=kroah.com@vger.kernel.org Tue Jun 18 14:25:14 2024
From: "Matthieu Baerts (NGI0)" <matttbe@kernel.org>
Date: Tue, 18 Jun 2024 14:24:45 +0200
Subject: mptcp: ensure snd_una is properly initialized on connect
To: stable@vger.kernel.org, gregkh@linuxfoundation.org
Cc: MPTCP Upstream <mptcp@lists.linux.dev>, Paolo Abeni <pabeni@redhat.com>, Mat Martineau <martineau@kernel.org>, Christoph Paasch <cpaasch@apple.com>, Matthieu Baerts <matttbe@kernel.org>, Jakub Kicinski <kuba@kernel.org>
Message-ID: <20240618122444.640369-2-matttbe@kernel.org>

From: Paolo Abeni <pabeni@redhat.com>

commit 8031b58c3a9b1db3ef68b3bd749fbee2e1e1aaa3 upstream.

This is strictly related to commit fb7a0d334894 ("mptcp: ensure snd_nxt
is properly initialized on connect"). It turns out that syzkaller can
trigger the retransmit after fallback and before processing any other
incoming packet - so that snd_una is still left uninitialized.

Address the issue explicitly initializing snd_una together with snd_nxt
and write_seq.

Suggested-by: Mat Martineau <martineau@kernel.org>
Fixes: 8fd738049ac3 ("mptcp: fallback in case of simultaneous connect")
Cc: stable@vger.kernel.org
Reported-by: Christoph Paasch <cpaasch@apple.com>
Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/485
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Reviewed-by: Mat Martineau <martineau@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://lore.kernel.org/r/20240607-upstream-net-20240607-misc-fixes-v1-1-1ab9ddfa3d00@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
[ Conflicts in protocol.c, similar to the ones from commit 99951b62bf20
  ("mptcp: ensure snd_nxt is properly initialized on connect"), with the
  same resolution. Note that in this version, 'snd_una' is an atomic64
  type, so use atomic64_set() instead, as it is done everywhere else. ]
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 net/mptcp/protocol.c |    1 +
 1 file changed, 1 insertion(+)

--- a/net/mptcp/protocol.c
+++ b/net/mptcp/protocol.c
@@ -2646,6 +2646,7 @@ static int mptcp_stream_connect(struct s
 		mptcp_subflow_early_fallback(msk, subflow);
 
 	WRITE_ONCE(msk->write_seq, subflow->idsn);
+	atomic64_set(&msk->snd_una, msk->write_seq);
 
 do_connect:
 	err = ssock->ops->connect(ssock, uaddr, addr_len, flags);


Patches currently in stable-queue which might be from kroah.com@vger.kernel.org are

queue-5.10/mptcp-pm-inc-rmaddr-mib-counter-once-per-rm_addr-id.patch
queue-5.10/mptcp-ensure-snd_una-is-properly-initialized-on-connect.patch
queue-5.10/mptcp-pm-update-add_addr-counters-after-connect.patch