From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794048642; b=ZyjX+77jNqMOf363oz7c2ASyEmc7TcwA2kqaIEaxkDeDWdycgbpI6+BnrHyMyK19TLWV pWvVdpL+gCS/zWQLCXbdekxvfTF5tzcclhKEYYzPNShecfA6p3UGPdg1krIXXdJ8x1IMc oAW+f1YS9uROLijK7vOuofUxjFtlUvc+yh/1Z/auoLEnYJwbmCZ8wESq3BfLUBK9uQ9Hz aiaA60L+k8XXIyJNIDMhh54nz8hFoTXizF0Ywo74OyeQ5HInTuu+rt1QG4aDDB/7hVUxF PXBVlj2gNOVfIb4GU6g4FLBkdwYPAxBKCJtQK6JvWFaH/E6K8+n5HU06vIzjjUIwLxA== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794048642; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: MIME-Version:Content-Type:Content-Transfer-Encoding; bh=5yTgIvNVTfJWEb9d9RIWYGa5VYS1s71N2kQ9a95q5X0=; b=W+BZCPnx7Uk3fCEIPVHNbsUEAHw13+d+fN5WhuFTWgzb5OpdRoDenElQRjGgh73NU7ZN xzfqfS2IGvtmAubsuc0fPad0KdNi4YPJY/bP4fkNhyapr0arFHtLqvmb1fnOWCnrPgQYA pCrQJWratvL5fBMXVgrATxoynAREoWiV3g7rRj5/55v2rRGNoQWin+FhXgb6mFKnqeAYE lA8Fnv9iYv7AnYBeSFfYfWf27pqhz+/EPdJo7NmkxU/fsbuXawvaZxze9WWytsCQOP6Mf a7qX0eFV0Xw3eqCATlW88eptB2iYyPF/wqsJbg31hQ9chrTS02P1NfpZ+/p89P5qssA== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=bI4Tj5LO; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 97F6E606A336 for ; Sat, 7 Nov 2026 10:50:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=bI4Tj5LO Received: by smtp.kernel.org (Postfix) with ESMTPSA id ED32F1F0089F; Sat, 7 Nov 2026 10:50:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794048642; bh=5yTgIvNVTfJWEb9d9RIWYGa5VYS1s71N2kQ9a95q5X0=; h=From:To:Cc:Subject:Date; b=bI4Tj5LOtw/6Up+yhXmHFR48p678EqkJMy7XQAAAuvvYlafQxStl0pYJi5vlF+yUU ZWGMQd710FDO/+QfSWHHbacLfgxGNBIS20aGbinxBsFYKPaX0BR07ENr8KyDGsd2NB H4kIiPzlETcsO03/E22gyqB5k766cXNzzexI4H+9fEa8u/VFx6jZyGR4ImrOn86BXk igIO4Wsz8KAd+WhzHUT3NqE5adTyJNUO27frWefvieaXbbVW3NYr5xSuUAaCIM8nQ6 PyYGtVg9s/Caah5cHzGxPEKowDXEm2rO6nEBvcQtGNjsFI0NeaH0r44D4DuOCFKOb9 bYkAP9eydFphQ== From: Sasha Levin To: quanyeyang@proton.me, matttbe@kernel.org, kuba@kernel.org Cc: stable@vger.kernel.org Subject: FAILED: patch "[PATCH] mptcp: reset msk state on early connect failure" failed to apply to 6.1-stable tree Date: Sat, 7 Nov 2026 05:50:40 -0500 Message-ID: <20261107055040-failed-6.1-29afe67082b2@kernel.org> X-Mailer: git-send-email 2.53.0 X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit 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 . 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 29afe67082b2d33ab2e90c56c337235d725f023f # git commit -s git send-email --to '' --in-reply-to '20261107055040-failed-6.1-29afe67082b2@kernel.org' --subject-prefix 'PATCH 6.1.y' 'HEAD^..' Thanks, Sasha ------------------ original commit in Linus's tree ------------------ >From 29afe67082b2d33ab2e90c56c337235d725f023f Mon Sep 17 00:00:00 2001 From: Quanye Yang Date: Tue, 13 Oct 2026 16:29:19 +0200 Subject: [PATCH] mptcp: reset msk state on early connect failure mptcp_connect() can fall back before the subflow SYN is sent, for example when the netns is in an MPTCP blackhole, token allocation fails, or MD5SIG is in use. If the subsequent subflow connect() fails immediately (EAFNOSUPPORT, ENETUNREACH, ...), __inet_stream_connect() returns while the socket is still SS_UNCONNECTED and never calls ->disconnect(). This was reported by Clashiko [1]. The error path only dropped the token and moved the msk back to TCP_CLOSE. MPTCP_FALLBACK_DONE, allow_subflows and request_mptcp were left as after early fallback, so a later connect() on the same fd stayed TCP-only. Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/633 [1] Fixes: 0235d075a592 ("mptcp: mark as fallback even early ones") Cc: stable@vger.kernel.org Signed-off-by: Quanye Yang Reviewed-by: Matthieu Baerts (NGI0) Signed-off-by: Matthieu Baerts (NGI0) Link: https://patch.msgid.link/20261013-net-mptcp-misc-fixes-7-3-rc8-v1-1-932c9b182fc7@kernel.org Signed-off-by: Jakub Kicinski --- net/mptcp/protocol.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index e89a69ab927c9..e6f73a5ee630a 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -4212,9 +4212,16 @@ static int mptcp_connect(struct sock *sk, struct sockaddr_unsized *uaddr, * subflow_finish_connect() */ if (unlikely(err)) { - /* avoid leaving a dangling token in an unconnected socket */ mptcp_token_destroy(msk); mptcp_set_state(sk, TCP_CLOSE); + + spin_lock_bh(&msk->fallback_lock); + msk->allow_subflows = true; + msk->allow_infinite_fallback = true; + clear_bit(MPTCP_FALLBACK_DONE, &msk->flags); + spin_unlock_bh(&msk->fallback_lock); + + mptcp_subflow_ctx_reset(mptcp_subflow_ctx(ssk)); return err; } -- 2.53.0