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=1794273591; b=sgMEBKnB8K6zQBwz2cB9wGKpJ+N1WVvNs4UYyVB4QBsNqua9UUHSsrA9jvjPGTnud8+l VHb+cppHWxPJHgoAZ/ZA79MqLRrlhY0NmyvTnTEUeh+tALZ+vro7IUbHjNLEOEQO3sPYL +BxJAs+0h1fGstvf0r6hvZ/OflVH7TlswBImSR99qenSnu1KWTbvbrPUE0J9r65nXbZxm Tfkbv3syeeqCdqxjhp83o7rYrwDIVa4HlWjH11aLwq6tcpIrnCLXw2MR+fL4btpb46X8u /PNrxibZoUnL7nOmI7DFiNZy751XfY3U2JpAHLYc3nRCUDk486oZXe/nO++lSmRiVZQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794273591; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: MIME-Version:Content-Type:Content-Transfer-Encoding; bh=QD9yBGn+tDF0mr/ojccIRckXVs5vU708t29lNBL6WwA=; b=hi3vvmq642Yq1FW/+WEB8i/KjfVSItkgdl7+d1hikjIkc9V8QVjQluULmTKiAzNJ/r4U EVsKpQaHfZVjdYeN4rUc9favTWhWxJ6Khhv/88zXr0E830INlARcS1wuWk5ArIUxW1K3a AvZNN/eLaLBXuhVgknTbvqBd/KI0GYVczN4dM0UOjuqXV/BQ1QsjnMxPw6jyvFgdAqD23 +wjD5S8LHuzB2vCa2/HwRjbAOZqT50ErdBZAreniKrPKARxsuacG6iiYhUF653l/M/SpP 0XklrtYVqaG9kjp09FwJC8f3S6Ju0oJn+Tv0/rc0jg6N+WQXwfkJ9DNTLuXTRGQyx2Q== 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="k/e/Jd+Q"; 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 2CA69606A333 for ; Tue, 10 Nov 2026 01:19:51 +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=k/e/Jd+Q Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7CA421F008A6; Tue, 10 Nov 2026 01:19:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794273591; bh=QD9yBGn+tDF0mr/ojccIRckXVs5vU708t29lNBL6WwA=; h=From:To:Cc:Subject:Date; b=k/e/Jd+QuZrzK8En8Juv2PbOT71Qv2FEdDfPvHFw73RgbnPDB6N5GuhwSBAUfNnmr xeJELcdcA6aGsYRiqUWB5CAe+ww6V+wacJy7GF+92mq0yzWcTRuDugj8wNGQrjPuro eIAE63eXTJGZb90q2jPR+paDEk4SN9rH0J4qBG1D5e9IY6xqKojhuik6kmtlu/0Pwu rVGdn6ygTl2AV8QxFU10mGNdb2/G5Go/Sfvy7KyTLCsS70M3CiZPbZM3qeIo0yvrDr PHS08ayXvEjBMZeAFBYg6YzF8C9yUOsVMxashwtRUBmmcUO7Uw6CZC7eMpKtL+OnBm BXZm/kMJkr5WQ== From: Sasha Levin To: kylebot@openai.com, matttbe@kernel.org, pabeni@redhat.com Cc: stable@vger.kernel.org Subject: FAILED: patch "[PATCH] mptcp: pm: kernel: use RCU to free endpoint listeners" failed to apply to 6.1-stable tree Date: Mon, 9 Nov 2026 20:19:49 -0500 Message-ID: <20261109201949-failed-6.1-49b09ae0bf57@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 49b09ae0bf57b4230187d4cdd0a370558e44a6e8 # git commit -s git send-email --to '' --in-reply-to '20261109201949-failed-6.1-49b09ae0bf57@kernel.org' --subject-prefix 'PATCH 6.1.y' 'HEAD^..' Thanks, Sasha ------------------ original commit in Linus's tree ------------------ >From 49b09ae0bf57b4230187d4cdd0a370558e44a6e8 Mon Sep 17 00:00:00 2001 From: Kyle Zeng Date: Thu, 29 Oct 2026 21:22:55 -0700 Subject: [PATCH] mptcp: pm: kernel: use RCU to free endpoint listeners mptcp_pm_nl_create_listen_socket() starts the TCP listener directly instead of going through mptcp_listen(). It consequently misses setting SOCK_RCU_FREE on the parent MPTCP socket. tcp_child_process() can invoke the listener's subflow_data_ready() callback without holding the MPTCP parent lock or a reference to the parent. An authenticated MP_JOIN racing with endpoint teardown can therefore access the parent after its last reference has been dropped. The ADD_ADDR error path can also close an already published listener. Set SOCK_RCU_FREE before __inet_listen_sk() publishes the TCP listener, matching mptcp_listen(). This protects the parent on every subsequent close path, including a failed endpoint addition. Fixes: 1729cf186d8a ("mptcp: create the listening socket for new port") Cc: stable@vger.kernel.org Signed-off-by: Kyle Zeng Reviewed-by: Matthieu Baerts (NGI0) Link: https://patch.msgid.link/20261030042255.74216-1-kylebot@openai.com Signed-off-by: Paolo Abeni --- net/mptcp/pm_kernel.c | 1 + 1 file changed, 1 insertion(+) diff --git a/net/mptcp/pm_kernel.c b/net/mptcp/pm_kernel.c index 1a77508132354..f7396628490e3 100644 --- a/net/mptcp/pm_kernel.c +++ b/net/mptcp/pm_kernel.c @@ -906,6 +906,7 @@ static int mptcp_pm_nl_create_listen_socket(struct sock *sk, * old status is known (TCP_CLOSE). */ inet_sk_state_store(newsk, TCP_LISTEN); + sock_set_flag(newsk, SOCK_RCU_FREE); lock_sock(ssk); WRITE_ONCE(mptcp_subflow_ctx(ssk)->pm_listener, true); err = __inet_listen_sk(ssk, backlog); -- 2.53.0