From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C764D3A48E3; Thu, 17 Sep 2026 15:57:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789660637; cv=none; b=dpFgTKUUC4lF9DL/hFp3wAD+9TrwrAYjHs72TfFLMIfHptjHzPBsCYVwKDfS6T50zHBbSfYBRyiWR4EIwx9DZ89xdIk1UI1WcfindMX08pxvklCyLZ+bGLL9aLcecp/MjOnMMS/Oz7ZOw+/xGKLzWyu6TQbgPAoiY/49HtmnP8Q= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789660637; c=relaxed/simple; bh=vFaO+Xp94YuPdB6YRQW/2IMJQDcBNK5IHLEqfkcuBDk=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ssu7GkuKxn74ER457PZvpp/Ro1g8LpKrS+L2bOVaZljRkNZYbNKOCoc2AFQLEeDLtzl7LMhDZ4fgiS7/37gsbyK+UaYPP/k4tipBDf0c45WRLbnJDpBRRqIEP8iWPo417NE2fKdF+ea+7qVdadYAvmHfbMpZ0Zu3l9QPcaywUCs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=ukIS3aFb; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="ukIS3aFb" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2597C1F000FF; Thu, 17 Sep 2026 15:57:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1789660635; bh=MqJfd8PG+OqyLFLidUGixvx7vXNnr9vaHjiC7FSrMmo=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=ukIS3aFbfh8S5ieW0AE97D72WCj93CRQfregxOSbB5WTS/YYJqtU4Ej6qT99Bvjbs aGM51sS4+yxotQwxlsrYM9Ga5C0mSXyCEogQBpHwocIYLuIICBAWtp7KnNNjM+C90u nWwm12qIAuU4Y+ga0/RJlg/j4S9FkuxlpgpPqiw8= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, syzbot+55c2a5c871441261ed14@syzkaller.appspotmail.com, Tao Cui , Kalpan Jani , "Matthieu Baerts (NGI0)" , Jakub Kicinski Subject: [PATCH 7.2 621/733] mptcp: pm: kernel: drop pending ADD_ADDR when removing ID0 Date: Thu, 17 Sep 2026 16:15:29 +0100 Message-ID: <20260917151408.011388298@linuxfoundation.org> X-Mailer: git-send-email 2.55.0 In-Reply-To: <20260917151350.597953846@linuxfoundation.org> References: <20260917151350.597953846@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: patches@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 7.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Kalpan Jani commit 2ac7d6e620764f1fc79eb4edd3610a7a661981ca upstream. The in-kernel MPTCP path manager can leave a stale ADD_ADDR announcement entry alive when removing the id 0 endpoint. This happens because the id 0 removal path does not tear down pending announcements, unlike the non-zero id path. When the PM later reselects id 0 after adding another signal endpoint, it finds the stale anno_list entry and hits WARN_ON_ONCE(mptcp_pm_is_kernel()) in mptcp_pm_announced_alloc(). Root cause: asymmetry between removal paths. - Non-zero id path: mptcp_nl_remove_subflow_and_signal_addr() calls mptcp_pm_remove_announced() to clean up. - Id 0 path: mptcp_nl_remove_id_zero_address() skips cleanup entirely. Fix by making the id 0 path symmetric: call mptcp_pm_announced_remove() and decrement add_addr_signaled before queuing the RM_ADDR. Subtle detail: signal endpoints are stored in anno_list with port 0, but msk_local carries the connection's local port. In other words, entries linked to ID0 paths should have port == 0. A follow-up patch will ensure that. mptcp_pm_announced_remove() uses use_port=true for comparison. So clear the port before the lookup. Fixes: 740d798e8767 ("mptcp: remove id 0 address") Cc: stable@vger.kernel.org Reported-by: syzbot+55c2a5c871441261ed14@syzkaller.appspotmail.com Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/620 Suggested-by: Tao Cui Signed-off-by: Kalpan Jani Reviewed-by: Matthieu Baerts (NGI0) Signed-off-by: Matthieu Baerts (NGI0) Link: https://patch.msgid.link/20260908-net-mptcp-misc-fixes-7-3-rc1-v2-4-df1de70348b6@kernel.org Signed-off-by: Jakub Kicinski Signed-off-by: Greg Kroah-Hartman --- net/mptcp/pm_kernel.c | 8 ++++++++ 1 file changed, 8 insertions(+) --- a/net/mptcp/pm_kernel.c +++ b/net/mptcp/pm_kernel.c @@ -1137,6 +1137,8 @@ static int mptcp_nl_remove_id_zero_addre while ((msk = mptcp_token_iter_next(net, &s_slot, &s_num)) != NULL) { struct sock *sk = (struct sock *)msk; struct mptcp_addr_info msk_local; + struct mptcp_addr_info anno_addr; + bool announced; if (list_empty(&msk->conn_list) || mptcp_pm_is_userspace(msk)) goto next; @@ -1146,7 +1148,13 @@ static int mptcp_nl_remove_id_zero_addre goto next; lock_sock(sk); + /* Drop a possibly pending ADD_ADDR for this address. */ + anno_addr = msk_local; + anno_addr.port = 0; + announced = mptcp_pm_announced_remove(msk, &anno_addr); spin_lock_bh(&msk->pm.lock); + if (announced) + msk->pm.add_addr_signaled--; mptcp_pm_remove_addr(msk, &list); mptcp_pm_rm_subflow(msk, &list); __mark_subflow_endp_available(msk, 0);