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 C0393241CB7; Tue, 8 Sep 2026 14:14:29 +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=1788876876; cv=none; b=NdeQzzVcHh6MOwzW+INy1WOBvYSBb2vQQl4ZQklfUIzAhTG5YVcLgIV6K2v/IrxPJd+t9zSDEQKcVfP50HikwGhWfmemeLI0WiOy8mwqQdxhH0+ncvbqlncM1arCyHajL3Fnjcne2zcZwGJXqF0Mn68ZlhaswGLQ5w5SCHM0W7g= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788876876; c=relaxed/simple; bh=xGnuahGwPP4f82k0zQU436ZpG60wJ/aEuwZt7vnyH40=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=JZMowbOyvbaJMgyEcJdSY8yHyvDzvm1srTkVqdecBgBvmfbMGSF/C06yaS+fPvjyrF1TRhMBk8gNz3KzY4oFGTpE2bXqoLTfs4nrPbFrJ9akpQxhocmTXx4yyjXnsIsoLgbYIHCQvSDu2CZnK5uVk/8usQCkUolRcTMEFe5WTPw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=HLmpwWLm; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="HLmpwWLm" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8C2B81F00AC4; Tue, 8 Sep 2026 14:14:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1788876865; bh=NqkLnNdB1iaPRZgzHgODWa8SlkXcWwYoiM8hBJRiEzc=; h=From:Date:Subject:References:In-Reply-To:To:Cc; b=HLmpwWLmY3lKHL14XJaUCgEBnNq58yiKP83mpEFIqmWz6bCK4TKq2nH5sxqNhFb1Y RXF2lxMhMJZbEUGSzljRwYf6PZO9I17NCO+02uJyQuPszaZYUggDcldE1eUYrP5LEE cicSGXc7aKq/tiCZ3pY4KDt5Ub320fxgTxwfWYgcAS5aJynB7ws8a+W2nIfpCr/GSb e0CIObRQCMoT/HwyZ2XQz+ysKab2/w3h7Oz697/vfOZZUBlie1NqyH9GP4XPg3iile JcQqlibgQY2wMMoKKEEpkOCotM5vhFRaAZVRr93nvpDTHuripXqTM3EH3LRINpI3jE 2T1qzMKkPaxWw== From: "Matthieu Baerts (NGI0)" Date: Tue, 08 Sep 2026 16:07:09 +0200 Subject: [PATCH net v2 04/15] mptcp: pm: kernel: drop pending ADD_ADDR when removing ID0 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260908-net-mptcp-misc-fixes-7-3-rc1-v2-4-df1de70348b6@kernel.org> References: <20260908-net-mptcp-misc-fixes-7-3-rc1-v2-0-df1de70348b6@kernel.org> In-Reply-To: <20260908-net-mptcp-misc-fixes-7-3-rc1-v2-0-df1de70348b6@kernel.org> To: Mat Martineau , Geliang Tang , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman Cc: netdev@vger.kernel.org, mptcp@lists.linux.dev, linux-kernel@vger.kernel.org, "Matthieu Baerts (NGI0)" , Kalpan Jani , stable@vger.kernel.org, syzbot+55c2a5c871441261ed14@syzkaller.appspotmail.com, Tao Cui X-Mailer: b4 0.16.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=2746; i=matttbe@kernel.org; h=from:subject:message-id; bh=BiUuBgq0c7aOBr6JJpkC2oZ8vE+NuO1ltFCd3RnPXgo=; b=owGbwMvMwCVWo/Th0Gd3rumMp9WSGLIWSGg+jpR9sNbqe1nXhsAXa379uDutLnXbovXn7/zav 0b1X/4OpY5SFgYxLgZZMUUW6bbI/JnPq3hLvPwsYOawMoEMYeDiFICJ/Ndn+Gd0e9v1v9Fh1xOO Vd13myd/YX9eZ2Xaaw/d9VUr1B41cisxMmzLNt0W/fz95528L7r9VhlP353YGSEjt/bf0ZqvZXr +/7gB X-Developer-Key: i=matttbe@kernel.org; a=openpgp; fpr=E8CB85F76877057A6E27F77AF6B7824F4269A073 From: Kalpan Jani 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) --- v2: use new helpers name, note about "port = 0". --- net/mptcp/pm_kernel.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/net/mptcp/pm_kernel.c b/net/mptcp/pm_kernel.c index 424f1a7f9248..1a7750813235 100644 --- a/net/mptcp/pm_kernel.c +++ b/net/mptcp/pm_kernel.c @@ -1137,6 +1137,8 @@ static int mptcp_nl_remove_id_zero_address(struct net *net, 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_address(struct net *net, 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); -- 2.55.0