From nobody Mon May 20 00:09:14 2024 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 385133FBA2; Wed, 28 Feb 2024 17:33:23 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709141604; cv=none; b=eVkwdsjfQz1t23ItedY8I5+PUAElD1S6OIWcXUCh/lA7lFTV4eOaEuLaHzBtio6RxShypJQ+dfXcg+g8Wx/BdUtabDpzcnhQTiWkTHJ5Q1gFSpc2VRN6ZMa9GODbUobSyB6ezH8HyNmtZeOWo1vCFpeYmJT0FD3Y49vnFRAHYCk= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1709141604; c=relaxed/simple; bh=FfXFOgopppvVLsW5cOe0NR3KU/BWgkF143jEE5pgNKA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=SPcDO7Pk4z2pg7BBcoxbAoPCOokgr+kHMw0+lXKP/mvw10oD6SDzIyJf3ogpUJEZ0KdAdt+Oi0d43QmFWgL4tzZDtXynFRjbnE6vp0t6JnB6E3SOq4LK+MPM23uFNa5tkS+CM0PuEhe8BNtbL4RxuDpn4qfUtlk9wzZEcW/HuS0= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=FH9W2eRF; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="FH9W2eRF" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D9888C433C7; Wed, 28 Feb 2024 17:33:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1709141603; bh=FfXFOgopppvVLsW5cOe0NR3KU/BWgkF143jEE5pgNKA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=FH9W2eRFtUyRn8psdkRfUlLDUdcoHzTqEnv4VwdEAWp8lRu+VrO3nhAwbKdOL8ZZd HuK60/7eUp2NYmOfCF2gkEjJHzIerGPaTVuXVI8Y1iWqnbVfWfi2q2WLL6ZCMHP1cw nFtObaCx69hQPtImoBfKlo9bDakwOrbGVr5Z299zhdux9EYjreW1xniGRcgrJcHeWN RUDqS5MPba8XgiY4pL706uvT+mrwHsq/xd8i06vbINwXI3l7+DYb/0r+tARLmoV4X/ Sxi9DmorV/j+4y3AGRrGOvnE7qZ6T2gQFEeC32yFizKqhLHjmpaCWTlwRLHB5jrmZo 581ZPk24gpp2A== From: "Matthieu Baerts (NGI0)" To: stable@vger.kernel.org, gregkh@linuxfoundation.org Cc: MPTCP Upstream , Paolo Abeni , Mat Martineau , Matthieu Baerts , "David S . Miller" , Matthieu Baerts Subject: [PATCH 5.15.y] mptcp: process pending subflow error on close Date: Wed, 28 Feb 2024 18:33:18 +0100 Message-ID: <20240228173317.257282-2-matttbe@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <2023100447-durable-snowiness-8b36@gregkh> References: <2023100447-durable-snowiness-8b36@gregkh> Precedence: bulk X-Mailing-List: mptcp@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=3847; i=matttbe@kernel.org; h=from:subject; bh=AxhVWTnQXa9rlO+K6340OWBbJnkCouY5MXuW8bT9f1c=; b=owEBbQKS/ZANAwAIAfa3gk9CaaBzAcsmYgBl325dsKoLj8rJGkAkclpCdaVMcSTOEQaii9TVp npzRl0qfUCJAjMEAAEIAB0WIQToy4X3aHcFem4n93r2t4JPQmmgcwUCZd9uXQAKCRD2t4JPQmmg c1eYD/9WyqkuYqCacy4+tBcMT6hDDaNpiSGFg0Tty45Srii6TjW9mse41LS9yKItV9bLZWAP7FM z45iNgW84+ElaJf9FR3g3im6iCL5Gn/eqQ1AP4WCku9q+EiN5/U67Ul5EZTnKlN5Ob0IOonqjXz FGaBQAbA2XckcfN8j91kN7/Kssa/CVJdmmte6L+adcOFDMibEpKWOVEIChvDabeHv0P2IhbNUg5 AhGOfNbROpWUlXaxH9H/yb1q1xbbkQmdCHZAVQYzQ1RXoNgjJHrbJvz3XRQpEAlbNq4+QsIMv+0 PSk+1slxqjMDgh+KsrdAY35VwSVMkyDAjX5BQzcopFKzrW7yj25OLrMNKkLQ9JUfzEtJyYvYQIR lwxNu2bdqSlpHtyBUAwxFYqRO84ZIYLbpaOVw2yvBSP50Us/0KGX1iD7juQ/v8KHUVWmrcIBoEY c4Cf/qg1rwIfLv1D0kDVoxtHLAP7Asu0e+zIkTYXg0Sk90reHNJjv7DuJ7s1Od+qhag42/OdNla BX1NZzx+jF3SPQiI7f0hns/BsPXJTx8w2o90bE6bhBvDX5usv3hwuj3kh6sluVNZ0oWy74vWA3u javvwAsMkOip8Kn7iynjvetDgYiCuGSaTAAuetYuJBQszvt/pUrna7oV3FkZVKGi+Diz6mOA+Om N87MB5ucdiJwBtQ== X-Developer-Key: i=matttbe@kernel.org; a=openpgp; fpr=E8CB85F76877057A6E27F77AF6B7824F4269A073 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" From: Paolo Abeni On incoming TCP reset, subflow closing could happen before error propagation. That in turn could cause the socket error being ignored, and a missing socket state transition, as reported by Daire-Byrne. Address the issues explicitly checking for subflow socket error at close time. To avoid code duplication, factor-out of __mptcp_error_report() a new helper implementing the relevant bits. Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/429 Fixes: 15cc10453398 ("mptcp: deliver ssk errors to msk") Cc: stable@vger.kernel.org Signed-off-by: Paolo Abeni Reviewed-by: Mat Martineau Signed-off-by: Matthieu Baerts Signed-off-by: David S. Miller (cherry picked from commit 9f1a98813b4b686482e5ef3c9d998581cace0ba6) Signed-off-by: Matthieu Baerts (NGI0) --- Notes: - a conflict in protocol.c, because commit 34cec5cd7abc ("mptcp: fix accept vs worker race") has not been backported to v5.15. It introduces a new label (out_release) in the modified context. --- net/mptcp/protocol.c | 63 ++++++++++++++++++++++++-------------------- 1 file changed, 34 insertions(+), 29 deletions(-) diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index 8382345af1d86..47844df9c0b4c 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -688,40 +688,44 @@ static bool __mptcp_ofo_queue(struct mptcp_sock *msk) return moved; } =20 +static bool __mptcp_subflow_error_report(struct sock *sk, struct sock *ssk) +{ + int err =3D sock_error(ssk); + int ssk_state; + + if (!err) + return false; + + /* only propagate errors on fallen-back sockets or + * on MPC connect + */ + if (sk->sk_state !=3D TCP_SYN_SENT && !__mptcp_check_fallback(mptcp_sk(sk= ))) + return false; + + /* We need to propagate only transition to CLOSE state. + * Orphaned socket will see such state change via + * subflow_sched_work_if_closed() and that path will properly + * destroy the msk as needed. + */ + ssk_state =3D inet_sk_state_load(ssk); + if (ssk_state =3D=3D TCP_CLOSE && !sock_flag(sk, SOCK_DEAD)) + inet_sk_state_store(sk, ssk_state); + WRITE_ONCE(sk->sk_err, -err); + + /* This barrier is coupled with smp_rmb() in mptcp_poll() */ + smp_wmb(); + sk_error_report(sk); + return true; +} + void __mptcp_error_report(struct sock *sk) { struct mptcp_subflow_context *subflow; struct mptcp_sock *msk =3D mptcp_sk(sk); =20 - mptcp_for_each_subflow(msk, subflow) { - struct sock *ssk =3D mptcp_subflow_tcp_sock(subflow); - int err =3D sock_error(ssk); - int ssk_state; - - if (!err) - continue; - - /* only propagate errors on fallen-back sockets or - * on MPC connect - */ - if (sk->sk_state !=3D TCP_SYN_SENT && !__mptcp_check_fallback(msk)) - continue; - - /* We need to propagate only transition to CLOSE state. - * Orphaned socket will see such state change via - * subflow_sched_work_if_closed() and that path will properly - * destroy the msk as needed. - */ - ssk_state =3D inet_sk_state_load(ssk); - if (ssk_state =3D=3D TCP_CLOSE && !sock_flag(sk, SOCK_DEAD)) - inet_sk_state_store(sk, ssk_state); - WRITE_ONCE(sk->sk_err, -err); - - /* This barrier is coupled with smp_rmb() in mptcp_poll() */ - smp_wmb(); - sk_error_report(sk); - break; - } + mptcp_for_each_subflow(msk, subflow) + if (__mptcp_subflow_error_report(sk, mptcp_subflow_tcp_sock(subflow))) + break; } =20 /* In most cases we will be able to lock the mptcp socket. If its already @@ -2309,6 +2313,7 @@ static void __mptcp_close_ssk(struct sock *sk, struct= sock *ssk, /* close acquired an extra ref */ __sock_put(ssk); } + __mptcp_subflow_error_report(sk, ssk); release_sock(ssk); =20 sock_put(ssk); --=20 2.43.0