From mboxrd@z Thu Jan 1 00:00:00 1970 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 BA2AD1C6BA for ; Wed, 4 Oct 2023 18:33:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="dv//qvaH" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 3A024C433C9; Wed, 4 Oct 2023 18:33:56 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1696444436; bh=QhRX9VTGNnKwZH6C3JrbbgCNwcxUImNvtwLBLhFpgK0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=dv//qvaH3uNkNbkWJ3aK0NmGkT0AIc0y0C8E75tR/eADf6HFPRqNSzfVRZoIRkEcp IQpDFLXxlvG3UFTzDFlFIQl9FK62uR6ItVL08z1oJPlRFt3uMyS5BBFsQL774I3FO0 t7rQ038uJDLzrnOnLf74dQEBZe0JTZtpANxKbZW0= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Paolo Abeni , Mat Martineau , Matthieu Baerts , "David S. Miller" Subject: [PATCH 6.5 250/321] mptcp: process pending subflow error on close Date: Wed, 4 Oct 2023 19:56:35 +0200 Message-ID: <20231004175240.854489466@linuxfoundation.org> X-Mailer: git-send-email 2.42.0 In-Reply-To: <20231004175229.211487444@linuxfoundation.org> References: <20231004175229.211487444@linuxfoundation.org> User-Agent: quilt/0.67 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 6.5-stable review patch. If anyone has any objections, please let me know. ------------------ From: Paolo Abeni commit 9f1a98813b4b686482e5ef3c9d998581cace0ba6 upstream. 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 Signed-off-by: Greg Kroah-Hartman --- net/mptcp/protocol.c | 63 +++++++++++++++++++++++++++------------------------ 1 file changed, 34 insertions(+), 29 deletions(-) --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -772,40 +772,44 @@ static bool __mptcp_ofo_queue(struct mpt return moved; } -void __mptcp_error_report(struct sock *sk) +static bool __mptcp_subflow_error_report(struct sock *sk, struct sock *ssk) { - struct mptcp_subflow_context *subflow; - struct mptcp_sock *msk = mptcp_sk(sk); + int err = sock_error(ssk); + int ssk_state; - mptcp_for_each_subflow(msk, subflow) { - struct sock *ssk = mptcp_subflow_tcp_sock(subflow); - int err = sock_error(ssk); - int ssk_state; + if (!err) + return false; - if (!err) - continue; + /* only propagate errors on fallen-back sockets or + * on MPC connect + */ + if (sk->sk_state != TCP_SYN_SENT && !__mptcp_check_fallback(mptcp_sk(sk))) + return false; - /* only propagate errors on fallen-back sockets or - * on MPC connect - */ - if (sk->sk_state != 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 = inet_sk_state_load(ssk); + if (ssk_state == 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; +} - /* 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 = inet_sk_state_load(ssk); - if (ssk_state == 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; - } +void __mptcp_error_report(struct sock *sk) +{ + struct mptcp_subflow_context *subflow; + struct mptcp_sock *msk = mptcp_sk(sk); + + mptcp_for_each_subflow(msk, subflow) + if (__mptcp_subflow_error_report(sk, mptcp_subflow_tcp_sock(subflow))) + break; } /* In most cases we will be able to lock the mptcp socket. If its already @@ -2417,6 +2421,7 @@ static void __mptcp_close_ssk(struct soc } out_release: + __mptcp_subflow_error_report(sk, ssk); release_sock(ssk); sock_put(ssk);