From patchwork Thu Dec 10 22:25:02 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mat Martineau X-Patchwork-Id: 341652 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8433EC433FE for ; Thu, 10 Dec 2020 23:11:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 4CC0C2332A for ; Thu, 10 Dec 2020 23:11:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390743AbgLJXLf (ORCPT ); Thu, 10 Dec 2020 18:11:35 -0500 Received: from mga04.intel.com ([192.55.52.120]:9293 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2387943AbgLJWbH (ORCPT ); Thu, 10 Dec 2020 17:31:07 -0500 IronPort-SDR: +Y9meKBeXzZ4Sa7CfWzUzJpqLVLCc4LHlQEmKejn1HM7Nt6sIR6jXqknj9weyh/QR9HhL/BDZj nzEZfEQq+6jQ== X-IronPort-AV: E=McAfee;i="6000,8403,9831"; a="171776488" X-IronPort-AV: E=Sophos;i="5.78,409,1599548400"; d="scan'208";a="171776488" Received: from orsmga006.jf.intel.com ([10.7.209.51]) by fmsmga104.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Dec 2020 14:25:14 -0800 IronPort-SDR: eqmyYaE+2k31xmoEijcNx50w6RdwwxKwiT5cNSZI+wuXeiFGSkTH30MNIGz3pDyKCd4zZn6IHN Qp5L/PS3vcTQ== X-IronPort-AV: E=Sophos;i="5.78,409,1599548400"; d="scan'208";a="338703756" Received: from mjmartin-nuc02.amr.corp.intel.com ([10.254.112.51]) by orsmga006-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 10 Dec 2020 14:25:14 -0800 From: Mat Martineau To: netdev@vger.kernel.org Cc: Florian Westphal , davem@davemloft.net, kuba@kernel.org, mptcp@lists.01.org, Matthieu Baerts , Mat Martineau Subject: [PATCH net-next 5/9] mptcp: hold mptcp socket before calling tcp_done Date: Thu, 10 Dec 2020 14:25:02 -0800 Message-Id: <20201210222506.222251-6-mathew.j.martineau@linux.intel.com> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201210222506.222251-1-mathew.j.martineau@linux.intel.com> References: <20201210222506.222251-1-mathew.j.martineau@linux.intel.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Florian Westphal When processing options from tcp reset path its possible that tcp_done(ssk) drops the last reference on the mptcp socket which results in use-after-free. Reviewed-by: Matthieu Baerts Signed-off-by: Florian Westphal Signed-off-by: Mat Martineau --- net/mptcp/subflow.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/net/mptcp/subflow.c b/net/mptcp/subflow.c index bf808f1fabe5..73e66a406d99 100644 --- a/net/mptcp/subflow.c +++ b/net/mptcp/subflow.c @@ -313,12 +313,17 @@ void mptcp_subflow_reset(struct sock *ssk) struct mptcp_subflow_context *subflow = mptcp_subflow_ctx(ssk); struct sock *sk = subflow->conn; + /* must hold: tcp_done() could drop last reference on parent */ + sock_hold(sk); + tcp_set_state(ssk, TCP_CLOSE); tcp_send_active_reset(ssk, GFP_ATOMIC); tcp_done(ssk); if (!test_and_set_bit(MPTCP_WORK_CLOSE_SUBFLOW, &mptcp_sk(sk)->flags) && schedule_work(&mptcp_sk(sk)->work)) - sock_hold(sk); + return; /* worker will put sk for us */ + + sock_put(sk); } static void subflow_finish_connect(struct sock *sk, const struct sk_buff *skb)