From patchwork Tue Jul 28 22:12:09 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mat Martineau X-Patchwork-Id: 1338051 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming-netdev@ozlabs.org Delivered-To: patchwork-incoming-netdev@ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=linux.intel.com Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4BGWBL5L8lz9sTR for ; Wed, 29 Jul 2020 08:12:26 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729875AbgG1WMZ (ORCPT ); Tue, 28 Jul 2020 18:12:25 -0400 Received: from mga02.intel.com ([134.134.136.20]:2588 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729801AbgG1WMT (ORCPT ); Tue, 28 Jul 2020 18:12:19 -0400 IronPort-SDR: /29rdmdxBPxI3iCKLXtNHKJoN7jLfiskasrKsI2kGzKq7f7OU4odf+nSuKQd7sKV/lGaNX2oRM oslYuTsZWvBA== X-IronPort-AV: E=McAfee;i="6000,8403,9696"; a="139342695" X-IronPort-AV: E=Sophos;i="5.75,408,1589266800"; d="scan'208";a="139342695" X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga003.fm.intel.com ([10.253.24.29]) by orsmga101.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 28 Jul 2020 15:12:16 -0700 IronPort-SDR: xZLeWAmymSd0EYMSbCJ5MipQUHsjdraHKxo1Tvw50vePsyOd3Cfzq5Jox/3fnpG4CXgk1+ijnC +BapMHouYT0A== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.75,408,1589266800"; d="scan'208";a="328468897" Received: from mjmartin-nuc02.amr.corp.intel.com ([10.254.116.118]) by FMSMGA003.fm.intel.com with ESMTP; 28 Jul 2020 15:12:15 -0700 From: Mat Martineau To: netdev@vger.kernel.org Cc: Mat Martineau , mptcp@lists.01.org, matthieu.baerts@tessares.net, pabeni@redhat.com Subject: [PATCH net-next 11/12] mptcp: Safely read sequence number when lock isn't held Date: Tue, 28 Jul 2020 15:12:09 -0700 Message-Id: <20200728221210.92841-12-mathew.j.martineau@linux.intel.com> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20200728221210.92841-1-mathew.j.martineau@linux.intel.com> References: <20200728221210.92841-1-mathew.j.martineau@linux.intel.com> MIME-Version: 1.0 Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org The MPTCP socket's write_seq member should be read with READ_ONCE() when the msk lock is not held. Signed-off-by: Mat Martineau --- net/mptcp/protocol.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c index f264ea15e081..f2455a68d231 100644 --- a/net/mptcp/protocol.c +++ b/net/mptcp/protocol.c @@ -1269,7 +1269,7 @@ static void mptcp_retransmit_handler(struct sock *sk) { struct mptcp_sock *msk = mptcp_sk(sk); - if (atomic64_read(&msk->snd_una) == msk->write_seq) { + if (atomic64_read(&msk->snd_una) == READ_ONCE(msk->write_seq)) { mptcp_stop_timer(sk); } else { set_bit(MPTCP_WORK_RTX, &msk->flags);