From mboxrd@z Thu Jan 1 00:00:00 1970 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=-9.7 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 199E2C3F68F for ; Fri, 13 Dec 2019 23:01:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F270C214D8 for ; Fri, 13 Dec 2019 23:01:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726793AbfLMXBn (ORCPT ); Fri, 13 Dec 2019 18:01:43 -0500 Received: from mga04.intel.com ([192.55.52.120]:64701 "EHLO mga04.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726708AbfLMXBa (ORCPT ); Fri, 13 Dec 2019 18:01:30 -0500 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga007.fm.intel.com ([10.253.24.52]) by fmsmga104.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 13 Dec 2019 15:01:29 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.69,311,1571727600"; d="scan'208";a="211506680" Received: from mjmartin-nuc02.mjmartin-nuc02 (HELO mjmartin-nuc02.sea.intel.com) ([10.251.17.224]) by fmsmga007.fm.intel.com with ESMTP; 13 Dec 2019 15:01:22 -0800 From: Mat Martineau To: netdev@vger.kernel.org, mptcp@lists.01.org Cc: Mat Martineau Subject: [PATCH net-next 09/11] tcp: Check for filled TCP option space before SACK Date: Fri, 13 Dec 2019 15:00:20 -0800 Message-Id: <20191213230022.28144-10-mathew.j.martineau@linux.intel.com> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20191213230022.28144-1-mathew.j.martineau@linux.intel.com> References: <20191213230022.28144-1-mathew.j.martineau@linux.intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org The SACK code would potentially add four bytes to the expected TCP option size even if all option space was already used. Signed-off-by: Mat Martineau --- net/ipv4/tcp_output.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c index 9e04d45bc0e4..710ab45badfa 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -748,6 +748,9 @@ static unsigned int tcp_established_options(struct sock *sk, struct sk_buff *skb size += TCPOLEN_TSTAMP_ALIGNED; } + if (size + TCPOLEN_SACK_BASE_ALIGNED >= MAX_TCP_OPTION_SPACE) + return size; + eff_sacks = tp->rx_opt.num_sacks + tp->rx_opt.dsack; if (unlikely(eff_sacks)) { const unsigned int remaining = MAX_TCP_OPTION_SPACE - size; -- 2.24.1