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=-8.7 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 E0A7CC31E5B for ; Mon, 17 Jun 2019 22:59:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C3C322084A for ; Mon, 17 Jun 2019 22:59:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728928AbfFQW7Y (ORCPT ); Mon, 17 Jun 2019 18:59:24 -0400 Received: from mga18.intel.com ([134.134.136.126]:10995 "EHLO mga18.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728730AbfFQW64 (ORCPT ); Mon, 17 Jun 2019 18:58:56 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga002.jf.intel.com ([10.7.209.21]) by orsmga106.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 17 Jun 2019 15:58:52 -0700 X-ExtLoop1: 1 Received: from mjmartin-nuc01.amr.corp.intel.com (HELO mjmartin-nuc01.sea.intel.com) ([10.241.98.42]) by orsmga002.jf.intel.com with ESMTP; 17 Jun 2019 15:58:52 -0700 From: Mat Martineau To: edumazet@google.com, netdev@vger.kernel.org Cc: Mat Martineau , cpaasch@apple.com, fw@strlen.de, pabeni@redhat.com, peter.krystad@linux.intel.com, dcaratti@redhat.com, matthieu.baerts@tessares.net Subject: [RFC PATCH net-next 28/33] tcp: Check for filled TCP option space before SACK Date: Mon, 17 Jun 2019 15:58:03 -0700 Message-Id: <20190617225808.665-29-mathew.j.martineau@linux.intel.com> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190617225808.665-1-mathew.j.martineau@linux.intel.com> References: <20190617225808.665-1-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 5fe9459bbd6a..e980546e330a 100644 --- a/net/ipv4/tcp_output.c +++ b/net/ipv4/tcp_output.c @@ -805,6 +805,9 @@ static unsigned int tcp_established_options(struct sock *sk, struct sk_buff *skb } } + 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; -- 2.22.0