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=-9.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, 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 B337AC47404 for ; Wed, 9 Oct 2019 23:08:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9669D218AC for ; Wed, 9 Oct 2019 23:08:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732450AbfJIXIr (ORCPT ); Wed, 9 Oct 2019 19:08:47 -0400 Received: from mga06.intel.com ([134.134.136.31]:40466 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732356AbfJIXIo (ORCPT ); Wed, 9 Oct 2019 19:08:44 -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 orsmga104.jf.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 09 Oct 2019 16:08:42 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.67,277,1566889200"; d="scan'208";a="205902522" Received: from mjmartin-nuc02.mjmartin-nuc02 (HELO mjmartin-nuc02.sea.intel.com) ([10.254.70.56]) by orsmga002.jf.intel.com with ESMTP; 09 Oct 2019 16:08:42 -0700 From: Mat Martineau To: netdev@vger.kernel.org, edumazet@google.com 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 v3 09/10] tcp: Check for filled TCP option space before SACK Date: Wed, 9 Oct 2019 16:08:08 -0700 Message-Id: <20191009230809.27387-10-mathew.j.martineau@linux.intel.com> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20191009230809.27387-1-mathew.j.martineau@linux.intel.com> References: <20191009230809.27387-1-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 8469a109f0aa..512e521101e1 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; -- 2.23.0