From patchwork Tue Sep 26 16:20:17 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Willem de Bruijn X-Patchwork-Id: 818727 X-Patchwork-Delegate: davem@davemloft.net Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Authentication-Results: ozlabs.org; spf=none (mailfrom) smtp.mailfrom=vger.kernel.org (client-ip=209.132.180.67; helo=vger.kernel.org; envelope-from=netdev-owner@vger.kernel.org; receiver=) Authentication-Results: ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="W3QagSt6"; dkim-atps=neutral Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 3y1mQJ6JXLz9t67 for ; Wed, 27 Sep 2017 02:20:24 +1000 (AEST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S968730AbdIZQUW (ORCPT ); Tue, 26 Sep 2017 12:20:22 -0400 Received: from mail-qt0-f195.google.com ([209.85.216.195]:32880 "EHLO mail-qt0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964791AbdIZQUU (ORCPT ); Tue, 26 Sep 2017 12:20:20 -0400 Received: by mail-qt0-f195.google.com with SMTP id b1so7359263qtc.0 for ; Tue, 26 Sep 2017 09:20:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id; bh=Dr3sQxwZhIjMrOD92Eqa0rU0Zm+Vkr186hK68TVU5hA=; b=W3QagSt6q3SkyrV2vhnEGhIry9y3yTCzuv/7D0EmBqcyG+FKLFDW22lCwmagFXQWSY 2Axovw75UDbBcS4bdZ+JORpvEF9I/Awg21zDMFQdEW9cBbsDD/SehfRbBZNMf9SCY4Jx OCiKZemSXCnGzyKmfL5p4+gyTT8L3lh0xPYmpqOFTIxFrq+wckmWxC4MgSyTzzq1Ypku j26cmuQQd7mT+WqRU2CEInxu5Ch//f2ckHoKaMxtLNZPBAztw02ZQH+mA4vSb4qI6XPG vgfCm6N9t+fVjBumsTpmJjBa0WYJhp2LuHeCKqjjzqolw+XB/utvlWgpPw5wjuCd2KwE 86dQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id; bh=Dr3sQxwZhIjMrOD92Eqa0rU0Zm+Vkr186hK68TVU5hA=; b=WOwiuuQW9+SY5oX7Xtfed+70UcqMQqmPmeox09SMzxYto6m/lrbMeqUgiEd5cTgmvn SjyJpKldU5d59Aaa+rztoKXqfgFBNhcJNzM8pYTaBGKYxTt0Dsb8oG5DXE3qiPAS8aNr xpuKucJCdE/EjpzuRrU9gpZRVweujasBZI33PnMkxAM0imQ1GjPiLimqyzb0oRZ9RJGF 0gfGYZkoNyI2xv7CnCTnkExzk+fnokQbOKBuNkgnlq2ncFsW61U9zJzo3ujvC/BQHIJT UOcdIo0RnjHW7hHvKyWUOmEAls5Rjws2RaHXmNTZj0d2xbx9Rzg0NxCqTtcCw2Lz4hUe tULQ== X-Gm-Message-State: AHPjjUhnHR2tH8CidYXnd6WJo0+OdOjSDNG4iltQGqMTKXDX5SsQG4qn v0yEYnIRot8F1at2Al/DAH+AMnZs X-Google-Smtp-Source: AOwi7QAlihBrmsv/ky4rgZqvSZ99Ge6nlevgOHzBv3GQEOUsRzJWMP32mEbDU8l7yAzny1O6YHDBpg== X-Received: by 10.200.41.148 with SMTP id 20mr15940312qts.69.1506442819685; Tue, 26 Sep 2017 09:20:19 -0700 (PDT) Received: from willemb1.nyc.corp.google.com ([100.101.212.81]) by smtp.gmail.com with ESMTPSA id k20sm7053401qtj.71.2017.09.26.09.20.19 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Tue, 26 Sep 2017 09:20:19 -0700 (PDT) From: Willem de Bruijn To: netdev@vger.kernel.org Cc: davem@davemloft.net, Willem de Bruijn Subject: [PATCH net] packet: only test po->has_vnet_hdr once in packet_snd Date: Tue, 26 Sep 2017 12:20:17 -0400 Message-Id: <20170926162017.60750-1-willemdebruijn.kernel@gmail.com> X-Mailer: git-send-email 2.14.1.821.g8fa685d3b7-goog Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org From: Willem de Bruijn Packet socket option po->has_vnet_hdr can be updated concurrently with other operations if no ring is attached. Do not test the option twice in packet_snd, as the value may change in between calls. A race on setsockopt disable may cause a packet > mtu to be sent without having GSO options set. Fixes: bfd5f4a3d605 ("packet: Add GSO/csum offload support.") Signed-off-by: Willem de Bruijn Reviewed-by: Eric Dumazet --- net/packet/af_packet.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index d288f52c53f7..1da0851f51f2 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -2840,6 +2840,7 @@ static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len) struct virtio_net_hdr vnet_hdr = { 0 }; int offset = 0; struct packet_sock *po = pkt_sk(sk); + bool has_vnet_hdr = false; int hlen, tlen, linear; int extra_len = 0; @@ -2883,6 +2884,7 @@ static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len) err = packet_snd_vnet_parse(msg, &len, &vnet_hdr); if (err) goto out_unlock; + has_vnet_hdr = true; } if (unlikely(sock_flag(sk, SOCK_NOFCS))) { @@ -2941,7 +2943,7 @@ static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len) skb->priority = sk->sk_priority; skb->mark = sockc.mark; - if (po->has_vnet_hdr) { + if (has_vnet_hdr) { err = virtio_net_hdr_to_skb(skb, &vnet_hdr, vio_le()); if (err) goto out_free;