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=-14.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SIGNED_OFF_BY,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 89F3DC43381 for ; Thu, 21 Feb 2019 14:45:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5970D20700 for ; Thu, 21 Feb 2019 14:45:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1550760320; bh=Dy3yATn5va4teAv7+qlA3Mu4dv73TxM8LyHcCw0KjuM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=zxO6+ZhyIMpHhsd/eOAE1rvhfbba+7ylgq0p27C1CetCpZe9h4kS+dbQswnTKvWtA oCgMiefmdr+eYlZYoTai7HKG2ojBbNskC5UiIPTcOvul81kHy5ZcYiGaPjn3KlU/bo EN9zd4Hm9dg2e+JMErFWQGWwTxg+SJd2hVxo52Y0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729129AbfBUOpT (ORCPT ); Thu, 21 Feb 2019 09:45:19 -0500 Received: from mail.kernel.org ([198.145.29.99]:38696 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729223AbfBUOnB (ORCPT ); Thu, 21 Feb 2019 09:43:01 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 8CD0620838; Thu, 21 Feb 2019 14:42:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1550760180; bh=Dy3yATn5va4teAv7+qlA3Mu4dv73TxM8LyHcCw0KjuM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=TTjlE4pcLGSUdxbE7gH7+x8akKF7z9A+iN7ucFecDUQI3IpV/ZCBc29NXcrF4YJva TbqWer+F/Shgw8WjYwfR2yo89ew9SQ9Gr7g64MzucnrUlNiNBrQf06Djz+9Z4UcAKF SzJFsCpr7HZ9DYEg+j6fn0U2l17JIRoQA7PoAqZo= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Willem de Bruijn , Maxim Mikityanskiy , Nicolas Dichtel , "David S. Miller" , Sasha Levin Subject: [PATCH 4.20 21/32] af_packet: fix raw sockets over 6in4 tunnel Date: Thu, 21 Feb 2019 15:36:09 +0100 Message-Id: <20190221125252.140464005@linuxfoundation.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190221125250.855065214@linuxfoundation.org> References: <20190221125250.855065214@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review X-Patchwork-Hint: ignore MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 4.20-stable review patch. If anyone has any objections, please let me know. ------------------ [ Upstream commit 88a8121dc1d3d0dbddd411b79ed236b6b6ea415c ] Since commit cb9f1b783850, scapy (which uses an AF_PACKET socket in SOCK_RAW mode) is unable to send a basic icmp packet over a sit tunnel: Here is a example of the setup: $ ip link set ntfp2 up $ ip addr add 10.125.0.1/24 dev ntfp2 $ ip tunnel add tun1 mode sit ttl 64 local 10.125.0.1 remote 10.125.0.2 dev ntfp2 $ ip addr add fd00:cafe:cafe::1/128 dev tun1 $ ip link set dev tun1 up $ ip route add fd00:200::/64 dev tun1 $ scapy >>> p = [] >>> p += IPv6(src='fd00:100::1', dst='fd00:200::1')/ICMPv6EchoRequest() >>> send(p, count=1, inter=0.1) >>> quit() $ ip -s link ls dev tun1 | grep -A1 "TX.*errors" TX: bytes packets errors dropped carrier collsns 0 0 1 0 0 0 The problem is that the network offset is set to the hard_header_len of the output device (tun1, ie 14 + 20) and in our case, because the packet is small (48 bytes) the pskb_inet_may_pull() fails (it tries to pull 40 bytes (ipv6 header) starting from the network offset). This problem is more generally related to device with variable hard header length. To avoid a too intrusive patch in the current release, a (ugly) workaround is proposed in this patch. It has to be cleaned up in net-next. Link: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=993675a3100b1 Link: http://patchwork.ozlabs.org/patch/1024489/ Fixes: cb9f1b783850 ("ip: validate header length on virtual device xmit") CC: Willem de Bruijn CC: Maxim Mikityanskiy Signed-off-by: Nicolas Dichtel Acked-by: Willem de Bruijn Signed-off-by: David S. Miller Signed-off-by: Sasha Levin --- net/packet/af_packet.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index d0945253f43b3..3b1a78906bc0c 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -2887,7 +2887,8 @@ static int packet_snd(struct socket *sock, struct msghdr *msg, size_t len) goto out_free; } else if (reserve) { skb_reserve(skb, -reserve); - if (len < reserve) + if (len < reserve + sizeof(struct ipv6hdr) && + dev->min_header_len != dev->hard_header_len) skb_reset_network_header(skb); } -- 2.19.1