From patchwork Thu Oct 24 14:01:54 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Beno=C3=AEt_Monin?= X-Patchwork-Id: 13849140 X-Patchwork-Delegate: kuba@kernel.org Received: from mout.gmx.net (mout.gmx.net [212.227.17.22]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 850F138DD1; Thu, 24 Oct 2024 14:02:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=212.227.17.22 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729778553; cv=none; b=iAAdEDSYuhq36+r5mvmSLLq58f9zgLNInNAa+BWbOOSdjmL/xtKl2NJWx1jbLqHv5wF0Vr1ZeEyZ8CjwqRc+JHViDgzvzYEBy2rsTp1xfJTWb2WALW417h3K8z98sWYuJdeFpehgjCo2TqwjpTPi6b6GnUvNBhhyjE8qlLIH8LI= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729778553; c=relaxed/simple; bh=Ipm8P50Y+llp0O+WOlfXkI4PWF637EaTo+hlh2/TUZw=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version:Content-Type; b=b7w9ax+6qifIlzhsMvUxv+1lkH6KBn0t7bvrXPFZdA26sGl6MbvhAosm4OM1MN2x1AYFKvTgY9mtJu3EZo51XgAXLUgsxbdycPaTQ5UhI2OmJmn7VLCnV3ybetuDl37bv6+bHlxOufRv5Yp5of55Pv0Cb5csZLjshXAztbW8gnk= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=gmx.fr; spf=pass smtp.mailfrom=gmx.fr; dkim=pass (2048-bit key) header.d=gmx.fr header.i=benoit.monin@gmx.fr header.b=XJ0jDcV7; arc=none smtp.client-ip=212.227.17.22 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=gmx.fr Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmx.fr Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmx.fr header.i=benoit.monin@gmx.fr header.b="XJ0jDcV7" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmx.fr; s=s31663417; t=1729778516; x=1730383316; i=benoit.monin@gmx.fr; bh=+Tg6T7Zx5JMzwVi2DSF1T6BeCmhZbKmA/yMe10eZSKY=; h=X-UI-Sender-Class:From:To:Cc:Subject:Date:Message-ID: MIME-Version:Content-Type:Content-Transfer-Encoding:cc: content-transfer-encoding:content-type:date:from:message-id: mime-version:reply-to:subject:to; b=XJ0jDcV7sHuS/XOStok0nsiUp7Syv3XmFgyBc819YvwaO1k8EBZoitlU3WifsNev MMv1xl4+/Zik6vl8Jo4HXRdkPA/absrj9VXRp34GmPic6fQ0MC9L3hdt1yyexZ1R6 5mAmUCoBNDagED9AKK0YG4mWBpnXXzA1ZQGcGKWHg4RGi6DwZyXXTrRXuvNjs/yVa O8tmdV1dc4WBP7Q+xI6WEUV2LluoFc6igWjlSZTmvauSN6ltlHzy719xvmNoznvVx UwR313X2Y+v/aDSNK5r/trrhP67utLoZhLNCHlS43hjEUm37IVYRa6FUo2iYHJVJc jZJqj7U8AXA2RR+P2A== X-UI-Sender-Class: 724b4f7f-cbec-4199-ad4e-598c01a50d3a Received: from pianobar.pianonet ([176.145.30.241]) by mail.gmx.net (mrgmx104 [212.227.17.174]) with ESMTPSA (Nemesis) id 1Mi2O1-1tZAMH02hV-00n7VR; Thu, 24 Oct 2024 16:01:56 +0200 From: =?utf-8?q?Beno=C3=AEt_Monin?= To: "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Jiri Pirko , Sebastian Andrzej Siewior , Lorenzo Bianconi Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, =?utf-8?q?Beno?= =?utf-8?q?=C3=AEt_Monin?= Subject: [PATCH v2 net] net: skip offload for NETIF_F_IPV6_CSUM if ipv6 header contains extension Date: Thu, 24 Oct 2024 16:01:54 +0200 Message-ID: <5fbeecfc311ea182aa1d1c771725ab8b4cac515e.1729778144.git.benoit.monin@gmx.fr> X-Mailer: git-send-email 2.47.0 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Provags-ID: V03:K1:giEvIU1I27U22AFCsK8eH0m33K+9irDl+kPrnl7RtlbzKSnY4fC jtP7AsYP7JtEmSlAjEenE57bcTd5ZcSaMNXWLKZwujYEs16psf7HOuR77omPFLLBE03Vm1V 9gHdzEqZ89yN43YIkAxTD/Qj6buecp+m4A9iruiG5GOsSnmaDXcqHbu0rCdcEaMetsPp3k9 0Hm+NT1Vpifbft4W9kRcQ== X-Spam-Flag: NO UI-OutboundReport: notjunk:1;M01:P0:zSkK1Tq1cBA=;xXxWl/24tyS998LC42LFKpHgDiy aLIXH3O+HiRvqGU/DrMPfWT7zzYGqgXOncyFrihaJVVaRxj0qhbkFlVUt/rWTFPeC09WMV1un oGn/IqSAsIXK27imPelqf0GKRP3hXFBz8S77YSKzKLW1m+77E0JPwynYjW0ZkGAZjIiRiOS/6 6kLuzKxOrGayUHxcR39ul/CmKTegzGfrfo4DfunvBQCwkCDNfSHG1Fr3qvzXh1HOOrAoL1iye C+ZO4Cjm8xJ0qhAMLUIgqa3a6EGf/ygFFAx/anxrwt/ZiDWNRQvURGWvljYTIkgDjeeDz9T4i 28gA9GR5yeleBMQXJKp0exDPsy/yVfumYWUmkGz+U7OVpcPPaEPc4F3lWX5uzZkIId/oEt/cA Y9GVe5ijoFmJQkUqgwFR5MiVzcS7NU+9sVwXe/Tm4Y2vWX1DQkZzNdbag/CI02Z0Dcdqnp7C5 xJq70xB491RXlKEEa3dAcDZfk8yVyC+tzXGfwdWVJfHWL46fhnF2iuFNMhi4wdIsJFr4v+Ptq 9yM333nxc+C/RQSsu/IGWXHhdLd/opX+Cl0ip2xKnjiWZP2er7VCXPnrG8FqjPPmidv+IYZLg rrm9KssLXK0gxyzaZsfSIZMg5RWEs+hN0rAc7Rg1hRpsqE2BejIuMBR9Dk1Suh5KYrGccXCyw tGgikNS6CpDRhuUlCTuJoRSusV49H0Lk2iO5tl0e1wza4KYUMl7837XR0IHCQU9urvL21wNxZ +MZNSP2bqUgEO2yBfQl1zb5MNzI8QbPCDyHv1ff07VXGtQr+waGgjI/HpD62wmoujOfz0Si/I 0uvB1/wiyYt6bwMK/qSs+9FmjuUpsQn87FpCClNw61cHY= X-Patchwork-Delegate: kuba@kernel.org As documented in skbuff.h, devices with NETIF_F_IPV6_CSUM capability can only checksum TCP and UDP over IPv6 if the IP header does not contains extension. This is enforced for UDP packets emitted from user-space to an IPv6 address as they go through ip6_make_skb(), which calls __ip6_append_data() where a check is done on the header size before setting CHECKSUM_PARTIAL. But the introduction of UDP encapsulation with fou6 added a code-path where it is possible to get an skb with a partial UDP checksum and an IPv6 header with extension: * fou6 adds a UDP header with a partial checksum if the inner packet does not contains a valid checksum. * ip6_tunnel adds an IPv6 header with a destination option extension header if encap_limit is non-zero (the default value is 4). The thread linked below describes in more details how to reproduce the problem with GRE-in-UDP tunnel. Add a check on the network header size in skb_csum_hwoffload_help() to make sure no IPv6 packet with extension header is handed to a network device with NETIF_F_IPV6_CSUM capability. Link: https://lore.kernel.org/netdev/26548921.1r3eYUQgxm@benoit.monin/T/#u Fixes: aa3463d65e7b ("fou: Add encap ops for IPv6 tunnels") Signed-off-by: Benoît Monin Reviewed-by: Willem de Bruijn --- changelog * v2: - patch against net instead of net-next - clarify documentation of NETIF_F_IPV6_CSUM - add link to thread describing the problem - add fixes tag - use vlan_get_protocol to check for IPv6 * v1: - https://lore.kernel.org/netdev/0dc0c2af98e96b1df20bd36aeaed4eb4e27d507e.1728056028.git.benoit.monin@gmx.fr/T/#u --- net/core/dev.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/net/core/dev.c b/net/core/dev.c index ea5fbcd133ae..8453e14d301b 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -3639,6 +3639,9 @@ int skb_csum_hwoffload_help(struct sk_buff *skb, return 0; if (features & (NETIF_F_IP_CSUM | NETIF_F_IPV6_CSUM)) { + if (vlan_get_protocol(skb) == htons(ETH_P_IPV6) && + skb_network_header_len(skb) != sizeof(struct ipv6hdr)) + goto sw_checksum; switch (skb->csum_offset) { case offsetof(struct tcphdr, check): case offsetof(struct udphdr, check): @@ -3646,6 +3649,7 @@ int skb_csum_hwoffload_help(struct sk_buff *skb, } } +sw_checksum: return skb_checksum_help(skb); } EXPORT_SYMBOL(skb_csum_hwoffload_help);