From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 76D862FD68B; Tue, 31 Mar 2026 17:01:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774976495; cv=none; b=cqMeYUmwtiuuEA6aIDcNV2WzU3fjy17Ud2aQR9Y6R0KQREsD6lOTKw2MAZmMKIpGsxps2IqTXzNlAGO7ZNKGH/IIT7zvBwOrb4gcpW581eov+LY5038AX9FyLAwpPm0nfFiDAnWhS6jlIwGv1JsA4yVTMnxjQfhXstddmrz5aGI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774976495; c=relaxed/simple; bh=Sq5QdBVTKz+Bms8tswGMHd/IfBNQev0lQYHYIrqYITA=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=E/w5ln35fJQHZiqwa8xAObm5Eq0EN/A/rM1kgHBLJPxqorgynAa8yVlTWSR7epItgWWs77wB078w8IdW+eHtN+AfU4ItkbcSqx4I4nIuJp3Zaw3nrSBjJtQl+2esV2CAAacNFNSwA6de6hFUTvgGlquKP0heZSUeRBZJtOsxqfQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=kkafOWR6; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="kkafOWR6" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E67F5C19423; Tue, 31 Mar 2026 17:01:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1774976495; bh=Sq5QdBVTKz+Bms8tswGMHd/IfBNQev0lQYHYIrqYITA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=kkafOWR6D3Nu05BUV1X5EpLvyK3CCzxOXTYCXUk+6tLn3aRq6vfSMXto2lSJrhLZ1 91SjDgTAjbdIORjwrK8dkxlVwmoLmCyGPTyDs8CnmOoMOeUfxI4WIU7WmpH8l9g5fO vnrD+yxS/OcV+jZwI/V1r/Cue1xb4N3Nx50FE27Y= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Xuan Zhuo , "Michael S. Tsirkin" , Paolo Abeni , Sasha Levin Subject: [PATCH 6.18 114/309] virtio-net: correct hdr_len handling for tunnel gso Date: Tue, 31 Mar 2026 18:20:17 +0200 Message-ID: <20260331161757.681242907@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260331161753.468533260@linuxfoundation.org> References: <20260331161753.468533260@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Xuan Zhuo [ Upstream commit 6c860dc02a8e60b438e26940227dfa641fcdb66a ] The commit a2fb4bc4e2a6a03 ("net: implement virtio helpers to handle UDP GSO tunneling.") introduces support for the UDP GSO tunnel feature in virtio-net. The virtio spec says: If the \field{gso_type} has the VIRTIO_NET_HDR_GSO_UDP_TUNNEL_IPV4 bit or VIRTIO_NET_HDR_GSO_UDP_TUNNEL_IPV6 bit set, \field{hdr_len} accounts for all the headers up to and including the inner transport. The commit did not update the hdr_len to include the inner transport. I observed that the "hdr_len" is 116 for this packet: 17:36:18.241105 52:55:00:d1:27:0a > 2e:2c:df:46:a9:e1, ethertype IPv4 (0x0800), length 2912: (tos 0x0, ttl 64, id 45197, offset 0, flags [none], proto UDP (17), length 2898) 192.168.122.100.50613 > 192.168.122.1.4789: [bad udp cksum 0x8106 -> 0x26a0!] VXLAN, flags [I] (0x08), vni 1 fa:c3:ba:82:05:ee > ce:85:0c:31:77:e5, ethertype IPv4 (0x0800), length 2862: (tos 0x0, ttl 64, id 14678, offset 0, flags [DF], proto TCP (6), length 2848) 192.168.3.1.49880 > 192.168.3.2.9898: Flags [P.], cksum 0x9266 (incorrect -> 0xaa20), seq 515667:518463, ack 1, win 64, options [nop,nop,TS val 2990048824 ecr 2798801412], length 2796 116 = 14(mac) + 20(ip) + 8(udp) + 8(vxlan) + 14(inner mac) + 20(inner ip) + 32(innner tcp) Fixes: a2fb4bc4e2a6a03 ("net: implement virtio helpers to handle UDP GSO tunneling.") Signed-off-by: Xuan Zhuo Link: https://patch.msgid.link/20260320021818.111741-3-xuanzhuo@linux.alibaba.com Acked-by: Michael S. Tsirkin Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin --- include/linux/virtio_net.h | 19 +++++++++++++++++++ 1 file changed, 19 insertions(+) diff --git a/include/linux/virtio_net.h b/include/linux/virtio_net.h index 361b60c8be680..f36d21b5bc19e 100644 --- a/include/linux/virtio_net.h +++ b/include/linux/virtio_net.h @@ -224,6 +224,22 @@ static inline void __virtio_net_set_hdrlen(const struct sk_buff *skb, hdr->hdr_len = __cpu_to_virtio16(little_endian, hdr_len); } +/* This function must be called after virtio_net_hdr_from_skb(). */ +static inline void __virtio_net_set_tnl_hdrlen(const struct sk_buff *skb, + struct virtio_net_hdr *hdr) +{ + u16 hdr_len; + + hdr_len = skb_inner_transport_offset(skb); + + if (hdr->gso_type == VIRTIO_NET_HDR_GSO_UDP_L4) + hdr_len += sizeof(struct udphdr); + else + hdr_len += inner_tcp_hdrlen(skb); + + hdr->hdr_len = __cpu_to_virtio16(true, hdr_len); +} + static inline int virtio_net_hdr_from_skb(const struct sk_buff *skb, struct virtio_net_hdr *hdr, bool little_endian, @@ -440,6 +456,9 @@ virtio_net_hdr_tnl_from_skb(const struct sk_buff *skb, if (ret) return ret; + if (feature_hdrlen && hdr->hdr_len) + __virtio_net_set_tnl_hdrlen(skb, hdr); + if (skb->protocol == htons(ETH_P_IPV6)) hdr->gso_type |= VIRTIO_NET_HDR_GSO_UDP_TUNNEL_IPV6; else -- 2.51.0