Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8BAC1C4332F for ; Mon, 27 Dec 2021 15:36:56 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238499AbhL0Pgz (ORCPT ); Mon, 27 Dec 2021 10:36:55 -0500 Received: from dfw.source.kernel.org ([139.178.84.217]:35146 "EHLO dfw.source.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238269AbhL0PeW (ORCPT ); Mon, 27 Dec 2021 10:34:22 -0500 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id 9BC9D61073; Mon, 27 Dec 2021 15:34:21 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 81A01C36AEA; Mon, 27 Dec 2021 15:34:20 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1640619261; bh=XTFuv+3trPRcX4iSAIMdG+6Y6HGP2IN8vMVxAYg76Is=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=moHryx6W1xVU+t3f6vGCjdzw5UYX+KZBfd2yIC7M+DQKr4xG0vc+AMCUDBTaF1WYh V9yee2Vt3caWa/FK/nzjuKXZUz3U5nWsJ9dO7+Bkgz95TOKCsP3mON9DZmBLftXPHZ 1nXPlQK49p6ErgQdFDAadiIFELDSOtJzAj6Zrtco= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Willem de Bruijn , Jakub Kicinski , Sasha Levin Subject: [PATCH 5.4 10/47] net: skip virtio_net_hdr_set_proto if protocol already set Date: Mon, 27 Dec 2021 16:30:46 +0100 Message-Id: <20211227151321.139250343@linuxfoundation.org> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20211227151320.801714429@linuxfoundation.org> References: <20211227151320.801714429@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Willem de Bruijn [ Upstream commit 1ed1d592113959f00cc552c3b9f47ca2d157768f ] virtio_net_hdr_set_proto infers skb->protocol from the virtio_net_hdr gso_type, to avoid packets getting dropped for lack of a proto type. Its protocol choice is a guess, especially in the case of UFO, where the single VIRTIO_NET_HDR_GSO_UDP label covers both UFOv4 and UFOv6. Skip this best effort if the field is already initialized. Whether explicitly from userspace, or implicitly based on an earlier call to dev_parse_header_protocol (which is more robust, but was introduced after this patch). Fixes: 9d2f67e43b73 ("net/packet: fix packet drop as of virtio gso") Signed-off-by: Willem de Bruijn Link: https://lore.kernel.org/r/20211220145027.2784293-1-willemdebruijn.kernel@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- include/linux/virtio_net.h | 3 +++ 1 file changed, 3 insertions(+) diff --git a/include/linux/virtio_net.h b/include/linux/virtio_net.h index 22dd48c825600..a960de68ac69e 100644 --- a/include/linux/virtio_net.h +++ b/include/linux/virtio_net.h @@ -25,6 +25,9 @@ static inline bool virtio_net_hdr_match_proto(__be16 protocol, __u8 gso_type) static inline int virtio_net_hdr_set_proto(struct sk_buff *skb, const struct virtio_net_hdr *hdr) { + if (skb->protocol) + return 0; + switch (hdr->gso_type & ~VIRTIO_NET_HDR_GSO_ECN) { case VIRTIO_NET_HDR_GSO_TCPV4: case VIRTIO_NET_HDR_GSO_UDP: -- 2.34.1