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=-7.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS 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 3589FC43441 for ; Thu, 29 Nov 2018 05:53:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 00C2E20834 for ; Thu, 29 Nov 2018 05:53:26 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 00C2E20834 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727848AbeK2Q5e (ORCPT ); Thu, 29 Nov 2018 11:57:34 -0500 Received: from mx1.redhat.com ([209.132.183.28]:43064 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727024AbeK2Q5e (ORCPT ); Thu, 29 Nov 2018 11:57:34 -0500 Received: from smtp.corp.redhat.com (int-mx08.intmail.prod.int.phx2.redhat.com [10.5.11.23]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 4DDC6307DABA; Thu, 29 Nov 2018 05:53:25 +0000 (UTC) Received: from jason-ThinkPad-T450s.redhat.com (ovpn-12-163.pek2.redhat.com [10.72.12.163]) by smtp.corp.redhat.com (Postfix) with ESMTP id 166BD19483; Thu, 29 Nov 2018 05:53:18 +0000 (UTC) From: Jason Wang To: mst@redhat.com, jasowang@redhat.com Cc: davem@davemloft.net, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH net] virtio-net: keep vnet header zeroed after processing XDP Date: Thu, 29 Nov 2018 13:53:16 +0800 Message-Id: <20181129055316.24090-1-jasowang@redhat.com> X-Scanned-By: MIMEDefang 2.84 on 10.5.11.23 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.5.110.42]); Thu, 29 Nov 2018 05:53:25 +0000 (UTC) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org We copy vnet header unconditionally in page_to_skb() this is wrong since XDP may modify the packet data. So let's keep a zeroed vnet header for not confusing the conversion between vnet header and skb metadata. In the future, we should able to detect whether or not the packet was modified and keep using the vnet header when packet was not touched. Fixes: f600b6905015 ("virtio_net: Add XDP support") Reported-by: Pavel Popa Signed-off-by: Jason Wang --- drivers/net/virtio_net.c | 14 +++++++++----- 1 file changed, 9 insertions(+), 5 deletions(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index cecfd77c9f3c..ea672145f6a6 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -365,7 +365,8 @@ static unsigned int mergeable_ctx_to_truesize(void *mrg_ctx) static struct sk_buff *page_to_skb(struct virtnet_info *vi, struct receive_queue *rq, struct page *page, unsigned int offset, - unsigned int len, unsigned int truesize) + unsigned int len, unsigned int truesize, + bool hdr_valid) { struct sk_buff *skb; struct virtio_net_hdr_mrg_rxbuf *hdr; @@ -387,7 +388,8 @@ static struct sk_buff *page_to_skb(struct virtnet_info *vi, else hdr_padded_len = sizeof(struct padded_vnet_hdr); - memcpy(hdr, p, hdr_len); + if (hdr_valid) + memcpy(hdr, p, hdr_len); len -= hdr_len; offset += hdr_padded_len; @@ -739,7 +741,8 @@ static struct sk_buff *receive_big(struct net_device *dev, struct virtnet_rq_stats *stats) { struct page *page = buf; - struct sk_buff *skb = page_to_skb(vi, rq, page, 0, len, PAGE_SIZE); + struct sk_buff *skb = page_to_skb(vi, rq, page, 0, len, + PAGE_SIZE, true); stats->bytes += len - vi->hdr_len; if (unlikely(!skb)) @@ -842,7 +845,8 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, rcu_read_unlock(); put_page(page); head_skb = page_to_skb(vi, rq, xdp_page, - offset, len, PAGE_SIZE); + offset, len, + PAGE_SIZE, false); return head_skb; } break; @@ -898,7 +902,7 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, goto err_skb; } - head_skb = page_to_skb(vi, rq, page, offset, len, truesize); + head_skb = page_to_skb(vi, rq, page, offset, len, truesize, !xdp_prog); curr_skb = head_skb; if (unlikely(!curr_skb)) -- 2.17.1