From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jason Wang Subject: [PATCH net V2 4/4] virtio-net: fix leaking page for gso packet during mergeable XDP Date: Tue, 22 May 2018 11:44:31 +0800 Message-ID: <1526960671-11782-5-git-send-email-jasowang@redhat.com> References: <1526960671-11782-1-git-send-email-jasowang@redhat.com> Cc: virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, John Fastabend To: mst@redhat.com, jasowang@redhat.com Return-path: Received: from mx3-rdu2.redhat.com ([66.187.233.73]:59362 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752687AbeEVDoy (ORCPT ); Mon, 21 May 2018 23:44:54 -0400 In-Reply-To: <1526960671-11782-1-git-send-email-jasowang@redhat.com> Sender: netdev-owner@vger.kernel.org List-ID: We need to drop refcnt to xdp_page if we see a gso packet. Otherwise it will be leaked. Fixing this by moving the check of gso packet above the linearizing logic. While at it, remove useless comment as well. Cc: John Fastabend Fixes: 72979a6c3590 ("virtio_net: xdp, add slowpath case for non contiguous buffers") Signed-off-by: Jason Wang --- drivers/net/virtio_net.c | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 326e247..032e1ac 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -707,6 +707,13 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, void *data; u32 act; + /* Transient failure which in theory could occur if + * in-flight packets from before XDP was enabled reach + * the receive path after XDP is loaded. + */ + if (unlikely(hdr->hdr.gso_type)) + goto err_xdp; + /* This happens when rx buffer size is underestimated * or headroom is not enough because of the buffer * was refilled before XDP is set. This should only @@ -727,14 +734,6 @@ static struct sk_buff *receive_mergeable(struct net_device *dev, xdp_page = page; } - /* Transient failure which in theory could occur if - * in-flight packets from before XDP was enabled reach - * the receive path after XDP is loaded. In practice I - * was not able to create this condition. - */ - if (unlikely(hdr->hdr.gso_type)) - goto err_xdp; - /* Allow consuming headroom but reserve enough space to push * the descriptor on if we get an XDP_TX return code. */ -- 2.7.4