From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jason Wang Subject: [PATCH net 4/4] virito-net: fix leaking page for gso packet during mergeable XDP Date: Mon, 21 May 2018 16:35:06 +0800 Message-ID: <1526891706-18516-5-git-send-email-jasowang__41994.8904346258$1526891787$gmane$org@redhat.com> References: <1526891706-18516-1-git-send-email-jasowang@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1526891706-18516-1-git-send-email-jasowang@redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org To: mst@redhat.com, jasowang@redhat.com Cc: netdev@vger.kernel.org, John Fastabend , linux-kernel@vger.kernel.org, virtualization@lists.linux-foundation.org List-Id: virtualization@lists.linuxfoundation.org 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. 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 | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 165a922..f8db809 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -707,6 +707,14 @@ 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. In practice I + * was not able to create this condition. + */ + 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 @@ -728,14 +736,6 @@ 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