From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, John Fastabend , Jason Wang , "David S. Miller" Subject: [PATCH 4.16 37/48] virtio-net: fix leaking page for gso packet during mergeable XDP Date: Sat, 9 Jun 2018 17:29:49 +0200 Message-Id: <20180609145950.392614553@linuxfoundation.org> In-Reply-To: <20180609145947.679103414@linuxfoundation.org> References: <20180609145947.679103414@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.16-stable review patch. If anyone has any objections, please let me know. ------------------ From: Jason Wang [ Upstream commit 3d62b2a0db505bbf9ed0755f254e45d775f9807f ] 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 Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman --- drivers/net/virtio_net.c | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-) --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -707,6 +707,13 @@ static struct sk_buff *receive_mergeable 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 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. */