virtio_net: fix memory leak inside XPD_TX with mergeable

commit 7a542bee27c6a57e45c33cbbdc963325fd6493af upstream.

When we call xdp_convert_buff_to_frame() to get xdpf, if it returns
NULL, we should check if xdp_page was allocated by xdp_linearize_page().
If it is newly allocated, it should be freed here alone. Just like any
other "goto err_xdp".

Fixes: 44fa2dbd4759 ("xdp: transition into using xdp_frame for ndo_xdp_xmit")
Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 53cefad..48fb7bd 100644 (file)
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -1017,8 +1017,11 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
                case XDP_TX:
                        stats->xdp_tx++;
                        xdpf = xdp_convert_buff_to_frame(&xdp);
-                       if (unlikely(!xdpf))
+                       if (unlikely(!xdpf)) {
+                               if (unlikely(xdp_page != page))
+                                       put_page(xdp_page);
                                goto err_xdp;
+                       }
                        err = virtnet_xdp_xmit(dev, 1, &xdpf, 0);
                        if (unlikely(!err)) {
                                xdp_return_frame_rx_napi(xdpf);