virtio_net: fix return value check in receive_mergeable()

The function virtqueue_get_buf_ctx() could return NULL, the return
value 'buf' need to be checked with NULL, not value 'ctx'.

Signed-off-by: Yunjian Wang <wangyunjian@huawei.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 511f8339fa96..7927e28f5336 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -714,7 +714,7 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
                 int num_skb_frags;
 
                 buf = virtqueue_get_buf_ctx(rq->vq, &len, &ctx);
-                if (unlikely(!ctx)) {
+                if (unlikely(!buf)) {
                         pr_debug("%s: rx error: %d buffers out of %d missing\n",
                                  dev->name, num_buf,
                                  virtio16_to_cpu(vi->vdev,