vsock/virtio: initialize vdev->priv before using VQs

BugLink: https://bugs.launchpad.net/bugs/1969110
[ Upstream commit 4b5f1ad5566ada230aaa2ce861b28d1895f1ea68 ]

When we fill VQs with empty buffers and kick the host, it may send
an interrupt. `vdev->priv` must be initialized before this since it
is used in the virtqueue callbacks.

Fixes: 0deab087b16a ("vsock/virtio: use RCU to avoid use-after-free on the_virtio_vsock")
Suggested-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Stefano Garzarella <sgarzare@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
(cherry picked from commit 10c6cb867ffa827a8364d0c481ec1438cd594652)
Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com>

diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c
index dad9ca65f4f9d6756970bd0dbac34202ea039a79..fb1b8f99f67998dda360454678b99a021e3c3806 100644 (file)
--- a/net/vmw_vsock/virtio_transport.c
+++ b/net/vmw_vsock/virtio_transport.c
@@ -622,6 +622,8 @@ static int virtio_vsock_probe(struct virtio_device *vdev)
        INIT_WORK(&vsock->event_work, virtio_transport_event_work);
        INIT_WORK(&vsock->send_pkt_work, virtio_transport_send_pkt_work);
 
+       vdev->priv = vsock;
+
        mutex_lock(&vsock->tx_lock);
        vsock->tx_run = true;
        mutex_unlock(&vsock->tx_lock);
@@ -639,7 +641,6 @@ static int virtio_vsock_probe(struct virtio_device *vdev)
        if (virtio_has_feature(vdev, VIRTIO_VSOCK_F_SEQPACKET))
                vsock->seqpacket_allow = true;
 
-       vdev->priv = vsock;
        rcu_assign_pointer(the_virtio_vsock, vsock);
 
        mutex_unlock(&the_virtio_vsock_mutex);