[PATCH 5.15 655/913] vsock/virtio: initialize vdev->priv before using VQs

[Greg Kroah-Hartman]

From: Stefano Garzarella <sgarzare@xxxxxxxxxx>

[ 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@xxxxxxxxxx>
Signed-off-by: Stefano Garzarella <sgarzare@xxxxxxxxxx>
Acked-by: Michael S. Tsirkin <mst@xxxxxxxxxx>
Reviewed-by: Stefan Hajnoczi <stefanha@xxxxxxxxxx>
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 net/vmw_vsock/virtio_transport.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c
index dad9ca65f4f9..fb1b8f99f679 100644
--- 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);
-- 
2.34.1