[PATCH v2] vsock/virtio: initialize the_virtio_vsock before using VQs

[Alexandru Matei <alexandru.matei@xxxxxxxxxx>]

Once VQs are filled with empty buffers and we kick the host,
it can send connection requests.  If 'the_virtio_vsock' is not
initialized before, replies are silently dropped and do not reach the host.

Fixes: 0deab087b16a ("vsock/virtio: use RCU to avoid use-after-free on the_virtio_vsock")
Signed-off-by: Alexandru Matei <alexandru.matei@xxxxxxxxxx>
---
v2: 
- split virtio_vsock_vqs_init in vqs_init and vqs_fill and moved 
  the_virtio_vsock initialization after vqs_init

 net/vmw_vsock/virtio_transport.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c
index e95df847176b..92738d1697c1 100644
--- a/net/vmw_vsock/virtio_transport.c
+++ b/net/vmw_vsock/virtio_transport.c
@@ -559,6 +559,11 @@ static int virtio_vsock_vqs_init(struct virtio_vsock *vsock)
 	vsock->tx_run = true;
 	mutex_unlock(&vsock->tx_lock);
 
+	return 0;
+}
+
+static void virtio_vsock_vqs_fill(struct virtio_vsock *vsock)
+{
 	mutex_lock(&vsock->rx_lock);
 	virtio_vsock_rx_fill(vsock);
 	vsock->rx_run = true;
@@ -568,8 +573,6 @@ static int virtio_vsock_vqs_init(struct virtio_vsock *vsock)
 	virtio_vsock_event_fill(vsock);
 	vsock->event_run = true;
 	mutex_unlock(&vsock->event_lock);
-
-	return 0;
 }
 
 static void virtio_vsock_vqs_del(struct virtio_vsock *vsock)
@@ -664,6 +667,7 @@ static int virtio_vsock_probe(struct virtio_device *vdev)
 		goto out;
 
 	rcu_assign_pointer(the_virtio_vsock, vsock);
+	virtio_vsock_vqs_fill(vsock);
 
 	mutex_unlock(&the_virtio_vsock_mutex);
 
@@ -736,6 +740,7 @@ static int virtio_vsock_restore(struct virtio_device *vdev)
 		goto out;
 
 	rcu_assign_pointer(the_virtio_vsock, vsock);
+	virtio_vsock_vqs_fill(vsock);
 
 out:
 	mutex_unlock(&the_virtio_vsock_mutex);
-- 
2.34.1