[PATCH 5.17 0801/1126] vsock/virtio: initialize vdev->priv before using VQs

Greg Kroah-Hartman
2022-04-05T09:13:32Z

From: Stefano Garzarella <sgarzare@redhat.com>

[ 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>
---
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 5afc194a58bb..3e5513934c9f 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