vsock/virtio: initialize the_virtio_vsock before using VQs

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.

virtio_transport_send_pkt() can queue packets once the_virtio_vsock is
set, but they won't be processed until vsock->tx_run is set to true. We
queue vsock->send_pkt_work when initialization finishes to send those
packets queued earlier.

Fixes: 0deab087b1 ("vsock/virtio: use RCU to avoid use-after-free on the_virtio_vsock")
Signed-off-by: Alexandru Matei <alexandru.matei@uipath.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Link: https://lore.kernel.org/r/20231024191742.14259-1-alexandru.matei@uipath.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This commit is contained in:
Alexandru Matei 2023-10-24 22:17:42 +03:00 committed by Jakub Kicinski
parent 1711435e3e
commit 53b08c4985

View File

@ -555,6 +555,11 @@ static int virtio_vsock_vqs_init(struct virtio_vsock *vsock)
virtio_device_ready(vdev);
return 0;
}
static void virtio_vsock_vqs_start(struct virtio_vsock *vsock)
{
mutex_lock(&vsock->tx_lock);
vsock->tx_run = true;
mutex_unlock(&vsock->tx_lock);
@ -569,7 +574,16 @@ static int virtio_vsock_vqs_init(struct virtio_vsock *vsock)
vsock->event_run = true;
mutex_unlock(&vsock->event_lock);
return 0;
/* virtio_transport_send_pkt() can queue packets once
* the_virtio_vsock is set, but they won't be processed until
* vsock->tx_run is set to true. We queue vsock->send_pkt_work
* when initialization finishes to send those packets queued
* earlier.
* We don't need to queue the other workers (rx, event) because
* as long as we don't fill the queues with empty buffers, the
* host can't send us any notification.
*/
queue_work(virtio_vsock_workqueue, &vsock->send_pkt_work);
}
static void virtio_vsock_vqs_del(struct virtio_vsock *vsock)
@ -664,6 +678,7 @@ static int virtio_vsock_probe(struct virtio_device *vdev)
goto out;
rcu_assign_pointer(the_virtio_vsock, vsock);
virtio_vsock_vqs_start(vsock);
mutex_unlock(&the_virtio_vsock_mutex);
@ -736,6 +751,7 @@ static int virtio_vsock_restore(struct virtio_device *vdev)
goto out;
rcu_assign_pointer(the_virtio_vsock, vsock);
virtio_vsock_vqs_start(vsock);
out:
mutex_unlock(&the_virtio_vsock_mutex);