[PATCH v4] vsock/virtio: initialize the_virtio_vsock before using VQs
From: Alexandru Matei <hidden>
Date: 2023-10-24 19:18:31
Also in:
kvm, lkml
Subsystem:
networking [general], the rest, virtio and vhost vsock driver, virtio core, vm sockets (af_vsock) · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds, Stefan Hajnoczi, Stefano Garzarella, "Michael S. Tsirkin", Jason Wang
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: 0deab087b16a ("vsock/virtio: use RCU to avoid use-after-free on the_virtio_vsock")
Signed-off-by: Alexandru Matei <redacted>
---
v4:
- moved queue_work for send_pkt_work in vqs_start and added comment explaining why
v3:
- renamed vqs_fill to vqs_start and moved tx_run initialization to it
- queued send_pkt_work at the end of initialization to send packets queued earlier
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 | 18 +++++++++++++++++-
1 file changed, 17 insertions(+), 1 deletion(-)
diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c
index e95df847176b..b80bf681327b 100644
--- a/net/vmw_vsock/virtio_transport.c
+++ b/net/vmw_vsock/virtio_transport.c@@ -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);
--
2.25.1