6.1-stable review patch. If anyone has any objections, please let me know.
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From: Alexandru Matei alexandru.matei@uipath.com
commit 53b08c4985158430fd6d035fb49443bada535210 upstream.
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 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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/vmw_vsock/virtio_transport.c | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-)
--- a/net/vmw_vsock/virtio_transport.c +++ b/net/vmw_vsock/virtio_transport.c @@ -590,6 +590,11 @@ static int virtio_vsock_vqs_init(struct
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); @@ -604,7 +609,16 @@ static int virtio_vsock_vqs_init(struct 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) @@ -707,6 +721,7 @@ static int virtio_vsock_probe(struct vir goto out;
rcu_assign_pointer(the_virtio_vsock, vsock); + virtio_vsock_vqs_start(vsock);
mutex_unlock(&the_virtio_vsock_mutex);
@@ -779,6 +794,7 @@ static int virtio_vsock_restore(struct v goto out;
rcu_assign_pointer(the_virtio_vsock, vsock); + virtio_vsock_vqs_start(vsock);
out: mutex_unlock(&the_virtio_vsock_mutex);