5.15-stable review patch. If anyone has any objections, please let me know.
------------------
From: Alexandru Matei <alexandru.matei@xxxxxxxxxx>
[ Upstream commit 53b08c4985158430fd6d035fb49443bada535210 ]
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@xxxxxxxxxx>
Reviewed-by: Stefano Garzarella <sgarzare@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20231024191742.14259-1-alexandru.matei@xxxxxxxxxx
Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
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 f6fa26228e5cf..0b41028ed544a 100644
--- 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_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);
@@ -604,7 +609,16 @@ 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)
@@ -707,6 +721,7 @@ 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);
@@ -779,6 +794,7 @@ 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);
--
2.42.0
