[PATCH v2] vhost-vsock: delete vqs in vhost_vsock_unrealize to avoid memleaks

[<pannengyuan@huawei.com>]

From: Pan Nengyuan <pannengyuan@huawei.com>

Receive/transmit/event vqs forgot to cleanup in vhost_vsock_unrealize. This
patch save receive/transmit vq pointer in realize() and cleanup vqs
through those vq pointers in unrealize(). The leak stack is as follow:

Direct leak of 21504 byte(s) in 3 object(s) allocated from:
  #0 0x7f86a1356970 (/lib64/libasan.so.5+0xef970)  ??:?
  #1 0x7f86a09aa49d (/lib64/libglib-2.0.so.0+0x5249d)  ??:?
  #2 0x5604852f85ca (./x86_64-softmmu/qemu-system-x86_64+0x2c3e5ca)  /mnt/sdb/qemu/hw/virtio/virtio.c:2333
  #3 0x560485356208 (./x86_64-softmmu/qemu-system-x86_64+0x2c9c208)  /mnt/sdb/qemu/hw/virtio/vhost-vsock.c:339
  #4 0x560485305a17 (./x86_64-softmmu/qemu-system-x86_64+0x2c4ba17)  /mnt/sdb/qemu/hw/virtio/virtio.c:3531
  #5 0x5604858e6b65 (./x86_64-softmmu/qemu-system-x86_64+0x322cb65)  /mnt/sdb/qemu/hw/core/qdev.c:865
  #6 0x5604861e6c41 (./x86_64-softmmu/qemu-system-x86_64+0x3b2cc41)  /mnt/sdb/qemu/qom/object.c:2102

Reported-by: Euler Robot <euler.robot@huawei.com>
Signed-off-by: Pan Nengyuan <pannengyuan@huawei.com>
---
Changes V2 to V1:
- delete virtqueues after vhost cleanup to avoid use-after-free
- aslo delete virtqueues in the error path of realize()
---
 hw/virtio/vhost-vsock.c         | 12 ++++++++++--
 include/hw/virtio/vhost-vsock.h |  2 ++
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/hw/virtio/vhost-vsock.c b/hw/virtio/vhost-vsock.c
index f5744363a8..b6cee479bb 100644
--- a/hw/virtio/vhost-vsock.c
+++ b/hw/virtio/vhost-vsock.c
@@ -335,8 +335,10 @@ static void vhost_vsock_device_realize(DeviceState *dev, Error **errp)
                 sizeof(struct virtio_vsock_config));
 
     /* Receive and transmit queues belong to vhost */
-    virtio_add_queue(vdev, VHOST_VSOCK_QUEUE_SIZE, vhost_vsock_handle_output);
-    virtio_add_queue(vdev, VHOST_VSOCK_QUEUE_SIZE, vhost_vsock_handle_output);
+    vsock->recv_vq = virtio_add_queue(vdev, VHOST_VSOCK_QUEUE_SIZE,
+                                      vhost_vsock_handle_output);
+    vsock->trans_vq = virtio_add_queue(vdev, VHOST_VSOCK_QUEUE_SIZE,
+                                       vhost_vsock_handle_output);
 
     /* The event queue belongs to QEMU */
     vsock->event_vq = virtio_add_queue(vdev, VHOST_VSOCK_QUEUE_SIZE,
@@ -363,6 +365,9 @@ static void vhost_vsock_device_realize(DeviceState *dev, Error **errp)
 err_vhost_dev:
     vhost_dev_cleanup(&vsock->vhost_dev);
 err_virtio:
+    virtio_delete_queue(vsock->recv_vq);
+    virtio_delete_queue(vsock->trans_vq);
+    virtio_delete_queue(vsock->event_vq);
     virtio_cleanup(vdev);
     close(vhostfd);
     return;
@@ -379,6 +384,9 @@ static void vhost_vsock_device_unrealize(DeviceState *dev, Error **errp)
     vhost_vsock_set_status(vdev, 0);
 
     vhost_dev_cleanup(&vsock->vhost_dev);
+    virtio_delete_queue(vsock->recv_vq);
+    virtio_delete_queue(vsock->trans_vq);
+    virtio_delete_queue(vsock->event_vq);
     virtio_cleanup(vdev);
 }
 
diff --git a/include/hw/virtio/vhost-vsock.h b/include/hw/virtio/vhost-vsock.h
index d509d67c4a..bc5a988ee5 100644
--- a/include/hw/virtio/vhost-vsock.h
+++ b/include/hw/virtio/vhost-vsock.h
@@ -33,6 +33,8 @@ typedef struct {
     struct vhost_virtqueue vhost_vqs[2];
     struct vhost_dev vhost_dev;
     VirtQueue *event_vq;
+    VirtQueue *recv_vq;
+    VirtQueue *trans_vq;
     QEMUTimer *post_load_timer;
 
     /*< public >*/
-- 
2.21.0.windows.1