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

[Stefano Garzarella]

On Wed, Jan 15, 2020 at 02:25:35PM +0800, address@hidden wrote:
> From: Pan Nengyuan <address@hidden>
> 
> 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 <address@hidden>
> Signed-off-by: Pan Nengyuan <address@hidden>
> ---
> 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(-)

Reviewed-by: Stefano Garzarella <address@hidden>

> 
> 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
> 
> 
> 

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