Re: [PATCH 1/2] virtio-blk: delete vqs on the error path in realize()

[Stefano Garzarella]

On Fri, Mar 27, 2020 at 11:56:49AM +0800, Pan Nengyuan wrote:
> virtio_vqs forgot to free on the error path in realize(). Fix that.
> 
> The asan stack:
> Direct leak of 14336 byte(s) in 1 object(s) allocated from:
>     #0 0x7f58b93fd970 in __interceptor_calloc (/lib64/libasan.so.5+0xef970)
>     #1 0x7f58b858249d in g_malloc0 (/lib64/libglib-2.0.so.0+0x5249d)
>     #2 0x5562cc627f49 in virtio_add_queue 
> /mnt/sdb/qemu/hw/virtio/virtio.c:2413
>     #3 0x5562cc4b524a in virtio_blk_device_realize 
> /mnt/sdb/qemu/hw/block/virtio-blk.c:1202
>     #4 0x5562cc613050 in virtio_device_realize 
> /mnt/sdb/qemu/hw/virtio/virtio.c:3615
>     #5 0x5562ccb7a568 in device_set_realized /mnt/sdb/qemu/hw/core/qdev.c:891
>     #6 0x5562cd39cd45 in property_set_bool /mnt/sdb/qemu/qom/object.c:2238
> 
> Reported-by: Euler Robot <address@hidden>
> Signed-off-by: Pan Nengyuan <address@hidden>
> ---
> Cc: Stefan Hajnoczi <address@hidden>
> Cc: Kevin Wolf <address@hidden>
> Cc: Max Reitz <address@hidden>
> Cc: address@hidden
> ---
>  hw/block/virtio-blk.c | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/hw/block/virtio-blk.c b/hw/block/virtio-blk.c
> index 142863a3b2..a6682c2ced 100644
> --- a/hw/block/virtio-blk.c
> +++ b/hw/block/virtio-blk.c
> @@ -1204,8 +1204,7 @@ static void virtio_blk_device_realize(DeviceState *dev, 
> Error **errp)
>      virtio_blk_data_plane_create(vdev, conf, &s->dataplane, &err);
>      if (err != NULL) {
>          error_propagate(errp, err);
> -        virtio_cleanup(vdev);
> -        return;
> +        goto fail;
>      }
>  
>      s->change = qemu_add_vm_change_state_handler(virtio_blk_dma_restart_cb, 
> s);
> @@ -1218,6 +1217,11 @@ static void virtio_blk_device_realize(DeviceState 
> *dev, Error **errp)
>                           conf->conf.lcyls,
>                           conf->conf.lheads,
>                           conf->conf.lsecs);

I think we should add a return here, otherwise we will remove the virt
queues also in the success case.

Thanks,
Stefano

> +fail:
> +    for (i = 0; i < conf->num_queues; i++) {
> +        virtio_del_queue(vdev, i);
> +    }
> +    virtio_cleanup(vdev);
>  }
>  
>  static void virtio_blk_device_unrealize(DeviceState *dev, Error **errp)
> -- 
> 2.18.2
> 
>