From mboxrd@z Thu Jan  1 00:00:00 1970
From: Jason Wang <jasowang@redhat.com>
Subject: Re: [PATCH] virtio-scsi: Fix hotcpu_notifier use-after-free with
	virtscsi_freeze
Date: Tue, 29 Oct 2013 11:27:00 +0800
Message-ID: <526F2B04.3090004@redhat.com>
References: <1382947263-22145-1-git-send-email-asias@redhat.com>
Mime-Version: 1.0
Content-Type: text/plain; charset="us-ascii"
Content-Transfer-Encoding: 7bit
Return-path: <virtualization-bounces@lists.linux-foundation.org>
In-Reply-To: <1382947263-22145-1-git-send-email-asias@redhat.com>
List-Unsubscribe: <https://lists.linuxfoundation.org/mailman/options/virtualization>,
	<mailto:virtualization-request@lists.linux-foundation.org?subject=unsubscribe>
List-Archive: <http://lists.linuxfoundation.org/pipermail/virtualization/>
List-Post: <mailto:virtualization@lists.linux-foundation.org>
List-Help: <mailto:virtualization-request@lists.linux-foundation.org?subject=help>
List-Subscribe: <https://lists.linuxfoundation.org/mailman/listinfo/virtualization>,
	<mailto:virtualization-request@lists.linux-foundation.org?subject=subscribe>
Sender: virtualization-bounces@lists.linux-foundation.org
Errors-To: virtualization-bounces@lists.linux-foundation.org
To: Asias He <asias@redhat.com>, kvm@vger.kernel.org
Cc: pbonzini@redhat.com, linux-scsi@vger.kernel.org, virtualization@lists.linux-foundation.org
List-Id: virtualization@lists.linuxfoundation.org

On 10/28/2013 04:01 PM, Asias He wrote:
> vqs are freed in virtscsi_freeze but the hotcpu_notifier is not
> unregistered. We will have a use-after-free usage when the notifier
> callback is called after virtscsi_freeze.
>
> Signed-off-by: Asias He <asias@redhat.com>
> ---
>  drivers/scsi/virtio_scsi.c | 15 ++++++++++++++-
>  1 file changed, 14 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/scsi/virtio_scsi.c b/drivers/scsi/virtio_scsi.c
> index 74b88ef..b26f1a5 100644
> --- a/drivers/scsi/virtio_scsi.c
> +++ b/drivers/scsi/virtio_scsi.c
> @@ -957,6 +957,10 @@ static void virtscsi_remove(struct virtio_device *vdev)
>  #ifdef CONFIG_PM
>  static int virtscsi_freeze(struct virtio_device *vdev)
>  {
> +	struct Scsi_Host *sh = virtio_scsi_host(vdev);
> +	struct virtio_scsi *vscsi = shost_priv(sh);
> +
> +	unregister_hotcpu_notifier(&vscsi->nb);
>  	virtscsi_remove_vqs(vdev);
>  	return 0;
>  }
> @@ -965,8 +969,17 @@ static int virtscsi_restore(struct virtio_device *vdev)
>  {
>  	struct Scsi_Host *sh = virtio_scsi_host(vdev);
>  	struct virtio_scsi *vscsi = shost_priv(sh);
> +	int err;
> +
> +	err = virtscsi_init(vdev, vscsi);
> +	if (err)
> +		return err;
> +
> +	err = register_hotcpu_notifier(&vscsi->nb);
> +	if (err)
> +		vdev->config->del_vqs(vdev);
>  
> -	return virtscsi_init(vdev, vscsi);
> +	return err;
>  }
>  #endif
>  
Acked-by: Jason Wang <jasowang@redhat.com>