Re: [PATCH] virtio-rng: make device ready before making request

[Laurent Vivier]

On 08/06/2022 08:14, Jason Wang wrote:
> Current virtio-rng does a entropy request before DRIVER_OK, this
> violates the spec and kernel will ignore the interrupt after commit
> 8b4ec69d7e09 ("virtio: harden vring IRQ").
>
> Fixing this by making device ready before the request.
>
> Fixes: 8b4ec69d7e09 ("virtio: harden vring IRQ")
> Reported-and-tested-by: syzbot+5b59d6d459306a556f54@xxxxxxxxxxxxxxxxxxxxxxxxx
> Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>
> ---
>   drivers/char/hw_random/virtio-rng.c | 2 ++
>   1 file changed, 2 insertions(+)
>
> diff --git a/drivers/char/hw_random/virtio-rng.c b/drivers/char/hw_random/virtio-rng.c
> index e856df7e285c..a6f3a8a2aca6 100644
> --- a/drivers/char/hw_random/virtio-rng.c
> +++ b/drivers/char/hw_random/virtio-rng.c
> @@ -159,6 +159,8 @@ static int probe_common(struct virtio_device *vdev)
>   		goto err_find;
>   	}
>   
> +	virtio_device_ready(vdev);
> +
>   	/* we always have a pending entropy request */
>   	request_entropy(vi);
>   

Reviewed-by: Laurent Vivier <lvivier@xxxxxxxxxx>