Received-SPF: pass (google.com: domain of linux-crypto-owner@vger.kernel.org designates 2620:137:e000::1:18 as permitted sender) client-ip=2620:137:e000::1:18;
Message-ID: <8733913f-b04b-f2c7-d7e2-d22740ab99af@redhat.com>
Date:   Wed, 8 Jun 2022 14:17:43 +0200
MIME-Version: 1.0
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:91.0) Gecko/20100101
 Thunderbird/91.9.0
Subject: Re: [PATCH] virtio-rng: make device ready before making request
Content-Language: en-US
To:     Jason Wang <jasowang@redhat.com>, mst@redhat.com, mpm@selenic.com,
        herbert@gondor.apana.org.au
Cc:     linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org,
        syzbot+5b59d6d459306a556f54@syzkaller.appspotmail.com
References: <20220608061422.38437-1-jasowang@redhat.com>
From:   Laurent Vivier <lvivier@redhat.com>
In-Reply-To: <20220608061422.38437-1-jasowang@redhat.com>
Content-Type: text/plain; charset=UTF-8; format=flowed
Content-Transfer-Encoding: 7bit
Precedence: bulk

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@syzkaller.appspotmail.com
> Signed-off-by: Jason Wang <jasowang@redhat.com>
> ---
>   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@redhat.com>