[PATCH] vduse: Disallow injecting interrupt before DRIVER_OK is set

Michael S. Tsirkin
Wed, 13 Oct 2021 11:26:48 -0000

On Thu, Sep 23, 2021 at 03:57:22PM +0800, Xie Yongji
wrote:
> The interrupt callback should not be triggered before DRIVER_OK
> is set. Otherwise, it might break the virtio device driver.
> So let's add a check to avoid the unexpected behavior.
>
> Fixes: c8a6153b6c59 ("vduse: Introduce VDUSE - vDPA Device in
Userspace")
> Signed-off-by: Xie Yongji <xieyongji at bytedance.com>

OK I guess, except - what about locking/ordering in all this?

> ---
>  drivers/vdpa/vdpa_user/vduse_dev.c | 8 ++++++++
>  1 file changed, 8 insertions(+)
>
> diff --git a/drivers/vdpa/vdpa_user/vduse_dev.c
b/drivers/vdpa/vdpa_user/vduse_dev.c
> index 29a38ecba19e..972c13a7e5da 100644
> --- a/drivers/vdpa/vdpa_user/vduse_dev.c
> +++ b/drivers/vdpa/vdpa_user/vduse_dev.c
> @@ -968,6 +968,10 @@ static long vduse_dev_ioctl(struct file *file,
unsigned int cmd,
>  		break;
>  	}
>  	case VDUSE_DEV_INJECT_CONFIG_IRQ:
> +		ret = -EINVAL;
> +		if (!(dev->status & VIRTIO_CONFIG_S_DRIVER_OK))
> +			break;
> +
>  		ret = 0;
>  		queue_work(vduse_irq_wq, &dev->inject);
>  		break;
> @@ -1047,6 +1051,10 @@ static long vduse_dev_ioctl(struct file *file,
unsigned int cmd,
>  	case VDUSE_VQ_INJECT_IRQ: {
>  		u32 index;
>
> +		ret = -EINVAL;
> +		if (!(dev->status & VIRTIO_CONFIG_S_DRIVER_OK))
> +			break;
> +
>  		ret = -EFAULT;
>  		if (get_user(index, (u32 __user *)argp))
>  			break;
> --
> 2.11.0