Re: [PATCH] vhost: fix length for cross region descriptor

[Jason Wang <jasowang@redhat.com>]

On 11/26/2012 11:57 PM, Michael S. Tsirkin wrote:
> If a single descriptor crosses a region, the
> second chunk length should be decremented
> by size translated so far, instead it includes
> the full descriptor length.
>
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> ---
>   drivers/vhost/vhost.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
> index ef8f598..5a3d0f1 100644
> --- a/drivers/vhost/vhost.c
> +++ b/drivers/vhost/vhost.c
> @@ -1049,7 +1049,7 @@ static int translate_desc(struct vhost_dev *dev, u64 addr, u32 len,
>   		}
>   		_iov = iov + ret;
>   		size = reg->memory_size - addr + reg->guest_phys_addr;
> -		_iov->iov_len = min((u64)len, size);
> +		_iov->iov_len = min((u64)len - s, size);
>   		_iov->iov_base = (void __user *)(unsigned long)
>   			(reg->userspace_addr + addr - reg->guest_phys_addr);
>   		s += size;

Acked-by: Jason Wang <jasowang@redhat.com>