s390/cio: return -EFAULT if copy_to_user() fails

The copy_to_user() function returns the number of bytes remaining to be
copied, but we want to return -EFAULT if the copy doesn't complete.

Fixes: e01bcdd61320 ("vfio: ccw: realize VFIO_DEVICE_GET_REGION_INFO ioctl")
Signed-off-by: Wang Qing <wangqing@vivo.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Link: https://lore.kernel.org/r/1614600093-13992-1-git-send-email-wangqing@vivo.com
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

diff --git a/drivers/s390/cio/vfio_ccw_ops.c b/drivers/s390/cio/vfio_ccw_ops.c
index 68106be4ba7a19b5fb182e820cf92cc132eb328e..557d0b888cd3ebd9b871249a76f3ab1b2f64148e 100644 (file)
--- a/drivers/s390/cio/vfio_ccw_ops.c
+++ b/drivers/s390/cio/vfio_ccw_ops.c
@@ -543,7 +543,7 @@ static ssize_t vfio_ccw_mdev_ioctl(struct mdev_device *mdev,
                if (ret)
                        return ret;
 
-               return copy_to_user((void __user *)arg, &info, minsz);
+               return copy_to_user((void __user *)arg, &info, minsz) ? -EFAULT : 0;
        }
        case VFIO_DEVICE_GET_REGION_INFO:
        {
@@ -561,7 +561,7 @@ static ssize_t vfio_ccw_mdev_ioctl(struct mdev_device *mdev,
                if (ret)
                        return ret;
 
-               return copy_to_user((void __user *)arg, &info, minsz);
+               return copy_to_user((void __user *)arg, &info, minsz) ? -EFAULT : 0;
        }
        case VFIO_DEVICE_GET_IRQ_INFO:
        {