From: Wang Qing <wangqing@vivo.com> commit 51c44babdc19aaf882e1213325a0ba291573308f upstream. 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.co... Signed-off-by: Heiko Carstens <hca@linux.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> --- drivers/s390/cio/vfio_ccw_ops.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/s390/cio/vfio_ccw_ops.c b/drivers/s390/cio/vfio_ccw_ops.c index dc5ff47de3fee..a7056c2322e01 100644 --- a/drivers/s390/cio/vfio_ccw_ops.c +++ b/drivers/s390/cio/vfio_ccw_ops.c @@ -341,7 +341,7 @@ 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: { @@ -362,7 +362,7 @@ 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: { -- 2.25.1