[PATCH 5.4 052/168] s390/crypto: return -EFAULT if copy_to_user() fails

From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

From: Wang Qing <redacted>

commit 942df4be7ab40195e2a839e9de81951a5862bc5b 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: e06670c5fe3b ("s390: vfio-ap: implement VFIO_DEVICE_GET_INFO ioctl")
Signed-off-by: Wang Qing <redacted>
Reviewed-by: Tony Krowiak <akrowiak@linux.ibm.com>
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Link: https://lore.kernel.org/r/1614600502-16714-1-git-send-email-wangqing@vivo.com (local)
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 drivers/s390/crypto/vfio_ap_ops.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/s390/crypto/vfio_ap_ops.c
+++ b/drivers/s390/crypto/vfio_ap_ops.c

@@ -1279,7 +1279,7 @@ static int vfio_ap_mdev_get_device_info(
 	info.num_regions = 0;
 	info.num_irqs = 0;
 
-	return copy_to_user((void __user *)arg, &info, minsz);
+	return copy_to_user((void __user *)arg, &info, minsz) ? -EFAULT : 0;
 }
 
 static ssize_t vfio_ap_mdev_ioctl(struct mdev_device *mdev,