[PATCH] vfio: checking of validity of user vaddr in vfio_dma_rw

[Yan Zhao <yan.y.zhao@intel.com>]

instead of calling __copy_to/from_user(), use copy_to_from_user() to
ensure vaddr range is a valid user address range before accessing them.

Cc: Kees Cook <keescook@chromium.org>

Fixes: 8d46c0cca5f4 ("vfio: introduce vfio_dma_rw to read/write a range of IOVAs")
Signed-off-by: Yan Zhao <yan.y.zhao@intel.com>
---
 drivers/vfio/vfio_iommu_type1.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index 3aefcc8e2933..fbc58284b333 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -2345,10 +2345,10 @@ static int vfio_iommu_type1_dma_rw_chunk(struct vfio_iommu *iommu,
 	vaddr = dma->vaddr + offset;
 
 	if (write)
-		*copied = __copy_to_user((void __user *)vaddr, data,
+		*copied = copy_to_user((void __user *)vaddr, data,
 					 count) ? 0 : count;
 	else
-		*copied = __copy_from_user(data, (void __user *)vaddr,
+		*copied = copy_from_user(data, (void __user *)vaddr,
 					   count) ? 0 : count;
 	if (kthread)
 		unuse_mm(mm);
-- 
2.17.1