vfio: fix ioctl error handling
Calling return copy_to_user(...) in an ioctl will not
do the right thing if there's a pagefault:
copy_to_user returns the number of bytes not copied
in this case.
Fix up vfio to do
return copy_to_user(...)) ?
-EFAULT : 0;
everywhere.
Cc: stable@vger.kernel.org
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index 6f1ea3d..75b24e9 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -999,7 +999,8 @@
info.iova_pgsizes = vfio_pgsize_bitmap(iommu);
- return copy_to_user((void __user *)arg, &info, minsz);
+ return copy_to_user((void __user *)arg, &info, minsz) ?
+ -EFAULT : 0;
} else if (cmd == VFIO_IOMMU_MAP_DMA) {
struct vfio_iommu_type1_dma_map map;
@@ -1032,7 +1033,8 @@
if (ret)
return ret;
- return copy_to_user((void __user *)arg, &unmap, minsz);
+ return copy_to_user((void __user *)arg, &unmap, minsz) ?
+ -EFAULT : 0;
}
return -ENOTTY;