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>
This commit is contained in:
Michael S. Tsirkin 2016-02-28 16:31:39 +02:00 committed by Alex Williamson
parent 81f70ba233
commit 8160c4e455
3 changed files with 16 additions and 8 deletions

View File

@ -446,7 +446,8 @@ static long vfio_pci_ioctl(void *device_data,
info.num_regions = VFIO_PCI_NUM_REGIONS;
info.num_irqs = VFIO_PCI_NUM_IRQS;
return copy_to_user((void __user *)arg, &info, minsz);
return copy_to_user((void __user *)arg, &info, minsz) ?
-EFAULT : 0;
} else if (cmd == VFIO_DEVICE_GET_REGION_INFO) {
struct pci_dev *pdev = vdev->pdev;
@ -520,7 +521,8 @@ static long vfio_pci_ioctl(void *device_data,
return -EINVAL;
}
return copy_to_user((void __user *)arg, &info, minsz);
return copy_to_user((void __user *)arg, &info, minsz) ?
-EFAULT : 0;
} else if (cmd == VFIO_DEVICE_GET_IRQ_INFO) {
struct vfio_irq_info info;
@ -555,7 +557,8 @@ static long vfio_pci_ioctl(void *device_data,
else
info.flags |= VFIO_IRQ_INFO_NORESIZE;
return copy_to_user((void __user *)arg, &info, minsz);
return copy_to_user((void __user *)arg, &info, minsz) ?
-EFAULT : 0;
} else if (cmd == VFIO_DEVICE_SET_IRQS) {
struct vfio_irq_set hdr;

View File

@ -219,7 +219,8 @@ static long vfio_platform_ioctl(void *device_data,
info.num_regions = vdev->num_regions;
info.num_irqs = vdev->num_irqs;
return copy_to_user((void __user *)arg, &info, minsz);
return copy_to_user((void __user *)arg, &info, minsz) ?
-EFAULT : 0;
} else if (cmd == VFIO_DEVICE_GET_REGION_INFO) {
struct vfio_region_info info;
@ -240,7 +241,8 @@ static long vfio_platform_ioctl(void *device_data,
info.size = vdev->regions[info.index].size;
info.flags = vdev->regions[info.index].flags;
return copy_to_user((void __user *)arg, &info, minsz);
return copy_to_user((void __user *)arg, &info, minsz) ?
-EFAULT : 0;
} else if (cmd == VFIO_DEVICE_GET_IRQ_INFO) {
struct vfio_irq_info info;
@ -259,7 +261,8 @@ static long vfio_platform_ioctl(void *device_data,
info.flags = vdev->irqs[info.index].flags;
info.count = vdev->irqs[info.index].count;
return copy_to_user((void __user *)arg, &info, minsz);
return copy_to_user((void __user *)arg, &info, minsz) ?
-EFAULT : 0;
} else if (cmd == VFIO_DEVICE_SET_IRQS) {
struct vfio_irq_set hdr;

View File

@ -999,7 +999,8 @@ static long vfio_iommu_type1_ioctl(void *iommu_data,
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 @@ static long vfio_iommu_type1_ioctl(void *iommu_data,
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;