vfio/pci: Add missing range check in vfio_pci_mmap

When mmaping an extra device region verify that the region index
derived from the mmap offset is valid.

Fixes: a15b1883fe ("vfio_pci: Allow mapping extra regions")
Cc: stable@vger.kernel.org
Signed-off-by: Christian A. Ehrhardt <lk@c--e.de>
Message-Id: <20210412214124.GA241759@lisa.in-ulm.de>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Cornelia Huck <cohuck@redhat.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
This commit is contained in:
Christian A. Ehrhardt 2021-04-12 23:41:24 +02:00 committed by Alex Williamson
parent d434405aaa
commit 909290786e

View File

@ -1656,6 +1656,8 @@ static int vfio_pci_mmap(void *device_data, struct vm_area_struct *vma)
index = vma->vm_pgoff >> (VFIO_PCI_OFFSET_SHIFT - PAGE_SHIFT);
if (index >= VFIO_PCI_NUM_REGIONS + vdev->num_regions)
return -EINVAL;
if (vma->vm_end < vma->vm_start)
return -EINVAL;
if ((vma->vm_flags & VM_SHARED) == 0)
@ -1664,7 +1666,7 @@ static int vfio_pci_mmap(void *device_data, struct vm_area_struct *vma)
int regnum = index - VFIO_PCI_NUM_REGIONS;
struct vfio_pci_region *region = vdev->region + regnum;
if (region && region->ops && region->ops->mmap &&
if (region->ops && region->ops->mmap &&
(region->flags & VFIO_REGION_INFO_FLAG_MMAP))
return region->ops->mmap(vdev, region, vma);
return -EINVAL;