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authorAlex Williamson <alex.williamson@redhat.com>2019-01-07 22:13:22 -0700
committerAlex Williamson <alex.williamson@redhat.com>2019-01-08 09:31:28 -0700
commit58fec830fc19208354895d9832785505046d6c01 (patch)
treea67fd59017fdf486f854b627c1128675660d9b4d /drivers/vfio
parentd1fc1176c055c9ec9c6ec4d113a284e0bad9d09a (diff)
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vfio/type1: Fix unmap overflow off-by-one
The below referenced commit adds a test for integer overflow, but in doing so prevents the unmap ioctl from ever including the last page of the address space. Subtract one to compare to the last address of the unmap to avoid the overflow and wrap-around. Fixes: 71a7d3d78e3c ("vfio/type1: silence integer overflow warning") Link: https://bugzilla.redhat.com/show_bug.cgi?id=1662291 Cc: stable@vger.kernel.org # v4.15+ Reported-by: Pei Zhang <pezhang@redhat.com> Debugged-by: Peter Xu <peterx@redhat.com> Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com> Reviewed-by: Peter Xu <peterx@redhat.com> Tested-by: Peter Xu <peterx@redhat.com> Reviewed-by: Cornelia Huck <cohuck@redhat.com> Signed-off-by: Alex Williamson <alex.williamson@redhat.com>
Diffstat (limited to 'drivers/vfio')
-rw-r--r--drivers/vfio/vfio_iommu_type1.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/drivers/vfio/vfio_iommu_type1.c b/drivers/vfio/vfio_iommu_type1.c
index 7651cfb14836..73652e21efec 100644
--- a/drivers/vfio/vfio_iommu_type1.c
+++ b/drivers/vfio/vfio_iommu_type1.c
@@ -878,7 +878,7 @@ static int vfio_dma_do_unmap(struct vfio_iommu *iommu,
return -EINVAL;
if (!unmap->size || unmap->size & mask)
return -EINVAL;
- if (unmap->iova + unmap->size < unmap->iova ||
+ if (unmap->iova + unmap->size - 1 < unmap->iova ||
unmap->size > SIZE_MAX)
return -EINVAL;