From 58fec830fc19208354895d9832785505046d6c01 Mon Sep 17 00:00:00 2001 From: Alex Williamson Date: Mon, 7 Jan 2019 22:13:22 -0700 Subject: 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 Debugged-by: Peter Xu Reviewed-by: Dan Carpenter Reviewed-by: Peter Xu Tested-by: Peter Xu Reviewed-by: Cornelia Huck Signed-off-by: Alex Williamson --- drivers/vfio/vfio_iommu_type1.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'drivers/vfio/vfio_iommu_type1.c') 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; -- cgit v1.2.3-59-g8ed1b