diff options
authorJulian Stecklina <>2013-10-09 10:03:52 +0200
committerGreg Kroah-Hartman <>2013-12-08 07:29:27 -0800
commit3de762b3d32ff3d0440ca809e1ba084c682f0ca7 (patch)
parent7dc39b55ecc16a4db44c820263c73a60fc750b27 (diff)
iommu/vt-d: Fixed interaction of VFIO_IOMMU_MAP_DMA with IOMMU address limits
commit f9423606ade08653dd8a43334f0a7fb45504c5cc upstream. The BUG_ON in drivers/iommu/intel-iommu.c:785 can be triggered from userspace via VFIO by calling the VFIO_IOMMU_MAP_DMA ioctl on a vfio device with any address beyond the addressing capabilities of the IOMMU. The problem is that the ioctl code calls iommu_iova_to_phys before it calls iommu_map. iommu_map handles the case that it gets addresses beyond the addressing capabilities of its IOMMU. intel_iommu_iova_to_phys does not. This patch fixes iommu_iova_to_phys to return NULL for addresses beyond what the IOMMU can handle. This in turn causes the ioctl call to fail in iommu_map and (correctly) return EFAULT to the user with a helpful warning message in the kernel log. Signed-off-by: Julian Stecklina <> Acked-by: Alex Williamson <> Signed-off-by: Joerg Roedel <> Signed-off-by: Greg Kroah-Hartman <>
1 files changed, 5 insertions, 1 deletions
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index fa004b112a8..25943a683d1 100644
--- a/drivers/iommu/intel-iommu.c
+++ b/drivers/iommu/intel-iommu.c
@@ -782,7 +782,11 @@ static struct dma_pte *pfn_to_dma_pte(struct dmar_domain *domain,
int offset;
- BUG_ON(addr_width < BITS_PER_LONG && pfn >> addr_width);
+ if (addr_width < BITS_PER_LONG && pfn >> addr_width)
+ /* Address beyond IOMMU's addressing capabilities. */
+ return NULL;
parent = domain->pgd;
while (level > 0) {