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authorJulian Stecklina <jsteckli@os.inf.tu-dresden.de>2013-10-09 10:03:52 +0200
committerJoerg Roedel <joro@8bytes.org>2013-11-01 12:46:25 +0100
commitf9423606ade08653dd8a43334f0a7fb45504c5cc (patch)
tree4e4ecf1d5baa286cf79c7f750e2f25219b0ac476 /drivers/iommu
parent05104a4e8713b27291c7bb49c1e7e68b4e243571 (diff)
downloadlinux-f9423606ade08653dd8a43334f0a7fb45504c5cc.tar.bz2
iommu/vt-d: Fixed interaction of VFIO_IOMMU_MAP_DMA with IOMMU address limits
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 <jsteckli@os.inf.tu-dresden.de> Acked-by: Alex Williamson <alex.williamson@redhat.com> Signed-off-by: Joerg Roedel <joro@8bytes.org>
Diffstat (limited to 'drivers/iommu')
-rw-r--r--drivers/iommu/intel-iommu.c6
1 files changed, 5 insertions, 1 deletions
diff --git a/drivers/iommu/intel-iommu.c b/drivers/iommu/intel-iommu.c
index 15e9b57e9cf0..40203ada635e 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(!domain->pgd);
- 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) {