diff options
| author | Julian Stecklina <jsteckli@os.inf.tu-dresden.de> | 2013-10-09 10:03:52 +0200 |
|---|---|---|
| committer | Joerg Roedel <joro@8bytes.org> | 2013-11-01 12:46:25 +0100 |
| commit | f9423606ade08653dd8a43334f0a7fb45504c5cc (patch) | |
| tree | 4e4ecf1d5baa286cf79c7f750e2f25219b0ac476 | |
| parent | 05104a4e8713b27291c7bb49c1e7e68b4e243571 (diff) | |
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>
| -rw-r--r-- | drivers/iommu/intel-iommu.c | 6 |
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) { |