[PATCH v9 7/7] iommu/vt-d: Check UAPI data processed by IOMMU core

Jacob Pan
2020-09-11T21:57:28Z

IOMMU generic layer already does sanity checks on UAPI data for version
match and argsz range based on generic information.

This patch adjusts the following data checking responsibilities:
- removes the redundant version check from VT-d driver
- removes the check for vendor specific data size
- adds check for the use of reserved/undefined flags

Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
---
drivers/iommu/intel/iommu.c | 3 +--
drivers/iommu/intel/svm.c | 11 +++++++++--
include/uapi/linux/iommu.h | 1 +
3 files changed, 11 insertions(+), 4 deletions(-)

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 461f3a6864d4..18ed3b3c70d7 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -5408,8 +5408,7 @@ intel_iommu_sva_invalidate(struct iommu_domain *domain, struct device *dev,
int ret = 0;
u64 size = 0;

- if (!inv_info || !dmar_domain ||
- inv_info->version != IOMMU_CACHE_INVALIDATE_INFO_VERSION_1)
+ if (!inv_info || !dmar_domain)
return -EINVAL;

if (!dev || !dev_is_pci(dev))
diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c
index 99353d6468fa..0cb9a15f1112 100644
--- a/drivers/iommu/intel/svm.c
+++ b/drivers/iommu/intel/svm.c
@@ -284,8 +284,15 @@ int intel_svm_bind_gpasid(struct iommu_domain *domain, struct device *dev,
if (WARN_ON(!iommu) || !data)
return -EINVAL;

- if (data->version != IOMMU_GPASID_BIND_VERSION_1 ||
- data->format != IOMMU_PASID_FORMAT_INTEL_VTD)
+ if (data->format != IOMMU_PASID_FORMAT_INTEL_VTD)
+ return -EINVAL;
+
+ /* IOMMU core ensures argsz is more than the start of the union */
+ if (data->argsz < offsetofend(struct iommu_gpasid_bind_data, vendor.vtd))
+ return -EINVAL;
+
+ /* Make sure no undefined flags are used in vendor data */
+ if (data->vendor.vtd.flags & ~(IOMMU_SVA_VTD_GPASID_LAST - 1))
return -EINVAL;

if (!dev_is_pci(dev))
diff --git a/include/uapi/linux/iommu.h b/include/uapi/linux/iommu.h
index c64bca5af419..1ebc23df4fbc 100644
--- a/include/uapi/linux/iommu.h
+++ b/include/uapi/linux/iommu.h
@@ -288,6 +288,7 @@ struct iommu_gpasid_bind_data_vtd {
#define IOMMU_SVA_VTD_GPASID_PWT (1 << 3) /* page-level write through */
#define IOMMU_SVA_VTD_GPASID_EMTE (1 << 4) /* extended mem type enable */
#define IOMMU_SVA_VTD_GPASID_CD (1 << 5) /* PASID-level cache disable */
+#define IOMMU_SVA_VTD_GPASID_LAST (1 << 6)
__u64 flags;
__u32 pat;
__u32 emt;
--
2.7.4