iommu/vt-d: Fix NULL pointer reference in intel_svm_bind_mm()

LuBaolu · joergroedel · commit c56cba5daf45 · 2019-03-01T10:23:36.000+01:00
Intel IOMMU could be turned off with intel_iommu=off. If Intel IOMMU is off, the intel_iommu struct will not be initialized. When device drivers call intel_svm_bind_mm(), the NULL pointer reference will happen there. Add dmar_disabled check to avoid NULL pointer reference. Cc: Ashok Raj <ashok.raj@intel.com> Cc: Jacob Pan <jacob.jun.pan@linux.intel.com> Reported-by: Dave Jiang <dave.jiang@intel.com> Fixes: 2f26e0a ("iommu/vt-d: Add basic SVM PASID support") Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com> Signed-off-by: Joerg Roedel <jroedel@suse.de>
diff --git a/drivers/iommu/intel-svm.c b/drivers/iommu/intel-svm.c
@@ -234,7 +234,7 @@ int intel_svm_bind_mm(struct device *dev, int *pasid, int flags, struct svm_dev_
 	int pasid_max;
 	int ret;
 
-	if (!iommu)
+	if (!iommu || dmar_disabled)
 		return -EINVAL;
 
 	if (dev_is_pci(dev)) {
