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....@intel.com> Cc: Jacob Pan <jacob.jun....@linux.intel.com> Reported-by: Dave Jiang <dave.ji...@intel.com> Fixes: 2f26e0a9c9860 ("iommu/vt-d: Add basic SVM PASID support") Signed-off-by: Lu Baolu <baolu...@linux.intel.com> --- drivers/iommu/intel-svm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/iommu/intel-svm.c b/drivers/iommu/intel-svm.c index c79540deaf00..3a4b09ae8561 100644 --- 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)) { -- 2.17.1