Merge tag 'iommu-fixes-v5.11-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu

Pull IOMMU fix from Joerg Roedel:
 "Fix a possible NULL-ptr dereference in dev_iommu_priv_get() which is
  too easy to accidentially trigger from IOMMU drivers.

  In the current case the AMD IOMMU driver triggered it on some machines
  in the IO-page-fault path, so fix it once and for all"

* tag 'iommu-fixes-v5.11-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/joro/iommu:
  iommu: Check dev->iommu in dev_iommu_priv_get() before dereferencing it

include/linux/iommu.h

@@ -616,7 +616,10 @@ static inline void dev_iommu_fwspec_set(struct device *dev,
 
 static inline void *dev_iommu_priv_get(struct device *dev)
 {
+	if (dev->iommu)
 		return dev->iommu->priv;
+	else
+		return NULL;
 }
 
 static inline void dev_iommu_priv_set(struct device *dev, void *priv)