[PATCH] iommu: Check dev->iommu in dev_iommu_priv_get() before dereferencing it

[Joerg Roedel]

From: Joerg Roedel <jroedel@xxxxxxx>

The dev_iommu_priv_get() needs a similar check to
dev_iommu_fwspec_get() to make sure no NULL-ptr is dereferenced.

Fixes: 05a0542b456e1 ("iommu/amd: Store dev_data as device iommu private data")
Reference: https://bugzilla.kernel.org/show_bug.cgi?id=211241
Cc: stable@xxxxxxxxxxxxxxx	# v5.8+
Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>
---
 include/linux/iommu.h | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index 524ffc2ff64f..5b3a7a08dc70 100644
--- a/include/linux/iommu.h
+++ b/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)
 {
-	return dev->iommu->priv;
+	if (dev->iommu)
+		return dev->iommu->priv;
+	else
+		return NULL;
 }
 
 static inline void dev_iommu_priv_set(struct device *dev, void *priv)
-- 
2.30.0