[PATCH] iommu: add null pointer check

[cgel . zte]

From: Lv Ruyi <lv.ruyi@xxxxxxxxxx>

kmem_cache_zalloc is a memory allocation function which can return NULL
when some internal memory errors happen. Add null pointer check to avoid
dereferencing null pointer.

Reported-by: Zeal Robot <zealci@xxxxxxxxxx>
Signed-off-by: Lv Ruyi <lv.ruyi@xxxxxxxxxx>
---
 drivers/iommu/fsl_pamu_domain.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/drivers/iommu/fsl_pamu_domain.c b/drivers/iommu/fsl_pamu_domain.c
index 69a4a62dc3b9..43849c027298 100644
--- a/drivers/iommu/fsl_pamu_domain.c
+++ b/drivers/iommu/fsl_pamu_domain.c
@@ -152,6 +152,10 @@ static void attach_device(struct fsl_dma_domain *dma_domain, int liodn, struct d
 	}
 
 	info = kmem_cache_zalloc(iommu_devinfo_cache, GFP_ATOMIC);
+	if (!info) {
+		spin_unlock_irqrestore(&device_domain_lock, flags);
+		return;
+	}
 
 	info->dev = dev;
 	info->liodn = liodn;
-- 
2.25.1