The non-blocking, non-coherent allocation path uses dma_alloc_from_pool(),
which returns the allocated page and fills cpu_addr only on success.

Do not rely on cpu_addr to detect allocation failure in this path. Check
the returned page directly before using it for the IOMMU mapping.

Fixes: 9420139f516d ("dma-pool: fix coherent pool allocations for IOMMU 
mappings")
Signed-off-by: Aneesh Kumar K.V (Arm) <[email protected]>
---
 drivers/iommu/dma-iommu.c | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 725c7adb0a8d..52c599f4472c 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -1671,13 +1671,16 @@ void *iommu_dma_alloc(struct device *dev, size_t size, 
dma_addr_t *handle,
        }
 
        if (IS_ENABLED(CONFIG_DMA_DIRECT_REMAP) &&
-           !gfpflags_allow_blocking(gfp) && !coherent)
+           !gfpflags_allow_blocking(gfp) && !coherent) {
                page = dma_alloc_from_pool(dev, PAGE_ALIGN(size), &cpu_addr,
                                           gfp, attrs, NULL);
-       else
+               if (!page)
+                       return NULL;
+       } else {
                cpu_addr = iommu_dma_alloc_pages(dev, size, &page, gfp, attrs);
-       if (!cpu_addr)
-               return NULL;
+               if (!cpu_addr)
+                       return NULL;
+       }
 
        *handle = __iommu_dma_map(dev, page_to_phys(page), size, ioprot,
                        dev->coherent_dma_mask);
-- 
2.43.0


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