On Thu, 4 Jun 2026 14:09:54 +0530
"Aneesh Kumar K.V (Arm)" <[email protected]> wrote:
> 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")
> Tested-by: Michael Kelley <[email protected]>
> Tested-by: Mostafa Saleh <[email protected]>
> Signed-off-by: Aneesh Kumar K.V (Arm) <[email protected]>
Reviewed-by: Petr Tesarik <[email protected]>
Petr T
> ---
> 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);
