Re: [PATCH] dma-direct: fix type mismatch in dma_direct_alloc_pages

From: Marek Szyprowski

Date: Fri Aug 14 2026 - 03:11:35 EST


On 14.08.2026 08:30, yangge1116@xxxxxxx wrote:
> From: Ge Yang <yangge1116@xxxxxxx>
>
> The pool allocation path directly returned the void* cpu virtual
> address from dma_direct_alloc_from_pool(), which is type‑mismatched
> against struct page *. Convert the dma_handle to page via
> dma_direct_to_page() instead.
>
> Fixes: 5b138c534fda ("dma-direct: factor out a dma_direct_alloc_from_pool helper")
> Signed-off-by: Ge Yang <yangge1116@xxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx

This is a duplicate of the patch already applied to dma-mapping-for-next, see

https://lore.kernel.org/r/20260717180442.110954-2-aneesh.kumar@xxxxxxxxxx

> ---
> kernel/dma/direct.c | 8 ++++++--
> 1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c
> index 4391b79..f496568 100644
> --- a/kernel/dma/direct.c
> +++ b/kernel/dma/direct.c
> @@ -356,8 +356,12 @@ struct page *dma_direct_alloc_pages(struct device *dev, size_t size,
> struct page *page;
> void *ret;
>
> - if (force_dma_unencrypted(dev) && dma_direct_use_pool(dev, gfp))
> - return dma_direct_alloc_from_pool(dev, size, dma_handle, gfp);
> + if (force_dma_unencrypted(dev) && dma_direct_use_pool(dev, gfp)) {
> + ret = dma_direct_alloc_from_pool(dev, size, dma_handle, gfp);
> + if (!ret)
> + return NULL;
> + return dma_direct_to_page(dev, *dma_handle);
> + }
>
> page = __dma_direct_alloc_pages(dev, size, gfp, false);
> if (!page)

Best regards
--
Marek Szyprowski, PhD
Samsung R&D Institute Poland