[PATCH v2] mmc: sdhci-of-bst: Fix memory leak in sdhci_bst_alloc_bounce_buffer()

[PATCH v2] mmc: sdhci-of-bst: Fix memory leak in sdhci_bst_alloc_bounce_buffer()

[Felix Gu]

In sdhci_bst_alloc_bounce_buffer(), if dma_alloc_coherent() fails, the
function immediately returns -ENOMEM without releasing the reserved
memory, which results in a memory leak.

Add the missing of_reserved_mem_device_release() call before returning
-ENOMEM to properly clean up the reserved memory.

Fixes: 695824f45629 ("mmc: sdhci: add Black Sesame Technologies BST C1200 controller driver")
Signed-off-by: Felix Gu <ustc.gu@gmail.com>
---
Changes in v2:
- Fix Adrian's comment.
- Link to v1: https://lore.kernel.org/r/20260301-bst-v1-1-ddbc22ec3ed9@gmail.com
---
 drivers/mmc/host/sdhci-of-bst.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/mmc/host/sdhci-of-bst.c b/drivers/mmc/host/sdhci-of-bst.c
index c124990a64f4..f8d3df715e1a 100644
--- a/drivers/mmc/host/sdhci-of-bst.c
+++ b/drivers/mmc/host/sdhci-of-bst.c
@@ -425,8 +425,10 @@ static int sdhci_bst_alloc_bounce_buffer(struct sdhci_host *host)
 
 	host->bounce_buffer = dma_alloc_coherent(mmc_dev(mmc), bounce_size,
 						 &host->bounce_addr, GFP_KERNEL);
-	if (!host->bounce_buffer)
+	if (!host->bounce_buffer) {
+		of_reserved_mem_device_release(mmc_dev(mmc));
 		return -ENOMEM;
+	}
 
 	host->bounce_buffer_size = bounce_size;
 

---
base-commit: 3fa5e5702a82d259897bd7e209469bc06368bf31
change-id: 20260301-bst-76bb7c6d7931

Best regards,
-- 
Felix Gu <ustc.gu@gmail.com>

Re: [PATCH v2] mmc: sdhci-of-bst: Fix memory leak in sdhci_bst_alloc_bounce_buffer()

[Ulf Hansson]

On Mon, 2 Mar 2026 at 14:47, Felix Gu <ustc.gu@gmail.com> wrote:
>
> In sdhci_bst_alloc_bounce_buffer(), if dma_alloc_coherent() fails, the
> function immediately returns -ENOMEM without releasing the reserved
> memory, which results in a memory leak.
>
> Add the missing of_reserved_mem_device_release() call before returning
> -ENOMEM to properly clean up the reserved memory.
>
> Fixes: 695824f45629 ("mmc: sdhci: add Black Sesame Technologies BST C1200 controller driver")
> Signed-off-by: Felix Gu <ustc.gu@gmail.com>

Applied for next, thanks!

Kind regards
Uffe


> ---
> Changes in v2:
> - Fix Adrian's comment.
> - Link to v1: https://lore.kernel.org/r/20260301-bst-v1-1-ddbc22ec3ed9@gmail.com
> ---
>  drivers/mmc/host/sdhci-of-bst.c | 4 +++-
>  1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mmc/host/sdhci-of-bst.c b/drivers/mmc/host/sdhci-of-bst.c
> index c124990a64f4..f8d3df715e1a 100644
> --- a/drivers/mmc/host/sdhci-of-bst.c
> +++ b/drivers/mmc/host/sdhci-of-bst.c
> @@ -425,8 +425,10 @@ static int sdhci_bst_alloc_bounce_buffer(struct sdhci_host *host)
>
>         host->bounce_buffer = dma_alloc_coherent(mmc_dev(mmc), bounce_size,
>                                                  &host->bounce_addr, GFP_KERNEL);
> -       if (!host->bounce_buffer)
> +       if (!host->bounce_buffer) {
> +               of_reserved_mem_device_release(mmc_dev(mmc));
>                 return -ENOMEM;
> +       }
>
>         host->bounce_buffer_size = bounce_size;
>
>
> ---
> base-commit: 3fa5e5702a82d259897bd7e209469bc06368bf31
> change-id: 20260301-bst-76bb7c6d7931
>
> Best regards,
> --
> Felix Gu <ustc.gu@gmail.com>
>