Re: [PATCH] ACPI/PCI: Fix memory leak fix in pci_acpi_preserve_config

From: Bjorn Helgaas
Date: Mon Aug 25 2025 - 18:37:43 EST


On Mon, Aug 25, 2025 at 02:46:42PM -0700, Nirmoy Das wrote:
> The pci_acpi_preserve_config() function is leaking memory by returning
> early without freeing the ACPI object on success. Fix that by always
> freeing the obj which is not needed by the caller.
>
> Fixes: 9d7d5db8e78e ("PCI: Move PRESERVE_BOOT_CONFIG _DSM evaluation to pci_register_host_bridge()")
> Signed-off-by: Nirmoy Das <nirmoyd@xxxxxxxxxx>

Applied to pci/misc for v6.18, thanks!

> ---
> drivers/pci/pci-acpi.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/pci/pci-acpi.c b/drivers/pci/pci-acpi.c
> index ddb25960ea47d..9369377725fa0 100644
> --- a/drivers/pci/pci-acpi.c
> +++ b/drivers/pci/pci-acpi.c
> @@ -122,6 +122,8 @@ phys_addr_t acpi_pci_root_get_mcfg_addr(acpi_handle handle)
>
> bool pci_acpi_preserve_config(struct pci_host_bridge *host_bridge)
> {
> + bool ret = false;
> +
> if (ACPI_HANDLE(&host_bridge->dev)) {
> union acpi_object *obj;
>
> @@ -135,11 +137,11 @@ bool pci_acpi_preserve_config(struct pci_host_bridge *host_bridge)
> 1, DSM_PCI_PRESERVE_BOOT_CONFIG,
> NULL, ACPI_TYPE_INTEGER);
> if (obj && obj->integer.value == 0)
> - return true;
> + ret = true;
> ACPI_FREE(obj);
> }
>
> - return false;
> + return ret;
> }
>
> /* _HPX PCI Setting Record (Type 0); same as _HPP */
> --
> 2.43.0
>