[PATCH v1 07/17] platform/x86: apple-gmux: Switch to use acpi_bus_get_primary_device()

Posted by Rafael J. Wysocki 2 days, 21 hours ago

From: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>

Replace acpi_get_first_physical_node() that is slated for removal
with acpi_bus_get_primary_device() that takes a reference to the
device it is about to return.

This addresses a potential use-after-free that may occur if the
device returned by acpi_get_first_physical_node() is removed right
after dropping its ACPI companion's physical_node_lock in that
function.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
---
 include/linux/apple-gmux.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/apple-gmux.h b/include/linux/apple-gmux.h
index 206d97ffda79..d7939c3a08fd 100644
--- a/include/linux/apple-gmux.h
+++ b/include/linux/apple-gmux.h
@@ -109,7 +109,7 @@ static inline bool apple_gmux_detect(struct pnp_dev *pnp_dev, enum apple_gmux_ty
 		if (!adev)
 			return false;
 
-		dev = get_device(acpi_get_first_physical_node(adev));
+		dev = acpi_bus_get_primary_device(adev);
 		acpi_dev_put(adev);
 		if (!dev)
 			return false;
-- 
2.51.0

Re: [PATCH v1 07/17] platform/x86: apple-gmux: Switch to use acpi_bus_get_primary_device()

Posted by Hans de Goede 2 days ago

Hi,

On 21-Sep-26 21:49, Rafael J. Wysocki wrote:
> From: "Rafael J. Wysocki" <rafael.j.wysocki@intel.com>
> 
> Replace acpi_get_first_physical_node() that is slated for removal
> with acpi_bus_get_primary_device() that takes a reference to the
> device it is about to return.
> 
> This addresses a potential use-after-free that may occur if the
> device returned by acpi_get_first_physical_node() is removed right
> after dropping its ACPI companion's physical_node_lock in that
> function.
> 
> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

Thanks, patch looks good to me:

Reviewed-by: Hans de Goede <johannes.goede@oss.qualcomm.com>

Regards,

Hans

> ---
>  include/linux/apple-gmux.h | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/include/linux/apple-gmux.h b/include/linux/apple-gmux.h
> index 206d97ffda79..d7939c3a08fd 100644
> --- a/include/linux/apple-gmux.h
> +++ b/include/linux/apple-gmux.h
> @@ -109,7 +109,7 @@ static inline bool apple_gmux_detect(struct pnp_dev *pnp_dev, enum apple_gmux_ty
>  		if (!adev)
>  			return false;
>  
> -		dev = get_device(acpi_get_first_physical_node(adev));
> +		dev = acpi_bus_get_primary_device(adev);
>  		acpi_dev_put(adev);
>  		if (!dev)
>  			return false;