[PATCH v2 0/1] platform/x86: asus-armoury: fix Use-After-Free and memory leak in driver init

[PATCH v2 0/1] platform/x86: asus-armoury: fix Use-After-Free and memory leak in driver init

[Marco Scardovi]

This patch series addresses a Use-After-Free (UAF) vulnerability
and a memory leak during driver initialization in the asus-armoury
driver.

Changes in v2:
- Restructured init_rog_tunables() to use local pointers
  (ac_rog_tunables, dc_rog_tunables) and only update the global
  static asus_armoury.rog_tunables structure once all allocations
  have successfully succeeded. This removes the risk of exposing
  freed or partially allocated pointers to the global struct.
- Removed redundant assignments to NULL in the error paths. Since
  initialization fails and the driver is not loaded, cleaning the
  global static pointers to NULL is not necessary.
- In init_rog_tunables(), replaced 'goto err_nomem' with direct
  'return -ENOMEM'. The 'err_nomem' label in the original code
  printed a generic OOM error message, which is discouraged in the
  kernel as the allocator already issues OOM details. Because that
  label did not perform rollback cleanup, a direct return is cleaner
  and simpler.
- Replaced inline cleanup in asus_fw_init() with a standard goto
  rollback block at the end of the function for cleaner error path
  styling.

Marco Scardovi (1):
  platform/x86: asus-armoury: fix Use-After-Free and memory leak in
    driver init

 drivers/platform/x86/asus-armoury.c | 38 ++++++++++++++++++-----------
 1 file changed, 24 insertions(+), 14 deletions(-)

-- 
2.55.0

[PATCH v2 1/1] platform/x86: asus-armoury: fix Use-After-Free and memory leak in driver init

[Marco Scardovi]

In init_rog_tunables(), if dc_limits are defined and allocating
dc_rog_tunables fails, the already allocated ac_rog_tunables gets
freed but the pointer stored in
asus_armoury.rog_tunables[ASUS_ROG_TUNABLE_AC] is not cleared. Since
init_rog_tunables() returns void, the driver initialization continues,
which can lead to a Use-After-Free (UAF) when asus_fw_attr_add()
accesses the freed AC tunables pointer.

Additionally, if init_rog_tunables() succeeds but asus_fw_attr_add()
fails, the allocated tunables are not freed, resulting in a memory leak.

Fix these issues by making init_rog_tunables() return an error code and
propagating it in asus_fw_init(). Defer setting the global pointers in
asus_armoury.rog_tunables until both tunables have been successfully
allocated. If asus_fw_attr_add() fails, release the allocated resources
using a standard goto rollback block in asus_fw_init().

Signed-off-by: Marco Scardovi <scardracs@disroot.org>
---
v2:
- Restructure init_rog_tunables() to use local pointers and defer assignment
  to the global struct until all allocations succeed, eliminating the need
  to set global pointers to NULL on error.
- Use a goto-rollback pattern in asus_fw_init() for cleaner error handling
  as requested by Ilpo.

 drivers/platform/x86/asus-armoury.c | 38 ++++++++++++++++++-----------
 1 file changed, 24 insertions(+), 14 deletions(-)

diff --git a/drivers/platform/x86/asus-armoury.c b/drivers/platform/x86/asus-armoury.c
index 495dc1e31d40..ea53a005bb25 100644
--- a/drivers/platform/x86/asus-armoury.c
+++ b/drivers/platform/x86/asus-armoury.c
@@ -989,7 +989,7 @@ static int asus_fw_attr_add(void)
 /* Init / exit ****************************************************************/
 
 /* Set up the min/max and defaults for ROG tunables */
-static void init_rog_tunables(void)
+static int init_rog_tunables(void)
 {
 	const struct power_limits *ac_limits, *dc_limits;
 	struct rog_tunables *ac_rog_tunables = NULL, *dc_rog_tunables = NULL;
@@ -1000,24 +1000,23 @@ static void init_rog_tunables(void)
 	dmi_id = dmi_first_match(power_limits);
 	if (!dmi_id) {
 		pr_warn("No matching power limits found for this system\n");
-		return;
+		return 0;
 	}
 
 	/* Get the power data for this system */
 	power_data = dmi_id->driver_data;
 	if (!power_data) {
 		pr_info("No power data available for this system\n");
-		return;
+		return 0;
 	}
 
 	/* Initialize AC power tunables */
 	ac_limits = power_data->ac_data;
 	if (ac_limits) {
-		ac_rog_tunables = kzalloc_obj(*asus_armoury.rog_tunables[ASUS_ROG_TUNABLE_AC]);
+		ac_rog_tunables = kzalloc_obj(*ac_rog_tunables);
 		if (!ac_rog_tunables)
-			goto err_nomem;
+			return -ENOMEM;
 
-		asus_armoury.rog_tunables[ASUS_ROG_TUNABLE_AC] = ac_rog_tunables;
 		ac_rog_tunables->power_limits = ac_limits;
 
 		/* Set initial AC values */
@@ -1060,13 +1059,12 @@ static void init_rog_tunables(void)
 	/* Initialize DC power tunables */
 	dc_limits = power_data->dc_data;
 	if (dc_limits) {
-		dc_rog_tunables = kzalloc_obj(*asus_armoury.rog_tunables[ASUS_ROG_TUNABLE_DC]);
+		dc_rog_tunables = kzalloc_obj(*dc_rog_tunables);
 		if (!dc_rog_tunables) {
 			kfree(ac_rog_tunables);
-			goto err_nomem;
+			return -ENOMEM;
 		}
 
-		asus_armoury.rog_tunables[ASUS_ROG_TUNABLE_DC] = dc_rog_tunables;
 		dc_rog_tunables->power_limits = dc_limits;
 
 		/* Set initial DC values */
@@ -1106,15 +1104,16 @@ static void init_rog_tunables(void)
 		pr_debug("No DC PPT limits defined\n");
 	}
 
-	return;
+	asus_armoury.rog_tunables[ASUS_ROG_TUNABLE_AC] = ac_rog_tunables;
+	asus_armoury.rog_tunables[ASUS_ROG_TUNABLE_DC] = dc_rog_tunables;
 
-err_nomem:
-	pr_err("Failed to allocate memory for tunables\n");
+	return 0;
 }
 
 static int __init asus_fw_init(void)
 {
 	char *wmi_uid;
+	int err;
 
 	wmi_uid = wmi_get_acpi_device_uid(ASUS_WMI_MGMT_GUID);
 	if (!wmi_uid)
@@ -1127,10 +1126,21 @@ static int __init asus_fw_init(void)
 	if (!strcmp(wmi_uid, ASUS_ACPI_UID_ASUSWMI))
 		return -ENODEV;
 
-	init_rog_tunables();
+	err = init_rog_tunables();
+	if (err)
+		return err;
 
 	/* Must always be last step to ensure data is available */
-	return asus_fw_attr_add();
+	err = asus_fw_attr_add();
+	if (err)
+		goto err_free_tunables;
+
+	return 0;
+
+err_free_tunables:
+	kfree(asus_armoury.rog_tunables[ASUS_ROG_TUNABLE_AC]);
+	kfree(asus_armoury.rog_tunables[ASUS_ROG_TUNABLE_DC]);
+	return err;
 }
 
 static void __exit asus_fw_exit(void)
-- 
2.55.0

Re: [PATCH v2 1/1] platform/x86: asus-armoury: fix Use-After-Free and memory leak in driver init

[Ilpo Järvinen]

On Wed, 1 Jul 2026, Marco Scardovi wrote:

> In init_rog_tunables(), if dc_limits are defined and allocating
> dc_rog_tunables fails, the already allocated ac_rog_tunables gets
> freed but the pointer stored in
> asus_armoury.rog_tunables[ASUS_ROG_TUNABLE_AC] is not cleared. Since
> init_rog_tunables() returns void, the driver initialization continues,
> which can lead to a Use-After-Free (UAF) when asus_fw_attr_add()
> accesses the freed AC tunables pointer.
> 
> Additionally, if init_rog_tunables() succeeds but asus_fw_attr_add()
> fails, the allocated tunables are not freed, resulting in a memory leak.
> 
> Fix these issues by making init_rog_tunables() return an error code and
> propagating it in asus_fw_init(). Defer setting the global pointers in
> asus_armoury.rog_tunables until both tunables have been successfully
> allocated. If asus_fw_attr_add() fails, release the allocated resources
> using a standard goto rollback block in asus_fw_init().
> 
> Signed-off-by: Marco Scardovi <scardracs@disroot.org>
> ---
> v2:
> - Restructure init_rog_tunables() to use local pointers and defer assignment
>   to the global struct until all allocations succeed, eliminating the need
>   to set global pointers to NULL on error.
> - Use a goto-rollback pattern in asus_fw_init() for cleaner error handling
>   as requested by Ilpo.
> 
>  drivers/platform/x86/asus-armoury.c | 38 ++++++++++++++++++-----------
>  1 file changed, 24 insertions(+), 14 deletions(-)
> 
> diff --git a/drivers/platform/x86/asus-armoury.c b/drivers/platform/x86/asus-armoury.c
> index 495dc1e31d40..ea53a005bb25 100644
> --- a/drivers/platform/x86/asus-armoury.c
> +++ b/drivers/platform/x86/asus-armoury.c
> @@ -989,7 +989,7 @@ static int asus_fw_attr_add(void)
>  /* Init / exit ****************************************************************/
>  
>  /* Set up the min/max and defaults for ROG tunables */
> -static void init_rog_tunables(void)
> +static int init_rog_tunables(void)
>  {
>  	const struct power_limits *ac_limits, *dc_limits;
>  	struct rog_tunables *ac_rog_tunables = NULL, *dc_rog_tunables = NULL;
> @@ -1000,24 +1000,23 @@ static void init_rog_tunables(void)
>  	dmi_id = dmi_first_match(power_limits);
>  	if (!dmi_id) {
>  		pr_warn("No matching power limits found for this system\n");
> -		return;
> +		return 0;
>  	}
>  
>  	/* Get the power data for this system */
>  	power_data = dmi_id->driver_data;
>  	if (!power_data) {
>  		pr_info("No power data available for this system\n");
> -		return;
> +		return 0;
>  	}
>  
>  	/* Initialize AC power tunables */
>  	ac_limits = power_data->ac_data;
>  	if (ac_limits) {
> -		ac_rog_tunables = kzalloc_obj(*asus_armoury.rog_tunables[ASUS_ROG_TUNABLE_AC]);
> +		ac_rog_tunables = kzalloc_obj(*ac_rog_tunables);
>  		if (!ac_rog_tunables)
> -			goto err_nomem;
> +			return -ENOMEM;
>  
> -		asus_armoury.rog_tunables[ASUS_ROG_TUNABLE_AC] = ac_rog_tunables;
>  		ac_rog_tunables->power_limits = ac_limits;
>  
>  		/* Set initial AC values */
> @@ -1060,13 +1059,12 @@ static void init_rog_tunables(void)
>  	/* Initialize DC power tunables */
>  	dc_limits = power_data->dc_data;
>  	if (dc_limits) {
> -		dc_rog_tunables = kzalloc_obj(*asus_armoury.rog_tunables[ASUS_ROG_TUNABLE_DC]);
> +		dc_rog_tunables = kzalloc_obj(*dc_rog_tunables);
>  		if (!dc_rog_tunables) {
>  			kfree(ac_rog_tunables);
> -			goto err_nomem;
> +			return -ENOMEM;
>  		}
>  
> -		asus_armoury.rog_tunables[ASUS_ROG_TUNABLE_DC] = dc_rog_tunables;
>  		dc_rog_tunables->power_limits = dc_limits;
>  
>  		/* Set initial DC values */
> @@ -1106,15 +1104,16 @@ static void init_rog_tunables(void)
>  		pr_debug("No DC PPT limits defined\n");
>  	}
>  
> -	return;
> +	asus_armoury.rog_tunables[ASUS_ROG_TUNABLE_AC] = ac_rog_tunables;
> +	asus_armoury.rog_tunables[ASUS_ROG_TUNABLE_DC] = dc_rog_tunables;
>  
> -err_nomem:
> -	pr_err("Failed to allocate memory for tunables\n");
> +	return 0;

This works as well but now we also want to convert it to use __free() 
+ no_free_ptr() so we can get rid of that manual kfree() to remove 
potential for future mem management errors.

...If you could add a second patch to this series to that effect, it would 
great.

--
 i.

>  }
>  
>  static int __init asus_fw_init(void)
>  {
>  	char *wmi_uid;
> +	int err;
>  
>  	wmi_uid = wmi_get_acpi_device_uid(ASUS_WMI_MGMT_GUID);
>  	if (!wmi_uid)
> @@ -1127,10 +1126,21 @@ static int __init asus_fw_init(void)
>  	if (!strcmp(wmi_uid, ASUS_ACPI_UID_ASUSWMI))
>  		return -ENODEV;
>  
> -	init_rog_tunables();
> +	err = init_rog_tunables();
> +	if (err)
> +		return err;
>  
>  	/* Must always be last step to ensure data is available */
> -	return asus_fw_attr_add();
> +	err = asus_fw_attr_add();
> +	if (err)
> +		goto err_free_tunables;
> +
> +	return 0;
> +
> +err_free_tunables:
> +	kfree(asus_armoury.rog_tunables[ASUS_ROG_TUNABLE_AC]);
> +	kfree(asus_armoury.rog_tunables[ASUS_ROG_TUNABLE_DC]);
> +	return err;
>  }
>  
>  static void __exit asus_fw_exit(void)
>