[PATCH v2] interconnect: imx: fix use-after-free in imx_icc_node_init_qos()

[PATCH v2] interconnect: imx: fix use-after-free in imx_icc_node_init_qos()

[Wentao Liang]

The function imx_icc_node_init_qos() manually manages the reference count
of struct device_node *dn using of_node_put(). However, some error paths
use dn after the put, leading to use-after-free. Convert to automatic
cleanup using __free(device_node) to ensure the reference is always
released when dn goes out of scope.

Fixes: f0d8048525d7 ("interconnect: Add imx core driver")
Cc: stable@vger.kernel.org
Signed-off-by: Wentao Liang <vulab@iscas.ac.cn>
---
Changes in v2:
- Use auto cheanup to fix the problem.
---
 drivers/interconnect/imx/imx.c | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/drivers/interconnect/imx/imx.c b/drivers/interconnect/imx/imx.c
index 9511f80cf041..e5fcdcb88cfb 100644
--- a/drivers/interconnect/imx/imx.c
+++ b/drivers/interconnect/imx/imx.c
@@ -120,7 +120,8 @@ static int imx_icc_node_init_qos(struct icc_provider *provider,
 	struct imx_icc_node *node_data = node->data;
 	const struct imx_icc_node_adj_desc *adj = node_data->desc->adj;
 	struct device *dev = provider->dev;
-	struct device_node *dn = NULL;
+	struct device_node *__free(device_nod) dn = of_parse_phandle(dev->of_node,
+			adj->phandle_name, 0);
 	struct platform_device *pdev;
 
 	if (adj->main_noc) {
@@ -128,7 +129,6 @@ static int imx_icc_node_init_qos(struct icc_provider *provider,
 		dev_dbg(dev, "icc node %s[%d] is main noc itself\n",
 			node->name, node->id);
 	} else {
-		dn = of_parse_phandle(dev->of_node, adj->phandle_name, 0);
 		if (!dn) {
 			dev_warn(dev, "Failed to parse %s\n",
 				 adj->phandle_name);
@@ -138,12 +138,10 @@ static int imx_icc_node_init_qos(struct icc_provider *provider,
 		if (!of_device_is_available(dn)) {
 			dev_warn(dev, "Missing property %s, skip scaling %s\n",
 				 adj->phandle_name, node->name);
-			of_node_put(dn);
 			return 0;
 		}
 
 		pdev = of_find_device_by_node(dn);
-		of_node_put(dn);
 		if (!pdev) {
 			dev_warn(dev, "node %s[%d] missing device for %pOF\n",
 				 node->name, node->id, dn);
-- 
2.34.1

Re: [PATCH v2] interconnect: imx: fix use-after-free in imx_icc_node_init_qos()

[Frank Li]

On Wed, Apr 08, 2026 at 03:30:22PM +0000, Wentao Liang wrote:
> The function imx_icc_node_init_qos() manually manages the reference count
> of struct device_node *dn using of_node_put(). However, some error paths
> use dn after the put, leading to use-after-free. Convert to automatic
> cleanup using __free(device_node) to ensure the reference is always
> released when dn goes out of scope.
>
> Fixes: f0d8048525d7 ("interconnect: Add imx core driver")
> Cc: stable@vger.kernel.org
> Signed-off-by: Wentao Liang <vulab@iscas.ac.cn>
> ---
> Changes in v2:
> - Use auto cheanup to fix the problem.
> ---

Reviewed-by: Frank Li <Frank.Li@nxp.com>

>  drivers/interconnect/imx/imx.c | 6 ++----
>  1 file changed, 2 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/interconnect/imx/imx.c b/drivers/interconnect/imx/imx.c
> index 9511f80cf041..e5fcdcb88cfb 100644
> --- a/drivers/interconnect/imx/imx.c
> +++ b/drivers/interconnect/imx/imx.c
> @@ -120,7 +120,8 @@ static int imx_icc_node_init_qos(struct icc_provider *provider,
>  	struct imx_icc_node *node_data = node->data;
>  	const struct imx_icc_node_adj_desc *adj = node_data->desc->adj;
>  	struct device *dev = provider->dev;
> -	struct device_node *dn = NULL;
> +	struct device_node *__free(device_nod) dn = of_parse_phandle(dev->of_node,
> +			adj->phandle_name, 0);
>  	struct platform_device *pdev;
>
>  	if (adj->main_noc) {
> @@ -128,7 +129,6 @@ static int imx_icc_node_init_qos(struct icc_provider *provider,
>  		dev_dbg(dev, "icc node %s[%d] is main noc itself\n",
>  			node->name, node->id);
>  	} else {
> -		dn = of_parse_phandle(dev->of_node, adj->phandle_name, 0);
>  		if (!dn) {
>  			dev_warn(dev, "Failed to parse %s\n",
>  				 adj->phandle_name);
> @@ -138,12 +138,10 @@ static int imx_icc_node_init_qos(struct icc_provider *provider,
>  		if (!of_device_is_available(dn)) {
>  			dev_warn(dev, "Missing property %s, skip scaling %s\n",
>  				 adj->phandle_name, node->name);
> -			of_node_put(dn);
>  			return 0;
>  		}
>
>  		pdev = of_find_device_by_node(dn);
> -		of_node_put(dn);
>  		if (!pdev) {
>  			dev_warn(dev, "node %s[%d] missing device for %pOF\n",
>  				 node->name, node->id, dn);
> --
> 2.34.1
>

Re: [PATCH v2] interconnect: imx: fix use-after-free in imx_icc_node_init_qos()

[kernel test robot]

Hi Wentao,

kernel test robot noticed the following build errors:

[auto build test ERROR on amd-pstate/linux-next]
[also build test ERROR on amd-pstate/bleeding-edge linus/master v7.0 next-20260424]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Wentao-Liang/interconnect-imx-fix-use-after-free-in-imx_icc_node_init_qos/20260424-225513
base:   https://git.kernel.org/pub/scm/linux/kernel/git/superm1/linux.git linux-next
patch link:    https://lore.kernel.org/r/20260408153022.401123-1-vulab%40iscas.ac.cn
patch subject: [PATCH v2] interconnect: imx: fix use-after-free in imx_icc_node_init_qos()
config: m68k-allmodconfig (https://download.01.org/0day-ci/archive/20260426/202604261347.QzG9r7Ym-lkp@intel.com/config)
compiler: m68k-linux-gcc (GCC) 15.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260426/202604261347.QzG9r7Ym-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202604261347.QzG9r7Ym-lkp@intel.com/

All errors (new ones prefixed by >>):

   drivers/interconnect/imx/imx.c: In function 'imx_icc_node_init_qos':
>> drivers/interconnect/imx/imx.c:123:16: error: cleanup argument not a function
     123 |         struct device_node *__free(device_nod) dn = of_parse_phandle(dev->of_node,
         |                ^~~~~~~~~~~


vim +123 drivers/interconnect/imx/imx.c

   116	
   117	static int imx_icc_node_init_qos(struct icc_provider *provider,
   118					 struct icc_node *node)
   119	{
   120		struct imx_icc_node *node_data = node->data;
   121		const struct imx_icc_node_adj_desc *adj = node_data->desc->adj;
   122		struct device *dev = provider->dev;
 > 123		struct device_node *__free(device_nod) dn = of_parse_phandle(dev->of_node,
   124				adj->phandle_name, 0);
   125		struct platform_device *pdev;
   126	
   127		if (adj->main_noc) {
   128			node_data->qos_dev = dev;
   129			dev_dbg(dev, "icc node %s[%d] is main noc itself\n",
   130				node->name, node->id);
   131		} else {
   132			if (!dn) {
   133				dev_warn(dev, "Failed to parse %s\n",
   134					 adj->phandle_name);
   135				return -ENODEV;
   136			}
   137			/* Allow scaling to be disabled on a per-node basis */
   138			if (!of_device_is_available(dn)) {
   139				dev_warn(dev, "Missing property %s, skip scaling %s\n",
   140					 adj->phandle_name, node->name);
   141				return 0;
   142			}
   143	
   144			pdev = of_find_device_by_node(dn);
   145			if (!pdev) {
   146				dev_warn(dev, "node %s[%d] missing device for %pOF\n",
   147					 node->name, node->id, dn);
   148				return -EPROBE_DEFER;
   149			}
   150			node_data->qos_dev = &pdev->dev;
   151			dev_dbg(dev, "node %s[%d] has device node %pOF\n",
   152				node->name, node->id, dn);
   153		}
   154	
   155		return dev_pm_qos_add_request(node_data->qos_dev,
   156					      &node_data->qos_req,
   157					      DEV_PM_QOS_MIN_FREQUENCY, 0);
   158	}
   159	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: [v2] interconnect: imx: fix use-after-free in imx_icc_node_init_qos()

[Markus Elfring]

…
> > use dn after the put, leading to use-after-free. Convert to automatic
> > cleanup using __free(device_node) to ensure the reference is always
> > released when dn goes out of scope.
…
> Reviewed-by: Frank Li <Frank.Li@nxp.com>

> >  drivers/interconnect/imx/imx.c | 6 ++----
…
> @@ -120,7 +120,8 @@ static int imx_icc_node_init_qos(struct icc_provider *provider,
>  	struct imx_icc_node *node_data = node->data;
>  	const struct imx_icc_node_adj_desc *adj = node_data->desc->adj;
>  	struct device *dev = provider->dev;
> -	struct device_node *dn = NULL;
> +	struct device_node *__free(device_nod) dn = of_parse_phandle(dev->of_node,
> +			adj->phandle_name, 0);

…

A typo was overlooked somehow.

Regards,
Markus

Re: [PATCH v2] interconnect: imx: fix use-after-free in imx_icc_node_init_qos()

[kernel test robot]

Hi Wentao,

kernel test robot noticed the following build errors:

[auto build test ERROR on amd-pstate/linux-next]
[also build test ERROR on amd-pstate/bleeding-edge linus/master shawnguo/for-next v7.0 next-20260424]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Wentao-Liang/interconnect-imx-fix-use-after-free-in-imx_icc_node_init_qos/20260424-225513
base:   https://git.kernel.org/pub/scm/linux/kernel/git/superm1/linux.git linux-next
patch link:    https://lore.kernel.org/r/20260408153022.401123-1-vulab%40iscas.ac.cn
patch subject: [PATCH v2] interconnect: imx: fix use-after-free in imx_icc_node_init_qos()
config: sparc64-allmodconfig (https://download.01.org/0day-ci/archive/20260426/202604262216.MLuzg6nl-lkp@intel.com/config)
compiler: clang version 23.0.0git (https://github.com/llvm/llvm-project 5bac06718f502014fade905512f1d26d578a18f3)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260426/202604262216.MLuzg6nl-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202604262216.MLuzg6nl-lkp@intel.com/

All errors (new ones prefixed by >>):

>> drivers/interconnect/imx/imx.c:123:22: error: use of undeclared identifier '__free_device_nod'; did you mean '__free_device_node'?
     123 |         struct device_node *__free(device_nod) dn = of_parse_phandle(dev->of_node,
         |                             ^~~~~~~~~~~~~~~~~~
   include/linux/cleanup.h:213:33: note: expanded from macro '__free'
     213 | #define __free(_name)   __cleanup(__free_##_name)
         |                                   ^~~~~~~~~~~~~~
   <scratch space>:42:1: note: expanded from here
      42 | __free_device_nod
         | ^~~~~~~~~~~~~~~~~
   include/linux/of.h:138:1: note: '__free_device_node' declared here
     138 | DEFINE_FREE(device_node, struct device_node *, if (_T) of_node_put(_T))
         | ^
   include/linux/cleanup.h:211:30: note: expanded from macro 'DEFINE_FREE'
     211 |         static __always_inline void __free_##_name(void *p) { _type _T = *(_type *)p; _free; }
         |                                     ^
   <scratch space>:227:1: note: expanded from here
     227 | __free_device_node
         | ^
   1 error generated.


vim +123 drivers/interconnect/imx/imx.c

   116	
   117	static int imx_icc_node_init_qos(struct icc_provider *provider,
   118					 struct icc_node *node)
   119	{
   120		struct imx_icc_node *node_data = node->data;
   121		const struct imx_icc_node_adj_desc *adj = node_data->desc->adj;
   122		struct device *dev = provider->dev;
 > 123		struct device_node *__free(device_nod) dn = of_parse_phandle(dev->of_node,
   124				adj->phandle_name, 0);
   125		struct platform_device *pdev;
   126	
   127		if (adj->main_noc) {
   128			node_data->qos_dev = dev;
   129			dev_dbg(dev, "icc node %s[%d] is main noc itself\n",
   130				node->name, node->id);
   131		} else {
   132			if (!dn) {
   133				dev_warn(dev, "Failed to parse %s\n",
   134					 adj->phandle_name);
   135				return -ENODEV;
   136			}
   137			/* Allow scaling to be disabled on a per-node basis */
   138			if (!of_device_is_available(dn)) {
   139				dev_warn(dev, "Missing property %s, skip scaling %s\n",
   140					 adj->phandle_name, node->name);
   141				return 0;
   142			}
   143	
   144			pdev = of_find_device_by_node(dn);
   145			if (!pdev) {
   146				dev_warn(dev, "node %s[%d] missing device for %pOF\n",
   147					 node->name, node->id, dn);
   148				return -EPROBE_DEFER;
   149			}
   150			node_data->qos_dev = &pdev->dev;
   151			dev_dbg(dev, "node %s[%d] has device node %pOF\n",
   152				node->name, node->id, dn);
   153		}
   154	
   155		return dev_pm_qos_add_request(node_data->qos_dev,
   156					      &node_data->qos_req,
   157					      DEV_PM_QOS_MIN_FREQUENCY, 0);
   158	}
   159	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki