[PATCH] phy: HiSilicon: Fix error handling in hi3670_pcie_get_resources_from_pcie

[PATCH] phy: HiSilicon: Fix error handling in hi3670_pcie_get_resources_from_pcie

[Ma Ke]

In hi3670_pcie_get_resources_from_pcie(), the reference obtained via
bus_find_device_by_of_node() is never released with put_device(). Each
call to this function increments the reference count of the PCIe
device without decrementing it, preventing proper device cleanup. And
the device node obtained via of_get_child_by_name() is never released
with of_node_put(). This could cause a leak of the node reference.

Add proper resource cleanup using goto labels to ensure all acquired
references are released before function return, regardless of the exit
path.

Found by code review.

Cc: stable@vger.kernel.org
Fixes: 73075011ffff ("phy: HiSilicon: Add driver for Kirin 970 PCIe PHY")
Signed-off-by: Ma Ke <make24@iscas.ac.cn>
---
 drivers/phy/hisilicon/phy-hi3670-pcie.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/drivers/phy/hisilicon/phy-hi3670-pcie.c b/drivers/phy/hisilicon/phy-hi3670-pcie.c
index dbc7dcce682b..4c67a7613261 100644
--- a/drivers/phy/hisilicon/phy-hi3670-pcie.c
+++ b/drivers/phy/hisilicon/phy-hi3670-pcie.c
@@ -560,7 +560,8 @@ static int hi3670_pcie_get_resources_from_pcie(struct hi3670_pcie_phy *phy)
 {
 	struct device_node *pcie_port;
 	struct device *dev = phy->dev;
-	struct device *pcie_dev;
+	struct device *pcie_dev = NULL;
+	int ret = 0;
 
 	pcie_port = of_get_child_by_name(dev->parent->of_node, "pcie");
 	if (!pcie_port) {
@@ -572,7 +573,8 @@ static int hi3670_pcie_get_resources_from_pcie(struct hi3670_pcie_phy *phy)
 	pcie_dev = bus_find_device_by_of_node(&platform_bus_type, pcie_port);
 	if (!pcie_dev) {
 		dev_err(dev, "Didn't find pcie device\n");
-		return -ENODEV;
+		ret = -ENODEV;
+		goto out_put_node;
 	}
 
 	/*
@@ -586,9 +588,14 @@ static int hi3670_pcie_get_resources_from_pcie(struct hi3670_pcie_phy *phy)
 	phy->apb = dev_get_regmap(pcie_dev, "kirin_pcie_apb");
 	if (!phy->apb) {
 		dev_err(dev, "Failed to get APB regmap\n");
-		return -ENODEV;
+		ret = -ENODEV;
+		goto out_put_device;
 	}
 
+out_put_device:
+	put_device(pcie_dev);
+out_put_node:
+	of_node_put(pcie_port);
 	return 0;
 }
 
-- 
2.17.1


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Re: [PATCH] phy: HiSilicon: Fix error handling in hi3670_pcie_get_resources_from_pcie

[kernel test robot]

Hi Ma,

kernel test robot noticed the following build warnings:

[auto build test WARNING on akpm-mm/mm-everything]
[also build test WARNING on linus/master v6.18-rc5 next-20251114]
[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/Ma-Ke/phy-HiSilicon-Fix-error-handling-in-hi3670_pcie_get_resources_from_pcie/20251116-153458
base:   https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
patch link:    https://lore.kernel.org/r/20251116073231.22676-1-make24%40iscas.ac.cn
patch subject: [PATCH] phy: HiSilicon: Fix error handling in hi3670_pcie_get_resources_from_pcie
config: m68k-randconfig-r072-20251117 (https://download.01.org/0day-ci/archive/20251117/202511170524.sEQYJ4MB-lkp@intel.com/config)
compiler: m68k-linux-gcc (GCC) 10.5.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20251117/202511170524.sEQYJ4MB-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/202511170524.sEQYJ4MB-lkp@intel.com/

All warnings (new ones prefixed by >>):

   drivers/phy/hisilicon/phy-hi3670-pcie.c: In function 'hi3670_pcie_get_resources_from_pcie':
>> drivers/phy/hisilicon/phy-hi3670-pcie.c:564:6: warning: variable 'ret' set but not used [-Wunused-but-set-variable]
     564 |  int ret = 0;
         |      ^~~


vim +/ret +564 drivers/phy/hisilicon/phy-hi3670-pcie.c

   558	
   559	static int hi3670_pcie_get_resources_from_pcie(struct hi3670_pcie_phy *phy)
   560	{
   561		struct device_node *pcie_port;
   562		struct device *dev = phy->dev;
   563		struct device *pcie_dev = NULL;
 > 564		int ret = 0;
   565	
   566		pcie_port = of_get_child_by_name(dev->parent->of_node, "pcie");
   567		if (!pcie_port) {
   568			dev_err(dev, "no pcie node found in %s\n",
   569				dev->parent->of_node->full_name);
   570			return -ENODEV;
   571		}
   572	
   573		pcie_dev = bus_find_device_by_of_node(&platform_bus_type, pcie_port);
   574		if (!pcie_dev) {
   575			dev_err(dev, "Didn't find pcie device\n");
   576			ret = -ENODEV;
   577			goto out_put_node;
   578		}
   579	
   580		/*
   581		 * We might just use NULL instead of the APB name, as the
   582		 * pcie-kirin currently registers directly just one regmap (although
   583		 * the DWC driver register other regmaps).
   584		 *
   585		 * Yet, it sounds safer to warrant that it will be accessing the
   586		 * right regmap. So, let's use the named version.
   587		 */
   588		phy->apb = dev_get_regmap(pcie_dev, "kirin_pcie_apb");
   589		if (!phy->apb) {
   590			dev_err(dev, "Failed to get APB regmap\n");
   591			ret = -ENODEV;
   592			goto out_put_device;
   593		}
   594	
   595	out_put_device:
   596		put_device(pcie_dev);
   597	out_put_node:
   598		of_node_put(pcie_port);
   599		return 0;
   600	}
   601	

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