linux-kernel - [PATCH v2 4/4] platform/x86: hp-bioscfg: Fix error handling in hp_add_other

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Date:   Fri, 10 Nov 2023 06:29:19 -0800
From:   Harshit Mogalapalli <harshit.m.mogalapalli@...cle.com>
To:     Jorge Lopez <jorge.lopez2@...com>,
        Hans de Goede <hdegoede@...hat.com>,
        Ilpo Järvinen <ilpo.jarvinen@...ux.intel.com>,
        Mark Gross <markgross@...nel.org>,
        Thomas Weißschuh <linux@...ssschuh.net>,
        platform-driver-x86@...r.kernel.org, linux-kernel@...r.kernel.org
Cc:     dan.carpenter@...aro.org, kernel-janitors@...r.kernel.org,
        error27@...il.com, vegard.nossum@...cle.com,
        harshit.m.mogalapalli@...cle.com, darren.kenny@...cle.com,
        kernel test robot <lkp@...el.com>
Subject: [PATCH v2 4/4] platform/x86: hp-bioscfg: Fix error handling in hp_add_other_attributes()

We have two issues:
1. Memory leak of 'attr_name_kobj' in the error handling path.
2. When kobject_init_and_add() fails on every subsequent error path call
   kobject_put() to cleanup.

Both of these issues will be fixed when we add kobject_put() in the goto
label, as kfree() is already part of kobject_put().

Fixes: a34fc329b189 ("platform/x86: hp-bioscfg: bioscfg")
Reported-by: kernel test robot <lkp@...el.com>
Reported-by: Dan Carpenter <error27@...il.com>
Closes: https://lore.kernel.org/r/202309201412.on0VXJGo-lkp@intel.com/
Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@...cle.com>
---
Only compile tested, based on static analysis
v1-> v2: Split this into mutliple patches doing one thing in a patch.
---
 drivers/platform/x86/hp/hp-bioscfg/bioscfg.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/platform/x86/hp/hp-bioscfg/bioscfg.c b/drivers/platform/x86/hp/hp-bioscfg/bioscfg.c
index 351d782f3e96..8c9f4f3227fc 100644
--- a/drivers/platform/x86/hp/hp-bioscfg/bioscfg.c
+++ b/drivers/platform/x86/hp/hp-bioscfg/bioscfg.c
@@ -575,75 +575,77 @@ static void release_attributes_data(void)
 /**
  * hp_add_other_attributes() - Initialize HP custom attributes not
  * reported by BIOS and required to support Secure Platform and Sure
  * Start.
  *
  * @attr_type: Custom HP attribute not reported by BIOS
  *
  * Initialize all 2 types of attributes: Platform and Sure Start
  * object.  Populates each attribute types respective properties
  * under sysfs files.
  *
  * Returns zero(0) if successful. Otherwise, a negative value.
  */
 static int hp_add_other_attributes(int attr_type)
 {
 	struct kobject *attr_name_kobj;
 	int ret;
 	char *attr_name;
 
 	attr_name_kobj = kzalloc(sizeof(*attr_name_kobj), GFP_KERNEL);
 	if (!attr_name_kobj)
 		return -ENOMEM;
 
 	mutex_lock(&bioscfg_drv.mutex);
 
 	/* Check if attribute type is supported */
 	switch (attr_type) {
 	case HPWMI_SECURE_PLATFORM_TYPE:
 		attr_name_kobj->kset = bioscfg_drv.authentication_dir_kset;
 		attr_name = SPM_STR;
 		break;
 
 	case HPWMI_SURE_START_TYPE:
 		attr_name_kobj->kset = bioscfg_drv.main_dir_kset;
 		attr_name = SURE_START_STR;
 		break;
 
 	default:
 		pr_err("Error: Unknown attr_type: %d\n", attr_type);
 		ret = -EINVAL;
-		goto err_other_attr_init;
+		kfree(attr_name_kobj);
+		goto unlock_drv_mutex;
 	}
 
 	ret = kobject_init_and_add(attr_name_kobj, &attr_name_ktype,
 				   NULL, "%s", attr_name);
 	if (ret) {
 		pr_err("Error encountered [%d]\n", ret);
-		kobject_put(attr_name_kobj);
 		goto err_other_attr_init;
 	}
 
 	/* Populate attribute data */
 	switch (attr_type) {
 	case HPWMI_SECURE_PLATFORM_TYPE:
 		ret = hp_populate_secure_platform_data(attr_name_kobj);
 		break;
 
 	case HPWMI_SURE_START_TYPE:
 		ret = hp_populate_sure_start_data(attr_name_kobj);
 		break;
 
 	default:
 		ret = -EINVAL;
 	}
 
 	if (ret)
 		goto err_other_attr_init;
 
 	mutex_unlock(&bioscfg_drv.mutex);
 	return 0;
 
 err_other_attr_init:
+	kobject_put(attr_name_kobj);
+unlock_drv_mutex:
 	mutex_unlock(&bioscfg_drv.mutex);
 	return ret;
 }
-- 
2.39.3