[PATCH v2 4/4] platform/x86: hp-bioscfg: Fix error handling in hp_add_other_attributes()

From: Harshit Mogalapalli
Date: Fri Nov 10 2023 - 13:18:19 EST


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@xxxxxxxxx>
Reported-by: Dan Carpenter <error27@xxxxxxxxx>
Closes: https://lore.kernel.org/r/202309201412.on0VXJGo-lkp@xxxxxxxxx/
Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@xxxxxxxxxx>
---
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