platform/x86: hp-bioscfg: Fix reference leak

If a duplicate attribute is found using kset_find_obj(), a reference
to that attribute is returned which needs to be disposed accordingly
using kobject_put(). Use kobject_put() to dispose the duplicate
attribute in such a case.
As a side note, a very similar bug was fixed in
commit 7295a99 ("platform/x86: dell-sysman: Fix reference leak"),
so it seems that the bug was copied from that driver.

Compile-tested only.

Fixes: a34fc32 ("platform/x86: hp-bioscfg: bioscfg")
Suggested-by: Ilpo Järvinen <[email protected]>
Reviewed-by: Ilpo Järvinen <[email protected]>
Signed-off-by: Armin Wolf <[email protected]>
Reviewed-by: Jorge Lopez <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Reviewed-by: Hans de Goede <[email protected]>
Signed-off-by: Hans de Goede <[email protected]>

Author: Wer-Wolf

drivers/platform/x86/hp/hp-bioscfg/bioscfg.c

@@ -659,7 +659,7 @@ static int hp_init_bios_package_attribute(enum hp_wmi_data_type attr_type,
 					  const char *guid, int min_elements,
 					  int instance_id)
 {
-	struct kobject *attr_name_kobj;
+	struct kobject *attr_name_kobj, *duplicate;
 	union acpi_object *elements;
 	struct kset *temp_kset;
 
@@ -704,8 +704,11 @@ static int hp_init_bios_package_attribute(enum hp_wmi_data_type attr_type,
 	}
 
 	/* All duplicate attributes found are ignored */
-	if (kset_find_obj(temp_kset, str_value)) {
+	duplicate = kset_find_obj(temp_kset, str_value);
+	if (duplicate) {
 		pr_debug("Duplicate attribute name found - %s\n", str_value);
+		/* kset_find_obj() returns a reference */
+		kobject_put(duplicate);
 		goto pack_attr_exit;
 	}
 
@@ -768,7 +771,7 @@ static int hp_init_bios_buffer_attribute(enum hp_wmi_data_type attr_type,
 					 const char *guid, int min_elements,
 					 int instance_id)
 {
-	struct kobject *attr_name_kobj;
+	struct kobject *attr_name_kobj, *duplicate;
 	struct kset *temp_kset;
 	char str[MAX_BUFF_SIZE];
 
@@ -794,8 +797,11 @@ static int hp_init_bios_buffer_attribute(enum hp_wmi_data_type attr_type,
 		temp_kset = bioscfg_drv.main_dir_kset;
 
 	/* All duplicate attributes found are ignored */
-	if (kset_find_obj(temp_kset, str)) {
+	duplicate = kset_find_obj(temp_kset, str);
+	if (duplicate) {
 		pr_debug("Duplicate attribute name found - %s\n", str);
+		/* kset_find_obj() returns a reference */
+		kobject_put(duplicate);
 		goto buff_attr_exit;
 	}