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 7295a996fdab ("platform/x86: dell-sysman: Fix reference leak"),
so it seems that the bug was copied from that driver.
Compile-tested only.
Fixes: a34fc329b189 ("platform/x86: hp-bioscfg: bioscfg")
Suggested-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Armin Wolf <W_Armin@gmx.de>
---
Chnages in v4:
- fix missing whitespace
- add Reviewed-by
Changes in v3:
- no changes
Changes in v2:
- add patch
---
drivers/platform/x86/hp/hp-bioscfg/bioscfg.c | 14 ++++++++++----
1 file changed, 10 insertions(+), 4 deletions(-)
diff --git a/drivers/platform/x86/hp/hp-bioscfg/bioscfg.c b/drivers/platform/x86/hp/hp-bioscfg/bioscfg.c
index 8c4f9e12f018..5798b49ddaba 100644
--- a/drivers/platform/x86/hp/hp-bioscfg/bioscfg.c
+++ b/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;
}
--
2.39.2Reviewed-by: Jorge Lopez <jorge.lopez2@hp.com>
> -----Original Message-----
> From: Armin Wolf <W_Armin@gmx.de>
> Sent: Monday, September 25, 2023 9:28 AM
> To: markpearson@lenovo.com; Lopez, Jorge A (Security)
> <jorge.lopez2@hp.com>
> Cc: hdegoede@redhat.com; markgross@kernel.org;
> ilpo.jarvinen@linux.intel.com; platform-driver-x86@vger.kernel.org; linux-
> kernel@vger.kernel.org
> Subject: [PATCH v4 2/2] platform/x86: hp-bioscfg: Fix reference leak
>
> CAUTION: External Email
>
> 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 7295a996fdab
> ("platform/x86: dell-sysman: Fix reference leak"), so it seems that the bug was
> copied from that driver.
>
> Compile-tested only.
>
> Fixes: a34fc329b189 ("platform/x86: hp-bioscfg: bioscfg")
> Suggested-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
> Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
> Signed-off-by: Armin Wolf <W_Armin@gmx.de>
> ---
> Chnages in v4:
> - fix missing whitespace
> - add Reviewed-by
> Changes in v3:
> - no changes
> Changes in v2:
> - add patch
> ---
> drivers/platform/x86/hp/hp-bioscfg/bioscfg.c | 14 ++++++++++----
> 1 file changed, 10 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/platform/x86/hp/hp-bioscfg/bioscfg.c
> b/drivers/platform/x86/hp/hp-bioscfg/bioscfg.c
> index 8c4f9e12f018..5798b49ddaba 100644
> --- a/drivers/platform/x86/hp/hp-bioscfg/bioscfg.c
> +++ b/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;
> }
>
> --
> 2.39.2
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