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(). This issue likely first appeared inside the
dell-wmi-sysman driver, see
commit 7295a996fdab ("platform/x86: dell-sysman: Fix reference leak").
However, it also seems that the bug was copied from this driver into
the think-lmi and hp-bioscfg drivers. Maybe a more abstract
fw_attr_class could prevent such issues in the future by abstracting
away the kobject handling?
Armin Wolf (2):
platform/x86: think-lmi: Fix reference leak
platform/x86: hp-bioscfg: Fix reference leak
drivers/platform/x86/hp/hp-bioscfg/bioscfg.c | 14 ++++++++----
drivers/platform/x86/think-lmi.c | 24 ++++++++++++++++----
2 files changed, 30 insertions(+), 8 deletions(-)
--
2.39.2
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 <[email protected]>
Signed-off-by: Armin Wolf <[email protected]>
---
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..0c83e66f8d0b 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
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(). Move the setting name validation into a separate
function to allow for this change without having to duplicate the
cleanup code for this setting.
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: 1bcad8e510b2 ("platform/x86: think-lmi: Fix issues with duplicate attributes")
Reviewed-by: Ilpo Järvinen <[email protected]>
Signed-off-by: Armin Wolf <[email protected]>
---
Changes in v3:
- add Reviewed-by
Changes in v2:
- no changes
---
drivers/platform/x86/think-lmi.c | 24 ++++++++++++++++++++----
1 file changed, 20 insertions(+), 4 deletions(-)
diff --git a/drivers/platform/x86/think-lmi.c b/drivers/platform/x86/think-lmi.c
index 4be6f28d4600..3a396b763c49 100644
--- a/drivers/platform/x86/think-lmi.c
+++ b/drivers/platform/x86/think-lmi.c
@@ -1344,6 +1344,24 @@ static void tlmi_release_attr(void)
kset_unregister(tlmi_priv.authentication_kset);
}
+static int tlmi_validate_setting_name(struct kset *attribute_kset, char *name)
+{
+ struct kobject *duplicate;
+
+ if (!strcmp(name, "Reserved"))
+ return -EINVAL;
+
+ duplicate = kset_find_obj(attribute_kset, name);
+ if (duplicate) {
+ pr_debug("Duplicate attribute name found - %s\n", name);
+ /* kset_find_obj() returns a reference */
+ kobject_put(duplicate);
+ return -EBUSY;
+ }
+
+ return 0;
+}
+
static int tlmi_sysfs_init(void)
{
int i, ret;
@@ -1372,10 +1390,8 @@ static int tlmi_sysfs_init(void)
continue;
/* check for duplicate or reserved values */
- if (kset_find_obj(tlmi_priv.attribute_kset, tlmi_priv.setting[i]->display_name) ||
- !strcmp(tlmi_priv.setting[i]->display_name, "Reserved")) {
- pr_debug("duplicate or reserved attribute name found - %s\n",
- tlmi_priv.setting[i]->display_name);
+ if (tlmi_validate_setting_name(tlmi_priv.attribute_kset,
+ tlmi_priv.setting[i]->display_name) < 0) {
kfree(tlmi_priv.setting[i]->possible_values);
kfree(tlmi_priv.setting[i]);
tlmi_priv.setting[i] = NULL;
--
2.39.2