[PATCH v3 0/3] platform/x86: think-lmi: Fix resource cleanup flaws

[PATCH v3 0/3] platform/x86: think-lmi: Fix resource cleanup flaws

[Kurt Borja]

Hi all,

First patch is a prerequisite in order to avoid NULL pointer
dereferences in error paths. Then two fixes follow.

Signed-off-by: Kurt Borja <kuurtb@gmail.com>
---
Changes in v3:
- Add Cc stable tags to all patches
- Rebase on top of the 'fixes' branch
- Link to v2: https://lore.kernel.org/r/20250628-lmi-fix-v2-0-c530e1c959d7@gmail.com

Changes in v2:

[PATCH 02]
  - Remove kobject_del() and commit message remark. It turns out it's
    optional to call this (my bad)
  - Leave only one fixes tag. The other two are not necessary.

- Link to v1: https://lore.kernel.org/r/20250628-lmi-fix-v1-0-c6eec9aa3ca7@gmail.com

---
Kurt Borja (3):
      platform/x86: think-lmi: Create ksets consecutively
      platform/x86: think-lmi: Fix kobject cleanup
      platform/x86: think-lmi: Fix sysfs group cleanup

 drivers/platform/x86/think-lmi.c | 90 ++++++++++++++--------------------------
 1 file changed, 30 insertions(+), 60 deletions(-)
---
base-commit: 173bbec6693f3f3f00dac144f3aa0cd62fb60d33
change-id: 20250628-lmi-fix-98143b10d9fd
-- 
 ~ Kurt

[PATCH v3 1/3] platform/x86: think-lmi: Create ksets consecutively

[Kurt Borja]

Avoid entering tlmi_release_attr() in error paths if both ksets are not
yet created.

This is accomplished by initializing them side by side.

Cc: stable@vger.kernel.org
Reviewed-by: Mark Pearson <mpearson-lenovo@squebb.ca>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Kurt Borja <kuurtb@gmail.com>
---
 drivers/platform/x86/think-lmi.c | 14 ++++++++------
 1 file changed, 8 insertions(+), 6 deletions(-)

diff --git a/drivers/platform/x86/think-lmi.c b/drivers/platform/x86/think-lmi.c
index 00b1e7c79a3d1e95621701530ea5e11015414498..4c10a26e7e5e3471f286136d671606acf68b401e 100644
--- a/drivers/platform/x86/think-lmi.c
+++ b/drivers/platform/x86/think-lmi.c
@@ -1455,6 +1455,14 @@ static int tlmi_sysfs_init(void)
 		goto fail_device_created;
 	}
 
+	tlmi_priv.authentication_kset = kset_create_and_add("authentication", NULL,
+							    &tlmi_priv.class_dev->kobj);
+	if (!tlmi_priv.authentication_kset) {
+		kset_unregister(tlmi_priv.attribute_kset);
+		ret = -ENOMEM;
+		goto fail_device_created;
+	}
+
 	for (i = 0; i < TLMI_SETTINGS_COUNT; i++) {
 		/* Check if index is a valid setting - skip if it isn't */
 		if (!tlmi_priv.setting[i])
@@ -1496,12 +1504,6 @@ static int tlmi_sysfs_init(void)
 	}
 
 	/* Create authentication entries */
-	tlmi_priv.authentication_kset = kset_create_and_add("authentication", NULL,
-								&tlmi_priv.class_dev->kobj);
-	if (!tlmi_priv.authentication_kset) {
-		ret = -ENOMEM;
-		goto fail_create_attr;
-	}
 	tlmi_priv.pwd_admin->kobj.kset = tlmi_priv.authentication_kset;
 	ret = kobject_add(&tlmi_priv.pwd_admin->kobj, NULL, "%s", "Admin");
 	if (ret)

-- 
2.50.0

[PATCH v3 2/3] platform/x86: think-lmi: Fix kobject cleanup

[Kurt Borja]

In tlmi_analyze(), allocated structs with an embedded kobject are freed
in error paths after the they were already initialized.

Fix this by first by avoiding the initialization of kobjects in
tlmi_analyze() and then by correctly cleaning them up in
tlmi_release_attr() using their kset's kobject list.

Cc: stable@vger.kernel.org
Fixes: a40cd7ef22fb ("platform/x86: think-lmi: Add WMI interface support on Lenovo platforms")
Fixes: 30e78435d3bf ("platform/x86: think-lmi: Split kobject_init() and kobject_add() calls")
Reviewed-by: Mark Pearson <mpearson-lenovo@squebb.ca>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Kurt Borja <kuurtb@gmail.com>
---
 drivers/platform/x86/think-lmi.c | 35 +++++++++++++++++++----------------
 1 file changed, 19 insertions(+), 16 deletions(-)

diff --git a/drivers/platform/x86/think-lmi.c b/drivers/platform/x86/think-lmi.c
index 4c10a26e7e5e3471f286136d671606acf68b401e..3e5e6e6031efcefe6b3d31bc144e738599566d98 100644
--- a/drivers/platform/x86/think-lmi.c
+++ b/drivers/platform/x86/think-lmi.c
@@ -1380,13 +1380,13 @@ static struct kobj_attribute debug_cmd = __ATTR_WO(debug_cmd);
 /* ---- Initialisation --------------------------------------------------------- */
 static void tlmi_release_attr(void)
 {
+	struct kobject *pos, *n;
 	int i;
 
 	/* Attribute structures */
 	for (i = 0; i < TLMI_SETTINGS_COUNT; i++) {
 		if (tlmi_priv.setting[i]) {
 			sysfs_remove_group(&tlmi_priv.setting[i]->kobj, &tlmi_attr_group);
-			kobject_put(&tlmi_priv.setting[i]->kobj);
 		}
 	}
 	sysfs_remove_file(&tlmi_priv.attribute_kset->kobj, &pending_reboot.attr);
@@ -1395,6 +1395,9 @@ static void tlmi_release_attr(void)
 	if (tlmi_priv.can_debug_cmd && debug_support)
 		sysfs_remove_file(&tlmi_priv.attribute_kset->kobj, &debug_cmd.attr);
 
+	list_for_each_entry_safe(pos, n, &tlmi_priv.attribute_kset->list, entry)
+		kobject_put(pos);
+
 	kset_unregister(tlmi_priv.attribute_kset);
 
 	/* Free up any saved signatures */
@@ -1403,19 +1406,17 @@ static void tlmi_release_attr(void)
 
 	/* Authentication structures */
 	sysfs_remove_group(&tlmi_priv.pwd_admin->kobj, &auth_attr_group);
-	kobject_put(&tlmi_priv.pwd_admin->kobj);
 	sysfs_remove_group(&tlmi_priv.pwd_power->kobj, &auth_attr_group);
-	kobject_put(&tlmi_priv.pwd_power->kobj);
 
 	if (tlmi_priv.opcode_support) {
 		sysfs_remove_group(&tlmi_priv.pwd_system->kobj, &auth_attr_group);
-		kobject_put(&tlmi_priv.pwd_system->kobj);
 		sysfs_remove_group(&tlmi_priv.pwd_hdd->kobj, &auth_attr_group);
-		kobject_put(&tlmi_priv.pwd_hdd->kobj);
 		sysfs_remove_group(&tlmi_priv.pwd_nvme->kobj, &auth_attr_group);
-		kobject_put(&tlmi_priv.pwd_nvme->kobj);
 	}
 
+	list_for_each_entry_safe(pos, n, &tlmi_priv.authentication_kset->list, entry)
+		kobject_put(pos);
+
 	kset_unregister(tlmi_priv.authentication_kset);
 }
 
@@ -1479,8 +1480,8 @@ static int tlmi_sysfs_init(void)
 
 		/* Build attribute */
 		tlmi_priv.setting[i]->kobj.kset = tlmi_priv.attribute_kset;
-		ret = kobject_add(&tlmi_priv.setting[i]->kobj, NULL,
-				  "%s", tlmi_priv.setting[i]->display_name);
+		ret = kobject_init_and_add(&tlmi_priv.setting[i]->kobj, &tlmi_attr_setting_ktype,
+					   NULL, "%s", tlmi_priv.setting[i]->display_name);
 		if (ret)
 			goto fail_create_attr;
 
@@ -1505,7 +1506,8 @@ static int tlmi_sysfs_init(void)
 
 	/* Create authentication entries */
 	tlmi_priv.pwd_admin->kobj.kset = tlmi_priv.authentication_kset;
-	ret = kobject_add(&tlmi_priv.pwd_admin->kobj, NULL, "%s", "Admin");
+	ret = kobject_init_and_add(&tlmi_priv.pwd_admin->kobj, &tlmi_pwd_setting_ktype,
+				   NULL, "%s", "Admin");
 	if (ret)
 		goto fail_create_attr;
 
@@ -1514,7 +1516,8 @@ static int tlmi_sysfs_init(void)
 		goto fail_create_attr;
 
 	tlmi_priv.pwd_power->kobj.kset = tlmi_priv.authentication_kset;
-	ret = kobject_add(&tlmi_priv.pwd_power->kobj, NULL, "%s", "Power-on");
+	ret = kobject_init_and_add(&tlmi_priv.pwd_power->kobj, &tlmi_pwd_setting_ktype,
+				   NULL, "%s", "Power-on");
 	if (ret)
 		goto fail_create_attr;
 
@@ -1524,7 +1527,8 @@ static int tlmi_sysfs_init(void)
 
 	if (tlmi_priv.opcode_support) {
 		tlmi_priv.pwd_system->kobj.kset = tlmi_priv.authentication_kset;
-		ret = kobject_add(&tlmi_priv.pwd_system->kobj, NULL, "%s", "System");
+		ret = kobject_init_and_add(&tlmi_priv.pwd_system->kobj, &tlmi_pwd_setting_ktype,
+					   NULL, "%s", "System");
 		if (ret)
 			goto fail_create_attr;
 
@@ -1533,7 +1537,8 @@ static int tlmi_sysfs_init(void)
 			goto fail_create_attr;
 
 		tlmi_priv.pwd_hdd->kobj.kset = tlmi_priv.authentication_kset;
-		ret = kobject_add(&tlmi_priv.pwd_hdd->kobj, NULL, "%s", "HDD");
+		ret = kobject_init_and_add(&tlmi_priv.pwd_hdd->kobj, &tlmi_pwd_setting_ktype,
+					   NULL, "%s", "HDD");
 		if (ret)
 			goto fail_create_attr;
 
@@ -1542,7 +1547,8 @@ static int tlmi_sysfs_init(void)
 			goto fail_create_attr;
 
 		tlmi_priv.pwd_nvme->kobj.kset = tlmi_priv.authentication_kset;
-		ret = kobject_add(&tlmi_priv.pwd_nvme->kobj, NULL, "%s", "NVMe");
+		ret = kobject_init_and_add(&tlmi_priv.pwd_nvme->kobj, &tlmi_pwd_setting_ktype,
+					   NULL, "%s", "NVMe");
 		if (ret)
 			goto fail_create_attr;
 
@@ -1579,8 +1585,6 @@ static struct tlmi_pwd_setting *tlmi_create_auth(const char *pwd_type,
 	new_pwd->maxlen = tlmi_priv.pwdcfg.core.max_length;
 	new_pwd->index = 0;
 
-	kobject_init(&new_pwd->kobj, &tlmi_pwd_setting_ktype);
-
 	return new_pwd;
 }
 
@@ -1685,7 +1689,6 @@ static int tlmi_analyze(struct wmi_device *wdev)
 		if (setting->possible_values)
 			strreplace(setting->possible_values, ',', ';');
 
-		kobject_init(&setting->kobj, &tlmi_attr_setting_ktype);
 		tlmi_priv.setting[i] = setting;
 		kfree(item);
 	}

-- 
2.50.0

[PATCH v3 3/3] platform/x86: think-lmi: Fix sysfs group cleanup

[Kurt Borja]

Many error paths in tlmi_sysfs_init() lead to sysfs groups being removed
when they were not even created.

Fix this by letting the kobject core manage these groups through their
kobj_type's defult_groups.

Cc: stable@vger.kernel.org
Fixes: a40cd7ef22fb ("platform/x86: think-lmi: Add WMI interface support on Lenovo platforms")
Reviewed-by: Mark Pearson <mpearson-lenovo@squebb.ca>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Kurt Borja <kuurtb@gmail.com>
---
 drivers/platform/x86/think-lmi.c | 43 ++++------------------------------------
 1 file changed, 4 insertions(+), 39 deletions(-)

diff --git a/drivers/platform/x86/think-lmi.c b/drivers/platform/x86/think-lmi.c
index 3e5e6e6031efcefe6b3d31bc144e738599566d98..ca8498f8b831ae5d5c1dcb3f0585e748975dd2c7 100644
--- a/drivers/platform/x86/think-lmi.c
+++ b/drivers/platform/x86/think-lmi.c
@@ -973,6 +973,7 @@ static const struct attribute_group auth_attr_group = {
 	.is_visible = auth_attr_is_visible,
 	.attrs = auth_attrs,
 };
+__ATTRIBUTE_GROUPS(auth_attr);
 
 /* ---- Attributes sysfs --------------------------------------------------------- */
 static ssize_t display_name_show(struct kobject *kobj, struct kobj_attribute *attr,
@@ -1188,6 +1189,7 @@ static const struct attribute_group tlmi_attr_group = {
 	.is_visible = attr_is_visible,
 	.attrs = tlmi_attrs,
 };
+__ATTRIBUTE_GROUPS(tlmi_attr);
 
 static void tlmi_attr_setting_release(struct kobject *kobj)
 {
@@ -1207,11 +1209,13 @@ static void tlmi_pwd_setting_release(struct kobject *kobj)
 static const struct kobj_type tlmi_attr_setting_ktype = {
 	.release        = &tlmi_attr_setting_release,
 	.sysfs_ops	= &kobj_sysfs_ops,
+	.default_groups = tlmi_attr_groups,
 };
 
 static const struct kobj_type tlmi_pwd_setting_ktype = {
 	.release        = &tlmi_pwd_setting_release,
 	.sysfs_ops	= &kobj_sysfs_ops,
+	.default_groups = auth_attr_groups,
 };
 
 static ssize_t pending_reboot_show(struct kobject *kobj, struct kobj_attribute *attr,
@@ -1381,14 +1385,8 @@ static struct kobj_attribute debug_cmd = __ATTR_WO(debug_cmd);
 static void tlmi_release_attr(void)
 {
 	struct kobject *pos, *n;
-	int i;
 
 	/* Attribute structures */
-	for (i = 0; i < TLMI_SETTINGS_COUNT; i++) {
-		if (tlmi_priv.setting[i]) {
-			sysfs_remove_group(&tlmi_priv.setting[i]->kobj, &tlmi_attr_group);
-		}
-	}
 	sysfs_remove_file(&tlmi_priv.attribute_kset->kobj, &pending_reboot.attr);
 	sysfs_remove_file(&tlmi_priv.attribute_kset->kobj, &save_settings.attr);
 
@@ -1405,15 +1403,6 @@ static void tlmi_release_attr(void)
 	kfree(tlmi_priv.pwd_admin->save_signature);
 
 	/* Authentication structures */
-	sysfs_remove_group(&tlmi_priv.pwd_admin->kobj, &auth_attr_group);
-	sysfs_remove_group(&tlmi_priv.pwd_power->kobj, &auth_attr_group);
-
-	if (tlmi_priv.opcode_support) {
-		sysfs_remove_group(&tlmi_priv.pwd_system->kobj, &auth_attr_group);
-		sysfs_remove_group(&tlmi_priv.pwd_hdd->kobj, &auth_attr_group);
-		sysfs_remove_group(&tlmi_priv.pwd_nvme->kobj, &auth_attr_group);
-	}
-
 	list_for_each_entry_safe(pos, n, &tlmi_priv.authentication_kset->list, entry)
 		kobject_put(pos);
 
@@ -1484,10 +1473,6 @@ static int tlmi_sysfs_init(void)
 					   NULL, "%s", tlmi_priv.setting[i]->display_name);
 		if (ret)
 			goto fail_create_attr;
-
-		ret = sysfs_create_group(&tlmi_priv.setting[i]->kobj, &tlmi_attr_group);
-		if (ret)
-			goto fail_create_attr;
 	}
 
 	ret = sysfs_create_file(&tlmi_priv.attribute_kset->kobj, &pending_reboot.attr);
@@ -1511,20 +1496,12 @@ static int tlmi_sysfs_init(void)
 	if (ret)
 		goto fail_create_attr;
 
-	ret = sysfs_create_group(&tlmi_priv.pwd_admin->kobj, &auth_attr_group);
-	if (ret)
-		goto fail_create_attr;
-
 	tlmi_priv.pwd_power->kobj.kset = tlmi_priv.authentication_kset;
 	ret = kobject_init_and_add(&tlmi_priv.pwd_power->kobj, &tlmi_pwd_setting_ktype,
 				   NULL, "%s", "Power-on");
 	if (ret)
 		goto fail_create_attr;
 
-	ret = sysfs_create_group(&tlmi_priv.pwd_power->kobj, &auth_attr_group);
-	if (ret)
-		goto fail_create_attr;
-
 	if (tlmi_priv.opcode_support) {
 		tlmi_priv.pwd_system->kobj.kset = tlmi_priv.authentication_kset;
 		ret = kobject_init_and_add(&tlmi_priv.pwd_system->kobj, &tlmi_pwd_setting_ktype,
@@ -1532,29 +1509,17 @@ static int tlmi_sysfs_init(void)
 		if (ret)
 			goto fail_create_attr;
 
-		ret = sysfs_create_group(&tlmi_priv.pwd_system->kobj, &auth_attr_group);
-		if (ret)
-			goto fail_create_attr;
-
 		tlmi_priv.pwd_hdd->kobj.kset = tlmi_priv.authentication_kset;
 		ret = kobject_init_and_add(&tlmi_priv.pwd_hdd->kobj, &tlmi_pwd_setting_ktype,
 					   NULL, "%s", "HDD");
 		if (ret)
 			goto fail_create_attr;
 
-		ret = sysfs_create_group(&tlmi_priv.pwd_hdd->kobj, &auth_attr_group);
-		if (ret)
-			goto fail_create_attr;
-
 		tlmi_priv.pwd_nvme->kobj.kset = tlmi_priv.authentication_kset;
 		ret = kobject_init_and_add(&tlmi_priv.pwd_nvme->kobj, &tlmi_pwd_setting_ktype,
 					   NULL, "%s", "NVMe");
 		if (ret)
 			goto fail_create_attr;
-
-		ret = sysfs_create_group(&tlmi_priv.pwd_nvme->kobj, &auth_attr_group);
-		if (ret)
-			goto fail_create_attr;
 	}
 
 	return ret;

-- 
2.50.0

Re: [PATCH v3 0/3] platform/x86: think-lmi: Fix resource cleanup flaws

[Ilpo Järvinen]

On Mon, 30 Jun 2025 14:31:18 -0300, Kurt Borja wrote:

> First patch is a prerequisite in order to avoid NULL pointer
> dereferences in error paths. Then two fixes follow.
> 
> 


Thank you for your contribution, it has been applied to my local
review-ilpo-fixes branch. Note it will show up in the public
platform-drivers-x86/review-ilpo-fixes branch only once I've pushed my
local branch there, which might take a while.

The list of commits applied:
[1/3] platform/x86: think-lmi: Create ksets consecutively
      commit: 8dab34ca77293b409c3223636dde915a22656748
[2/3] platform/x86: think-lmi: Fix kobject cleanup
      commit: 9110056fe10b0519529bdbbac37311a5037ea0c2
[3/3] platform/x86: think-lmi: Fix sysfs group cleanup
      commit: 4f30f946f27b7f044cf8f3f1f353dee1dcd3517a

--
 i.