[PATCH 6.1 006/131] platform/x86: think-lmi: Fix reference leak

Greg Kroah-Hartman
2023-10-16T08:52:12Z

From: Armin Wolf <W_Armin@gmx.de>

[ Upstream commit 528ab3e605cabf2f9c9bd5944d3bfe15f6e94f81 ]

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: Mark Pearson <mpearson-lenovo@squebb.ca>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Armin Wolf <W_Armin@gmx.de>
Link: https://lore.kernel.org/r/20230925142819.74525-2-W_Armin@gmx.de
Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 f6290221d139d..6641f934f15bf 100644
--- a/drivers/platform/x86/think-lmi.c
+++ b/drivers/platform/x86/think-lmi.c
@@ -1245,6 +1245,24 @@ 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;
@@ -1273,10 +1291,8 @@ 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;
--
2.40.1