Commit c59ab4ce authored by Hans de Goede's avatar Hans de Goede
Browse files

platform/x86: dell-wmi-sysman: Fix possible NULL pointer deref on exit 



It is possible for release_attributes_data() to get called when the
main_dir_kset has not been created yet, move the removal of the bios-reset
sysfs attr to under a if (main_dir_kset) check to avoid a NULL pointer
deref.

Fixes: e8a60aa7 ("platform/x86: Introduce support for Systems Management Driver over WMI for Dell Systems")
Cc: Divya Bharathi <Divya_Bharathi@dell.com>
Cc: Mario Limonciello <mario.limonciello@dell.com>
Reported-by: default avatarAlexander Naumann <alexandernaumann@gmx.de>
Signed-off-by: default avatarHans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20210321115901.35072-3-hdegoede@redhat.com
parent d939cd96

drivers/platform/x86/dell/dell-wmi-sysman/sysman.c

+2 −9
Original line number Diff line number Diff line
@@ -225,12 +225,6 @@ static int create_attributes_level_sysfs_files(void) 
	return ret;

}



static void release_reset_bios_data(void)

{

	sysfs_remove_file(&wmi_priv.main_dir_kset->kobj, &reset_bios.attr);

	sysfs_remove_file(&wmi_priv.main_dir_kset->kobj, &pending_reboot.attr);

}



static ssize_t wmi_sysman_attr_show(struct kobject *kobj, struct attribute *attr,

				    char *buf)

{
@@ -373,8 +367,6 @@ static void destroy_attribute_objs(struct kset *kset) 
 */

static void release_attributes_data(void)

{

	release_reset_bios_data();



	mutex_lock(&wmi_priv.mutex);

	exit_enum_attributes();

	exit_int_attributes();
@@ -386,12 +378,13 @@ static void release_attributes_data(void) 
		wmi_priv.authentication_dir_kset = NULL;

	}

	if (wmi_priv.main_dir_kset) {

		sysfs_remove_file(&wmi_priv.main_dir_kset->kobj, &reset_bios.attr);

		sysfs_remove_file(&wmi_priv.main_dir_kset->kobj, &pending_reboot.attr);

		destroy_attribute_objs(wmi_priv.main_dir_kset);

		kset_unregister(wmi_priv.main_dir_kset);

		wmi_priv.main_dir_kset = NULL;

	}

	mutex_unlock(&wmi_priv.mutex);



}



/**