Commit c41e0121 authored by Mark Pearson's avatar Mark Pearson Committed by Hans de Goede
Browse files

platform/x86: think-lmi: mutex protection around multiple WMI calls 



When an attribute is being changed if the Admin account is enabled, or if
a password is being updated then multiple WMI calls are needed.
Add mutex protection to ensure no race conditions are introduced.

Fixes: b49f72e7 ("platform/x86: think-lmi: Certificate authentication support")
Signed-off-by: default avatarMark Pearson <mpearson-lenovo@squebb.ca>
Reviewed-by: default avatarIlpo Järvinen <ilpo.jarvinen@linux.intel.com>
Reviewed-by: default avatarHans de Goede <hdegoede@redhat.com>
Link: https://lore.kernel.org/r/20230601200552.4396-1-mpearson-lenovo@squebb.ca


Signed-off-by: default avatarHans de Goede <hdegoede@redhat.com>
parent 416a87c9

drivers/platform/x86/think-lmi.c

+10 −0
Original line number Diff line number Diff line
@@ -14,6 +14,7 @@ 
#include <linux/acpi.h>

#include <linux/errno.h>

#include <linux/fs.h>

#include <linux/mutex.h>

#include <linux/string.h>

#include <linux/types.h>

#include <linux/dmi.h>
@@ -195,6 +196,7 @@ static const char * const level_options[] = { 
};

static struct think_lmi tlmi_priv;

static struct class *fw_attr_class;

static DEFINE_MUTEX(tlmi_mutex);



/* ------ Utility functions ------------*/

/* Strip out CR if one is present */
@@ -437,6 +439,9 @@ static ssize_t new_password_store(struct kobject *kobj, 
	/* Strip out CR if one is present, setting password won't work if it is present */

	strip_cr(new_pwd);



	/* Use lock in case multiple WMI operations needed */

	mutex_lock(&tlmi_mutex);



	pwdlen = strlen(new_pwd);

	/* pwdlen == 0 is allowed to clear the password */

	if (pwdlen && ((pwdlen < setting->minlen) || (pwdlen > setting->maxlen))) {
@@ -493,6 +498,7 @@ static ssize_t new_password_store(struct kobject *kobj, 
		kfree(auth_str);

	}

out:

	mutex_unlock(&tlmi_mutex);

	kfree(new_pwd);

	return ret ?: count;

}
@@ -981,6 +987,9 @@ static ssize_t current_value_store(struct kobject *kobj, 
	/* Strip out CR if one is present */

	strip_cr(new_setting);



	/* Use lock in case multiple WMI operations needed */

	mutex_lock(&tlmi_mutex);



	/* Check if certificate authentication is enabled and active */

	if (tlmi_priv.certificate_support && tlmi_priv.pwd_admin->cert_installed) {

		if (!tlmi_priv.pwd_admin->signature || !tlmi_priv.pwd_admin->save_signature) {
@@ -1039,6 +1048,7 @@ static ssize_t current_value_store(struct kobject *kobj, 
		kobject_uevent(&tlmi_priv.class_dev->kobj, KOBJ_CHANGE);

	}

out:

	mutex_unlock(&tlmi_mutex);

	kfree(auth_str);

	kfree(set_str);

	kfree(new_setting);