linux-stable/drivers/platform/x86/intel-wmi-thunderbolt.c
Mario Limonciello 12933ea2b8 platform/x86: intel-wmi-thunderbolt: Silence error cases
These were raised by Lukas Wunner as potential DOS attacks against
the system log by passing bad data to sysfs.

Signed-off-by: Mario Limonciello <mario.limonciello@dell.com>
Signed-off-by: Darren Hart (VMware) <dvhart@infradead.org>
2017-09-22 15:08:19 -07:00

98 lines
2.5 KiB
C

/*
* WMI Thunderbolt driver
*
* Copyright (C) 2017 Dell Inc. All Rights Reserved.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 as published
* by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*/
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/acpi.h>
#include <linux/device.h>
#include <linux/fs.h>
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/string.h>
#include <linux/sysfs.h>
#include <linux/types.h>
#include <linux/wmi.h>
#define INTEL_WMI_THUNDERBOLT_GUID "86CCFD48-205E-4A77-9C48-2021CBEDE341"
static ssize_t force_power_store(struct device *dev,
struct device_attribute *attr,
const char *buf, size_t count)
{
struct acpi_buffer input;
acpi_status status;
u8 mode;
input.length = sizeof(u8);
input.pointer = &mode;
mode = hex_to_bin(buf[0]);
if (mode == 0 || mode == 1) {
status = wmi_evaluate_method(INTEL_WMI_THUNDERBOLT_GUID, 0, 1,
&input, NULL);
if (ACPI_FAILURE(status))
return -ENODEV;
} else {
return -EINVAL;
}
return count;
}
static DEVICE_ATTR_WO(force_power);
static struct attribute *tbt_attrs[] = {
&dev_attr_force_power.attr,
NULL
};
static const struct attribute_group tbt_attribute_group = {
.attrs = tbt_attrs,
};
static int intel_wmi_thunderbolt_probe(struct wmi_device *wdev)
{
int ret;
ret = sysfs_create_group(&wdev->dev.kobj, &tbt_attribute_group);
kobject_uevent(&wdev->dev.kobj, KOBJ_CHANGE);
return ret;
}
static int intel_wmi_thunderbolt_remove(struct wmi_device *wdev)
{
sysfs_remove_group(&wdev->dev.kobj, &tbt_attribute_group);
kobject_uevent(&wdev->dev.kobj, KOBJ_CHANGE);
return 0;
}
static const struct wmi_device_id intel_wmi_thunderbolt_id_table[] = {
{ .guid_string = INTEL_WMI_THUNDERBOLT_GUID },
{ },
};
static struct wmi_driver intel_wmi_thunderbolt_driver = {
.driver = {
.name = "intel-wmi-thunderbolt",
},
.probe = intel_wmi_thunderbolt_probe,
.remove = intel_wmi_thunderbolt_remove,
.id_table = intel_wmi_thunderbolt_id_table,
};
module_wmi_driver(intel_wmi_thunderbolt_driver);
MODULE_ALIAS("wmi:" INTEL_WMI_THUNDERBOLT_GUID);
MODULE_AUTHOR("Mario Limonciello <mario.limonciello@dell.com>");
MODULE_DESCRIPTION("Intel WMI Thunderbolt force power driver");
MODULE_LICENSE("GPL");