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linux-next/drivers/leds/leds-da903x.c
Johan Hovold 6f4aa35744 leds: da903x: fix use-after-free on unbind
Several MFD child drivers register their class devices directly under
the parent device. This means you cannot blindly do devres conversions
so that deregistration ends up being tied to the parent device,
something which leads to use-after-free on driver unbind when the class
device is released while still being registered.

Fixes: eed16255d6 ("leds: da903x: Use devm_led_classdev_register")
Cc: stable <stable@vger.kernel.org>     # 4.6
Cc: Amitoj Kaur Chawla <amitoj1606@gmail.com>
Signed-off-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Pavel Machek <pavel@ucw.cz>
2020-06-22 10:37:58 +02:00

148 lines
3.6 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* LEDs driver for Dialog Semiconductor DA9030/DA9034
*
* Copyright (C) 2008 Compulab, Ltd.
* Mike Rapoport <mike@compulab.co.il>
*
* Copyright (C) 2006-2008 Marvell International Ltd.
* Eric Miao <eric.miao@marvell.com>
*/
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/platform_device.h>
#include <linux/leds.h>
#include <linux/mfd/da903x.h>
#include <linux/slab.h>
#define DA9030_LED1_CONTROL 0x20
#define DA9030_LED2_CONTROL 0x21
#define DA9030_LED3_CONTROL 0x22
#define DA9030_LED4_CONTROL 0x23
#define DA9030_LEDPC_CONTROL 0x24
#define DA9030_MISC_CONTROL_A 0x26 /* Vibrator Control */
#define DA9034_LED1_CONTROL 0x35
#define DA9034_LED2_CONTROL 0x36
#define DA9034_VIBRA 0x40
struct da903x_led {
struct led_classdev cdev;
struct device *master;
int id;
int flags;
};
#define DA9030_LED_OFFSET(id) ((id) - DA9030_ID_LED_1)
#define DA9034_LED_OFFSET(id) ((id) - DA9034_ID_LED_1)
static int da903x_led_set(struct led_classdev *led_cdev,
enum led_brightness value)
{
struct da903x_led *led =
container_of(led_cdev, struct da903x_led, cdev);
uint8_t val;
int offset, ret = -EINVAL;
switch (led->id) {
case DA9030_ID_LED_1:
case DA9030_ID_LED_2:
case DA9030_ID_LED_3:
case DA9030_ID_LED_4:
case DA9030_ID_LED_PC:
offset = DA9030_LED_OFFSET(led->id);
val = led->flags & ~0x87;
val |= value ? 0x80 : 0; /* EN bit */
val |= (0x7 - (value >> 5)) & 0x7; /* PWM<2:0> */
ret = da903x_write(led->master, DA9030_LED1_CONTROL + offset,
val);
break;
case DA9030_ID_VIBRA:
val = led->flags & ~0x80;
val |= value ? 0x80 : 0; /* EN bit */
ret = da903x_write(led->master, DA9030_MISC_CONTROL_A, val);
break;
case DA9034_ID_LED_1:
case DA9034_ID_LED_2:
offset = DA9034_LED_OFFSET(led->id);
val = (value * 0x5f / LED_FULL) & 0x7f;
val |= (led->flags & DA9034_LED_RAMP) ? 0x80 : 0;
ret = da903x_write(led->master, DA9034_LED1_CONTROL + offset,
val);
break;
case DA9034_ID_VIBRA:
val = value & 0xfe;
ret = da903x_write(led->master, DA9034_VIBRA, val);
break;
}
return ret;
}
static int da903x_led_probe(struct platform_device *pdev)
{
struct led_info *pdata = dev_get_platdata(&pdev->dev);
struct da903x_led *led;
int id, ret;
if (pdata == NULL)
return 0;
id = pdev->id;
if (!((id >= DA9030_ID_LED_1 && id <= DA9030_ID_VIBRA) ||
(id >= DA9034_ID_LED_1 && id <= DA9034_ID_VIBRA))) {
dev_err(&pdev->dev, "invalid LED ID (%d) specified\n", id);
return -EINVAL;
}
led = devm_kzalloc(&pdev->dev, sizeof(struct da903x_led), GFP_KERNEL);
if (!led)
return -ENOMEM;
led->cdev.name = pdata->name;
led->cdev.default_trigger = pdata->default_trigger;
led->cdev.brightness_set_blocking = da903x_led_set;
led->cdev.brightness = LED_OFF;
led->id = id;
led->flags = pdata->flags;
led->master = pdev->dev.parent;
ret = led_classdev_register(led->master, &led->cdev);
if (ret) {
dev_err(&pdev->dev, "failed to register LED %d\n", id);
return ret;
}
platform_set_drvdata(pdev, led);
return 0;
}
static int da903x_led_remove(struct platform_device *pdev)
{
struct da903x_led *led = platform_get_drvdata(pdev);
led_classdev_unregister(&led->cdev);
return 0;
}
static struct platform_driver da903x_led_driver = {
.driver = {
.name = "da903x-led",
},
.probe = da903x_led_probe,
.remove = da903x_led_remove,
};
module_platform_driver(da903x_led_driver);
MODULE_DESCRIPTION("LEDs driver for Dialog Semiconductor DA9030/DA9034");
MODULE_AUTHOR("Eric Miao <eric.miao@marvell.com>");
MODULE_AUTHOR("Mike Rapoport <mike@compulab.co.il>");
MODULE_LICENSE("GPL");
MODULE_ALIAS("platform:da903x-led");