Commit 491403b9 authored by Abdurrahman Hussain's avatar Abdurrahman Hussain Committed by Guenter Roeck
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hwmon: (pmbus/adm1266) register the gpio_chip after pmbus_do_probe() 



adm1266_probe() calls adm1266_config_gpio() -- which goes on to
devm_gpiochip_add_data() and exposes the gpio_chip callbacks to
gpiolib -- before pmbus_do_probe() has initialised the per-client
PMBus state (notably the pmbus_lock mutex the core hands out via
pmbus_get_data()).

That ordering is already a latent hazard: any GPIO access that lands
between adm1266_config_gpio() and the end of pmbus_do_probe() (for
example a sysfs read from a user space agent that opens the gpiochip
the instant gpiolib advertises it) races pmbus_do_probe()'s own
device accesses with no serialisation.

Move adm1266_config_gpio() down past pmbus_do_probe() so the chip
isn't reachable from userspace until the PMBus state it depends on
is fully initialised.

Fixes: d98dfad3 ("hwmon: (pmbus/adm1266) Add support for GPIOs")
Cc: stable@vger.kernel.org
Signed-off-by: default avatarAbdurrahman Hussain <abdurrahman@nexthop.ai>
Reviewed-by: default avatarBartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20260518-adm1266-gpio-fixes-v3-4-e425e4f88139@nexthop.ai


Signed-off-by: default avatarGuenter Roeck <linux@roeck-us.net>
parent a7232f68

drivers/hwmon/pmbus/adm1266.c

+4 −4
Original line number Diff line number Diff line
@@ -473,10 +473,6 @@ static int adm1266_probe(struct i2c_client *client) 
	crc8_populate_msb(pmbus_crc_table, 0x7);

	mutex_init(&data->buf_mutex);



	ret = adm1266_config_gpio(data);

	if (ret < 0)

		return ret;



	ret = adm1266_set_rtc(data);

	if (ret < 0)

		return ret;
@@ -489,6 +485,10 @@ static int adm1266_probe(struct i2c_client *client) 
	if (ret)

		return ret;



	ret = adm1266_config_gpio(data);

	if (ret < 0)

		return ret;



	adm1266_init_debugfs(data);



	return 0;