From 06b7cf395b1fb652a50db39674a759658fbfba0d Mon Sep 17 00:00:00 2001 From: Guenter Roeck Date: Fri, 21 Aug 2026 07:49:15 -0700 Subject: [PATCH] hwmon: (sht4x) Add missing locks Sashiko reports: Heater sysfs callbacks (heater_enable_store, heater_power_store, and heater_time_store) are exposed to data races without the hwmon lock. If a user-space process reads hwmon data while another process enables the heater, heater_enable_store() executes without holding hwmon_lock(dev). This can interleave I2C commands and mutate shared state (data->heating_complete and data->data_pending) concurrently with sht4x_read_values(), leading to corrupted I2C sequences. Fixes: 53dfa12299c1 ("hwmon: (sht4x) Rely on subsystem locking") Cc: Alessandro Zini Signed-off-by: Guenter Roeck Link: https://patch.msgid.link/20260821144916.2889031-1-linux@roeck-us.net --- drivers/hwmon/sht4x.c | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/drivers/hwmon/sht4x.c b/drivers/hwmon/sht4x.c index 9cace0e8acda..7a0dc2ed723d 100644 --- a/drivers/hwmon/sht4x.c +++ b/drivers/hwmon/sht4x.c @@ -277,6 +277,8 @@ static ssize_t heater_enable_store(struct device *dev, heating_time_bound = 1100; } + guard(hwmon_lock)(dev); + if (time_before(jiffies, data->heating_complete)) return -EBUSY; @@ -314,6 +316,8 @@ static ssize_t heater_power_store(struct device *dev, if (power != 20 && power != 110 && power != 200) return -EINVAL; + guard(hwmon_lock)(dev); + data->heater_power = power; return count; @@ -344,6 +348,8 @@ static ssize_t heater_time_store(struct device *dev, if (time != 100 && time != 1000) return -EINVAL; + guard(hwmon_lock)(dev); + data->heater_time = time; return count;