From f9ca37239d2fda0678a68ecf5a196a121f3f3f61 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Mon, 26 Aug 2024 18:21:59 +0200 Subject: [PATCH] thermal: sysfs: Add sanity checks for trip temperature and hysteresis [ Upstream commit 874b6476fa888e79e41daf7653384c8d70927b90 ] Add sanity checks for new trip temperature and hysteresis values to trip_point_temp_store() and trip_point_hyst_store() to prevent trip point threshold from falling below THERMAL_TEMP_INVALID. However, still allow user space to pass THERMAL_TEMP_INVALID as the new trip temperature value to invalidate the trip if necessary. Also allow the hysteresis to be updated when the temperature is invalid to allow user space to avoid having to adjust hysteresis after a valid temperature has been set, but in that case just change the value and do nothing else. Fixes: be0a3600aa1e ("thermal: sysfs: Rework the handling of trip point updates") Cc: 6.8+ # 6.8+ Signed-off-by: Rafael J. Wysocki Reviewed-by: Lukasz Luba Link: https://patch.msgid.link/12528772.O9o76ZdvQC@rjwysocki.net Signed-off-by: Sasha Levin --- drivers/thermal/thermal_sysfs.c | 50 +++++++++++++++++++++++++-------- 1 file changed, 38 insertions(+), 12 deletions(-) diff --git a/drivers/thermal/thermal_sysfs.c b/drivers/thermal/thermal_sysfs.c index 2709455486776..d628dd67be5cc 100644 --- a/drivers/thermal/thermal_sysfs.c +++ b/drivers/thermal/thermal_sysfs.c @@ -111,18 +111,26 @@ trip_point_temp_store(struct device *dev, struct device_attribute *attr, mutex_lock(&tz->lock); - if (temp != trip->temperature) { - if (tz->ops.set_trip_temp) { - ret = tz->ops.set_trip_temp(tz, trip, temp); - if (ret) - goto unlock; - } + if (temp == trip->temperature) + goto unlock; - thermal_zone_set_trip_temp(tz, trip, temp); + /* Arrange the condition to avoid integer overflows. */ + if (temp != THERMAL_TEMP_INVALID && + temp <= trip->hysteresis + THERMAL_TEMP_INVALID) { + ret = -EINVAL; + goto unlock; + } - __thermal_zone_device_update(tz, THERMAL_TRIP_CHANGED); + if (tz->ops.set_trip_temp) { + ret = tz->ops.set_trip_temp(tz, trip, temp); + if (ret) + goto unlock; } + thermal_zone_set_trip_temp(tz, trip, temp); + + __thermal_zone_device_update(tz, THERMAL_TRIP_CHANGED); + unlock: mutex_unlock(&tz->lock); @@ -152,15 +160,33 @@ trip_point_hyst_store(struct device *dev, struct device_attribute *attr, mutex_lock(&tz->lock); - if (hyst != trip->hysteresis) { - thermal_zone_set_trip_hyst(tz, trip, hyst); + if (hyst == trip->hysteresis) + goto unlock; + + /* + * Allow the hysteresis to be updated when the temperature is invalid + * to allow user space to avoid having to adjust hysteresis after a + * valid temperature has been set, but in that case just change the + * value and do nothing else. + */ + if (trip->temperature == THERMAL_TEMP_INVALID) { + WRITE_ONCE(trip->hysteresis, hyst); + goto unlock; + } - __thermal_zone_device_update(tz, THERMAL_TRIP_CHANGED); + if (trip->temperature - hyst <= THERMAL_TEMP_INVALID) { + ret = -EINVAL; + goto unlock; } + thermal_zone_set_trip_hyst(tz, trip, hyst); + + __thermal_zone_device_update(tz, THERMAL_TRIP_CHANGED); + +unlock: mutex_unlock(&tz->lock); - return count; + return ret ? ret : count; } static ssize_t -- 2.47.3