Patch "thermal: sysfs: Add sanity checks for trip temperature and hysteresis" has been added to the 6.11-stable tree

[Sasha Levin <sashal@xxxxxxxxxx>]

This is a note to let you know that I've just added the patch titled

    thermal: sysfs: Add sanity checks for trip temperature and hysteresis

to the 6.11-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     thermal-sysfs-add-sanity-checks-for-trip-temperature.patch
and it can be found in the queue-6.11 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.



commit 872ec8f8250f0f8f01157681c72b813f987f4009
Author: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Date:   Mon Aug 26 18:21:59 2024 +0200

    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+ <stable@xxxxxxxxxxxxxxx> # 6.8+
    Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
    Reviewed-by: Lukasz Luba <lukasz.luba@xxxxxxx>
    Link: https://patch.msgid.link/12528772.O9o76ZdvQC@xxxxxxxxxxxxx
    Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>

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