[PATCH v2 1/3] thermal: hwmon: Fix critical temperature attribute removal

[Rafael J. Wysocki]

From: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>

Since the return value of thermal_zone_crit_temp_valid() depends on
the behavior of the thermal zone .get_crit_temp() callback which
may change over time in theory, thermal_remove_hwmon_sysfs() may
attempt to remove a critical temperature attribute that has not
been created, passing a pointer to an uninitialized attribute
structure to device_remove_file().

To avoid that, set a flag in struct thermal_hwmon_temp after creating
a critical temperature attribute and use the value of that flag to
decide whether or not the attribute needs to be removed.

Fixes: e8db5d6736a7 ("thermal: hwmon: Make the check for critical temp valid consistent")
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
---

v1 -> v2: New patch (due to sashiko.dev feedback)

---
 drivers/thermal/thermal_hwmon.c |    5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

--- a/drivers/thermal/thermal_hwmon.c
+++ b/drivers/thermal/thermal_hwmon.c
@@ -40,6 +40,7 @@ struct thermal_hwmon_temp {
 	struct thermal_zone_device *tz;
 	struct thermal_hwmon_attr temp_input;	/* hwmon sys attr */
 	struct thermal_hwmon_attr temp_crit;	/* hwmon sys attr */
+	bool temp_crit_present;
 };
 
 static LIST_HEAD(thermal_hwmon_list);
@@ -191,6 +192,8 @@ int thermal_add_hwmon_sysfs(struct therm
 					    &temp->temp_crit.attr);
 		if (result)
 			goto unregister_input;
+
+		temp->temp_crit_present = true;
 	}
 
 	mutex_lock(&thermal_hwmon_list_lock);
@@ -235,7 +238,7 @@ void thermal_remove_hwmon_sysfs(struct t
 	}
 
 	device_remove_file(hwmon->device, &temp->temp_input.attr);
-	if (thermal_zone_crit_temp_valid(tz))
+	if (temp->temp_crit_present)
 		device_remove_file(hwmon->device, &temp->temp_crit.attr);
 
 	mutex_lock(&thermal_hwmon_list_lock);