thermal: hwmon: Fix critical temperature attribute removal

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@intel.com>
Link: https://patch.msgid.link/2437056.ElGaqSPkdT@rafael.j.wysocki
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/thermal/thermal_hwmon.c b/drivers/thermal/thermal_hwmon.c
index b624892bc6d669cf51e44c32d1a496541e1f7d39..597c33c8a55508e0aac8a288313624a8fc85074d 100644 (file)
--- 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 thermal_zone_device *tz)
                                            &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 thermal_zone_device *tz)
        }
 
        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);