From 8e563d8db50f303171aceb79eec0807e7ba06951 Mon Sep 17 00:00:00 2001 From: "Rafael J. Wysocki" Date: Thu, 30 Apr 2026 14:57:32 -0400 Subject: [PATCH] thermal: core: Fix thermal zone governor cleanup issues [ Upstream commit 41ff66baf81c6541f4f985dd7eac4494d03d9440 ] If thermal_zone_device_register_with_trips() fails after adding a thermal governor to the thermal zone being registered, the governor is not removed from it as appropriate which may lead to a memory leak. In turn, thermal_zone_device_unregister() calls thermal_set_governor() without acquiring the thermal zone lock beforehand which may race with a governor update via sysfs and may lead to a use-after-free in that case. Address these issues by adding two thermal_set_governor() calls, one to thermal_release() to remove the governor from the given thermal zone, and one to the thermal zone registration error path to cover failures preceding the thermal zone device registration. Fixes: e33df1d2f3a0 ("thermal: let governors have private data for each thermal zone") Cc: All applicable Signed-off-by: Rafael J. Wysocki Link: https://patch.msgid.link/5092923.31r3eYUQgx@rafael.j.wysocki [ adapted context for missing mutex_destroy/complete ] Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- drivers/thermal/thermal_core.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c index bb3a4b672036..acea77b7c8d9 100644 --- a/drivers/thermal/thermal_core.c +++ b/drivers/thermal/thermal_core.c @@ -778,6 +778,7 @@ static void thermal_release(struct device *dev) sizeof("thermal_zone") - 1)) { tz = to_thermal_zone(dev); thermal_zone_destroy_device_groups(tz); + thermal_set_governor(tz, NULL); kfree(tz); } else if (!strncmp(dev_name(dev), "cooling_device", sizeof("cooling_device") - 1)) { @@ -1260,8 +1261,10 @@ thermal_zone_device_register(const char *type, int num_trips, int mask, /* sys I/F */ /* Add nodes that are always present via .groups */ result = thermal_zone_create_device_groups(tz, mask); - if (result) + if (result) { + thermal_set_governor(tz, NULL); goto remove_id; + } /* A new thermal zone needs to be updated anyway. */ atomic_set(&tz->need_update, 1); @@ -1385,8 +1388,6 @@ void thermal_zone_device_unregister(struct thermal_zone_device *tz) cancel_delayed_work_sync(&tz->poll_queue); - thermal_set_governor(tz, NULL); - thermal_remove_hwmon_sysfs(tz); ida_simple_remove(&thermal_tz_ida, tz->id); ida_destroy(&tz->ida);