thermal: of: Fix OF node leak in thermal_of_zone_register()

thermal_of_zone_register() calls of_thermal_zone_find() which will
iterate over OF nodes with for_each_available_child_of_node() to find
matching thermal zone node.  When it finds such, it exits the loop and
returns the node.  Prematurely ending for_each_available_child_of_node()
loops requires dropping OF node reference, thus success of
of_thermal_zone_find() means that caller must drop the reference.

Fixes: 3fd6d6e2b4e8 ("thermal/of: Rework the thermal device tree initialization")
Cc: All applicable <stable@vger.kernel.org>
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Chen-Yu Tsai <wenst@chromium.org>
Reviewed-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://patch.msgid.link/20240814195823.437597-2-krzysztof.kozlowski@linaro.org
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

diff --git a/drivers/thermal/thermal_of.c b/drivers/thermal/thermal_of.c
index 30f8d6e70484c8de3b4584d81186de5179d5dcb2..b08a9b64718d3ac7f56a34b8e6f63f29d8e88119 100644 (file)
--- a/drivers/thermal/thermal_of.c
+++ b/drivers/thermal/thermal_of.c
@@ -491,7 +491,8 @@ static struct thermal_zone_device *thermal_of_zone_register(struct device_node *
        trips = thermal_of_trips_init(np, &ntrips);
        if (IS_ERR(trips)) {
                pr_err("Failed to find trip points for %pOFn id=%d\n", sensor, id);
-               return ERR_CAST(trips);
+               ret = PTR_ERR(trips);
+               goto out_of_node_put;
        }
 
        ret = thermal_of_monitor_init(np, &delay, &pdelay);
@@ -519,6 +520,7 @@ static struct thermal_zone_device *thermal_of_zone_register(struct device_node *
                goto out_kfree_trips;
        }
 
+       of_node_put(np);
        kfree(trips);
 
        ret = thermal_zone_device_enable(tz);
@@ -533,6 +535,8 @@ static struct thermal_zone_device *thermal_of_zone_register(struct device_node *
 
 out_kfree_trips:
        kfree(trips);
+out_of_node_put:
+       of_node_put(np);
 
        return ERR_PTR(ret);
 }