pmdomain: core: Reset genpd->states to avoid freeing invalid data

If genpd_alloc_data() allocates data for the default power-states for the
genpd, let's make sure to also reset the pointer in the error path. This
makes sure a genpd provider driver doesn't end up trying to free the data
again, but using an invalid pointer.

Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>
Reviewed-by: Dhruva Gole <d-gole@ti.com>
Link: https://lore.kernel.org/r/20250402120613.1116711-1-ulf.hansson@linaro.org

Author: Ulf Hansson

drivers/pmdomain/core.c

@@ -2287,8 +2287,10 @@ static int genpd_alloc_data(struct generic_pm_domain *genpd)
 	return 0;
 put:
 	put_device(&genpd->dev);
-	if (genpd->free_states == genpd_free_default_power_state)
+	if (genpd->free_states == genpd_free_default_power_state) {
 		kfree(genpd->states);
+		genpd->states = NULL;
+	}
 free:
 	if (genpd_is_cpu_domain(genpd))
 		free_cpumask_var(genpd->cpus);