In the Linux kernel, the following vulnerability has been resolved:
clk: qcom: gdsc: tear down per-domain genpds in gdsc_unregister()
gdsc_unregister() removes the OF provider entry and tears down the
parent/subdomain wiring, but never calls pm_genpd_remove() on the
individual generic_pm_domain structures registered by gdsc_init():
void gdsc_unregister(struct gdsc_desc *desc)
{
struct device *dev = desc->dev;
size_t num = desc->num;
gdsc_pm_subdomain_remove(desc, num);
of_genpd_del_provider(dev->of_node);
}
That leaves dangling entries on the global gpd_list. After a provider
unbind/rebind cycle (deferred-probe replay during early boot, real
module unload of a clk driver that owns GDSCs, or an OF-overlay tear-
down) the next gdsc_init() will end up trying to re-register a name
that is still in the list and pm_genpd_init() returns -EEXIST.
While we are here, flip the order so the consumer-facing OF provider
entry is the first thing removed — otherwise a fresh
of_genpd_get_from_provider() call racing with the teardown could
attach to a domain that is mid-removal.
Iterate the scs[] array and pm_genpd_remove() each registered domain
after the subdomain links are torn down. The regulators stay devm-
managed (devm_regulator_get_optional() in gdsc_register()), so the
release happens automatically when the underlying device is unbound;
just the genpd accounting needs to be undone explicitly.
