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…

Overview

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.

Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.