In the Linux kernel, the following vulnerability has been resolved:
clk: mediatek: Do a runtime PM get on controllers during probe
mt8183-mfgcfg has a mutual dependency with genpd during the probing stage, which leads to a deadlock in the following call stack:
CPU0: genpd_lock --> clk_prepare_lock genpd_power_off_work_fn() genpd_lock() generic_pm_domain::power_off() clk_unprepare() clk_prepare_lock()
CPU1: clk_prepare_lock --> genpd_lock clk_register() __clk_core_init() clk_prepare_lock() clk_pm_runtime_get() genpd_lock()
Do a runtime PM get at the probe function to make sure clk_register() won't acquire the genpd lock. Instead of only modifying mt8183-mfgcfg, do this on all mediatek clock controller probings because we don't believe this would cause any regression.
Verified on MT8183 and MT8192 Chromebooks.
Exploitability
AV:LAC:LPR:LUI:NScope
S:UImpact
C:NI:NA:H5.5/CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H