In the Linux kernel, the following vulnerability has been resolved:
ASoC: cs35l34: drain threaded IRQ before runtime suspend
cs35l34_runtime_suspend() currently switches the codec into
regcache_cache_only(true), asserts reset low, and powers the device off
without first quiescing the threaded IRQ registered by
devm_request_threaded_irq(). That leaves a window where
cs35l34_irq_thread() can still run after suspend has removed live
hardware access.
A running system can reach this during runtime PM while the driver still
has critical fault IRQs unmasked. If the threaded handler runs in that
window, it reads volatile INT_STATUS_1..4 after cache_only has been
enabled, ignores the regmap_read() failures, and can still execute the
PROT_RELEASE_CTL release sequence or the BST fault power-down writes.
Use disable_irq() before entering cache_only/reset-low/power-off so any
in-flight threaded handler is drained and no new IRQ thread can run
while the device is suspended. Re-enable the IRQ only after
runtime_resume() has restored live register access with regcache_sync().
Since probe only logs request_threaded_irq() failures and keeps going,
track whether the IRQ was actually installed before disabling or
re-enabling it.
