In the Linux kernel, the following vulnerability has been resolved:
regulator: core: use system_freezable_wq for init complete work
schedule_delayed_work() uses system_wq, which is non-freezable, allowing
regulator_init_complete_work to run concurrently with system suspend. This
work fires ~30s after boot to disable unused regulators via I2C. When it
races with PM suspend, the I2C adapter may already be suspended, triggering
a -ESHUTDOWN warning in __i2c_transfer():
WARNING: … at __i2c_transfer+0x36c/0x3c8
Call trace:
__i2c_transfer
i2c_transfer
regmap_i2c_write
_regmap_update_bits
regulator_disable_regmap
_regulator_do_disable
regulator_late_cleanup
regulator_init_complete_work_function
process_one_work
Switch to system_freezable_wq so the work is frozen before any device
is suspended, eliminating the race.
