AZL-92718

In the Linux kernel, the following vulnerability has been resolved:

hwmon: (lm90) Stop work before releasing hwmon device

Sashiko reports:

In lm90probe(), the devm action to cancel the alertwork and reportwork (lm90restoreconf) is registered in lm90initclient() before devmhwmondeviceregisterwithinfo() is called.

Because devm executes cleanup actions in reverse order during module unbind or probe failure, the hwmon device is unregistered and freed first.

If lm90alertwork() or lm90reportalarms() runs in the window between the hwmon device being freed and the delayed works being cancelled, lm90updatealarms() will dereference the freed data->hwmon_dev here.

Fix the problem by canceling the workers separately after registering the hwmon device and before registering the interrupt handler. This ensures that the workers are canceled after interrupts are disabled and before the hwmon device is released. Add "shutdown" flag to indicate that device shutdown is in progress to prevent workers from being re-armed.