ACPICA: Fix error code path in acpi_ds_call_control_method()

CVE-2022-50411

What is CVE-2022-50411?

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

ACPICA: Fix error code path in acpi_ds_call_control_method()

A use-after-free in acpi_ps_parse_aml() after a failing invocaion of acpi_ds_call_control_method() is reported by KASAN [1] and code inspection reveals that next_walk_state pushed to the thread by acpi_ds_create_walk_state() is freed on errors, but it is not popped from the thread beforehand. Thus acpi_ds_get_current_walk_state() called by acpi_ps_parse_aml() subsequently returns it as the new walk state which is incorrect.

To address this, make acpi_ds_call_control_method() call acpi_ds_pop_walk_state() to pop next_walk_state from the thread before returning an error.

References