CVE-2022-49493: Use After Free

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

ASoC: rt5645: Fix errorenous cleanup order

There is a logic error when removing rt5645 device as the function rt5645_i2c_remove() first cancel the &rt5645->jack_detect_work and delete the &rt5645->btn_check_timer latter. However, since the timer handler rt5645_btn_check_callback() will re-queue the jack_detect_work, this cleanup order is buggy.

That is, once the del_timer_sync in rt5645_i2c_remove is concurrently run with the rt5645_btn_check_callback, the canceled jack_detect_work will be rescheduled again, leading to possible use-after-free.

This patch fix the issue by placing the del_timer_sync function before the cancel_delayed_work_sync.