CVE-2023-52629

In the Linux kernel, the following vulnerability has been resolved: sh:
push-switch: Reorder cleanup operations to avoid use-after-free bug The
original code puts flush_work() before timer_shutdown_sync() in
switch_drv_remove(). Although we use flush_work() to stop the worker, it
could be rescheduled in switch_timer(). As a result, a use-after-free bug
can occur. The details are shown below: (cpu 0) | (cpu 1)
switch_drv_remove() | flush_work() | … | switch_timer // timer |
schedule_work(&psw->work) timer_shutdown_sync() | … | switch_work_handler
// worker kfree(psw) // free | | psw->state = 0 // use This patch puts
timer_shutdown_sync() before flush_work() to mitigate the bugs. As a
result, the worker and timer will be stopped safely before the deallocate
operations.