In the Linux kernel, the following vulnerability has been resolved:watchdog: cpu5wdt.c: Fix use-after-free bug caused by cpu5wdt_triggerWhen the cpu5wdt module is removing, the origin code uses del_timer() tode-activate the timer. If the timer handler is running, del_timer() couldnot stop it and will return directly. If the port region is released byrelease_region() and then the timer handler cpu5wdt_trigger() calls outb()to write into the region that is released, the use-after-free bug willhappen.Change del_timer() to timer_shutdown_sync() in order that the timer handlercould be finished before the port region is released.
