kernel: Integer overflow in the alarm_timer_nsleep function

A flaw was found in the alarmtimernsleep function in kernel/time/alarmtimer.c in the Linux kernel. The ktimeaddsafe function is not used and an integer overflow can happen causing an alarm not to fire or possibly a denial-of-service if using a large relative timeout...

UBUNTU-CVE-2018-13053

The alarmtimernsleep function in kernel/time/alarmtimer.c in the Linux kernel through 4.17.3 has an integer overflow via a large relative timeout because ktimeaddsafe is not used...