[SRU][T][PATCH 0/1] CVE-2017-18344 - Incorrect POSIX timer validation

[Tyler Hicks]

https://people.canonical.com/~ubuntu-security/cve/2017/CVE-2017-18344.html

 The timer_create syscall implementation in kernel/time/posix-timers.c in
 the Linux kernel before 4.14.8 doesn't properly validate the
 sigevent->sigev_notify field, which leads to out-of-bounds access in the
 show_timer function (called when /proc/$PID/timers is read). This allows
 userspace applications to read arbitrary kernel memory (on a kernel built
 with CONFIG_POSIX_TIMERS and CONFIG_CHECKPOINT_RESTORE).

This is backported from upstream and tested with a PoC that I wrote. Xenial has
already picked up this fix via linux-stable. Bionic released with this fix.

Tyler