A race condition was found in util-linux before 2.32.1 in the way su handled the management of child processes. A local authenticated attacker could use this flaw to kill other processes with root privileges under specific conditions.
https://www.debian.org/security/2017/dsa-3793
https://security.gentoo.org/glsa/201706-02
https://github.com/karelzak/util-linux/commit/dffab154d29a288aa171ff50263ecc8f2e14a891
https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2017-2616
https://access.redhat.com/errata/RHSA-2017:0907
http://www.securitytracker.com/id/1038271