The ndisc_router_discovery function in net/ipv6/ndisc.c in the Neighbor Discovery (ND) protocol implementation in the IPv6 stack in the Linux kernel before 3.19.6 allows remote attackers to reconfigure a hop-limit setting via a small hop_limit value in a Router Advertisement (RA) message.
https://github.com/torvalds/linux/commit/6fd99094de2b83d1d4c8457f2c83483b2828e75a
https://bugzilla.redhat.com/show_bug.cgi?id=1203712
http://www.securitytracker.com/id/1032417
http://www.securityfocus.com/bid/74315
http://www.oracle.com/technetwork/topics/security/linuxbulletinjan2016-2867209.html
http://www.oracle.com/technetwork/topics/security/bulletinoct2015-2511968.html
http://www.debian.org/security/2015/dsa-3237
http://rhn.redhat.com/errata/RHSA-2015-1564.html
http://rhn.redhat.com/errata/RHSA-2015-1534.html
http://rhn.redhat.com/errata/RHSA-2015-1221.html
http://lists.opensuse.org/opensuse-security-announce/2015-09/msg00004.html
http://lists.opensuse.org/opensuse-security-announce/2015-08/msg00011.html
http://lists.opensuse.org/opensuse-security-announce/2015-07/msg00023.html
http://lists.fedoraproject.org/pipermail/package-announce/2015-April/155908.html
http://lists.fedoraproject.org/pipermail/package-announce/2015-April/155854.html
http://lists.fedoraproject.org/pipermail/package-announce/2015-April/155804.html