The sock_setsockopt function in net/core/sock.c in the Linux kernel before 3.5.7 does not ensure that a keepalive action is associated with a stream socket, which allows local users to cause a denial of service (system crash) by leveraging the ability to create a raw socket.
http://lists.opensuse.org/opensuse-security-announce/2015-04/msg00000.html
http://lists.opensuse.org/opensuse-security-announce/2015-04/msg00020.html
http://marc.info/?l=bugtraq&m=142722450701342&w=2
http://marc.info/?l=bugtraq&m=142722544401658&w=2
https://bugzilla.redhat.com/show_bug.cgi?id=1141742
https://github.com/torvalds/linux/commit/3e10986d1d698140747fcfc2761ec9cb64c1d582