Xen 3.2.x through 4.6.x does not limit the number of printk console messages when logging certain pmu and profiling hypercalls, which allows local guests to cause a denial of service via a sequence of crafted (1) HYPERCALL_xenoprof_op hypercalls, which are not properly handled in the do_xenoprof_op function in common/xenoprof.c, or (2) HYPERVISOR_xenpmu_op hypercalls, which are not properly handled in the do_xenpmu_op function in arch/x86/cpu/vpmu.c.
https://security.gentoo.org/glsa/201604-03
http://xenbits.xen.org/xsa/advisory-152.html
http://www.securitytracker.com/id/1034035
http://www.securityfocus.com/bid/77363
http://www.debian.org/security/2015/dsa-3414
http://support.citrix.com/article/CTX202404
http://lists.opensuse.org/opensuse-updates/2015-11/msg00063.html
http://lists.fedoraproject.org/pipermail/package-announce/2015-November/171249.html
http://lists.fedoraproject.org/pipermail/package-announce/2015-November/171185.html
http://lists.fedoraproject.org/pipermail/package-announce/2015-November/171082.html