Race condition in the relinquish_memory function in arch/arm/domain.c in Xen 4.6.x and earlier allows local domains with partial management control to cause a denial of service (host crash) via vectors involving the destruction of a domain and using XENMEM_decrease_reservation to reduce the memory of the domain.
Debian Linux Security Advisory 3414-1 - Multiple security issues have been found in the Xen virtualisation solution, which may result in denial of service or information disclosure.