The vgic_v2_to_sgi function in arch/arm/vgic-v2.c in Xen 4.5.x, when running on ARM hardware with general interrupt controller (GIC) version 2, allows local guest users to cause a denial of service (host crash) by writing an invalid value to the GICD.SGIR register.
Improper Input Validation The product receives input or data, but it does
not validate or incorrectly validates that the input has the
properties that are required to process the data safely and
correctly.