An issue was discovered in Xen through 4.12.x allowing 32-bit Arm guest OS users to cause a DoS (out-of-bounds access) because certain bit iteration is mishandled. In a number of places bitmaps are being used by the hypervisor to track certain state. Iteration over all bits involves functions which may misbehave in certain corner cases. 64-bit Arm systems are not vulnerable.
Created xen tracking bugs for this issue:
Affects: fedora-all [bug 1801084]