Xen · Xen · CVE-2026-42492
Xenstore, to have an up-to-date picture of the entire system, wants to
know of domains appearing and disappearing. To make this more robust, a
new XEN DOMCTL get domain state was introduced. The management of the
bitmap underlying that operation is tied into the binding of the
VIRQ DOM EXC virtual IRQ. Unfortunately an error path there would tear
down the bitmap even in cases when it wasn't set up. Unprivileged domains
can trigger that error path.