In the Linux kernel, the following vulnerability has been resolved: KVM: arm64: vgic: Take a refcount on IRQs referenced by last_lr_irq Referencing the last interrupt inserted in an LR is rather fragile, as this interrupt can vanish if a concurrently unmapped LPI. Solve this by bumping up the refcount on the interrupt when populating last_lr_irq, and drop it at vgic_prune_ap_list() time, when LPIs are being reclaimed.