In the Linux kernel, the following vulnerability has been resolved: irqchip/gic-v4: Don't allow a VMOVP on a dying VPE Kunkun Jiang reported that there is a small window of opportunity for userspace to force a change of affinity for a VPE while the VPE has already been unmapped, but the corresponding doorbell interrupt still visible in /proc/irq/. Plug the race by checking the value of vmappcount, which tracks whether the VPE is mapped ot not, and returning an error in this case. This involves making vmappcount common to both GICv4.1 and its v4.0 ancestor.