In the Linux kernel, the following vulnerability has been resolved:
KVM: arm64: vgic-v2: Check for non-NULL vCPU in vgicv2parse_attr()
vgicv2parseattr() is responsible for finding the vCPU that matches the user-provided CPUID, which (of course) may not be valid. If the ID is invalid, kvmgetvcpuby_id() returns NULL, which isn't handled gracefully.
Similar to the GICv3 uaccess flow, check that kvmgetvcpubyid() actually returns something and fail the ioctl if not.