CVE-2026-98470: KVM: arm64: Don't WARN on an unknown VM ioctl in protected mode

In the Linux kernel, the following vulnerability has been resolved:

KVM: arm64: Don't WARN on an unknown VM ioctl in protected mode

kvmpkvmioctlallowed() WARNs when kvmgetcapforkvmioctl() doesn't find the ioctl number in vmioctlcaps[], and kvmarchvmioctl() calls it for every number the generic code doesn't handle, so ioctl(vmfd, 0xdeadbeef) from userspace taints a pKVM host and panics it under paniconwarn. The lookup is fed userspace input: return false, and userspace gets the -EINVAL kvmarchvmioctl() returns for that number on a host without pKVM.