published October 18, 2026
In the Linux kernel, the following vulnerability has been resolved:
KVM: arm64: Don't WARN on an unknown VM ioctl in protected mode
kvm_pkvm_ioctl_allowed() WARNs when kvm_get_cap_for_kvm_ioctl() doesn't
find the ioctl number in vm_ioctl_caps[], and kvm_arch_vm_ioctl() calls
it for every number the generic code doesn't handle, so
ioctl(vm_fd, 0xdeadbeef) from userspace taints a pKVM host and panics it
under panic_on_warn. The lookup is fed userspace input: return false,
and userspace gets the -EINVAL kvm_arch_vm_ioctl() returns for that
number on a host without pKVM.