The vcpu_scan_ioapic function in arch/x86/kvm/x86.c in the Linux kernel through 4.19.2 allows local users to cause a denial of service (NULL pointer dereference and BUG) via crafted system calls that reach a situation where ioapic is uninitialized.Referenceshttps://usn.ubuntu.com/3879-2/https://usn.ubuntu.com/3872-1/https://usn.ubuntu.com/3878-1/https://usn.ubuntu.com/3879-1/https://usn.ubuntu.com/3871-5/https://usn.ubuntu.com/3878-2/https://usn.ubuntu.com/3871-4/http://www.securityfocus.com/bid/105987https://usn.ubuntu.com/3871-1/https://usn.ubuntu.com/3871-3/https://lists.debian.org/debian-lts-announce/2019/03/msg00017.htmlhttps://lkml.org/lkml/2018/11/20/580
