In the Linux kernel before 4.20.8, kvm_ioctl_create_device in virt/kvm/kvm_main.c mishandles reference counting because of a race condition, leading to a use-after-free.
https://www.exploit-db.com/exploits/46388/
https://usn.ubuntu.com/3933-2/
https://usn.ubuntu.com/3933-1/
https://usn.ubuntu.com/3932-2/
https://usn.ubuntu.com/3932-1/
https://usn.ubuntu.com/3931-2/
https://usn.ubuntu.com/3931-1/
https://usn.ubuntu.com/3930-2/
https://usn.ubuntu.com/3930-1/
https://support.f5.com/csp/article/K11186236?utm_source=f5support&%3Butm_medium=RSS
https://support.f5.com/csp/article/K11186236
https://lists.debian.org/debian-lts-announce/2019/05/msg00002.html
https://lists.debian.org/debian-lts-announce/2019/04/msg00004.html
https://lists.debian.org/debian-lts-announce/2019/03/msg00034.html
https://github.com/torvalds/linux/commit/cfa39381173d5f969daf43582c95ad679189cbc9
https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.9.156
https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.20.8
https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.19.21
https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.14.99
https://bugs.chromium.org/p/project-zero/issues/detail?id=1765
https://access.redhat.com/errata/RHSA-2020:0103
https://access.redhat.com/errata/RHSA-2019:3967
https://access.redhat.com/errata/RHSA-2019:2809
https://access.redhat.com/errata/RHSA-2019:0833
https://access.redhat.com/errata/RHSA-2019:0818
https://access.redhat.com/errata/RHBA-2019:0959