The prepare_vmcs02 function in arch/x86/kvm/vmx.c in the Linux kernel through 4.13.3 does not ensure that the “CR8-load exiting” and “CR8-store exiting” L0 vmcs02 controls exist in cases where L1 omits the “use TPR shadow” vmcs12 control, which allows KVM L2 guest OS users to obtain read and write access to the hardware CR8 register.
[
{
"product": "Linux kernel through 4.13.3",
"vendor": "n/a",
"versions": [
{
"status": "affected",
"version": "Linux kernel through 4.13.3"
}
]
}
]
git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=51aa68e7d57e3217192d88ce90fd5b8ef29ec94f
www.debian.org/security/2017/dsa-3981
www.securityfocus.com/bid/100856
access.redhat.com/errata/RHSA-2018:0676
access.redhat.com/errata/RHSA-2018:1062
access.redhat.com/errata/RHSA-2019:1946
bugzilla.redhat.com/show_bug.cgi?id=1491224
github.com/torvalds/linux/commit/51aa68e7d57e3217192d88ce90fd5b8ef29ec94f
usn.ubuntu.com/3698-1/
usn.ubuntu.com/3698-2/
www.spinics.net/lists/kvm/msg155414.html