VOMIT (go/vomit) has received an external vulnerability report for the Linux kernel.
Advisory: CVE-2018-18021
Details: http://vomit.googleplex.com/advisory?id=CVE/CVE-2018-18021
CVSS severity score: 3.6/10.0
Description:
arch/arm64/kvm/guest.c in KVM in the Linux kernel before 4.18.12 on the arm64 platform mishandles the KVM_SET_ON_REG ioctl. This is exploitable by attackers who can create virtual machines. An attacker can arbitrarily redirect the hypervisor flow of control (with full register control). An attacker can also cause a denial of service (hypervisor panic) via an illegal exception return. This occurs because of insufficient restrictions on userspace access to the core register file, and because PSTATE.M validation does not prevent unintended execution modes.
This bug was filed by http://go/vomit
Please contact us at vomit-team@google.com if you need any assistance.
Comment 1 by groeck@chromium.org
, Nov 28Labels: Security_Severity-Low Security_Impact-None Pri-3
Owner: groeck@chromium.org
Status: WontFix (was: Untriaged)
Upstream commits 2a3f93459d ("arm64: KVM: Sanitize PSTATE.M when being set from userspace") and d26c25a9d19b ("arm64: KVM: Tighten guest core register access from userspace"). chromeos-4.19 is not affected per commit message. Fixed in chromeos-4.4 and chromeos-4.14 with stable release merges. KVM is not enabled in older chromeos kernels. Marking as WontFix.