Description
The msr_mtrr_valid function in arch/x86/kvm/mtrr.c in the Linux kernel before 4.6.1 supports MSR 0x2f8, which allows guest OS users to read or write to the kvm_arch_vcpu data structure, and consequently obtain sensitive information or cause a denial of service (system crash), via a crafted ioctl call.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | linux | 4.5.4-1 | — |
| Debian 13 | linux | 4.5.4-1 | — |
| Debian 12 | linux | 4.5.4-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 16.04 LTS | linux | 4.4.0-22.40 | USN-2979-1 |
| Ubuntu 14.04 LTS | linux-lts-wily | 4.2.0-36.42~14.04.1 | USN-2978-2 |
| Ubuntu 14.04 LTS | linux-lts-xenial | 4.4.0-22.40~14.04.1 | USN-2979-2 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | kernel-source | 4.8.13-1.1 | openSUSE-SU-2024:10128-1 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 7 | dtrace-modules-3.8.13-118.28.1.el6uek +1 | 0.4.5-3.el6 | ELSA-2019-4316, ELSA-2018-4300 |
| Oracle Linux 7 | dtrace-modules-3.8.13-118.28.1.el7uek +1 | 0.4.5-3.el7 | ELSA-2019-4316, ELSA-2018-4300 |
| Oracle Linux 7 | kernel-uek +5 | 3.8.13-118.28.1.el7uek | ELSA-2019-4316, ELSA-2018-4300 |
Advisories 6
- USN-2979-1 linux vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- USN-2978-2 linux-lts-wily vulnerabilities Ubuntu Security Notices (USN) · Feb 10, 2026
- USN-2979-2 linux-lts-xenial vulnerabilities Ubuntu Security Notices (USN) · Feb 10, 2026
- openSUSE-SU-2024:10128-1 kernel-debug-4.8.13-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026
- ELSA-2019-4316 Important: Unbreakable Enterprise kernel security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Jan 4, 2019
- ELSA-2018-4300 Important: Unbreakable Enterprise kernel security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Dec 6, 2018
References
- http://www.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.6.1
- https://github.com/torvalds/linux/commit/9842df62004f366b9fed2423e24df10542ee0dc5
- [oss-security] 20160516 CVE-2016-3713 Linux kernel: kvm: OOB r/w access issue with MSR 0x2F8 mailing-list
- http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=9842df62004f366b9fed2423e24df10542ee0dc5
- https://bugzilla.redhat.com/show_bug.cgi?id=1332139