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.
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 | 4.18.10-2 | — |
| Debian 13 | linux | 4.18.10-2 | — |
| Debian 12 | linux | 4.18.10-2 | — |
| Debian 9 | linux | 4.9.110-3+deb9u6 | DSA-4313-1 |
| Debian 8 | linux-4.9 | 4.9.144-3.1~deb8u1 | DLA-1715-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 24.04 LTS | linux-gcp-6.11 +4 | No fix yet | — |
| Ubuntu 22.04 LTS | linux-riscv +2 | No fix yet | — |
| Ubuntu 20.04 LTS | linux-gke +3 | No fix yet | — |
| Ubuntu 18.04 LTS | linux | 4.15.0-47.50 | USN-3931-1 |
| Ubuntu 18.04 LTS | linux-aws | 4.15.0-1035.37 | USN-3931-1 |
| Ubuntu 18.04 LTS | linux-gcp | 4.15.0-1029.31 | USN-3931-1 |
| Ubuntu 18.04 LTS | linux-kvm | 4.15.0-1031.31 | USN-3931-1 |
| Ubuntu 18.04 LTS | linux-oem | 4.15.0-1035.40 | USN-3931-1 |
| Ubuntu 18.04 LTS | linux-oracle | 4.15.0-1010.12 | USN-3931-1 |
| Ubuntu 18.04 LTS | linux-raspi2 | 4.15.0-1033.35 | USN-3931-1 |
| Ubuntu 16.04 LTS | linux | 4.4.0-139.165 | USN-3821-1 |
| Ubuntu 16.04 LTS | linux-aws | 4.4.0-1072.82 | USN-3821-1 |
| Ubuntu 16.04 LTS | linux-aws-hwe | 4.15.0-1035.37~16.04.1 | USN-3931-2 |
| Ubuntu 16.04 LTS | linux-azure | 4.15.0-1041.45 | USN-3931-2 |
| Ubuntu 16.04 LTS | linux-gcp | 4.15.0-1029.31~16.04.1 | USN-3931-2 |
| Ubuntu 16.04 LTS | linux-hwe | 4.15.0-47.50~16.04.1 | USN-3931-2 |
| Ubuntu 16.04 LTS | linux-kvm | 4.4.0-1037.43 | USN-3821-1 |
| Ubuntu 16.04 LTS | linux-oracle | 4.15.0-1010.12~16.04.1 | USN-3931-2 |
| Ubuntu 16.04 LTS | linux-raspi2 | 4.4.0-1100.108 | USN-3821-1 |
| Ubuntu 16.04 LTS | linux-snapdragon | 4.4.0-1104.109 | USN-3821-1 |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 14.04 LTS | linux-aws | 4.4.0-1034.37 | USN-3821-2 |
| Ubuntu 14.04 LTS | linux-azure | 4.15.0-1041.45~14.04.1 | USN-3931-2 |
| Ubuntu 14.04 LTS | linux-lts-xenial | 4.4.0-139.165~14.04.1 | USN-3821-2 |
| Ubuntu Pro FIPS-updates 16.04 LTS | linux-fips | 4.4.0-1008.10 | — |
| Ubuntu Pro 14.04 LTS | linux | No fix yet | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 7 | perf +14 | 4.14.0-115.2.2.el7a | RHSA-2018:3656 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2 | perf +8 | 4.14.77-80.57.amzn2 | ALAS2-2018-1100 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 7 | perf +10 | 4.14.35-1818.4.5.el7uek | ELSA-2018-4270 |
Advisories 9
- USN-3931-1 linux, linux-aws, linux-gcp, linux-kvm, linux-oem, linux-oracle, linux-raspi2 vulnerabilities Ubuntu Security Notices (USN) · Sep 7, 2026
- USN-3931-2 linux-hwe, linux-aws-hwe, linux-azure, linux-gcp, linux-oracle vulnerabilities Ubuntu Security Notices (USN) · Sep 7, 2026
- RHSA-2018:3656 Red Hat Security Advisory: kernel-alt security and bug fix update Red Hat Security Advisories (RHSA) · Jun 29, 2026
- USN-3821-2 linux-lts-xenial, linux-aws vulnerabilities Ubuntu Security Notices (USN) · Jun 3, 2026
- USN-3821-1 linux, linux-aws, linux-kvm, linux-raspi2, linux-snapdragon vulnerabilities Ubuntu Security Notices (USN) · Jun 3, 2026
- DSA-4313-1 linux - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-1715-1 linux-4.9 - security update Debian Security (DSA / DLA) · Mar 9, 2026
- ALAS2-2018-1100 Moderate: kernel security update (Amazon Linux 2) Amazon Linux Security Center (ALAS) · Apr 8, 2025
- ELSA-2018-4270 Important: Unbreakable Enterprise kernel security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Nov 8, 2018
References
- USN-3821-1 vendor-advisory
- https://github.com/torvalds/linux/commit/2a3f93459d689d990b3ecfbe782fec89b97d3279
- https://www.openwall.com/lists/oss-security/2018/10/02/2
- https://cdn.kernel.org/pub/linux/kernel/v4.x/ChangeLog-4.18.12
- RHSA-2018:3656 vendor-advisory
- https://github.com/torvalds/linux/commit/d26c25a9d19b5976b319af528886f89cf455692d
- 105550 vdb-entry
- USN-3821-2 vendor-advisory
- http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=2a3f93459d689d990b3ecfbe782fec89b97d3279
- http://git.kernel.org/cgit/linux/kernel/git/torvalds/linux.git/commit/?id=d26c25a9d19b5976b319af528886f89cf455692d
- DSA-4313 vendor-advisory
- USN-3931-1 vendor-advisory
- USN-3931-2 vendor-advisory