Description
The __switch_to function in arch/x86/kernel/process_64.c in the Linux kernel does not properly context-switch IOPL on 64-bit PV Xen guests, which allows local guest OS users to gain privileges, cause a denial of service (guest OS crash), or obtain sensitive information by leveraging I/O port access.
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 | 4.5.1-1 | — |
| Debian 13 | linux | 4.5.1-1 | — |
| Debian 12 | linux | 4.5.1-1 | — |
| Debian 8 | linux | 3.16.7-ckt25-2+deb8u2 | DSA-3607-1 |
| Debian 7 | linux | 3.2.81-1 | DLA-516-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 24.04 LTS | linux-riscv +6 | No fix yet | — |
| Ubuntu 22.04 LTS | linux-riscv +2 | No fix yet | — |
| Ubuntu 20.04 LTS | linux-gke +4 | No fix yet | — |
| Ubuntu 18.04 LTS | linux-gcp +3 | No fix yet | — |
| Ubuntu 16.04 LTS | linux | 4.4.0-22.39 | USN-2965-1 |
| Ubuntu 16.04 LTS | linux-raspi2 | 4.4.0-1010.12 | USN-2965-3 |
| Ubuntu 16.04 LTS | linux-snapdragon | 4.4.0-1013.14 | USN-2965-4 |
Show 2 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 14.04 LTS | linux | 3.13.0-86.130 | USN-2968-1 |
| Ubuntu 14.04 LTS | linux-lts-utopic | 3.16.0-71.91~14.04.1 | USN-2969-1 |
| Ubuntu 14.04 LTS | linux-lts-vivid | 3.19.0-59.65~14.04.1 | USN-2970-1 |
| Ubuntu 14.04 LTS | linux-lts-wily | 4.2.0-36.41~14.04.1 | USN-2971-2 |
| Ubuntu 14.04 LTS | linux-lts-xenial | 4.4.0-22.39~14.04.1 | USN-2965-2 |
| Ubuntu Pro 20.04 LTS | linux-azure-fde-5.15 | No fix yet | — |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 7 | dtrace-modules-3.8.13-118.15.2.el6uek | 0.4.5-3.el6 | ELSA-2016-3656 |
| Oracle Linux 7 | dtrace-modules-3.8.13-118.15.2.el7uek | 0.4.5-3.el7 | ELSA-2016-3656 |
| Oracle Linux 7 | dtrace-modules-4.1.12-32.2.3.el6uek | 0.5.1-1.el6 | ELSA-2016-3529 |
| Oracle Linux 7 | dtrace-modules-4.1.12-32.2.3.el7uek | 0.5.1-1.el7 | ELSA-2016-3529 |
| Oracle Linux 7 | kernel-uek +5 | 3.8.13-118.15.2.el7uek | ELSA-2016-3656, ELSA-2016-3529 |
Advisories 12
- USN-2965-1 linux vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- USN-2968-1 linux vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- DLA-516-1 linux - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DSA-3607-1 linux - security update Debian Security (DSA / DLA) · Mar 9, 2026
- USN-2969-1 linux-lts-utopic vulnerabilities Ubuntu Security Notices (USN) · Feb 10, 2026
- USN-2970-1 linux-lts-vivid vulnerabilities Ubuntu Security Notices (USN) · Feb 10, 2026
- USN-2971-2 linux-lts-wily vulnerabilities Ubuntu Security Notices (USN) · Feb 10, 2026
- USN-2965-2 linux-lts-xenial vulnerabilities Ubuntu Security Notices (USN) · Feb 10, 2026
- USN-2965-3 linux-raspi2 vulnerabilities Ubuntu Security Notices (USN) · Feb 10, 2026
- USN-2965-4 linux-snapdragon vulnerability Ubuntu Security Notices (USN) · Feb 10, 2026
- ELSA-2016-3656 Important: Unbreakable Enterprise kernel security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Dec 21, 2016
- ELSA-2016-3529 Important: kernel-uek security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Mar 28, 2016
References
- USN-2971-2 vendor-advisory
- http://xenbits.xen.org/xsa/advisory-171.html
- USN-2970-1 vendor-advisory
- http://www.oracle.com/technetwork/topics/security/linuxbulletinapr2016-2952096.html
- USN-2969-1 vendor-advisory
- USN-2968-1 vendor-advisory
- USN-2971-3 vendor-advisory
- USN-2997-1 vendor-advisory
- DSA-3607 vendor-advisory
- USN-2971-1 vendor-advisory
- USN-2996-1 vendor-advisory
- USN-2968-2 vendor-advisory
- 1035308 vdb-entry
- 84594 vdb-entry