Description
A use-after-free issue was found in the way the Linux kernel's KVM hypervisor processed posted interrupts when nested(=1) virtualization is enabled. In nested_get_vmcs12_pages(), in case of an error while processing posted interrupt address, it unmaps the 'pi_desc_page' without resetting 'pi_desc' descriptor address, which is later used in pi_test_and_clear_on(). A guest user/process could use this flaw to crash the host kernel resulting in DoS or potentially gain privileged access to a system. Kernel versions before 4.14.91 and before 4.19.13 are vulnerable.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| The Linux Foundation | kernel: | before 4.14.91, before 4.19.13 | — |
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 | 4.19.13-1 | — |
| Debian 13 | linux | 4.19.13-1 | — |
| Debian 12 | linux | 4.19.13-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 18.04 LTS | linux | 4.15.0-44.47 | USN-3871-1 |
| Ubuntu 18.04 LTS | linux-aws | 4.15.0-1032.34 | USN-3871-3 |
| Ubuntu 18.04 LTS | linux-azure | 4.15.0-1037.39 | USN-3871-5 |
| Ubuntu 18.04 LTS | linux-gcp | 4.15.0-1027.28 | USN-3871-3 |
| Ubuntu 18.04 LTS | linux-gcp-edge | 4.18.0-1006.7~18.04.1 | — |
| Ubuntu 18.04 LTS | linux-hwe | 4.18.0-14.15~18.04.1 | USN-3872-1 |
| Ubuntu 18.04 LTS | linux-kvm | 4.15.0-1029.29 | USN-3871-3 |
| Ubuntu 18.04 LTS | linux-oem | 4.15.0-1033.38 | USN-3871-3 |
| Ubuntu 18.04 LTS | linux-oracle | 4.15.0-1008.10 | — |
| Ubuntu 18.04 LTS | linux-raspi2 | 4.15.0-1031.33 | USN-3871-3 |
| Ubuntu 16.04 LTS | linux-aws-hwe | 4.15.0-1032.34~16.04.1 | USN-3871-4 |
| Ubuntu 16.04 LTS | linux-azure | 4.15.0-1037.39~16.04.1 | USN-3871-5 |
| Ubuntu 16.04 LTS | linux-gcp | 4.15.0-1027.28~16.04.1 | USN-3871-4 |
| Ubuntu 16.04 LTS | linux-hwe | 4.15.0-45.48~16.04.1 | USN-3871-4 |
| Ubuntu 16.04 LTS | linux-oracle | 4.15.0-1008.10~16.04.1 | — |
| Ubuntu 14.04 LTS | linux-azure | 4.15.0-1037.39~14.04.2 | USN-3871-5 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 12 SP3 | kernel-syms +2 | 4.4.180-94.150.1 | SUSE-SU-2021:3935-1 |
| SLES 12 SP3 | kgraft-patch-SLE12-SP3_Update_41 | 1-4.3.1 | SUSE-SU-2021:3935-1 |
| SLES 12 SP2 | kernel-syms +2 | 4.4.121-92.161.1 | SUSE-SU-2021:3929-1 |
Show 4 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 12 SP3 | kernel-syms +2 | 4.4.180-94.150.1 | SUSE-SU-2021:3935-1 |
| SLES for SAP 12 SP3 | kgraft-patch-SLE12-SP3_Update_41 | 1-4.3.1 | SUSE-SU-2021:3935-1 |
| SUSE OpenStack Cloud Crowbar 8 | kernel-syms +2 | 4.4.180-94.150.1 | SUSE-SU-2021:3935-1 |
| SUSE OpenStack Cloud Crowbar 8 | kgraft-patch-SLE12-SP3_Update_41 | 1-4.3.1 | SUSE-SU-2021:3935-1 |
| SUSE OpenStack Cloud 8 | kernel-syms +2 | 4.4.180-94.150.1 | SUSE-SU-2021:3935-1 |
| SUSE OpenStack Cloud 8 | kgraft-patch-SLE12-SP3_Update_41 | 1-4.3.1 | SUSE-SU-2021:3935-1 |
| SUSE HPE Helion OpenStack 8 | kernel-syms +2 | 4.4.180-94.150.1 | SUSE-SU-2021:3935-1 |
| SUSE HPE Helion OpenStack 8 | kgraft-patch-SLE12-SP3_Update_41 | 1-4.3.1 | SUSE-SU-2021:3935-1 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 7 | perf +10 | 4.14.35-1844.2.5.el7uek | ELSA-2019-4541 |
Advisories 8
- USN-3871-1 linux vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- USN-3871-3 linux-aws, linux-gcp, linux-kvm, linux-oem, linux-raspi2 vulnerabilities Ubuntu Security Notices (USN) · Feb 10, 2026
- USN-3871-4 linux-hwe, linux-aws-hwe, linux-gcp vulnerabilities Ubuntu Security Notices (USN) · Feb 10, 2026
- USN-3871-5 linux-azure vulnerabilities Ubuntu Security Notices (USN) · Feb 10, 2026
- USN-3872-1 linux-hwe vulnerabilities Ubuntu Security Notices (USN) · Feb 10, 2026
- SUSE-SU-2021:3929-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2021:3935-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- ELSA-2019-4541 Important: Unbreakable Enterprise kernel security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Feb 12, 2019
References
- https://marc.info/?l=kvm&m=154514994222809&w=2
- USN-3872-1 vendor-advisory
- USN-3878-1 vendor-advisory
- USN-3871-5 vendor-advisory
- USN-3878-2 vendor-advisory
- USN-3871-4 vendor-advisory
- 106254 vdb-entry
- https://lwn.net/Articles/775720/
- USN-3871-1 vendor-advisory
- https://lwn.net/Articles/775721/
- USN-3871-3 vendor-advisory
- https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2018-16882
- https://support.f5.com/csp/article/K80557033