Description
In the Linux kernel, the following vulnerability has been resolved:
ipv6: fix a BUG in rt6_get_pcpu_route() under PREEMPT_RT
On PREEMPT_RT kernels, after rt6_get_pcpu_route() returns NULL, the
current task can be preempted. Another task running on the same CPU
may then execute rt6_make_pcpu_route() and successfully install a
pcpu_rt entry. When the first task resumes execution, its cmpxchg()
in rt6_make_pcpu_route() will fail because rt6i_pcpu is no longer
NULL, triggering the BUG_ON(prev). It's easy to reproduce it by adding
mdelay() after rt6_get_pcpu_route().
Using preempt_disable/enable is not appropriate here because
ip6_rt_pcpu_alloc() may sleep.
Fix this by handling the cmpxchg() failure gracefully on PREEMPT_RT:
free our allocation and return the existing pcpu_rt installed by
another task. The BUG_ON is replaced by WARN_ON_ONCE for non-PREEMPT_RT
kernels where such races should not occur.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Linux | Linux | 6.12 | 6.12.64 |
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 | 6.18.5-1 | — |
| Debian 13 | linux | 6.12.69-1 | DSA-6126-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Nvidia-BlueField 24.04 LTS | linux-bluefield | No fix yet | — |
| Ubuntu Nvidia-BlueField 22.04 LTS | linux-bluefield | No fix yet | — |
| Ubuntu 25.10 | linux | 6.17.0-22.22 | USN-8177-1 |
| Ubuntu 25.10 | linux-realtime | 6.17.0-1010.11 | USN-8177-1 |
| Ubuntu 24.04 LTS | linux +26 | No fix yet | — |
| Ubuntu 24.04 LTS | linux-nvidia-6.17 | 6.17.0-1018.18 | — |
| Ubuntu 24.04 LTS | linux-nvidia-tegra | 6.8.0-1022.22 | USN-8265-1 |
| Ubuntu 22.04 LTS | linux +57 | No fix yet | — |
| Ubuntu 22.04 LTS | linux-nvidia-tegra | 5.15.0-1057.57 | USN-8187-1 |
| Ubuntu 22.04 LTS | linux-nvidia-tegra-igx | 5.15.0-1046.46 | USN-8187-1 |
Show 9 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | linux-gke +28 | No fix yet | — |
| Ubuntu 18.04 LTS | linux-gcp +14 | No fix yet | — |
| Ubuntu 16.04 LTS | linux-hwe-edge | No fix yet | — |
| Ubuntu Pro Realtime 24.04 LTS | linux-raspi-realtime | 6.8.0-2042.43 | USN-8204-1 |
| Ubuntu Pro Realtime 24.04 LTS | linux-realtime | 6.8.1-1047.48 | USN-8184-1 |
| Ubuntu Pro Realtime 24.04 LTS | linux-realtime-6.14 | No fix yet | — |
| Ubuntu Pro Realtime 24.04 LTS | linux-realtime-6.17 | 6.17.0-1010.11~24.04.1 | USN-8177-2 |
| Ubuntu Pro Realtime 22.04 LTS | linux-intel-iot-realtime | 5.15.0-1097.99 | USN-8186-1 |
| Ubuntu Pro Realtime 22.04 LTS | linux-realtime | 5.15.0-1104.113 | USN-8186-1 |
| Ubuntu Pro Realtime 22.04 LTS | linux-realtime-6.8 | 6.8.1-1047.48~22.04.1 | USN-8184-1 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-fips +3 | No fix yet | — |
| Ubuntu Pro FIPS-updates 22.04 LTS | linux-fips +3 | No fix yet | — |
| Ubuntu Pro FIPS-preview 22.04 LTS | linux-fips +3 | No fix yet | — |
| Ubuntu Pro 20.04 LTS | linux-aws-5.15 +9 | No fix yet | — |
| Ubuntu Pro 20.04 LTS | linux-nvidia-tegra-5.15 | 5.15.0-1057.57~20.04.1 | USN-8162-1 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | kernel-64kb +6 | 6.4.0-150700.53.31.1 | SUSE-SU-2026:0447-1 |
| SLES 15 SP7 | kernel-azure +2 | 6.4.0-150700.20.27.1 | SUSE-SU-2026:0472-1 |
| SLES 15 SP7 | kernel-default-base | 6.4.0-150700.53.31.1.150700.17.21.1 | SUSE-SU-2026:0447-1 |
Show 5 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | kernel-64kb +8 | 6.12.0-160000.26.1 | SUSE-SU-2026:20599-1 |
| SLES for SAP 16.0 | kernel-default-base | 6.12.0-160000.26.1.160000.2.7 | SUSE-SU-2026:20599-1 |
| SLES 16.0 | kernel-64kb +8 | 6.12.0-160000.26.1 | SUSE-SU-2026:20615-1, SUSE-SU-2026:20599-1 |
| SLES 16.0 | kernel-default-base | 6.12.0-160000.26.1.160000.2.7 | SUSE-SU-2026:20599-1 |
| SLE Micro 6.2 | kernel-default-base | 6.12.0-160000.26.1.160000.2.7 | SUSE-SU-2026:20555-1 |
| SLE Micro 6.2 | kernel-rt +5 | 6.12.0-160000.26.1 | SUSE-SU-2026:20570-1, SUSE-SU-2026:20555-1 |
| SLE Live Patching 15 SP7 | kernel-default | 6.4.0-150700.53.31.1 | SUSE-SU-2026:0447-1 |
| SLE Live Patching 15 SP7 | kernel-livepatch-SLE15-SP7-RT_Update_9 | 1-150700.1.3.2 | SUSE-SU-2026:0587-1 |
| SLE Live Patching 15 SP7 | kernel-livepatch-SLE15-SP7_Update_9 | 1-150700.15.3.1 | SUSE-SU-2026:0447-1 |
| SUSE Real Time Module 15 SP7 | kernel-rt | 6.4.0-150700.7.31.2 | SUSE-SU-2026:0587-1 |
| SUSE Real Time Module 15 SP7 | kernel-syms-rt +1 | 6.4.0-150700.7.31.1 | SUSE-SU-2026:0587-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 16.0 | kernel-default-base | 6.12.0-160000.26.1.160000.2.7 | openSUSE-SU-2026:20287-1 |
| openSUSE Leap 16.0 | kernel-rt +11 | 6.12.0-160000.26.1 | openSUSE-SU-2026:20287-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | kernel-livepatch-6.12.64-87.122 | 1:1.0-0.amzn2023 | ALAS2023-2026-1423 |
| Amazon Linux 2023 | perf6.12 +14 | 1:6.12.64-87.122.amzn2023 | ALAS2023-2026-1423 |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 9 | kernel-uek +34 | 6.12.0-108.64.6.3.el10uek | ELSA-2026-50112 |
Advisories 20
- WID-SEC-2026-0086 Linux Kernel: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 12, 2026
- USN-8204-1 linux-raspi-realtime vulnerabilities Ubuntu Security Notices (USN) · Nov 4, 2026
- USN-8184-1 linux-realtime, linux-realtime-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 4, 2026
- USN-8187-1 linux-nvidia-tegra, linux-nvidia-tegra-igx vulnerabilities Ubuntu Security Notices (USN) · Nov 4, 2026
- USN-8186-1 linux-intel-iot-realtime, linux-realtime vulnerabilities Ubuntu Security Notices (USN) · Nov 4, 2026
- USN-8265-1 linux-nvidia-tegra vulnerabilities Ubuntu Security Notices (USN) · Nov 4, 2026
- USN-8177-2 linux-realtime-6.17 vulnerabilities Ubuntu Security Notices (USN) · Nov 4, 2026
- USN-8177-1 linux, linux-realtime vulnerabilities Ubuntu Security Notices (USN) · Nov 4, 2026
- USN-8162-1 linux-nvidia-tegra-5.15 vulnerabilities Ubuntu Security Notices (USN) · Nov 4, 2026
- SUSE-SU-2026:20570-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Jul 9, 2026
- openSUSE-SU-2026:20287-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2026:20615-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2026:20599-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2026:20555-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2026:0587-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2026:0472-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2026:0447-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- DSA-6126-1 linux - security update Debian Security (DSA / DLA) · Mar 9, 2026
- ELSA-2026-50112 Important: Unbreakable Enterprise kernel security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Feb 20, 2026
- ALAS2023-2026-1423 Important: kernel6.12 security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Feb 11, 2026