Description
In the Linux kernel, the following vulnerability has been resolved:
Revert "sched/fair: Make sure to try to detach at least one movable task"
This reverts commit b0defa7ae03ecf91b8bfd10ede430cff12fcbd06.
b0defa7ae03ec changed the load balancing logic to ignore env.max_loop if
all tasks examined to that point were pinned. The goal of the patch was
to make it more likely to be able to detach a task buried in a long list
of pinned tasks. However, this has the unfortunate side effect of
creating an O(n) iteration in detach_tasks(), as we now must fully
iterate every task on a cpu if all or most are pinned. Since this load
balance code is done with rq lock held, and often in softirq context, it
is very easy to trigger hard lockups. We observed such hard lockups with
a user who affined O(10k) threads to a single cpu.
When I discussed this with Vincent he initially suggested that we keep
the limit on the number of tasks to detach, but increase the number of
tasks we can search. However, after some back and forth on the mailing
list, he recommended we instead revert the original patch, as it seems
likely no one was actually getting hit by the original issue.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Linux | Linux | 6.1 | 6.1.100 |
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 | 6.9.10-1 | — |
| Debian 13 | linux | 6.9.10-1 | — |
| Debian 12 | linux | 6.1.106-1 | — |
| Debian 11 | linux-6.1 | 6.1.119-1~deb11u1 | DLA-4008-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 24.04 LTS | linux | 6.8.0-48.48 | USN-7089-1 |
| Ubuntu 24.04 LTS | linux-aws | 6.8.0-1018.20 | USN-7089-3 |
| Ubuntu 24.04 LTS | linux-azure | 6.8.0-1017.20 | USN-7089-2 |
| Ubuntu 24.04 LTS | linux-gcp +1 | 6.8.0-1017.19 | USN-7095-1, USN-7089-2 |
| Ubuntu 24.04 LTS | linux-gke | 6.8.0-1013.17 | USN-7089-6 |
| Ubuntu 24.04 LTS | linux-gkeop | 6.8.0-1002.4 | USN-7156-1 |
| Ubuntu 24.04 LTS | linux-ibm | 6.8.0-1015.15 | USN-7089-2 |
| Ubuntu 24.04 LTS | linux-lowlatency | 6.8.0-48.48.3 | USN-7089-7 |
| Ubuntu 24.04 LTS | linux-nvidia-lowlatency | 6.8.0-1017.19.1 | USN-7095-1 |
| Ubuntu 24.04 LTS | linux-oem-6.8 | 6.8.0-1016.16 | USN-7089-4 |
| Ubuntu 24.04 LTS | linux-oracle | 6.8.0-1015.16 | USN-7089-3 |
| Ubuntu 24.04 LTS | linux-raspi | 6.8.0-1014.16 | USN-7089-5 |
| Ubuntu 24.04 LTS | linux-riscv | 6.8.0-48.48.1 | — |
| Ubuntu 22.04 LTS | linux-aws-6.8 | 6.8.0-1018.19~22.04.1 | USN-7089-3 |
| Ubuntu 22.04 LTS | linux-azure-6.8 | 6.8.0-1017.20~22.04.1 | USN-7090-1 |
| Ubuntu 22.04 LTS | linux-gcp-6.8 +1 | 6.8.0-1017.19~22.04.1 | USN-7095-1, USN-7089-1 |
| Ubuntu 22.04 LTS | linux-hwe-6.8 | 6.8.0-48.48~22.04.1 | USN-7089-1 |
| Ubuntu 22.04 LTS | linux-lowlatency-hwe-6.8 | 6.8.0-48.48.3~22.04.1 | USN-7089-7 |
| Ubuntu 22.04 LTS | linux-oracle-6.8 | 6.8.0-1015.15~22.04.1 | USN-7089-3 |
| Ubuntu 22.04 LTS | linux-riscv +32 | No fix yet | — |
| Ubuntu 22.04 LTS | linux-riscv-6.8 | 6.8.0-48.48.1~22.04.2 | — |
| Ubuntu 20.04 LTS | linux-gke +26 | No fix yet | — |
| Ubuntu 18.04 LTS | linux-gcp +13 | No fix yet | — |
| Ubuntu 16.04 LTS | linux-hwe-edge | No fix yet | — |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro Realtime 24.04 LTS | linux-raspi-realtime | 6.8.0-2013.14 | — |
| Ubuntu Pro Realtime 24.04 LTS | linux-realtime | 6.8.1-1011.11 | — |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 9 | bpftool | 7.4.0-503.11.1.el9_5 | RHSA-2024:9315 |
| RHEL 9 | rv +67 | 5.14.0-503.11.1.el9_5 | RHSA-2024:9315 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP6 | kernel-64kb +6 | 6.4.0-150600.23.22.1 | SUSE-SU-2024:3383-1 |
| SLES 15 SP6 | kernel-azure +2 | 6.4.0-150600.8.11.1 | SUSE-SU-2024:3194-1 |
| SLES 15 SP6 | kernel-default-base | 6.4.0-150600.23.22.1.150600.12.8.3 | SUSE-SU-2024:3383-1 |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLE Micro 6.0 | kernel-default-base | 6.4.0-17.1.1.51 | SUSE-SU-2025:20044-1 |
| SLE Micro 6.0 | kernel-livepatch-MICRO-6-0_Update_2 +1 | 1-1.1 | SUSE-SU-2025:20047-1, SUSE-SU-2025:20044-1 |
| SLE Micro 6.0 | kernel-rt +1 | 6.4.0-10.1 | SUSE-SU-2025:20047-1 |
| SLE Micro 6.0 | kernel-source +2 | 6.4.0-19.1 | SUSE-SU-2025:20044-1 |
| SLE Live Patching 15 SP6 | kernel-default | 6.4.0-150600.23.22.1 | SUSE-SU-2024:3383-1 |
| SLE Live Patching 15 SP6 | kernel-livepatch-SLE15-SP6-RT_Update_2 | 1-150600.1.3.2 | SUSE-SU-2024:3195-1 |
| SLE Live Patching 15 SP6 | kernel-livepatch-SLE15-SP6_Update_4 | 1-150600.13.3.3 | SUSE-SU-2024:3383-1 |
| SUSE Real Time Module 15 SP6 | kernel-rt +2 | 6.4.0-150600.10.8.3 | SUSE-SU-2024:3195-1 |
| SUSE Real Time Module 15 SP6 | kernel-syms-rt | 6.4.0-150600.10.8.1 | SUSE-SU-2024:3195-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 15.6 | dtb-aarch64 +10 | 6.4.0-150600.23.22.1 | SUSE-SU-2024:3383-1 |
| openSUSE Leap 15.6 | kernel-azure +2 | 6.4.0-150600.8.11.1 | SUSE-SU-2024:3194-1 |
| openSUSE Leap 15.6 | kernel-default-base | 6.4.0-150600.23.22.1.150600.12.8.3 | SUSE-SU-2024:3383-1 |
| openSUSE Leap 15.6 | kernel-rt +2 | 6.4.0-150600.10.8.3 | SUSE-SU-2024:3195-1 |
| openSUSE Leap 15.6 | kernel-syms-rt | 6.4.0-150600.10.8.1 | SUSE-SU-2024:3195-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | kernel-livepatch-6.1.102-108.177 | 1.0-0.amzn2023 | ALAS2023-2024-679 |
| Amazon Linux 2023 | perf +14 | 6.1.102-108.177.amzn2023 | ALAS2023-2024-679 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | kernel | 6.6.43.1-7 | — |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 9 | bpftool | 7.4.0-503.11.1.el9_5 | ELSA-2024-9315 |
| Oracle Linux 9 | rv +28 | 5.14.0-503.11.1.el9_5 | ELSA-2024-9315 |
Advisories 20
- RHSA-2024:9315 Red Hat Security Advisory: kernel security update Red Hat Security Advisories (RHSA) · Nov 13, 2026
- USN-7156-1 linux-gkeop vulnerabilities Ubuntu Security Notices (USN) · Oct 29, 2026
- USN-7095-1 linux-nvidia, linux-nvidia-6.8, linux-nvidia-lowlatency vulnerabilities Ubuntu Security Notices (USN) · Oct 29, 2026
- USN-7090-1 linux-azure-6.8 vulnerabilities Ubuntu Security Notices (USN) · Oct 29, 2026
- USN-7089-6 linux-gke vulnerabilities Ubuntu Security Notices (USN) · Oct 26, 2026
- USN-7089-3 linux-aws, linux-aws-6.8, linux-oracle, linux-oracle-6.8 vulnerabilities Ubuntu Security Notices (USN) · Oct 26, 2026
- USN-7089-7 linux-lowlatency, linux-lowlatency-hwe-6.8 vulnerabilities Ubuntu Security Notices (USN) · Oct 26, 2026
- USN-7089-2 linux-azure, linux-gcp, linux-ibm vulnerabilities Ubuntu Security Notices (USN) · Oct 26, 2026
- USN-7089-1 linux, linux-gcp-6.8, linux-hwe-6.8 vulnerabilities Ubuntu Security Notices (USN) · Oct 26, 2026
- USN-7089-5 linux-raspi vulnerabilities Ubuntu Security Notices (USN) · Oct 26, 2026
- USN-7089-4 linux-oem-6.8 vulnerabilities Ubuntu Security Notices (USN) · Oct 26, 2026
- SUSE-SU-2025:20047-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- SUSE-SU-2025:20044-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Mar 23, 2026
- DLA-4008-1 linux-6.1 - security update Debian Security (DSA / DLA) · Mar 9, 2026
- WID-SEC-2024-1788 Linux Kernel: Mehrere Schwachstellen ermöglichen nicht spezifizierten Angriff BSI CERT-Bund (WID) · Feb 16, 2026
- SUSE-SU-2024:3195-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2024:3383-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- SUSE-SU-2024:3194-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Feb 4, 2026
- ALAS2023-2024-679 Important: kernel security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Oct 18, 2025
- ELSA-2024-9315 Moderate: kernel security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Nov 14, 2024