Description
In the Linux kernel, the following vulnerability has been resolved:
sched/deadline: only set free_cpus for online runqueues
Commit 16b269436b72 ("sched/deadline: Modify cpudl::free_cpus
to reflect rd->online") introduced the cpudl_set/clear_freecpu
functions to allow the cpu_dl::free_cpus mask to be manipulated
by the deadline scheduler class rq_on/offline callbacks so the
mask would also reflect this state.
Commit 9659e1eeee28 ("sched/deadline: Remove cpu_active_mask
from cpudl_find()") removed the check of the cpu_active_mask to
save some processing on the premise that the cpudl::free_cpus
mask already reflected the runqueue online state.
Unfortunately, there are cases where it is possible for the
cpudl_clear function to set the free_cpus bit for a CPU when the
deadline runqueue is offline. When this occurs while a CPU is
connected to the default root domain the flag may retain the bad
state after the CPU has been unplugged. Later, a different CPU
that is transitioning through the default root domain may push a
deadline task to the powered down CPU when cpudl_find sees its
free_cpus bit is set. If this happens the task will not have the
opportunity to run.
One example is outlined here:
https://lore.kernel.org/lkml/20250110233010.2339521-1-opendmb@gmail.com
Another occurs when the last deadline task is migrated from a
CPU that has an offlined runqueue. The dequeue_task member of
the deadline scheduler class will eventually call cpudl_clear
and set the free_cpus bit for the CPU.
This commit modifies the cpudl_clear function to be aware of the
online state of the deadline runqueue so that the free_cpus mask
can be updated appropriately.
It is no longer necessary to manage the mask outside of the
cpudl_set/clear functions so the cpudl_set/clear_freecpu
functions are removed. In addition, since the free_cpus mask is
now only updated under the cpudl lock the code was changed to
use the non-atomic __cpumask functions.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Linux | Linux | 4.0 | 5.15.198 |
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 | 6.18.3-1 | — |
| Debian 13 | linux | 6.12.69-1 | DSA-6126-1 |
| Debian 12 | linux | 6.1.162-1 | DSA-6127-1 |
| Debian 11 | linux-6.1 | 6.1.162-1~deb11u1 | DLA-4476-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Nvidia-BlueField 24.04 LTS | linux-bluefield | 6.8.0-1017.21 | — |
| Ubuntu Nvidia-BlueField 22.04 LTS | linux-bluefield | 5.15.0-1086.88 | — |
| Ubuntu 25.10 | linux | 6.17.0-22.22 | USN-8177-1 |
| Ubuntu 25.10 | linux-aws +1 | 6.17.0-1012.12 | USN-8183-2, USN-8183-1 |
| Ubuntu 25.10 | linux-azure +1 | 6.17.0-1013.13 | USN-8245-1 |
| Ubuntu 25.10 | linux-azure-fde | No fix yet | — |
| Ubuntu 25.10 | linux-oracle | 6.17.0-1011.11 | USN-8183-2 |
| Ubuntu 25.10 | linux-realtime | 6.17.0-1010.11 | USN-8177-1 |
| Ubuntu 25.10 | linux-riscv | 6.17.0-22.22.1 | — |
| Ubuntu 24.04 LTS | linux | 6.8.0-110.110 | USN-8179-1 |
| Ubuntu 24.04 LTS | linux-aws | 6.8.0-1052.55 | USN-8179-1 |
| Ubuntu 24.04 LTS | linux-aws-6.17 +1 | 6.17.0-1012.12~24.04.1 | USN-8183-2, USN-8183-1 |
| Ubuntu 24.04 LTS | linux-azure | 6.8.0-1054.60 | USN-8258-1 |
| Ubuntu 24.04 LTS | linux-azure-6.17 | 6.17.0-1013.13~24.04.1 | USN-8245-1 |
| Ubuntu 24.04 LTS | linux-azure-fde | 6.8.0-1058.65 | — |
| Ubuntu 24.04 LTS | linux-azure-nvidia | 6.8.0-1039.42 | — |
| Ubuntu 24.04 LTS | linux-gcp | 6.8.0-1054.57 | USN-8179-1 |
| Ubuntu 24.04 LTS | linux-gke | 6.8.0-1050.56 | USN-8179-1 |
| Ubuntu 24.04 LTS | linux-gkeop | 6.8.0-1037.40 | USN-8179-1 |
| Ubuntu 24.04 LTS | linux-hwe-6.17 | 6.17.0-22.22~24.04.1 | USN-8183-2 |
| Ubuntu 24.04 LTS | linux-ibm | 6.8.0-1051.51 | USN-8179-1 |
| Ubuntu 24.04 LTS | linux-lowlatency | 6.8.0-110.110.1 | USN-8179-1 |
| Ubuntu 24.04 LTS | linux-nvidia | 6.8.0-1051.54 | USN-8185-1 |
| Ubuntu 24.04 LTS | linux-nvidia-6.17 | 6.17.0-1018.18 | — |
| Ubuntu 24.04 LTS | linux-nvidia-lowlatency | 6.8.0-1051.54.1 | USN-8185-2 |
| Ubuntu 24.04 LTS | linux-nvidia-tegra | 6.8.0-1022.22 | USN-8265-1 |
| Ubuntu 24.04 LTS | linux-oem-6.17 | 6.17.0-1020.20 | USN-8245-1 |
| Ubuntu 24.04 LTS | linux-oracle | 6.8.0-1049.50 | USN-8203-1 |
| Ubuntu 24.04 LTS | linux-oracle-6.17 | 6.17.0-1011.11~24.04.1 | USN-8183-2 |
| Ubuntu 24.04 LTS | linux-raspi | 6.8.0-1052.56 | USN-8179-3 |
| Ubuntu 24.04 LTS | linux-riscv +18 | No fix yet | — |
| Ubuntu 24.04 LTS | linux-riscv-6.17 | 6.17.0-22.22.1~24.04.1 | — |
| Ubuntu 24.04 LTS | linux-xilinx | 6.8.0-1028.29 | USN-8261-1 |
| Ubuntu 22.04 LTS | linux +1 | 5.15.0-173.183 | USN-8096-1 |
| Ubuntu 22.04 LTS | linux-aws | 5.15.0-1103.110 | USN-8096-1 |
| Ubuntu 22.04 LTS | linux-aws-6.8 | 6.8.0-1052.55~22.04.1 | USN-8179-1 |
| Ubuntu 22.04 LTS | linux-azure | 5.15.0-1109.118 | USN-8163-2 |
| Ubuntu 22.04 LTS | linux-azure-6.8 | 6.8.0-1059.65~22.04.1 | USN-8440-1 |
| Ubuntu 22.04 LTS | linux-azure-fde | 5.15.0-1109.118.1 | — |
| Ubuntu 22.04 LTS | linux-azure-fde-6.8 | 6.8.0-1058.65~22.04.1 | — |
| Ubuntu 22.04 LTS | linux-gcp | 5.15.0-1103.112 | USN-8096-1 |
| Ubuntu 22.04 LTS | linux-gcp-6.8 | 6.8.0-1054.57~22.04.1 | USN-8179-4 |
| Ubuntu 22.04 LTS | linux-gke | 5.15.0-1099.105 | USN-8096-3 |
| Ubuntu 22.04 LTS | linux-gkeop | 5.15.0-1086.94 | USN-8096-1 |
| Ubuntu 22.04 LTS | linux-hwe-6.8 +1 | 6.8.0-110.110~22.04.1 | USN-8179-3 |
| Ubuntu 22.04 LTS | linux-ibm +1 | 5.15.0-1097.100 | USN-8141-1, USN-8096-1 |
| Ubuntu 22.04 LTS | linux-ibm-6.8 | 6.8.0-1051.51~22.04.1 | USN-8179-3 |
| Ubuntu 22.04 LTS | linux-intel-iotg | 5.15.0-1098.104 | USN-8096-1 |
| Ubuntu 22.04 LTS | linux-kvm | 5.15.0-1095.100 | USN-8096-1 |
| Ubuntu 22.04 LTS | linux-lowlatency-hwe-6.8 | 6.8.0-110.110.1~22.04.1 | USN-8179-1 |
| Ubuntu 22.04 LTS | linux-nvidia | 5.15.0-1098.99 | USN-8096-1 |
| Ubuntu 22.04 LTS | linux-nvidia-6.8 | 6.8.0-1051.54~22.04.1 | USN-8185-1 |
| Ubuntu 22.04 LTS | linux-nvidia-tegra | 5.15.0-1055.55 | USN-8096-1 |
| Ubuntu 22.04 LTS | linux-nvidia-tegra-igx | 5.15.0-1044.44 | USN-8096-5 |
| Ubuntu 22.04 LTS | linux-oracle | 5.15.0-1100.106 | USN-8096-1 |
| Ubuntu 22.04 LTS | linux-oracle-6.8 | 6.8.0-1049.50~22.04.1 | USN-8203-1 |
| Ubuntu 22.04 LTS | linux-riscv +32 | No fix yet | — |
| Ubuntu 22.04 LTS | linux-xilinx-zynqmp | 5.15.0-1067.71 | USN-8096-1 |
Show 18 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 | 5.15.0-1094.96 | USN-8116-1 |
| Ubuntu Pro Realtime 22.04 LTS | linux-realtime | 5.15.0-1102.111 | USN-8096-4 |
| Ubuntu Pro Realtime 22.04 LTS | linux-realtime-6.8 | 6.8.1-1047.48~22.04.1 | USN-8184-1 |
| Ubuntu Pro FIPS 20.04 LTS | linux-fips +3 | No fix yet | — |
| Ubuntu Pro FIPS 18.04 LTS | linux-fips +3 | No fix yet | — |
| Ubuntu Pro FIPS 16.04 LTS | linux-fips | No fix yet | — |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-aws-fips | 6.8.0-1052.55+fips1 | USN-8179-2 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-azure-fips | 6.8.0-1053.59+fips1 | — |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-fips | 6.8.0-110.110+fips2 | USN-8179-2 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-gcp-fips | 6.8.0-1054.57+fips1 | USN-8179-2 |
| Ubuntu Pro FIPS-updates 22.04 LTS | linux-aws-fips | 5.15.0-1103.110+fips1 | USN-8096-2 |
| Ubuntu Pro FIPS-updates 22.04 LTS | linux-azure-fips | 5.15.0-1109.118+fips1 | USN-8163-1 |
| Ubuntu Pro FIPS-updates 22.04 LTS | linux-fips | 5.15.0-173.183+fips1 | USN-8096-2 |
| Ubuntu Pro FIPS-updates 22.04 LTS | linux-gcp-fips | 5.15.0-1103.112+fips1 | USN-8096-2 |
| Ubuntu Pro FIPS-updates 20.04 LTS | linux-fips +3 | No fix yet | — |
| Ubuntu Pro FIPS-updates 18.04 LTS | linux-fips +3 | No fix yet | — |
| Ubuntu Pro FIPS-updates 16.04 LTS | linux-fips | No fix yet | — |
| Ubuntu Pro FIPS-preview 22.04 LTS | linux-fips +3 | No fix yet | — |
| Ubuntu Pro 20.04 LTS | linux +10 | No fix yet | — |
| Ubuntu Pro 20.04 LTS | linux-aws-5.15 | 5.15.0-1103.110~20.04.1 | USN-8096-3 |
| Ubuntu Pro 20.04 LTS | linux-azure-5.15 | 5.15.0-1110.119~20.04.1 | USN-8243-1 |
| Ubuntu Pro 20.04 LTS | linux-gcp-5.15 | 5.15.0-1103.112~20.04.1 | USN-8096-3 |
| Ubuntu Pro 20.04 LTS | linux-hwe-5.15 +1 | 5.15.0-173.183~20.04.1 | USN-8096-3 |
| Ubuntu Pro 20.04 LTS | linux-ibm-5.15 | 5.15.0-1097.100~20.04.1 | USN-8096-1 |
| Ubuntu Pro 20.04 LTS | linux-intel-iotg-5.15 | 5.15.0-1098.104~20.04.1 | USN-8096-3 |
| Ubuntu Pro 20.04 LTS | linux-nvidia-tegra-5.15 | 5.15.0-1055.55~20.04.1 | USN-8096-1 |
| Ubuntu Pro 20.04 LTS | linux-oracle-5.15 | 5.15.0-1100.106~20.04.1 | USN-8096-3 |
| Ubuntu Pro 20.04 LTS | linux-riscv-5.15 | 5.15.0-1097.101~20.04.1 | — |
| Ubuntu Pro 18.04 LTS | linux +12 | No fix yet | — |
| Ubuntu Pro 16.04 LTS | linux +7 | No fix yet | — |
| Ubuntu Pro 14.04 LTS | linux-aws +2 | No fix yet | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | kernel-64kb +8 | 6.12.0-160000.38.1 | SUSE-SU-2026:23902-1 |
| SLES for SAP 16.0 | kernel-default-base | 6.12.0-160000.38.1.160000.2.23 | SUSE-SU-2026:23902-1 |
| SLES 16.0 | kernel-64kb +8 | 6.12.0-160000.38.1 | SUSE-SU-2026:23902-1, SUSE-SU-2026:23897-1 |
| SLES 16.0 | kernel-default-base | 6.12.0-160000.38.1.160000.2.23 | SUSE-SU-2026:23902-1 |
| SLE Micro 6.2 | kernel-default-base | 6.12.0-160000.38.1.160000.2.23 | SUSE-SU-2026:23887-1 |
| SLE Micro 6.2 | kernel-rt +5 | 6.12.0-160000.38.1 | SUSE-SU-2026:23887-1, SUSE-SU-2026:23881-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 16.0 | kernel-default-base | 6.12.0-160000.38.1.160000.2.22 | openSUSE-SU-2026:21910-1 |
| openSUSE Leap 16.0 | kernel-rt +11 | 6.12.0-160000.38.1 | openSUSE-SU-2026:21910-1 |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | kernel-livepatch-6.12.64-87.122 +1 | 1:1.0-0.amzn2023 | ALAS2023-2026-1494, ALAS2023-2026-1423 |
| Amazon Linux 2023 | perf +14 | 1:6.1.161-183.298.amzn2023 | ALAS2023-2026-1494 |
| Amazon Linux 2023 | perf6.12 +14 | 1:6.12.64-87.122.amzn2023 | ALAS2023-2026-1423 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | kernel | 6.6.121.1-1 | — |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 9 | kernel-uek +34 | 6.12.0-108.64.6.3.el10uek | ELSA-2026-50112 |
| Oracle Linux 8 | bpftool +18 | 5.15.0-318.199.3.2.el9uek | ELSA-2026-50145 |
Advisories 41
- WID-SEC-2026-0086 Linux Kernel: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 12, 2026
- USN-8440-1 linux-azure-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 7, 2026
- USN-8096-1 linux, linux-aws, linux-gcp, linux-gkeop, linux-ibm, linux-ibm-5.15, linux-intel-iotg, linux-kvm, linux-lowlatency, linux-nvidia, linux-nvidia-tegra, linux-nvidia-tegra-5.15, linux-oracle, linux-xilinx-zynqmp vulnerabilities Ubuntu Security Notices (USN) · Nov 4, 2026
- USN-8179-1 linux, linux-aws, linux-aws-6.8, linux-gcp, linux-gke, linux-gkeop, linux-ibm, linux-lowlatency, linux-lowlatency-hwe-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 4, 2026
- USN-8183-2 linux-aws, linux-aws-6.17, linux-hwe-6.17, linux-oracle, linux-oracle-6.17 vulnerabilities Ubuntu Security Notices (USN) · Nov 4, 2026
- USN-8243-1 linux-azure-5.15 vulnerabilities Ubuntu Security Notices (USN) · Nov 4, 2026
- USN-8203-1 linux-oracle, linux-oracle-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 4, 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-8185-1 linux-nvidia, linux-nvidia-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 4, 2026
- USN-8185-2 linux-nvidia-lowlatency vulnerabilities Ubuntu Security Notices (USN) · Nov 4, 2026
- USN-8096-3 linux-aws-5.15, linux-gcp-5.15, linux-gke, linux-hwe-5.15, linux-intel-iotg-5.15, linux-lowlatency-hwe-5.15, linux-oracle-5.15 vulnerabilities Ubuntu Security Notices (USN) · Nov 4, 2026
- USN-8179-3 linux-hwe-6.8, linux-ibm-6.8, linux-raspi vulnerabilities Ubuntu Security Notices (USN) · Nov 4, 2026
- USN-8265-1 linux-nvidia-tegra vulnerabilities Ubuntu Security Notices (USN) · Nov 4, 2026
- USN-8258-1 linux-azure vulnerabilities Ubuntu Security Notices (USN) · Nov 4, 2026
- USN-8116-1 linux-intel-iot-realtime vulnerabilities Ubuntu Security Notices (USN) · Nov 4, 2026
- USN-8179-4 linux-gcp-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 4, 2026
- USN-8096-2 linux-fips, linux-aws-fips, linux-gcp-fips vulnerabilities Ubuntu Security Notices (USN) · Nov 4, 2026
- USN-8163-1 linux-azure-fips vulnerabilities Ubuntu Security Notices (USN) · Nov 4, 2026
- USN-8183-1 linux-gcp, linux-gcp-6.17 vulnerabilities Ubuntu Security Notices (USN) · Nov 4, 2026
- USN-8245-1 linux-azure, linux-azure-6.17, linux-oem-6.17 vulnerabilities Ubuntu Security Notices (USN) · Nov 4, 2026
- USN-8177-2 linux-realtime-6.17 vulnerabilities Ubuntu Security Notices (USN) · Nov 4, 2026
- USN-8141-1 linux-raspi vulnerabilities Ubuntu Security Notices (USN) · Nov 4, 2026
- USN-8179-2 linux-aws-fips, linux-fips, linux-gcp-fips vulnerabilities Ubuntu Security Notices (USN) · Nov 4, 2026
- USN-8163-2 linux-azure vulnerabilities Ubuntu Security Notices (USN) · Nov 4, 2026
- USN-8096-5 linux-nvidia-tegra-igx vulnerabilities Ubuntu Security Notices (USN) · Nov 4, 2026
- USN-8177-1 linux, linux-realtime vulnerabilities Ubuntu Security Notices (USN) · Nov 4, 2026
- USN-8096-4 linux-realtime vulnerabilities Ubuntu Security Notices (USN) · Nov 4, 2026
- SUSE-SU-2026:23902-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Sep 30, 2026
- SUSE-SU-2026:23881-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Sep 30, 2026
- SUSE-SU-2026:23887-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Sep 30, 2026
- SUSE-SU-2026:23897-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Sep 30, 2026
- openSUSE-SU-2026:21910-1 Security update for the Linux Kernel SUSE / openSUSE Security Updates · Sep 25, 2026
- USN-8261-1 linux-xilinx vulnerabilities Ubuntu Security Notices (USN) · Sep 7, 2026
- ALAS2023-2026-1494 Important: kernel security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Mar 27, 2026
- ELSA-2026-50145 Important: Unbreakable Enterprise kernel security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Mar 10, 2026
- DSA-6127-1 linux - security update Debian Security (DSA / DLA) · Mar 9, 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
- DLA-4476-1 linux-6.1 - security update Debian Security (DSA / DLA) · Feb 10, 2026
References
- https://git.kernel.org/stable/c/9019e399684e3cc68c4a3f050e268f74d69c1317
- https://git.kernel.org/stable/c/fb36846cbcc936954f2ad2bffdff13d16c0be08a
- https://git.kernel.org/stable/c/91e448e69aca4bb0ba2e998eb3e555644db7322b
- https://git.kernel.org/stable/c/dbc61834b0412435df21c71410562d933e4eba49
- https://git.kernel.org/stable/c/3ed049fbfb4d75b4e0b8ab54c934f485129d5dc8
- https://git.kernel.org/stable/c/382748c05e58a9f1935f5a653c352422375566ea