Description
In the Linux kernel, the following vulnerability has been resolved:
drbd: add missing kref_get in handle_write_conflicts
With `two-primaries` enabled, DRBD tries to detect "concurrent" writes
and handle write conflicts, so that even if you write to the same sector
simultaneously on both nodes, they end up with the identical data once
the writes are completed.
In handling "superseeded" writes, we forgot a kref_get,
resulting in a premature drbd_destroy_device and use after free,
and further to kernel crashes with symptoms.
Relevance: No one should use DRBD as a random data generator, and apparently
all users of "two-primaries" handle concurrent writes correctly on layer up.
That is cluster file systems use some distributed lock manager,
and live migration in virtualization environments stops writes on one node
before starting writes on the other node.
Which means that other than for "test cases",
this code path is never taken in real life.
FYI, in DRBD 9, things are handled differently nowadays. We still detect
"write conflicts", but no longer try to be smart about them.
We decided to disconnect hard instead: upper layers must not submit concurrent
writes. If they do, that's their fault.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Linux | Linux | 4.5 | 5.4.297 |
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 | 6.16.3-1 | — |
| Debian 13 | linux | 6.12.43-1 | — |
| Debian 12 | linux | 6.1.153-1 | DSA-6009-1 |
| Debian 11 | linux | 5.10.244-1 | DLA-4327-1 |
| Debian 11 | linux-6.1 | 6.1.153-1~deb11u1 | DLA-4328-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Nvidia-BlueField 24.04 LTS | linux-bluefield | 6.8.0-1016.20 | — |
| Ubuntu Nvidia-BlueField 22.04 LTS | linux-bluefield | 5.15.0-1081.83 | — |
| Ubuntu 25.10 | linux-azure-fde | No fix yet | — |
| Ubuntu 24.04 LTS | linux | 6.8.0-100.100 | USN-8028-1 |
| Ubuntu 24.04 LTS | linux-aws +1 | 6.8.0-1046.49 | USN-8028-5 |
| Ubuntu 24.04 LTS | linux-azure | 6.8.0-1046.52 | USN-8074-1 |
| Ubuntu 24.04 LTS | linux-azure-fde | 6.8.0-1046.53 | — |
| Ubuntu 24.04 LTS | linux-azure-nvidia | 6.8.0-1039.42 | — |
| Ubuntu 24.04 LTS | linux-gcp | 6.8.0-1047.50 | USN-8031-3 |
| Ubuntu 24.04 LTS | linux-gke | 6.8.0-1043.48 | USN-8031-3 |
| Ubuntu 24.04 LTS | linux-gkeop | 6.8.0-1030.33 | USN-8028-5 |
| Ubuntu 24.04 LTS | linux-ibm | 6.8.0-1044.44 | USN-8028-8 |
| Ubuntu 24.04 LTS | linux-intel +19 | No fix yet | — |
| Ubuntu 24.04 LTS | linux-lowlatency | 6.8.0-100.100.1 | USN-8052-1 |
| Ubuntu 24.04 LTS | linux-nvidia-lowlatency | 6.8.0-1046.49.1 | USN-8028-7 |
| Ubuntu 24.04 LTS | linux-nvidia-tegra | 6.8.0-1020.20 | — |
| Ubuntu 24.04 LTS | linux-oracle | 6.8.0-1043.44 | USN-8028-5 |
| Ubuntu 24.04 LTS | linux-raspi | 6.8.0-1047.51 | USN-8028-1 |
| Ubuntu 24.04 LTS | linux-xilinx | 6.8.0-1023.24 | USN-8052-2 |
| Ubuntu 22.04 LTS | linux +1 | 5.15.0-163.173 | USN-7909-1 |
| Ubuntu 22.04 LTS | linux-aws | 5.15.0-1097.104 | USN-7909-1 |
| Ubuntu 22.04 LTS | linux-aws-6.8 +1 | 6.8.0-1046.49~22.04.1 | USN-8028-5 |
| Ubuntu 22.04 LTS | linux-azure | 5.15.0-1101.110 | USN-7910-2 |
| Ubuntu 22.04 LTS | linux-azure-6.8 | 6.8.0-1051.57~22.04.1 | USN-8126-1 |
| Ubuntu 22.04 LTS | linux-azure-fde | 5.15.0-1102.111.1 | — |
| Ubuntu 22.04 LTS | linux-azure-fde-6.8 | 6.8.0-1046.53~22.04.1 | — |
| Ubuntu 22.04 LTS | linux-gcp | 5.15.0-1097.106 | USN-7909-4 |
| Ubuntu 22.04 LTS | linux-gcp-6.8 | 6.8.0-1047.50~22.04.2 | USN-8031-1 |
| Ubuntu 22.04 LTS | linux-gke | 5.15.0-1093.99 | USN-7909-4 |
| Ubuntu 22.04 LTS | linux-gkeop | 5.15.0-1080.88 | USN-7909-4 |
| Ubuntu 22.04 LTS | linux-hwe-6.8 +1 | 6.8.0-100.100~22.04.1 | USN-8028-6 |
| Ubuntu 22.04 LTS | linux-ibm +1 | 5.15.0-1091.94 | USN-7909-5, USN-7909-1 |
| Ubuntu 22.04 LTS | linux-ibm-6.8 | 6.8.0-1044.44~22.04.1 | USN-8028-8 |
| Ubuntu 22.04 LTS | linux-intel-iotg | 5.15.0-1092.98 | USN-7909-1 |
| Ubuntu 22.04 LTS | linux-kvm | 5.15.0-1089.94 | USN-7933-1 |
| Ubuntu 22.04 LTS | linux-lowlatency-hwe-6.8 | 6.8.0-100.100.1~22.04.1 | USN-8028-6 |
| Ubuntu 22.04 LTS | linux-nvidia | 5.15.0-1092.93 | USN-7909-1 |
| Ubuntu 22.04 LTS | linux-nvidia-tegra | 5.15.0-1049.49 | USN-7909-1 |
| Ubuntu 22.04 LTS | linux-nvidia-tegra-igx | 5.15.0-1038.38 | USN-7909-1 |
| Ubuntu 22.04 LTS | linux-oracle | 5.15.0-1094.100 | USN-7909-1 |
| Ubuntu 22.04 LTS | linux-oracle-6.8 | 6.8.0-1043.44~22.04.1 | USN-8028-5 |
| Ubuntu 22.04 LTS | linux-riscv +32 | No fix yet | — |
| Ubuntu 22.04 LTS | linux-xilinx-zynqmp | 5.15.0-1061.65 | USN-7909-1 |
Show 16 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 | 6.8.0-2037.38 | USN-8028-3 |
| Ubuntu Pro Realtime 24.04 LTS | linux-realtime | 6.8.1-1041.42 | USN-8028-3 |
| Ubuntu Pro Realtime 24.04 LTS | linux-realtime-6.14 | No fix yet | — |
| Ubuntu Pro Realtime 22.04 LTS | linux-intel-iot-realtime | 5.15.0-1089.91 | USN-7909-2 |
| Ubuntu Pro Realtime 22.04 LTS | linux-realtime | 5.15.0-1096.105 | USN-7909-2 |
| Ubuntu Pro Realtime 22.04 LTS | linux-realtime-6.8 | 6.8.1-1041.42~22.04.1 | USN-8028-2 |
| 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-updates 24.04 LTS | linux-aws-fips | 6.8.0-1046.49+fips1 | USN-8028-4 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-azure-fips | 6.8.0-1046.52+fips1 | USN-8074-2 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-fips | 6.8.0-100.100+fips1 | USN-8028-4 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-gcp-fips | 6.8.0-1047.50+fips1 | USN-8031-2 |
| Ubuntu Pro FIPS-updates 22.04 LTS | linux-aws-fips | 5.15.0-1097.104+fips1 | USN-7909-3 |
| Ubuntu Pro FIPS-updates 22.04 LTS | linux-azure-fips | 5.15.0-1101.110+fips1 | USN-7910-1 |
| Ubuntu Pro FIPS-updates 22.04 LTS | linux-fips | 5.15.0-163.173+fips1 | USN-7909-3 |
| Ubuntu Pro FIPS-updates 22.04 LTS | linux-gcp-fips | 5.15.0-1097.106+fips1 | USN-7909-3 |
| 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-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 | 5.15.0-1097.104~20.04.1 | USN-7909-1 |
| Ubuntu Pro 20.04 LTS | linux-azure-5.15 | 5.15.0-1102.111~20.04.1 | USN-7938-1 |
| Ubuntu Pro 20.04 LTS | linux-gcp-5.15 | 5.15.0-1097.106~20.04.1 | USN-7909-1 |
| Ubuntu Pro 20.04 LTS | linux-hwe-5.15 +1 | 5.15.0-163.173~20.04.1 | USN-7909-1 |
| Ubuntu Pro 20.04 LTS | linux-ibm-5.15 | 5.15.0-1091.94~20.04.1 | USN-7909-1 |
| Ubuntu Pro 20.04 LTS | linux-intel-iotg-5.15 | 5.15.0-1092.98~20.04.1 | USN-7909-1 |
| Ubuntu Pro 20.04 LTS | linux-nvidia-tegra-5.15 | 5.15.0-1049.49~20.04.1 | USN-7909-1 |
| Ubuntu Pro 20.04 LTS | linux-oracle-5.15 | 5.15.0-1094.100~20.04.1 | USN-7909-1 |
| Ubuntu Pro 20.04 LTS | linux-riscv-5.15 | 5.15.0-1092.96~20.04.1 | — |
| Ubuntu Pro 18.04 LTS | linux +12 | No fix yet | — |
| Ubuntu Pro 16.04 LTS | linux-gcp +4 | No fix yet | — |
| Ubuntu Pro 14.04 LTS | linux-azure | No fix yet | — |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | kernel-livepatch-6.12.46-66.121 +1 | 1:1.0-0.amzn2023 | ALAS2023-2025-1208, ALAS2023-2025-1186 |
| Amazon Linux 2023 | perf +14 | 1:6.1.150-174.273.amzn2023 | ALAS2023-2025-1186 |
| Amazon Linux 2023 | perf6.12 +14 | 1:6.12.46-66.121.amzn2023 | ALAS2023-2025-1208 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | kernel | 6.6.104.2-1 | — |
| Azure Linux 2 (CBL-Mariner) | kernel | 5.15.200.1-1 | — |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 9 | kernel-uek +34 | 6.12.0-104.43.4.2.el10uek | ELSA-2025-20662 |
| Oracle Linux 8 | bpftool +18 | 5.15.0-314.193.5.3.el9uek | ELSA-2025-25757 |
| Oracle Linux 7 | kernel-uek +6 | 5.4.17-2136.348.3.el8uek | ELSA-2025-20663 |
| Oracle Linux 7 | kernel-uek-tools | 5.4.17-2136.348.3.el7uek | ELSA-2025-20663 |
Advisories 39
- WID-SEC-2025-1976 Linux Kernel: Mehrere Schwachstellen ermöglichen Denial of Service BSI CERT-Bund (WID) · Nov 12, 2026
- USN-7909-1 linux, linux-aws, linux-aws-5.15, linux-gcp-5.15, linux-hwe-5.15, linux-ibm, linux-ibm-5.15, linux-intel-iotg, linux-intel-iotg-5.15, linux-lowlatency, linux-lowlatency-hwe-5.15, linux-nvidia, linux-nvidia-tegra, linux-nvidia-tegra-5.15, linux-nvidia-tegra-igx, linux-oracle, linux-oracle-5.15, linux-xilinx-zynqmp vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8028-5 linux-aws, linux-aws-6.8, linux-gkeop, linux-nvidia, linux-nvidia-6.8, linux-oracle, linux-oracle-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8126-1 linux-azure-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8028-8 linux-ibm, linux-ibm-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8028-6 linux-hwe-6.8, linux-lowlatency-hwe-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8052-1 linux-lowlatency vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8052-2 linux-xilinx vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8074-1 linux-azure vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8074-2 linux-azure-fips vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8031-3 linux-gcp, linux-gke vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8028-4 linux-aws-fips, linux-fips vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8028-1 linux, linux-raspi vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8028-3 linux-realtime, linux-raspi-realtime vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8028-7 linux-nvidia-lowlatency vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8028-2 linux-realtime-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8031-2 linux-gcp-fips vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8031-1 linux-gcp-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-7909-3 linux-aws-fips, linux-fips, linux-gcp-fips vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-7909-4 linux-gcp, linux-gke, linux-gkeop vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-7938-1 linux-azure-5.15 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-7933-1 linux-kvm vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-7909-5 linux-raspi vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-7910-2 linux-azure vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-7909-2 linux-intel-iot-realtime, linux-realtime vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-7910-1 linux-azure-fips vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- SSA-082556 SSA-082556: Vulnerabilities in the additional GNU/Linux subsystem of the SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP V3.1.5 Siemens ProductCERT · Oct 13, 2026
- ICSA-26-134-10 Siemens SIMATIC CISA ICS & IT advisories · May 14, 2026
- ICSA-25-162-05 Siemens SIMATIC S7-1500 CPU family CISA ICS & IT advisories · May 14, 2026
- NCSC-2026-0147 Kwetsbaarheden verholpen in Siemens-producten NCSC-NL (Netherlands) · May 13, 2026
- SSA-032379 SSA-032379: Multiple Vulnerabilities in SIMATIC CN 4100 Before V5.0 Siemens ProductCERT · May 12, 2026
- DLA-4327-1 linux - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DSA-6009-1 linux - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-4328-1 linux-6.1 - security update Debian Security (DSA / DLA) · Mar 9, 2026
- ELSA-2025-25757 Important: Unbreakable Enterprise kernel security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · Nov 10, 2025
- ALAS2023-2025-1208 Important: kernel6.12 security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Oct 18, 2025
- ELSA-2025-20662 Important: Unbreakable Enterprise kernel security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Oct 14, 2025
- ELSA-2025-20663 Important: Unbreakable Enterprise kernel security update (Oracle Linux 7) Oracle Linux Security Advisories (ELSA) · Oct 11, 2025
- ALAS2023-2025-1186 Important: kernel security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · Oct 2, 2025
References
- https://git.kernel.org/stable/c/0336bfe9c237476bd7c45605a36ca79c2bca62e5
- https://git.kernel.org/stable/c/810cd546a29bfac90ed1328ea01d693d4bd11cb1
- https://git.kernel.org/stable/c/84ef8dd3238330d1795745ece83b19f0295751bf
- https://git.kernel.org/stable/c/57418de35420cedab035aa1da8a26c0499b7f575
- https://git.kernel.org/stable/c/9f53b2433ad248cd3342cc345f56f5c7904bd8c4
- https://git.kernel.org/stable/c/7d483ad300fc0a06f69b019dda8f74970714baf8
- https://git.kernel.org/stable/c/46e3763dcae0ffcf8fcfaff4fc10a90a92ffdd89
- https://git.kernel.org/stable/c/3a896498f6f577e57bf26aaa93b48c22b6d20c20
- https://git.kernel.org/stable/c/00c9c9628b49e368d140cfa61d7df9b8922ec2a8