Description
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: fix null pointer dereference in alloc_preauth_hash()
The Client send malformed smb2 negotiate request. ksmbd return error
response. Subsequently, the client can send smb2 session setup even
thought conn->preauth_info is not allocated.
This patch add KSMBD_SESS_NEED_SETUP status of connection to ignore
session setup request if smb2 negotiate phase is not complete.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Linux | Linux | 5.15 | 6.1.191 |
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 | 6.12.25-1 | — |
| Debian 13 | linux | 6.12.25-1 | — |
| Debian 12 | linux | No fix yet | — |
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 | No fix yet | — |
| Ubuntu 25.10 | linux-azure-fde | No fix yet | — |
| Ubuntu 25.04 | linux | 6.14.0-22.22 | USN-7594-1 |
| Ubuntu 25.04 | linux-aws +3 | 6.14.0-1007.7 | USN-7594-3, USN-7594-2, USN-7594-1 |
| Ubuntu 25.04 | linux-gcp | 6.14.0-1008.8 | USN-7594-1 |
| Ubuntu 25.04 | linux-realtime | 6.14.0-1004.4 | USN-7594-1 |
| Ubuntu 24.04 LTS | linux | 6.8.0-101.101 | USN-8059-1 |
| Ubuntu 24.04 LTS | linux-aws +1 | 6.8.0-1047.50 | USN-8059-8, USN-8059-6 |
| Ubuntu 24.04 LTS | linux-azure | 6.8.0-1051.57 | USN-8125-1 |
| Ubuntu 24.04 LTS | linux-azure-6.11 | 6.11.0-1018.18~24.04.1 | USN-7628-1 |
| 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 | 6.8.0-1048.51 | USN-8059-3 |
| Ubuntu 24.04 LTS | linux-gcp-6.11 | 6.11.0-1016.16~24.04.1 | USN-7605-1 |
| Ubuntu 24.04 LTS | linux-gke | 6.8.0-1044.49 | USN-8059-3 |
| Ubuntu 24.04 LTS | linux-gkeop | 6.8.0-1031.34 | USN-8059-1 |
| Ubuntu 24.04 LTS | linux-hwe-6.11 | 6.11.0-28.28~24.04.1 | USN-7605-1 |
| Ubuntu 24.04 LTS | linux-ibm | 6.8.0-1045.45 | USN-8059-6 |
| Ubuntu 24.04 LTS | linux-intel +4 | No fix yet | — |
| Ubuntu 24.04 LTS | linux-lowlatency | 6.8.0-101.101.1 | USN-8059-1 |
| Ubuntu 24.04 LTS | linux-lowlatency-hwe-6.11 | 6.11.0-1015.16~24.04.2 | USN-7605-2 |
| Ubuntu 24.04 LTS | linux-nvidia-6.11 | 6.11.0-1012.12 | — |
| Ubuntu 24.04 LTS | linux-nvidia-lowlatency | 6.8.0-1047.50.1 | USN-8059-8 |
| Ubuntu 24.04 LTS | linux-nvidia-tegra | 6.8.0-1020.20 | — |
| Ubuntu 24.04 LTS | linux-oem-6.11 | 6.11.0-1024.24 | USN-7606-1 |
| Ubuntu 24.04 LTS | linux-oracle | 6.8.0-1044.45 | USN-8059-1 |
| Ubuntu 24.04 LTS | linux-raspi | 6.8.0-1048.52 | USN-8059-1 |
| Ubuntu 24.04 LTS | linux-xilinx | 6.8.0-1024.25 | USN-8059-6 |
Show 10 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 22.04 LTS | linux +49 | No fix yet | — |
| Ubuntu 22.04 LTS | linux-aws-6.8 +1 | 6.8.0-1047.50~22.04.1 | USN-8059-8, USN-8059-6 |
| 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-6.8 | 6.8.0-1058.65~22.04.1 | — |
| Ubuntu 22.04 LTS | linux-gcp-6.8 | 6.8.0-1048.51~22.04.1 | USN-8059-3 |
| Ubuntu 22.04 LTS | linux-hwe-6.8 +1 | 6.8.0-101.101~22.04.1 | USN-8059-1 |
| Ubuntu 22.04 LTS | linux-ibm-6.8 | 6.8.0-1045.45~22.04.1 | USN-8059-6 |
| Ubuntu 22.04 LTS | linux-lowlatency-hwe-6.8 | 6.8.0-101.101.1~22.04.1 | USN-8059-1 |
| Ubuntu 22.04 LTS | linux-oracle-6.8 | 6.8.0-1044.45~22.04.1 | USN-8059-3 |
| 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 | 6.8.0-2038.39 | USN-8059-2 |
| Ubuntu Pro Realtime 24.04 LTS | linux-realtime | 6.8.1-1042.43 | USN-8059-4 |
| Ubuntu Pro Realtime 22.04 LTS | linux-realtime +1 | No fix yet | — |
| Ubuntu Pro Realtime 22.04 LTS | linux-realtime-6.8 | 6.8.1-1042.43~22.04.1 | USN-8059-4 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-aws-fips | 6.8.0-1047.50+fips1 | USN-8059-7 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-azure-fips | 6.8.0-1047.53+fips1 | USN-8059-9 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-fips | 6.8.0-101.101+fips1 | USN-8059-5 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-gcp-fips | 6.8.0-1048.51+fips1 | USN-8059-5 |
| 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 +10 | No fix yet | — |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 9 | kernel-uek +34 | 6.12.0-101.33.4.3.el10uek | ELSA-2025-20530, ELSA-2025-20480 |
Advisories 22
- WID-SEC-2025-0844 Linux Kernel: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 12, 2026
- USN-8126-1 linux-azure-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8125-1 linux-azure vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-7628-1 linux-azure, linux-azure-6.11 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-7605-1 linux, linux-aws, linux-gcp, linux-gcp-6.11, linux-hwe-6.11, linux-oracle, linux-raspi, linux-realtime vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-7605-2 linux-lowlatency, linux-lowlatency-hwe-6.11 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-7606-1 linux-oem-6.11 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8059-1 linux, linux-gkeop, linux-hwe-6.8, linux-lowlatency, linux-lowlatency-hwe-6.8, linux-oracle, linux-raspi vulnerabilities Ubuntu Security Notices (USN) · Oct 27, 2026
- USN-8059-9 linux-azure-fips vulnerabilities Ubuntu Security Notices (USN) · Oct 27, 2026
- USN-8059-5 linux-fips, linux-gcp-fips vulnerabilities Ubuntu Security Notices (USN) · Oct 27, 2026
- USN-8059-6 linux-aws, linux-aws-6.8, linux-ibm, linux-ibm-6.8, linux-xilinx vulnerabilities Ubuntu Security Notices (USN) · Oct 27, 2026
- USN-8059-2 linux-raspi-realtime vulnerabilities Ubuntu Security Notices (USN) · Oct 27, 2026
- USN-8059-3 linux-gcp, linux-gcp-6.8, linux-gke, linux-oracle-6.8 vulnerabilities Ubuntu Security Notices (USN) · Oct 27, 2026
- USN-8059-4 linux-realtime, linux-realtime-6.8 vulnerabilities Ubuntu Security Notices (USN) · Oct 27, 2026
- USN-8059-7 linux-aws-fips vulnerabilities Ubuntu Security Notices (USN) · Oct 27, 2026
- USN-8059-8 linux-nvidia, linux-nvidia-6.8, linux-nvidia-lowlatency vulnerabilities Ubuntu Security Notices (USN) · Oct 27, 2026
- WID-SEC-2026-1118 Dell PowerProtect Data Domain OS: Mehrere Schwachstellen BSI CERT-Bund (WID) · Aug 5, 2026
- USN-7594-2 linux-azure vulnerabilities Ubuntu Security Notices (USN) · Feb 4, 2026
- USN-7594-1 linux, linux-gcp, linux-raspi, linux-realtime vulnerabilities Ubuntu Security Notices (USN) · Feb 4, 2026
- USN-7594-3 linux-aws, linux-oracle vulnerabilities Ubuntu Security Notices (USN) · Feb 4, 2026
- ELSA-2025-20530 Important: Unbreakable Enterprise kernel security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Aug 18, 2025
- ELSA-2025-20480 Important: Unbreakable Enterprise kernel security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Jul 17, 2025
References
- https://git.kernel.org/stable/c/2d3461d6ae74ebdcd4d65128c855198649bcadcd
- https://git.kernel.org/stable/c/cce57cd8c5dead24127cf2308fdd60fcad2d6ba6
- https://git.kernel.org/stable/c/ca8bed31edf728a662ef9d6f39f50e7a7dc2b5ad
- https://git.kernel.org/stable/c/8f216b33a5e1b3489c073b1ea1b3d7cb63c8dc4d
- https://git.kernel.org/stable/c/b8eb243e670ecf30e91524dd12f7260dac07d335
- https://git.kernel.org/stable/c/c8b5b7c5da7d0c31c9b7190b4a7bba5281fc4780
- https://www.zerodayinitiative.com/advisories/ZDI-25-310/