Description
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: validate session id and tree id in the compound request
This patch validate session id and tree id in compound request.
If first operation in the compound is SMB2 ECHO request, ksmbd bypass
session and tree validation. So work->sess and work->tcon could be NULL.
If secound request in the compound access work->sess or tcon, It cause
NULL pointer dereferecing error.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Linux | Linux | 5.15 | 5.15.121 |
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 | 6.3.11-1 | — |
| Debian 13 | linux | 6.3.11-1 | — |
| Debian 12 | linux | 6.1.37-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Nvidia-BlueField 22.04 LTS | linux-bluefield | 5.15.0-1027.29 | — |
| Ubuntu 24.04 LTS | linux-raspi-realtime | No fix yet | — |
| Ubuntu 22.04 LTS | linux | 5.15.0-86.96 | USN-6416-1 |
| Ubuntu 22.04 LTS | linux-aws | 5.15.0-1047.52 | USN-6416-1 |
| Ubuntu 22.04 LTS | linux-aws-6.2 | 6.2.0-1015.15~22.04.1 | USN-6464-1 |
| Ubuntu 22.04 LTS | linux-azure | 5.15.0-1049.56 | USN-6416-1 |
| Ubuntu 22.04 LTS | linux-azure-6.2 +1 | 6.2.0-1016.16~22.04.1 | USN-6464-1 |
| Ubuntu 22.04 LTS | linux-azure-fde | 5.15.0-1049.56.1 | USN-6416-1 |
| Ubuntu 22.04 LTS | linux-azure-fde-6.2 | 6.2.0-1016.16~22.04.1.1 | USN-6464-1 |
| Ubuntu 22.04 LTS | linux-gcp | 5.15.0-1044.52 | USN-6416-1 |
| Ubuntu 22.04 LTS | linux-gcp-6.2 | 6.2.0-1018.20~22.04.1 | USN-6464-1 |
| Ubuntu 22.04 LTS | linux-gke +1 | 5.15.0-1044.49 | USN-6416-1 |
| Ubuntu 22.04 LTS | linux-gkeop | 5.15.0-1030.35 | USN-6416-1 |
| Ubuntu 22.04 LTS | linux-hwe-6.2 | 6.2.0-36.37~22.04.1 | USN-6464-1 |
| Ubuntu 22.04 LTS | linux-ibm +1 | 5.15.0-1040.43 | USN-6416-3, USN-6416-1 |
| Ubuntu 22.04 LTS | linux-intel-iotg | 5.15.0-1043.49 | USN-6445-1 |
| Ubuntu 22.04 LTS | linux-lowlatency | 5.15.0-86.95 | USN-6416-1 |
| Ubuntu 22.04 LTS | linux-nvidia | 5.15.0-1037.37 | USN-6416-1 |
| Ubuntu 22.04 LTS | linux-nvidia-6.2 | 6.2.0-1011.11 | USN-6466-1 |
| Ubuntu 22.04 LTS | linux-nvidia-tegra | 5.15.0-1018.18 | — |
| Ubuntu 22.04 LTS | linux-nvidia-tegra-igx | 5.15.0-1005.5 | — |
| Ubuntu 22.04 LTS | linux-oem-6.1 | 6.1.0-1019.19 | — |
| Ubuntu 22.04 LTS | linux-oracle | 5.15.0-1045.51 | USN-6416-1 |
| Ubuntu 22.04 LTS | linux-riscv +12 | No fix yet | — |
| Ubuntu 22.04 LTS | linux-starfive-6.2 | 6.2.0-1009.10~22.04.1 | USN-6520-1 |
| Ubuntu 22.04 LTS | linux-xilinx-zynqmp | 5.15.0-1025.29 | — |
| Ubuntu 20.04 LTS | linux-aws-5.15 | 5.15.0-1047.52~20.04.1 | USN-6416-1 |
| Ubuntu 20.04 LTS | linux-azure-5.15 | 5.15.0-1049.56~20.04.1 | USN-6416-1 |
| Ubuntu 20.04 LTS | linux-azure-fde-5.15 | 5.15.0-1049.56~20.04.1.1 | USN-6416-1 |
| Ubuntu 20.04 LTS | linux-gcp-5.15 | 5.15.0-1044.52~20.04.1 | USN-6416-1 |
| Ubuntu 20.04 LTS | linux-gke +26 | No fix yet | — |
| Ubuntu 20.04 LTS | linux-gkeop-5.15 | 5.15.0-1030.35~20.04.1 | USN-6416-1 |
| Ubuntu 20.04 LTS | linux-hwe-5.15 | 5.15.0-86.96~20.04.1 | USN-6416-2 |
| Ubuntu 20.04 LTS | linux-ibm-5.15 | 5.15.0-1040.43~20.04.1 | USN-6416-1 |
| Ubuntu 20.04 LTS | linux-intel-iotg-5.15 | 5.15.0-1043.49~20.04.1 | USN-6445-2 |
| Ubuntu 20.04 LTS | linux-lowlatency-hwe-5.15 | 5.15.0-86.95~20.04.1 | USN-6416-1 |
| Ubuntu 20.04 LTS | linux-nvidia-tegra-5.15 | 5.15.0-1018.18~20.04.1 | — |
| Ubuntu 20.04 LTS | linux-oracle-5.15 | 5.15.0-1045.51~20.04.1 | USN-6416-2 |
| Ubuntu 20.04 LTS | linux-riscv-5.15 | 5.15.0-1043.47~20.04.1 | — |
| Ubuntu 18.04 LTS | linux-gcp +13 | No fix yet | — |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 16.04 LTS | linux-hwe-edge | No fix yet | — |
| Ubuntu Pro Realtime 22.04 LTS | linux-intel-iot-realtime | 5.15.0-1040.42 | — |
| Ubuntu Pro Realtime 22.04 LTS | linux-realtime | 5.15.0-1048.54 | — |
| Ubuntu Pro FIPS-preview 22.04 LTS | linux-fips | No fix yet | — |
Advisories 9
- WID-SEC-2025-1858 Linux Kernel: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 10, 2026
- USN-6416-1 linux, linux-aws, linux-aws-5.15, linux-azure, linux-azure-5.15, linux-azure-fde, linux-azure-fde-5.15, linux-gcp, linux-gcp-5.15, linux-gke, linux-gkeop, linux-gkeop-5.15, linux-ibm, linux-ibm-5.15, linux-kvm, linux-lowlatency, linux-lowlatency-hwe-5.15, linux-nvidia, linux-oracle vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-6464-1 linux, linux-aws, linux-aws-6.2, linux-azure, linux-azure-6.2, linux-azure-fde-6.2, linux-gcp, linux-gcp-6.2, linux-hwe-6.2, linux-kvm, linux-lowlatency, linux-lowlatency-hwe-6.2, linux-oracle, linux-raspi, linux-starfive vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-6416-2 linux-hwe-5.15, linux-oracle-5.15 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-6445-1 linux-intel-iotg vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-6466-1 linux-nvidia-6.2 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-6445-2 linux-intel-iotg-5.15 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-6416-3 linux-raspi vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-6520-1 linux-starfive-6.2 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026