Description
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: Fix race condition in RPC handle list access
The 'sess->rpc_handle_list' XArray manages RPC handles within a ksmbd
session. Access to this list is intended to be protected by
'sess->rpc_lock' (an rw_semaphore). However, the locking implementation was
flawed, leading to potential race conditions.
In ksmbd_session_rpc_open(), the code incorrectly acquired only a read lock
before calling xa_store() and xa_erase(). Since these operations modify
the XArray structure, a write lock is required to ensure exclusive access
and prevent data corruption from concurrent modifications.
Furthermore, ksmbd_session_rpc_method() accessed the list using xa_load()
without holding any lock at all. This could lead to reading inconsistent
data or a potential use-after-free if an entry is concurrently removed and
the pointer is dereferenced.
Fix these issues by:
1. Using down_write() and up_write() in ksmbd_session_rpc_open()
to ensure exclusive access during XArray modification, and ensuring
the lock is correctly released on error paths.
2. Adding down_read() and up_read() in ksmbd_session_rpc_method()
to safely protect the lookup.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Linux | Linux | 5.15.145 – < 5.16, 6.3 | 5.16 |
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 | 6.17.6-1 | — |
| Debian 13 | linux | 6.12.57-1 | — |
| 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 | 6.8.0-1022.26 | — |
| Ubuntu Nvidia-BlueField 22.04 LTS | linux-bluefield | No fix yet | — |
| Ubuntu 25.10 | linux | 6.17.0-14.14 | USN-8029-1 |
| Ubuntu 25.10 | linux-aws +2 | 6.17.0-1007.7 | USN-8030-1, USN-8029-2 |
| Ubuntu 25.10 | linux-azure +1 | 6.17.0-1008.8 | USN-8029-3, USN-8029-1 |
| Ubuntu 25.10 | linux-azure-fde | No fix yet | — |
| Ubuntu 25.10 | linux-realtime | 6.17.0-1006.7 | USN-8029-1 |
| Ubuntu 25.10 | linux-riscv | 6.17.0-14.14.1 | — |
| Ubuntu 24.04 LTS | linux | 6.8.0-117.117 | USN-8278-1 |
| Ubuntu 24.04 LTS | linux-aws | 6.8.0-1055.58 | USN-8278-1 |
| Ubuntu 24.04 LTS | linux-aws-6.17 +1 | 6.17.0-1007.7~24.04.1 | — |
| Ubuntu 24.04 LTS | linux-azure | 6.8.0-1056.62 | USN-8278-2 |
| 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 | 6.8.0-1058.61 | USN-8278-1 |
| Ubuntu 24.04 LTS | linux-gcp-6.17 | 6.17.0-1008.8~24.04.1 | — |
| Ubuntu 24.04 LTS | linux-gke | 6.8.0-1054.60 | USN-8278-1 |
| Ubuntu 24.04 LTS | linux-gkeop | 6.8.0-1041.44 | USN-8278-1 |
| Ubuntu 24.04 LTS | linux-ibm | 6.8.0-1055.56 | USN-8278-1 |
| Ubuntu 24.04 LTS | linux-lowlatency | 6.8.0-117.117.1 | USN-8278-1 |
| Ubuntu 24.04 LTS | linux-nvidia | 6.8.0-1054.57 | USN-8289-1 |
| Ubuntu 24.04 LTS | linux-nvidia-6.17 | 6.17.0-1008.8 | — |
| Ubuntu 24.04 LTS | linux-nvidia-lowlatency | 6.8.0-1054.57.1 | USN-8289-1 |
| Ubuntu 24.04 LTS | linux-nvidia-tegra | 6.8.0-1024.24 | USN-8296-2 |
| Ubuntu 24.04 LTS | linux-oem-6.17 | 6.17.0-1011.11 | USN-8048-1 |
| Ubuntu 24.04 LTS | linux-oracle | 6.8.0-1054.55 | — |
| Ubuntu 24.04 LTS | linux-raspi | 6.8.0-1056.60 | USN-8278-1 |
| Ubuntu 24.04 LTS | linux-riscv +18 | No fix yet | — |
| Ubuntu 24.04 LTS | linux-xilinx | 6.8.0-1032.33 | USN-8499-1 |
| Ubuntu 22.04 LTS | linux +49 | No fix yet | — |
| Ubuntu 22.04 LTS | linux-aws-6.8 | 6.8.0-1057.60~22.04.1 | — |
| 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-6.8 | 6.8.0-1058.65~22.04.1 | — |
| Ubuntu 22.04 LTS | linux-gcp-6.8 | 6.8.0-1060.63~22.04.1 | — |
| Ubuntu 22.04 LTS | linux-hwe-6.8 | 6.8.0-124.124~22.04.1 | — |
| Ubuntu 22.04 LTS | linux-ibm-6.8 | 6.8.0-1055.56~22.04.1 | USN-8278-1 |
| Ubuntu 22.04 LTS | linux-lowlatency-hwe-6.8 | 6.8.0-117.117.1~22.04.1 | USN-8278-1 |
| Ubuntu 22.04 LTS | linux-nvidia-6.8 | 6.8.0-1054.57~22.04.1 | USN-8289-2 |
| Ubuntu 22.04 LTS | linux-oracle-6.8 | 6.8.0-1054.55~22.04.1 | — |
| Ubuntu 22.04 LTS | linux-riscv-6.8 | 6.8.0-117.117~22.04.1 | — |
Show 8 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 | 6.8.0-2045.46 | USN-8278-1 |
| Ubuntu Pro Realtime 24.04 LTS | linux-realtime | 6.8.1-1051.52 | USN-8278-1 |
| Ubuntu Pro Realtime 24.04 LTS | linux-realtime-6.14 | No fix yet | — |
| Ubuntu Pro Realtime 24.04 LTS | linux-realtime-6.17 | 6.17.0-1006.7~24.04.1 | — |
| Ubuntu Pro Realtime 22.04 LTS | linux-realtime +1 | No fix yet | — |
| Ubuntu Pro Realtime 22.04 LTS | linux-realtime-6.8 | 6.8.1-1051.52~22.04.1 | USN-8278-1 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-aws-fips | 6.8.0-1055.58+fips1 | USN-8278-1 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-azure-fips | 6.8.0-1059.65+fips1 | USN-8393-1 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-fips | 6.8.0-116.116+fips1 | USN-8296-1 |
| Ubuntu Pro FIPS-updates 24.04 LTS | linux-gcp-fips | 6.8.0-1058.61+fips1 | USN-8278-1 |
| Ubuntu Pro FIPS-updates 22.04 LTS | linux-fips +3 | No fix yet | — |
| Ubuntu Pro 20.04 LTS | linux-aws-5.15 +10 | No fix yet | — |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | kernel-source | 6.17.7-1.1 | openSUSE-SU-2025:15702-1 |
| openSUSE Tumbleweed | kernel-source-longterm | 6.18.16-1.1 | openSUSE-SU-2026:10301-1 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 2 (CBL-Mariner) | kernel | No fix yet | — |
Advisories 19
- WID-SEC-2025-2431 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-8499-1 linux-xilinx vulnerabilities Ubuntu Security Notices (USN) · Nov 7, 2026
- USN-8393-1 linux-azure-fips vulnerabilities Ubuntu Security Notices (USN) · Nov 7, 2026
- USN-8278-1 linux, linux-aws, linux-aws-fips, linux-gcp, linux-gcp-fips, linux-gke, linux-gkeop, linux-ibm, linux-ibm-6.8, linux-lowlatency, linux-lowlatency-hwe-6.8, linux-raspi, linux-raspi-realtime, linux-realtime, linux-realtime-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 5, 2026
- USN-8289-1 linux-nvidia, linux-nvidia-lowlatency vulnerabilities Ubuntu Security Notices (USN) · Nov 5, 2026
- USN-8289-2 linux-nvidia-6.8 vulnerabilities Ubuntu Security Notices (USN) · Nov 5, 2026
- USN-8278-2 linux-azure vulnerabilities Ubuntu Security Notices (USN) · Nov 5, 2026
- USN-8296-1 linux-fips vulnerabilities Ubuntu Security Notices (USN) · Nov 4, 2026
- USN-8296-2 linux-nvidia-tegra vulnerabilities Ubuntu Security Notices (USN) · Nov 4, 2026
- USN-8029-2 linux-aws, linux-oracle vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8048-1 linux-oem-6.17 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8029-3 linux-azure vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8030-1 linux-gcp vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-8029-1 linux, linux-raspi, linux-realtime vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- openSUSE-SU-2025:15702-1 kernel-devel-6.17.7-1.1 on GA media SUSE / openSUSE Security Updates · Mar 23, 2026
- DSA-6127-1 linux - security update Debian Security (DSA / DLA) · Mar 9, 2026
- openSUSE-SU-2026:10301-1 kernel-devel-longterm-6.18.16-1.1 on GA media SUSE / openSUSE Security Updates · Mar 8, 2026
- DLA-4476-1 linux-6.1 - security update Debian Security (DSA / DLA) · Feb 10, 2026
References
- https://git.kernel.org/stable/c/69674b029002b1d90b655f014bdf64f404efa54d
- https://git.kernel.org/stable/c/6b615a8fb3af0baf8126cde3d4fee97d57222ffc
- https://git.kernel.org/stable/c/5cc679ba0f4505936124cd4179ba66bb0a4bd9f3
- https://git.kernel.org/stable/c/6bd7e0e55dcea2cf0d391bbc21c2eb069b4be3e1
- https://git.kernel.org/stable/c/305853cce379407090a73b38c5de5ba748893aee