Description
In the Linux kernel, the following vulnerability has been resolved:
ksmbd: fix race condition between session lookup and expire
Thread A + Thread B
ksmbd_session_lookup | smb2_sess_setup
sess = xa_load |
|
| xa_erase(&conn->sessions, sess->id);
|
| ksmbd_session_destroy(sess) --> kfree(sess)
|
// UAF! |
sess->last_active = jiffies |
+
This patch add rwsem to fix race condition between ksmbd_session_lookup
and ksmbd_expire_session.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Linux | Linux | 6.1.29 – < 6.1.57, 6.2.16 – < 6.3, 6.3.2 – < 6.4, 6.4 | 6.1.57 |
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 | 6.5.8-1 | — |
| Debian 13 | linux | 6.5.8-1 | — |
| Debian 12 | linux | 6.1.64-1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 24.04 LTS | linux-raspi | 6.7.0-1001.1 | — |
| Ubuntu 24.04 LTS | linux-raspi-realtime | No fix yet | — |
| Ubuntu 22.04 LTS | linux +1 | 5.15.0-102.112 | USN-6725-1 |
| Ubuntu 22.04 LTS | linux-aws | 5.15.0-1057.63 | USN-6725-2 |
| Ubuntu 22.04 LTS | linux-azure | 5.15.0-1060.69 | USN-6725-1 |
| Ubuntu 22.04 LTS | linux-azure-fde | 5.15.0-1060.69.1 | USN-6725-1 |
| Ubuntu 22.04 LTS | linux-gcp | 5.15.0-1055.63 | USN-6725-1 |
| Ubuntu 22.04 LTS | linux-gcp-6.5 | 6.5.0-1013.13~22.04.1 | — |
| Ubuntu 22.04 LTS | linux-gke +1 | 5.15.0-1054.59 | USN-6725-1 |
| Ubuntu 22.04 LTS | linux-gkeop | 5.15.0-1040.46 | USN-6725-1 |
| Ubuntu 22.04 LTS | linux-hwe-6.5 | 6.5.0-17.17~22.04.1 | — |
| Ubuntu 22.04 LTS | linux-ibm +1 | 5.15.0-1050.53 | USN-6725-1 |
| Ubuntu 22.04 LTS | linux-intel-iotg | 5.15.0-1052.58 | USN-6725-1 |
| Ubuntu 22.04 LTS | linux-lowlatency-hwe-6.5 | 6.5.0-17.17.1.1.1~22.04.1 | — |
| Ubuntu 22.04 LTS | linux-nvidia | 5.15.0-1048.48 | USN-6725-1 |
| Ubuntu 22.04 LTS | linux-nvidia-6.5 | 6.5.0-1014.14 | — |
| Ubuntu 22.04 LTS | linux-oem-6.5 | 6.5.0-1014.15 | — |
| Ubuntu 22.04 LTS | linux-oracle | 5.15.0-1055.61 | USN-6725-1 |
| Ubuntu 22.04 LTS | linux-oracle-6.5 | 6.5.0-1015.15~22.04.1 | — |
| Ubuntu 22.04 LTS | linux-riscv +24 | No fix yet | — |
| Ubuntu 20.04 LTS | linux-aws-5.15 | 5.15.0-1057.63~20.04.1 | USN-6725-2 |
| Ubuntu 20.04 LTS | linux-azure-5.15 | 5.15.0-1060.69~20.04.1 | USN-6725-1 |
| Ubuntu 20.04 LTS | linux-azure-fde-5.15 | 5.15.0-1060.69~20.04.1.1 | USN-6725-1 |
| Ubuntu 20.04 LTS | linux-gcp-5.15 | 5.15.0-1055.63~20.04.1 | USN-6725-1 |
| Ubuntu 20.04 LTS | linux-gke +26 | No fix yet | — |
| Ubuntu 20.04 LTS | linux-gkeop-5.15 | 5.15.0-1040.46~20.04.1 | USN-6725-1 |
| Ubuntu 20.04 LTS | linux-hwe-5.15 +1 | 5.15.0-102.112~20.04.1 | USN-6725-1 |
| Ubuntu 20.04 LTS | linux-ibm-5.15 | 5.15.0-1050.53~20.04.1 | USN-6725-1 |
| Ubuntu 20.04 LTS | linux-intel-iotg-5.15 | 5.15.0-1052.58~20.04.1 | USN-6725-1 |
| Ubuntu 20.04 LTS | linux-oracle-5.15 | 5.15.0-1055.61~20.04.1 | USN-6725-1 |
| Ubuntu 18.04 LTS | linux-gcp +14 | No fix yet | — |
| Ubuntu 16.04 LTS | linux-hwe-edge | No fix yet | — |
Advisories 3
- USN-6725-1 linux, 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-hwe-5.15, linux-ibm, linux-ibm-5.15, linux-intel-iotg, linux-intel-iotg-5.15, linux-kvm, linux-lowlatency, linux-lowlatency-hwe-5.15, linux-nvidia, linux-oracle, linux-oracle-5.15, linux-raspi vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- USN-6725-2 linux-aws, linux-aws-5.15 vulnerabilities Ubuntu Security Notices (USN) · Nov 3, 2026
- WID-SEC-2024-0511 Linux Kernel: Mehrere Schwachstellen ermöglichen Denial of Service und unspezifische Angriffe BSI CERT-Bund (WID) · Feb 15, 2026