Updated: 2026-02-27 01:22:18.622957
Description:
In the Linux kernel, the following vulnerability has been resolved: l2tp: close all race conditions in l2tp_tunnel_register() The code in l2tp_tunnel_register() is racy in several ways: 1. It modifies the tunnel socket _after_ publishing it. 2. It calls setup_udp_tunnel_sock() on an existing socket without locking. 3. It changes sock lock class on fly, which triggers many syzbot reports. This patch amends all of them by moving socket initialization code before publishing and under sock lock. As suggested by Jakub, the l2tp lockdep class is not necessary as we can just switch to bh_lock_sock_nested().
| Links | NIST | CIRCL | RHEL | Ubuntu |
| Severity | Score | |
|---|---|---|
| CVSS Version 2.x | 0.0 | |
| CVSS Version 3.x | MEDIUM | 4.7 |
| OS name | Project name | Version | Score | Severity | Status | Errata | Last updated | Statement |
|---|---|---|---|---|---|---|---|---|
| AlmaLinux 9.2 ESU | kernel | 5.14.0 | 4.7 | MEDIUM | Ignored | 2025-04-25 06:43:23 | This issue is a local, high‑complexity race in the kernel’s L2TP tunnel registration path that r... | |
| CentOS 8.4 ELS | kernel | 4.18.0 | 4.7 | MEDIUM | Ignored | 2025-04-25 06:43:23 | Ignored due to low severity | |
| CentOS 8.5 ELS | kernel | 4.18.0 | 4.7 | MEDIUM | Ignored | 2025-04-25 06:43:24 | Ignored due to low severity | |
| Ubuntu 16.04 ELS | linux-hwe | 4.15.0 | 4.7 | MEDIUM | Released | CLSA-2025:1747431461 | 2025-05-18 05:07:37 | |
| Ubuntu 16.04 ELS | linux | 4.4.0 | 4.7 | MEDIUM | Ignored | 2025-04-25 03:48:45 | ||
| Ubuntu 18.04 ELS | linux | 4.15.0 | 4.7 | MEDIUM | Released | CLSA-2025:1747430081 | 2025-05-18 05:07:04 |