CVE-2023-53020

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().

The following products are affected by CVE-2023-53020 vulnerability.

Here, you will find a curated list of external links that provide in-depth information to CVE-2023-53020.

URL	Resource
https://git.kernel.org/stable/c/0b2c59720e65885a394a017d0cf9cab118914682
https://git.kernel.org/stable/c/2d77e5c0ad79004b5ef901895437e9cce6dfcc7e
https://git.kernel.org/stable/c/77e8ed776cdb1a24b2aab8fe7c6f1f154235e1ce
https://git.kernel.org/stable/c/cef0845b6dcfa2f6c2c832e7f9622551456c741d
https://lore.kernel.org/linux-cve-announce/2025032717-CVE-2023-53020-1042@gregkh/T
https://nvd.nist.gov/vuln/detail/CVE-2023-53020
https://www.cve.org/CVERecord?id=CVE-2023-53020