SB20260528163 - Race condition in Linux kernel net ovpn driver

Description

This security bulletin contains information about 1 vulnerability.

1) Race condition (CVE-ID: CVE-2026-45918)

CWE-ID: CWE-362 - Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear

The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to a race condition in ovpn_tcp_socket_detach() when deleting a peer after keepalive expiration while the associated TCP socket is being closed concurrently. A local user can trigger concurrent peer release and socket close operations to cause a denial of service.

The issue occurs because sk->sk_socket may become NULL during tcp_close() before the detach routine restores the original socket operations.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/94560267d6c41b1ff3fafbab726e3f8a55a6af34
• https://git.kernel.org/stable/c/b9142cf4e066c825ec68752a7dcaceda700bbe26
• https://git.kernel.org/stable/c/f998b2c4bec487063a586695159f9a1856e81c56