CVE-2026-45918
published 2026-05-27CVE-2026-45918: In the Linux kernel, the following vulnerability has been resolved: ovpn: tcp - don't deref NULL sk_socket member after tcp_close() When deleting a peer in…
In the Linux kernel, the following vulnerability has been resolved:
ovpn: tcp - don't deref NULL sk_socket member after tcp_close()
When deleting a peer in case of keepalive expiration, the peer is
removed from the OpenVPN hashtable and is temporary inserted in a
"release list" for further processing.
This happens in:
ovpn_peer_keepalive_work()
unlock_ovpn(release_list)
This processing includes detaching from the socket being used to
talk to this peer, by restoring its original proto and socket
ops/callbacks.
In case of TCP it may happen that, while the peer is sitting in
the release list, userspace decides to close the socket.
This will result in a concurrent execution of:
tcp_close(sk)
__tcp_close(sk)
sock_orphan(sk)
sk_set_socket(sk, NULL)
The last function call will set sk->sk_socket to NULL.
When the releasing routine is resumed, ovpn_tcp_socket_detach()
will attempt to dereference sk->sk_socket to restore its original
ops member. This operation will crash due to sk->sk_socket being NULL.
Fix this race condition by testing-and-accessing
sk->sk_socket atomically under sk->sk_callback_lock.
Affected
5 ranges
| Vendor | Product | Version range | Fixed in |
|---|---|---|---|
| linux | linux | — | — |
| linux | linux | >= 11851cbd60ea1e5abbd97619d69845ead99303d6 < f998b2c4bec487063a586695159f9a1856e81c56 | f998b2c4bec487063a586695159f9a1856e81c56 |
| linux | linux | >= 11851cbd60ea1e5abbd97619d69845ead99303d6 < b9142cf4e066c825ec68752a7dcaceda700bbe26 | b9142cf4e066c825ec68752a7dcaceda700bbe26 |
| linux | linux | >= 11851cbd60ea1e5abbd97619d69845ead99303d6 < 94560267d6c41b1ff3fafbab726e3f8a55a6af34 | 94560267d6c41b1ff3fafbab726e3f8a55a6af34 |
| linux | linux_kernel | — | — |