CVE-2026-64045In the Linux kernel, the following vulnerability has been resolved: ovpn: tcp - use cached peer pointer in ovpn_tcp_close() ovpn_tcp_close() loads the ovpn_socket via rcu_dereference_sk_user_data() u…

In the Linux kernel, the following vulnerability has been resolved: ovpn: tcp - use cached peer pointer in ovpn_tcp_close() ovpn_tcp_close() loads the ovpn_socket via rcu_dereference_sk_user_data() under rcu_read_lock(), takes a reference on sock->peer, caches the peer pointer in a local, and drops the read lock. It then passes sock->peer (rather than the cached local) to ovpn_peer_del(), re-dereferencing the ovpn_socket after the RCU read section has ended. Unlike ovpn_tcp_sendmsg(), which uses the same "load under RCU, use after unlock" pattern but is protected by lock_sock() held across the function, ovpn_tcp_close() runs without the socket lock: inet_release() invokes sk_prot->close() without taking lock_sock first. ovpn_socket_release() can therefore complete its kref_put -> detach -> synchronize_rcu -> kfree(sock) sequence concurrently, in the window after ovpn_tcp_close() drops rcu_read_lock() but before it dereferences sock->peer. The synchronize_rcu() in ovpn_socket_release() protects readers that use the dereferenced pointer inside the RCU read section, not those that escape the pointer to a local and use it afterwards. A reproducer follows the pattern of commit 94560267d6c4 ("ovpn: tcp - don't deref NULL sk_socket member after tcp_close()"): trigger a peer removal (keepalive expiration or netlink OVPN_CMD_DEL_PEER) at the same moment userspace closes the TCP fd. That commit fixed the detach-side of the same race window; this one fixes the close-side at a different victim. Tighten the entry block to read sock->peer exactly once into the cached peer local, and route all subsequent uses (the hold check, the ovpn_peer_del() call, and the prot->close() invocation) through that local. sock->peer is only ever written once in ovpn_socket_new() under lock_sock(), before rcu_assign_sk_user_data() publishes the ovpn_socket, and is never reassigned afterwards - but the previous multi-read pattern made that invariant implicit rather than explicit. The same multi-read shape exists in ovpn_tcp_recvmsg(), ovpn_tcp_sendmsg(), ovpn_tcp_data_ready() and ovpn_tcp_write_space(); those will be cleaned up via a dedicated helper in a follow-up net-next series.

CVSS

8.4 HIGH (v3.1, NVD)CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Weakness (CWE)

CWE-476

Known exploited

Not in CISA's KEV catalog

EPSS (exploitation in the next 30 days)

Not loaded for this CVE

Assigned by

Not given

NVD analysis

Analyzed

Record last updated

Sep 2, 2026

First seen by InfoSec Signals

Oct 9, 2026

The CVE record on cve.org · NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.