ovpn: tcp - use cached peer pointer in ovpn_tcp_close()

{
  "id": "81aed7e13879b747340568ade804b32f4a607cfe3f807c98522d37862cf49549",
  "url": "https://osv.dev/vulnerability/CVE-2026-64045",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "ovpn: tcp - use cached peer pointer in ovpn_tcp_close()",
    "summary": "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 ",
    "evidence": "osv:CVE-2026-64045",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.18.34",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "7.0.11",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-64045",
      "aliases": [
        "CVE-2026-64045"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
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                  "introduced": "11851cbd60ea1e5abbd97619d69845ead99303d6"
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                {
                  "fixed": "e5460eb7238c19d651a9b22b2378b587033a4095"
                },
                {
                  "fixed": "d3ef441907fca7c340979e577a3db3bb634bf166"
                },
                {
                  "fixed": "775d8d7ad02aa345e1588424a6a8b9ae49fb9012"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64045.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.16.0"
                },
                {
                  "fixed": "6.18.34"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.19.0"
                },
                {
                  "fixed": "7.0.11"
                }
              ]
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          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-64045.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:30.852696278Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/775d8d7ad02aa345e1588424a6a8b9ae49fb9012",
        "https://git.kernel.org/stable/c/d3ef441907fca7c340979e577a3db3bb634bf166",
        "https://git.kernel.org/stable/c/e5460eb7238c19d651a9b22b2378b587033a4095",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64045.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-64045",
        "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
      ],
      "provider_metadata": {
        "cna_assigner": "Linux",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64045.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-64045",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 498149,
  "published_at": "2026-07-19T15:39:30.526+00:00"
}