ovpn: avoid putting unrelated P2P peer on socket release

{
  "id": "5be61c7cc9326939c0d6043874d39df35c80d8d56858bab211d02395f222fdea",
  "url": "https://osv.dev/vulnerability/CVE-2026-68342",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "ovpn: avoid putting unrelated P2P peer on socket release",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: ovpn: avoid putting unrelated P2P peer on socket release ovpn_peer_release_p2p() is called when an OVPN UDP socket is being destroyed. It checks the currently published P2P peer and releases it only if that peer still uses the socket being destroyed. A peer replacement can publish a new peer before the old UDP socket is destroyed. When the old socket destruction path runs afterwards, ovpn_peer_release_p2p() observes the new peer through ovpn->peer. Since the new peer uses a different socket, the function takes the socket mismatch branch. That branch still calls ovpn_peer_put(peer). At this point, however, peer is the currently published replacement peer, not the peer associated with the socket being destroyed. Dropping its reference can free it while ovpn->peer still points to it, leading to later use-after-free accesses from the peer and socket cleanup paths. KASAN reports this as a slab-use-after-free on the kmalloc-1k ovpn_peer object. In the reproducer, the object is allocated from ovpn_peer_new() via ovpn_nl_peer_new_doit(), and freed through ovpn_peer_release_rcu() from RCU callback processing. Observed access sites include ovpn_peer_remove(), ovpn_socket_release(), ovpn_nl_peer_del_notify(), and unlock_ovpn(). Fix this by returning from the socket mismatch branch without putting the peer.",
    "evidence": "osv:CVE-2026-68342",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.18.42",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "7.1.6",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2026-68342",
      "aliases": [
        "CVE-2026-68342"
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "f6226ae7a0cd47aaa9175aca6a1e19600f884cbf"
                },
                {
                  "fixed": "c5bf6b39be235ef578af4d39872f0c68cda3b937"
                },
                {
                  "fixed": "016a50379d17b886d12a4efa5211a418e035fe70"
                },
                {
                  "fixed": "b52c5103f64ee825996ca1ab8df7283cde8c5f86"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-68342.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.16.0"
                },
                {
                  "fixed": "6.18.42"
                }
              ]
            },
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.19.0"
                },
                {
                  "fixed": "7.1.6"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-68342.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:32.437908808Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/016a50379d17b886d12a4efa5211a418e035fe70",
        "https://git.kernel.org/stable/c/b52c5103f64ee825996ca1ab8df7283cde8c5f86",
        "https://git.kernel.org/stable/c/c5bf6b39be235ef578af4d39872f0c68cda3b937",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/68xxx/CVE-2026-68342.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-68342",
        "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/2026/68xxx/CVE-2026-68342.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-68342",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 499668,
  "published_at": "2026-08-10T12:03:18.852+00:00"
}