{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/net/ovpn/tcp.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "e5460eb7238c19d651a9b22b2378b587033a4095",
              "status": "affected",
              "version": "11851cbd60ea1e5abbd97619d69845ead99303d6",
              "versionType": "git"
            },
            {
              "lessThan": "d3ef441907fca7c340979e577a3db3bb634bf166",
              "status": "affected",
              "version": "11851cbd60ea1e5abbd97619d69845ead99303d6",
              "versionType": "git"
            },
            {
              "lessThan": "775d8d7ad02aa345e1588424a6a8b9ae49fb9012",
              "status": "affected",
              "version": "11851cbd60ea1e5abbd97619d69845ead99303d6",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/net/ovpn/tcp.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.16"
            },
            {
              "lessThan": "6.16",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.34",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.0.*",
              "status": "unaffected",
              "version": "7.0.11",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.34",
                  "versionStartIncluding": "6.16",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.0.11",
                  "versionStartIncluding": "6.16",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1",
                  "versionStartIncluding": "6.16",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\novpn: tcp - use cached peer pointer in ovpn_tcp_close()\n\novpn_tcp_close() loads the ovpn_socket via rcu_dereference_sk_user_data()\nunder rcu_read_lock(), takes a reference on sock-\u003epeer, caches the peer\npointer in a local, and drops the read lock. It then passes sock-\u003epeer\n(rather than the cached local) to ovpn_peer_del(), re-dereferencing the\novpn_socket after the RCU read section has ended.\n\nUnlike ovpn_tcp_sendmsg(), which uses the same \"load under RCU, use\nafter unlock\" pattern but is protected by lock_sock() held across the\nfunction, ovpn_tcp_close() runs without the socket lock: inet_release()\ninvokes sk_prot-\u003eclose() without taking lock_sock first.\n\novpn_socket_release() can therefore complete its kref_put -\u003e detach -\u003e\nsynchronize_rcu -\u003e kfree(sock) sequence concurrently, in the window\nafter ovpn_tcp_close() drops rcu_read_lock() but before it dereferences\nsock-\u003epeer. The synchronize_rcu() in ovpn_socket_release() protects\nreaders that use the dereferenced pointer inside the RCU read section,\nnot those that escape the pointer to a local and use it afterwards.\n\nA reproducer follows the pattern of commit 94560267d6c4 (\"ovpn: tcp -\ndon\u0027t deref NULL sk_socket member after tcp_close()\"): trigger a peer\nremoval (keepalive expiration or netlink OVPN_CMD_DEL_PEER) at the same\nmoment userspace closes the TCP fd. That commit fixed the detach-side\nof the same race window; this one fixes the close-side at a different\nvictim.\n\nTighten the entry block to read sock-\u003epeer exactly once into the cached\npeer local, and route all subsequent uses (the hold check, the\novpn_peer_del() call, and the prot-\u003eclose() invocation) through that\nlocal. sock-\u003epeer is only ever written once in ovpn_socket_new() under\nlock_sock(), before rcu_assign_sk_user_data() publishes the ovpn_socket,\nand is never reassigned afterwards - but the previous multi-read pattern\nmade that invariant implicit rather than explicit. The same multi-read\nshape exists in ovpn_tcp_recvmsg(), ovpn_tcp_sendmsg(),\novpn_tcp_data_ready() and ovpn_tcp_write_space(); those will be cleaned\nup via a dedicated helper in a follow-up net-next series."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "baseScore": 8.4,
            "baseSeverity": "HIGH",
            "vectorString": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "scenarios": [
            {
              "lang": "en",
              "value": "AV:L - The vulnerable code runs only in ovpn_tcp_close(), reached via the close() syscall path (inet_release() -\u003e sk_prot-\u003eclose) on a TCP socket attached to the ovpn driver. Remote network packets do not directly invoke this function.\nAC:L - The reproducer is a race between closing the TCP fd and concurrent peer removal (keepalive expiry or OVPN_CMD_DEL_PEER). The attacker controls both sides by timing close() against peer deletion, and can retry until the window is hit.\nPR:N - On an internet-facing OpenVPN server with kernel TCP offload, a remote VPN peer needs no Linux credentials: stopping traffic triggers kernel keepalive expiry and ovpn_socket_release(), while the local daemon concurrently closes the TCP socket as part of normal teardown.\nUI:N - Exploitation does not require any victim user action beyond normal automated VPN server operation reacting to peer timeout or disconnect.\nS:U - Impact is confined to kernel memory corruption and privilege escalation within the host kernel; it does not cross a VM, container, or IOMMU security boundary.\nC:H - This is a use-after-free: after RCU ends, ovpn_tcp_close() re-dereferences sock-\u003epeer on a freed ovpn_socket, enabling reads of attacker-influenced freed heap contents and potential information disclosure.\nI:H - The stale sock-\u003epeer pointer is passed to ovpn_peer_del(), which operates on peer structures and locks; corrupted pointers can cause arbitrary kernel memory corruption exploitable for control-flow hijacking.\nA:H - The UAF can cause kernel oops/panic during peer deletion or TCP close, and use-after-free on kmalloc objects routinely causes system crashes even when not fully weaponized."
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-08-05T12:38:37.111Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/e5460eb7238c19d651a9b22b2378b587033a4095"
        },
        {
          "url": "https://git.kernel.org/stable/c/d3ef441907fca7c340979e577a3db3bb634bf166"
        },
        {
          "url": "https://git.kernel.org/stable/c/775d8d7ad02aa345e1588424a6a8b9ae49fb9012"
        }
      ],
      "title": "ovpn: tcp - use cached peer pointer in ovpn_tcp_close()",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-64045",
    "datePublished": "2026-07-19T15:39:30.526Z",
    "dateReserved": "2026-07-19T07:54:57.029Z",
    "dateUpdated": "2026-08-05T12:38:37.111Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}