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GHSA-74FM-4XXG-774P

Vulnerability from github – Published: 2026-07-19 18:31 – Updated: 2026-07-19 18:31

Details

In the Linux kernel, the following vulnerability has been resolved:

ovpn: fix race between deleting interface and adding new peer

While deleting an existing ovpn interface, there is a very narrow window where adding a new peer via netlink may cause the netdevice to hang and prevent its unregistration.

It may happen during ovpn_dellink(), when all existing peers are freed and the device is queued for deregistration, but a CMD_PEER_NEW message comes in adding a new peer that takes again a reference to the netdev.

At this point there is no way to release the device because we are under the assumption that all peers were already released.

Fix the race condition by releasing all peers in ndo_uninit(), when the netdevice has already been removed from the netdev list.

Also ovpn_peer_add() has now an extra check that forces the function to bail out if the device reg_state is not REGISTERED. This way any incoming CMD_PEER_NEW racing with the interface deletion routine will simply stop before adding the peer.

Note that the above check happens while holding the netdev_lock to prevent racing netdev state changes.

ovpn_dellink() is now empty and can be removed.

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{
  "affected": [],
  "aliases": [
    "CVE-2026-64043"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-07-19T16:17:44Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\novpn: fix race between deleting interface and adding new peer\n\nWhile deleting an existing ovpn interface, there is a very\nnarrow window where adding a new peer via netlink may cause\nthe netdevice to hang and prevent its unregistration.\n\nIt may happen during ovpn_dellink(), when all existing peers are\nfreed and the device is queued for deregistration, but a\nCMD_PEER_NEW message comes in adding a new peer that takes again\na reference to the netdev.\n\nAt this point there is no way to release the device because we are\nunder the assumption that all peers were already released.\n\nFix the race condition by releasing all peers in ndo_uninit(),\nwhen the netdevice has already been removed from the netdev\nlist.\n\nAlso ovpn_peer_add() has now an extra check that forces the\nfunction to bail out if the device reg_state is not REGISTERED.\nThis way any incoming CMD_PEER_NEW racing with the interface\ndeletion routine will simply stop before adding the peer.\n\nNote that the above check happens while holding the netdev_lock\nto prevent racing netdev state changes.\n\novpn_dellink() is now empty and can be removed.",
  "id": "GHSA-74fm-4xxg-774p",
  "modified": "2026-07-19T18:31:50Z",
  "published": "2026-07-19T18:31:50Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-64043"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/097d62df38314c14b88fab9096f3461baf158e2b"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/982422b11e6f95f766a8cd2c2b1cbdb77e234a61"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/de9fec2a6645f5b4d23398cd870a33e2703728d9"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

CVE-2026-64043 (GCVE-0-2026-64043)

Vulnerability from cvelistv5 – Published: 2026-07-19 15:39 – Updated: 2026-07-19 15:39

Title

ovpn: fix race between deleting interface and adding new peer

Summary

In the Linux kernel, the following vulnerability has been resolved: ovpn: fix race between deleting interface and adding new peer While deleting an existing ovpn interface, there is a very narrow window where adding a new peer via netlink may cause the netdevice to hang and prevent its unregistration. It may happen during ovpn_dellink(), when all existing peers are freed and the device is queued for deregistration, but a CMD_PEER_NEW message comes in adding a new peer that takes again a reference to the netdev. At this point there is no way to release the device because we are under the assumption that all peers were already released. Fix the race condition by releasing all peers in ndo_uninit(), when the netdevice has already been removed from the netdev list. Also ovpn_peer_add() has now an extra check that forces the function to bail out if the device reg_state is not REGISTERED. This way any incoming CMD_PEER_NEW racing with the interface deletion routine will simply stop before adding the peer. Note that the above check happens while holding the netdev_lock to prevent racing netdev state changes. ovpn_dellink() is now empty and can be removed.

Severity

No CVSS data available.

Assigner

Linux

References

3 references

URL	Tags
https://git.kernel.org/stable/c/097d62df38314c14b…
https://git.kernel.org/stable/c/de9fec2a6645f5b4d…
https://git.kernel.org/stable/c/982422b11e6f95f76…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 80747caef33d77f5c1b3d24644e6d7dae69066b5 , < 097d62df38314c14b88fab9096f3461baf158e2b (git) Affected: 80747caef33d77f5c1b3d24644e6d7dae69066b5 , < de9fec2a6645f5b4d23398cd870a33e2703728d9 (git) Affected: 80747caef33d77f5c1b3d24644e6d7dae69066b5 , < 982422b11e6f95f766a8cd2c2b1cbdb77e234a61 (git)
Linux	Linux	Affected: 6.16 Unaffected: 0 , < 6.16 (semver) Unaffected: 6.18.34 , ≤ 6.18.* (semver) Unaffected: 7.0.11 , ≤ 7.0.* (semver) Unaffected: 7.1 , ≤ * (original_commit_for_fix)

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "drivers/net/ovpn/main.c",
            "drivers/net/ovpn/peer.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "097d62df38314c14b88fab9096f3461baf158e2b",
              "status": "affected",
              "version": "80747caef33d77f5c1b3d24644e6d7dae69066b5",
              "versionType": "git"
            },
            {
              "lessThan": "de9fec2a6645f5b4d23398cd870a33e2703728d9",
              "status": "affected",
              "version": "80747caef33d77f5c1b3d24644e6d7dae69066b5",
              "versionType": "git"
            },
            {
              "lessThan": "982422b11e6f95f766a8cd2c2b1cbdb77e234a61",
              "status": "affected",
              "version": "80747caef33d77f5c1b3d24644e6d7dae69066b5",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "drivers/net/ovpn/main.c",
            "drivers/net/ovpn/peer.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: fix race between deleting interface and adding new peer\n\nWhile deleting an existing ovpn interface, there is a very\nnarrow window where adding a new peer via netlink may cause\nthe netdevice to hang and prevent its unregistration.\n\nIt may happen during ovpn_dellink(), when all existing peers are\nfreed and the device is queued for deregistration, but a\nCMD_PEER_NEW message comes in adding a new peer that takes again\na reference to the netdev.\n\nAt this point there is no way to release the device because we are\nunder the assumption that all peers were already released.\n\nFix the race condition by releasing all peers in ndo_uninit(),\nwhen the netdevice has already been removed from the netdev\nlist.\n\nAlso ovpn_peer_add() has now an extra check that forces the\nfunction to bail out if the device reg_state is not REGISTERED.\nThis way any incoming CMD_PEER_NEW racing with the interface\ndeletion routine will simply stop before adding the peer.\n\nNote that the above check happens while holding the netdev_lock\nto prevent racing netdev state changes.\n\novpn_dellink() is now empty and can be removed."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-07-19T15:39:29.225Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/097d62df38314c14b88fab9096f3461baf158e2b"
        },
        {
          "url": "https://git.kernel.org/stable/c/de9fec2a6645f5b4d23398cd870a33e2703728d9"
        },
        {
          "url": "https://git.kernel.org/stable/c/982422b11e6f95f766a8cd2c2b1cbdb77e234a61"
        }
      ],
      "title": "ovpn: fix race between deleting interface and adding new peer",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-64043",
    "datePublished": "2026-07-19T15:39:29.225Z",
    "dateReserved": "2026-07-19T07:54:57.029Z",
    "dateUpdated": "2026-07-19T15:39:29.225Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

Action not permitted

GHSA-74FM-4XXG-774P

CVE-2026-64043 (GCVE-0-2026-64043)

Tags

Sightings

Nomenclature