GHSA-2495-48WF-CQX2
Vulnerability from github – Published: 2026-08-27 06:31 – Updated: 2026-08-27 06:31In the Linux kernel, the following vulnerability has been resolved:
ovpn: defer key slot crypto freeing to workqueue
Key slots are released through a kref and the existing release path frees the AEAD transforms from an RCU callback. That is not safe for all crypto implementations: crypto_free_aead can sleep, for example when an async or hardware implementation has teardown work to complete.
Use queue_rcu_work for key-slot release. This keeps the RCU grace period needed by lockless key-slot readers, but runs the actual crypto teardown from workqueue context where sleeping is allowed. Once the rcu_work callback runs, pre-existing RCU readers are gone, and the final kref put already proves that no transform user remains, so the worker can release the AEAD transforms and free the slot directly.
The previous patch drains ovpn_wq during module exit, so queued key-slot teardown work cannot outlive module text.
{
"affected": [],
"aliases": [
"CVE-2026-74750"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-08-26T15:16:54Z",
"severity": "HIGH"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\novpn: defer key slot crypto freeing to workqueue\n\nKey slots are released through a kref and the existing release path\nfrees the AEAD transforms from an RCU callback. That is not safe for all\ncrypto implementations: crypto_free_aead can sleep, for example when an\nasync or hardware implementation has teardown work to complete.\n\nUse queue_rcu_work for key-slot release. This keeps the RCU grace period\nneeded by lockless key-slot readers, but runs the actual crypto teardown\nfrom workqueue context where sleeping is allowed. Once the rcu_work\ncallback runs, pre-existing RCU readers are gone, and the final kref put\nalready proves that no transform user remains, so the worker can release\nthe AEAD transforms and free the slot directly.\n\nThe previous patch drains ovpn_wq during module exit, so queued key-slot\nteardown work cannot outlive module text.",
"id": "GHSA-2495-48wf-cqx2",
"modified": "2026-08-27T06:31:31Z",
"published": "2026-08-27T06:31:31Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-74750"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/0f77ed5ee91946ea63e29f2e0ff9dc9e722d8da3"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/2da3dfa1ddfe55a065f484750c83660e3bd4ac00"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
]
}
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
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- 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.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.