net/tcp-ao: fix use-after-free of key in del_async path

{
  "id": "51d8bb565ee69af969da9496b3ec11c91ca0a5d8c667d6d6d7eb186669a0ec28",
  "url": "https://osv.dev/vulnerability/CVE-2026-53389",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "net/tcp-ao: fix use-after-free of key in del_async path",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: net/tcp-ao: fix use-after-free of key in del_async path In tcp_ao_delete_key(), the del_async path skips the current_key and rnext_key validity checks present in the synchronous path, assuming these pointers are always NULL on LISTEN sockets. However, if a key was added with set_current=1/set_rnext=1 while the socket was in CLOSE state, current_key and rnext_key will be non-NULL after listen() transitions the socket to LISTEN. When such a key is deleted with del_async=1, hlist_del_rcu() and call_rcu() free the key without clearing the dangling pointers. After the RCU grace period, getsockopt(TCP_AO_INFO) dereferences current_key->sndid and rnext_key->rcvid from freed slab memory. Clear current_key and rnext_key in the del_async path when they reference the key being deleted.",
    "evidence": "osv:CVE-2026-53389",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.12.95",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.18.38",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "7.1.3",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-53389",
      "aliases": [
        "CVE-2026-53389"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
        }
      ],
      "affected": [
        {
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              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
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                  "fixed": "e77fbefd1269b5c123e7c651a1ebdce1b87d19a0"
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                {
                  "fixed": "7ddc29a094d96e9b3aa280433c6dc443df9eabf2"
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                {
                  "fixed": "5ba9950bc9078e19b69cca1e56d1553b125c6857"
                }
              ]
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          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-53389.json"
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        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
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                  "introduced": "6.7.0"
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                  "fixed": "6.18.38"
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            {
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              "events": [
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                  "introduced": "6.19.0"
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                  "fixed": "7.1.3"
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          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-53389.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:27.427941105Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/5ba9950bc9078e19b69cca1e56d1553b125c6857",
        "https://git.kernel.org/stable/c/6ce7ef41743740ce15c2061561b784148b565b3f",
        "https://git.kernel.org/stable/c/7ddc29a094d96e9b3aa280433c6dc443df9eabf2",
        "https://git.kernel.org/stable/c/e77fbefd1269b5c123e7c651a1ebdce1b87d19a0",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53389.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-53389",
        "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/2026/53xxx/CVE-2026-53389.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-53389",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 493633,
  "published_at": "2026-07-19T12:01:54.386+00:00"
}