FKIE_CVE-2026-53389

Vulnerability from fkie_nvd - Published: 2026-07-19 12:16 - Updated: 2026-07-20 15:16
Severity
7.8 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
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.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/5ba9950bc9078e19b69cca1e56d1553b125c6857
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/6ce7ef41743740ce15c2061561b784148b565b3f
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/7ddc29a094d96e9b3aa280433c6dc443df9eabf2
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/e77fbefd1269b5c123e7c651a1ebdce1b87d19a0
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/ipv4/tcp_ao.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "6ce7ef41743740ce15c2061561b784148b565b3f",
              "status": "affected",
              "version": "d6732b95b6fbbc6d5bb9d2f809e275763640c4a2",
              "versionType": "git"
            },
            {
              "lessThan": "e77fbefd1269b5c123e7c651a1ebdce1b87d19a0",
              "status": "affected",
              "version": "d6732b95b6fbbc6d5bb9d2f809e275763640c4a2",
              "versionType": "git"
            },
            {
              "lessThan": "7ddc29a094d96e9b3aa280433c6dc443df9eabf2",
              "status": "affected",
              "version": "d6732b95b6fbbc6d5bb9d2f809e275763640c4a2",
              "versionType": "git"
            },
            {
              "lessThan": "5ba9950bc9078e19b69cca1e56d1553b125c6857",
              "status": "affected",
              "version": "d6732b95b6fbbc6d5bb9d2f809e275763640c4a2",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/ipv4/tcp_ao.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.7"
            },
            {
              "lessThan": "6.7",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.95",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.38",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.3",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2-rc1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/tcp-ao: fix use-after-free of key in del_async path\n\nIn tcp_ao_delete_key(), the del_async path skips the current_key\nand rnext_key validity checks present in the synchronous path,\nassuming these pointers are always NULL on LISTEN sockets.  However,\nif a key was added with set_current=1/set_rnext=1 while the socket\nwas in CLOSE state, current_key and rnext_key will be non-NULL\nafter listen() transitions the socket to LISTEN.\n\nWhen such a key is deleted with del_async=1, hlist_del_rcu() and\ncall_rcu() free the key without clearing the dangling pointers.\nAfter the RCU grace period, getsockopt(TCP_AO_INFO) dereferences\ncurrent_key-\u003esndid and rnext_key-\u003ercvid from freed slab memory.\n\nClear current_key and rnext_key in the del_async path when they\nreference the key being deleted."
    }
  ],
  "id": "CVE-2026-53389",
  "lastModified": "2026-07-20T15:16:41.410",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 7.8,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.9,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-07-19T12:16:49.890",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/5ba9950bc9078e19b69cca1e56d1553b125c6857"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/6ce7ef41743740ce15c2061561b784148b565b3f"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/7ddc29a094d96e9b3aa280433c6dc443df9eabf2"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/e77fbefd1269b5c123e7c651a1ebdce1b87d19a0"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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