CVE-2026-68338

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: net/packet: avoid fanout hook re-registration after unregister packet_set_ring() temporarily detaches a socket from packet delivery while reconfiguring its ring. It records the previous running state, clears po->num, unregisters the protocol hook when needed, drops po->bind_lock, and later restores po->num and re-registers the hook from the saved was_running value. That unlocked window can race with NETDEV_UNREGISTER. The notifier can observe the socket as not running, skip __unregister_prot_hook(), and invalidate the per-socket binding by setting po->ifindex to -1 and clearing po->prot_hook.dev. A one-member fanout group can still retain its shared fanout hook device pointer. When packet_set_ring() resumes, re-registering solely from the stale was_running state can re-add the fanout hook after the device has been unregistered. Treat po->ifindex == -1 as an invalidated binding after reacquiring po->bind_lock. This is distinct from ifindex 0, the normal unbound/wildcard state: ifindex -1 marks an existing device binding that was invalidated when the device was unregistered. Restore po->num as before, but do not re-register the hook if device unregister already detached the socket.

Severity

HIGH

CVSS score

7.8 (v3.1)

Vulnerability status

Received

Source identifier

416baaa9-dc9f-4396-8d5f-8c081fb06d67

Published

2026-08-10 13:20:24.230000

Last modified

2026-10-19 22:17:13.900000

View original CVE JSON

{
  "id": "CVE-2026-68338",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-08-10T13:20:24.230",
  "lastModified": "2026-10-19T22:17:13.900",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/packet: avoid fanout hook re-registration after unregister\n\npacket_set_ring() temporarily detaches a socket from packet delivery while\nreconfiguring its ring. It records the previous running state, clears\npo->num, unregisters the protocol hook when needed, drops po->bind_lock,\nand later restores po->num and re-registers the hook from the saved\nwas_running value.\n\nThat unlocked window can race with NETDEV_UNREGISTER. The notifier can\nobserve the socket as not running, skip __unregister_prot_hook(), and\ninvalidate the per-socket binding by setting po->ifindex to -1 and clearing\npo->prot_hook.dev. A one-member fanout group can still retain its shared\nfanout hook device pointer. When packet_set_ring() resumes, re-registering\nsolely from the stale was_running state can re-add the fanout hook after\nthe device has been unregistered.\n\nTreat po->ifindex == -1 as an invalidated binding after reacquiring\npo->bind_lock. This is distinct from ifindex 0, the normal\nunbound/wildcard state: ifindex -1 marks an existing device binding that\nwas invalidated when the device was unregistered. Restore po->num as\nbefore, but do not re-register the hook if device unregister already\ndetached the socket."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "net/packet/af_packet.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "dc99f600698dcac69b8f56dda9a8a00d645c5ffc",
              "lessThan": "acb40ebfa5c4d62f84339fcbf713f2a9fd033a71",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "dc99f600698dcac69b8f56dda9a8a00d645c5ffc",
              "lessThan": "c820f4b7f2fa38f8769db0d0cefdd94e2721504d",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "dc99f600698dcac69b8f56dda9a8a00d645c5ffc",
              "lessThan": "4628efbdc7affd094181f5263e65c1062e31f15f",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "dc99f600698dcac69b8f56dda9a8a00d645c5ffc",
              "lessThan": "80ec024d53a05c60ad1d08968dcf745f10c1665c",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "dc99f600698dcac69b8f56dda9a8a00d645c5ffc",
              "lessThan": "0a052e0808e015e68144a9877e6ef42b952c49fa",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "dc99f600698dcac69b8f56dda9a8a00d645c5ffc",
              "lessThan": "1bc55c29cd85818e9052f17deb287d5a11fb817f",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "dc99f600698dcac69b8f56dda9a8a00d645c5ffc",
              "lessThan": "a885387dae7986a55bae5c77a15bdd447f64e9b9",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "dc99f600698dcac69b8f56dda9a8a00d645c5ffc",
              "lessThan": "50aff80475abd3533eef4320477037e6fcc6b56e",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "net/packet/af_packet.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "3.1",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "3.1",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "5.10.265",
              "lessThanOrEqual": "5.10.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "5.15.216",
              "lessThanOrEqual": "5.15.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.1.183",
              "lessThanOrEqual": "6.1.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.6.148",
              "lessThanOrEqual": "6.6.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.12.101",
              "lessThanOrEqual": "6.12.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.42",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.1.6",
              "lessThanOrEqual": "7.1.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2",
              "lessThanOrEqual": "*",
              "versionType": "original_commit_for_fix",
              "status": "unaffected"
            }
          ]
        }
      ]
    }
  ],
  "metrics": {
    "cvssMetricV31": [
      {
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary",
        "cvssData": {
          "version": "3.1",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "baseScore": 7.8,
          "baseSeverity": "HIGH",
          "attackVector": "LOCAL",
          "attackComplexity": "LOW",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "availabilityImpact": "HIGH"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.9
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "timestamp": "2026-10-16T15:47:16.591778Z",
          "id": "CVE-2026-68338",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "version": "2.0.3"
        }
      }
    ]
  },
  "weaknesses": [
    {
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "type": "Secondary",
      "description": [
        {
          "lang": "en",
          "value": "CWE-362"
        }
      ]
    }
  ],
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/0a052e0808e015e68144a9877e6ef42b952c49fa",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
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    },
    {
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    },
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    },
    {
      "url": "https://git.kernel.org/stable/c/a885387dae7986a55bae5c77a15bdd447f64e9b9",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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}