Vulnerability-Lookup

GHSA-MGHJ-W558-VM84

Vulnerability from github – Published: 2026-07-20 18:32 – Updated: 2026-07-20 18:32

Details

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

net/sched: dualpi2: fix GSO backlog accounting

When DualPI2 splits a GSO skb into N segments, it propagates N additional packets to its parent before returning NET_XMIT_SUCCESS. The parent then accounts for the original skb once more, leaving its qlen one larger than the number of packets actually queued.

With QFQ as the parent, after all real packets are dequeued, QFQ still has a non-zero qlen while its in-service aggregate has no active classes. qfq_choose_next_agg() returns NULL and qfq_dequeue() passes the result to qfq_peek_skb(), causing a NULL pointer dereference.

Follow the same pattern used by tbf_segment() and taprio: count only successfully queued segments, propagate the difference between the original skb and those segments, and return NET_XMIT_SUCCESS whenever at least one segment was queued.

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{
  "affected": [],
  "aliases": [
    "CVE-2026-64207"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-07-20T17:18:22Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: dualpi2: fix GSO backlog accounting\n\nWhen DualPI2 splits a GSO skb into N segments, it propagates N\nadditional packets to its parent before returning NET_XMIT_SUCCESS.\nThe parent then accounts for the original skb once more, leaving its\nqlen one larger than the number of packets actually queued.\n\nWith QFQ as the parent, after all real packets are dequeued, QFQ still\nhas a non-zero qlen while its in-service aggregate has no active\nclasses. qfq_choose_next_agg() returns NULL and qfq_dequeue() passes\nthe result to qfq_peek_skb(), causing a NULL pointer dereference.\n\nFollow the same pattern used by tbf_segment() and taprio: count only\nsuccessfully queued segments, propagate the difference between the\noriginal skb and those segments, and return NET_XMIT_SUCCESS whenever\nat least one segment was queued.",
  "id": "GHSA-mghj-w558-vm84",
  "modified": "2026-07-20T18:32:34Z",
  "published": "2026-07-20T18:32:34Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-64207"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/05ed733b65ab977dd931e7f7ac0f62fdb81205c2"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/806586e33891066487db1f002be3d455cda6b516"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c4b70c1512b8f9f33f23c2c8196dfd1210207681"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

CVE-2026-64207 (GCVE-0-2026-64207)

Vulnerability from cvelistv5 – Published: 2026-07-20 16:27 – Updated: 2026-07-20 16:27

Title

net/sched: dualpi2: fix GSO backlog accounting

Summary

In the Linux kernel, the following vulnerability has been resolved: net/sched: dualpi2: fix GSO backlog accounting When DualPI2 splits a GSO skb into N segments, it propagates N additional packets to its parent before returning NET_XMIT_SUCCESS. The parent then accounts for the original skb once more, leaving its qlen one larger than the number of packets actually queued. With QFQ as the parent, after all real packets are dequeued, QFQ still has a non-zero qlen while its in-service aggregate has no active classes. qfq_choose_next_agg() returns NULL and qfq_dequeue() passes the result to qfq_peek_skb(), causing a NULL pointer dereference. Follow the same pattern used by tbf_segment() and taprio: count only successfully queued segments, propagate the difference between the original skb and those segments, and return NET_XMIT_SUCCESS whenever at least one segment was queued.

Severity

No CVSS data available.

Assigner

Linux

References

3 references

URL	Tags
https://git.kernel.org/stable/c/c4b70c1512b8f9f33…
https://git.kernel.org/stable/c/806586e3389106648…
https://git.kernel.org/stable/c/05ed733b65ab977dd…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 8f9516daedd67097a0c6e463fcb7a42b5ee9d477 , < c4b70c1512b8f9f33f23c2c8196dfd1210207681 (git) Affected: 8f9516daedd67097a0c6e463fcb7a42b5ee9d477 , < 806586e33891066487db1f002be3d455cda6b516 (git) Affected: 8f9516daedd67097a0c6e463fcb7a42b5ee9d477 , < 05ed733b65ab977dd931e7f7ac0f62fdb81205c2 (git)
Linux	Linux	Affected: 6.17 Unaffected: 0 , < 6.17 (semver) Unaffected: 6.18.39 , ≤ 6.18.* (semver) Unaffected: 7.1.4 , ≤ 7.1.* (semver) Unaffected: 7.2-rc1 , ≤ * (original_commit_for_fix)

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "net/sched/sch_dualpi2.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "c4b70c1512b8f9f33f23c2c8196dfd1210207681",
              "status": "affected",
              "version": "8f9516daedd67097a0c6e463fcb7a42b5ee9d477",
              "versionType": "git"
            },
            {
              "lessThan": "806586e33891066487db1f002be3d455cda6b516",
              "status": "affected",
              "version": "8f9516daedd67097a0c6e463fcb7a42b5ee9d477",
              "versionType": "git"
            },
            {
              "lessThan": "05ed733b65ab977dd931e7f7ac0f62fdb81205c2",
              "status": "affected",
              "version": "8f9516daedd67097a0c6e463fcb7a42b5ee9d477",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "net/sched/sch_dualpi2.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "6.17"
            },
            {
              "lessThan": "6.17",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.39",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2-rc1",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.39",
                  "versionStartIncluding": "6.17",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.1.4",
                  "versionStartIncluding": "6.17",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.2-rc1",
                  "versionStartIncluding": "6.17",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet/sched: dualpi2: fix GSO backlog accounting\n\nWhen DualPI2 splits a GSO skb into N segments, it propagates N\nadditional packets to its parent before returning NET_XMIT_SUCCESS.\nThe parent then accounts for the original skb once more, leaving its\nqlen one larger than the number of packets actually queued.\n\nWith QFQ as the parent, after all real packets are dequeued, QFQ still\nhas a non-zero qlen while its in-service aggregate has no active\nclasses. qfq_choose_next_agg() returns NULL and qfq_dequeue() passes\nthe result to qfq_peek_skb(), causing a NULL pointer dereference.\n\nFollow the same pattern used by tbf_segment() and taprio: count only\nsuccessfully queued segments, propagate the difference between the\noriginal skb and those segments, and return NET_XMIT_SUCCESS whenever\nat least one segment was queued."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-07-20T16:27:54.447Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
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          "url": "https://git.kernel.org/stable/c/c4b70c1512b8f9f33f23c2c8196dfd1210207681"
        },
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          "url": "https://git.kernel.org/stable/c/806586e33891066487db1f002be3d455cda6b516"
        },
        {
          "url": "https://git.kernel.org/stable/c/05ed733b65ab977dd931e7f7ac0f62fdb81205c2"
        }
      ],
      "title": "net/sched: dualpi2: fix GSO backlog accounting",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
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  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-64207",
    "datePublished": "2026-07-20T16:27:54.447Z",
    "dateReserved": "2026-07-19T15:36:31.769Z",
    "dateUpdated": "2026-07-20T16:27:54.447Z",
    "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.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.

Action not permitted

GHSA-MGHJ-W558-VM84

CVE-2026-64207 (GCVE-0-2026-64207)

Tags

Sightings

Nomenclature