Vulnerability-Lookup

FKIE_CVE-2026-97923

Vulnerability from fkie_nvd - Published: 2026-09-25 11:17 - Updated: 2026-09-25 11:17

Severity

Summary

In the Linux kernel, the following vulnerability has been resolved: tracing: Free histogram the var ref when its initialization fails create_var_ref() allocates a VAR_REF hist_field and then calls init_var_ref() to fill it in. When that fails the field is leaked. commit 656fe2ba85e8 ("tracing: Use hist trigger's var_ref array to destroy var_refs") made destroy_hist_field() return early for HIST_FIELD_FL_VAR_REF, since var refs are freed by walking the trigger's var_refs[] array instead. create_var_ref() adds the field to that array only after init_var_ref() has succeeded, so on this path the field is in neither place and nothing frees it. The call was correct when it was written, before var refs were taken out of destroy_hist_field(). init_var_ref() cannot free it either. The caller owns the field, so init_var_ref() undoes only its own string allocations and leaves the field alone. Freeing it there would leave create_var_ref() passing freed memory to destroy_hist_field(), which reads its flags. Call __destroy_hist_field(), which frees the field without consulting the flag.

References

	URL	Tags
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/222abcbe7866fef04563b6eb89fb21f627dcbc77
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/516001d53e6b2ea95a251ee2ef54a1a689a3fd58
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/74375caa20fe5165807b4334c783d1790b01f02a
	416baaa9-dc9f-4396-8d5f-8c081fb06d67	https://git.kernel.org/stable/c/a69baeac38677270656e85753d93856a076dee57

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "kernel/trace/trace_events_hist.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "74375caa20fe5165807b4334c783d1790b01f02a",
              "status": "affected",
              "version": "656fe2ba85e81d00e4447bf77b8da2be3c47acb2",
              "versionType": "git"
            },
            {
              "lessThan": "222abcbe7866fef04563b6eb89fb21f627dcbc77",
              "status": "affected",
              "version": "656fe2ba85e81d00e4447bf77b8da2be3c47acb2",
              "versionType": "git"
            },
            {
              "lessThan": "a69baeac38677270656e85753d93856a076dee57",
              "status": "affected",
              "version": "656fe2ba85e81d00e4447bf77b8da2be3c47acb2",
              "versionType": "git"
            },
            {
              "lessThan": "516001d53e6b2ea95a251ee2ef54a1a689a3fd58",
              "status": "affected",
              "version": "656fe2ba85e81d00e4447bf77b8da2be3c47acb2",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "836717841a30d7845cdf9cb806ee0ff3bfa7135a",
              "versionType": "git"
            },
            {
              "lessThan": "4.20",
              "status": "affected",
              "version": "4.19.100",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "kernel/trace/trace_events_hist.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "5.0"
            },
            {
              "lessThan": "5.0",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.111",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.53",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.7",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3-rc3",
              "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\ntracing: Free histogram the var ref when its initialization fails\n\ncreate_var_ref() allocates a VAR_REF hist_field and then calls\ninit_var_ref() to fill it in. When that fails the field is leaked.\n\ncommit 656fe2ba85e8 (\"tracing: Use hist trigger\u0027s var_ref array to destroy\nvar_refs\") made destroy_hist_field() return early for\nHIST_FIELD_FL_VAR_REF, since var refs are freed by walking the trigger\u0027s\nvar_refs[] array instead. create_var_ref() adds the field to that array\nonly after init_var_ref() has succeeded, so on this path the field is in\nneither place and nothing frees it. The call was correct when it was\nwritten, before var refs were taken out of destroy_hist_field().\n\ninit_var_ref() cannot free it either. The caller owns the field, so\ninit_var_ref() undoes only its own string allocations and leaves the\nfield alone. Freeing it there would leave create_var_ref() passing freed\nmemory to destroy_hist_field(), which reads its flags.\n\nCall __destroy_hist_field(), which frees the field without consulting\nthe flag."
    }
  ],
  "id": "CVE-2026-97923",
  "lastModified": "2026-09-25T11:17:19.413",
  "metrics": {},
  "published": "2026-09-25T11:17:19.413",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/222abcbe7866fef04563b6eb89fb21f627dcbc77"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/516001d53e6b2ea95a251ee2ef54a1a689a3fd58"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/74375caa20fe5165807b4334c783d1790b01f02a"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/a69baeac38677270656e85753d93856a076dee57"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}

CVE-2026-97923 (GCVE-0-2026-97923)

Vulnerability from cvelistv5 – Published: 2026-09-25 10:22 – Updated: 2026-09-25 10:22

Title

tracing: Free histogram the var ref when its initialization fails

Summary

Severity

No CVSS data available.

Assigner

Linux mitre root

References

4 references

URL	Tags
https://git.kernel.org/stable/c/74375caa20fe51658…
https://git.kernel.org/stable/c/222abcbe7866fef04…
https://git.kernel.org/stable/c/a69baeac386772706…
https://git.kernel.org/stable/c/516001d53e6b2ea95…

Impacted products

2 products

Vendor	Product	Version
Linux	Linux	Affected: 656fe2ba85e81d00e4447bf77b8da2be3c47acb2 , < 74375caa20fe5165807b4334c783d1790b01f02a (git) Affected: 656fe2ba85e81d00e4447bf77b8da2be3c47acb2 , < 222abcbe7866fef04563b6eb89fb21f627dcbc77 (git) Affected: 656fe2ba85e81d00e4447bf77b8da2be3c47acb2 , < a69baeac38677270656e85753d93856a076dee57 (git) Affected: 656fe2ba85e81d00e4447bf77b8da2be3c47acb2 , < 516001d53e6b2ea95a251ee2ef54a1a689a3fd58 (git) Affected: 836717841a30d7845cdf9cb806ee0ff3bfa7135a (git) Affected: 4.19.100 , < 4.20 (semver)
Linux	Linux	Affected: 5.0 Unaffected: 0 , < 5.0 (semver) Unaffected: 6.12.111 , ≤ 6.12.* (semver) Unaffected: 6.18.53 , ≤ 6.18.* (semver) Unaffected: 7.2.7 , ≤ 7.2.* (semver) Unaffected: 7.3-rc3 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "kernel/trace/trace_events_hist.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "74375caa20fe5165807b4334c783d1790b01f02a",
              "status": "affected",
              "version": "656fe2ba85e81d00e4447bf77b8da2be3c47acb2",
              "versionType": "git"
            },
            {
              "lessThan": "222abcbe7866fef04563b6eb89fb21f627dcbc77",
              "status": "affected",
              "version": "656fe2ba85e81d00e4447bf77b8da2be3c47acb2",
              "versionType": "git"
            },
            {
              "lessThan": "a69baeac38677270656e85753d93856a076dee57",
              "status": "affected",
              "version": "656fe2ba85e81d00e4447bf77b8da2be3c47acb2",
              "versionType": "git"
            },
            {
              "lessThan": "516001d53e6b2ea95a251ee2ef54a1a689a3fd58",
              "status": "affected",
              "version": "656fe2ba85e81d00e4447bf77b8da2be3c47acb2",
              "versionType": "git"
            },
            {
              "status": "affected",
              "version": "836717841a30d7845cdf9cb806ee0ff3bfa7135a",
              "versionType": "git"
            },
            {
              "lessThan": "4.20",
              "status": "affected",
              "version": "4.19.100",
              "versionType": "semver"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "kernel/trace/trace_events_hist.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
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              "version": "5.0"
            },
            {
              "lessThan": "5.0",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.111",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.53",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.2.*",
              "status": "unaffected",
              "version": "7.2.7",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.3-rc3",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.12.111",
                  "versionStartIncluding": "5.0",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "6.18.53",
                  "versionStartIncluding": "5.0",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
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                  "versionStartIncluding": "5.0",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "7.3-rc3",
                  "versionStartIncluding": "5.0",
                  "vulnerable": true
                },
                {
                  "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                  "versionStartIncluding": "4.19.100",
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                }
              ],
              "negate": false,
              "operator": "OR"
            }
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      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ntracing: Free histogram the var ref when its initialization fails\n\ncreate_var_ref() allocates a VAR_REF hist_field and then calls\ninit_var_ref() to fill it in. When that fails the field is leaked.\n\ncommit 656fe2ba85e8 (\"tracing: Use hist trigger\u0027s var_ref array to destroy\nvar_refs\") made destroy_hist_field() return early for\nHIST_FIELD_FL_VAR_REF, since var refs are freed by walking the trigger\u0027s\nvar_refs[] array instead. create_var_ref() adds the field to that array\nonly after init_var_ref() has succeeded, so on this path the field is in\nneither place and nothing frees it. The call was correct when it was\nwritten, before var refs were taken out of destroy_hist_field().\n\ninit_var_ref() cannot free it either. The caller owns the field, so\ninit_var_ref() undoes only its own string allocations and leaves the\nfield alone. Freeing it there would leave create_var_ref() passing freed\nmemory to destroy_hist_field(), which reads its flags.\n\nCall __destroy_hist_field(), which frees the field without consulting\nthe flag."
        }
      ],
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        "dateUpdated": "2026-09-25T10:22:42.300Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
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        },
        {
          "url": "https://git.kernel.org/stable/c/a69baeac38677270656e85753d93856a076dee57"
        },
        {
          "url": "https://git.kernel.org/stable/c/516001d53e6b2ea95a251ee2ef54a1a689a3fd58"
        }
      ],
      "title": "tracing: Free histogram the var ref when its initialization fails",
      "x_generator": {
        "engine": "bippy-1.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
    "assignerShortName": "Linux",
    "cveId": "CVE-2026-97923",
    "datePublished": "2026-09-25T10:22:42.300Z",
    "dateReserved": "2026-09-25T10:18:58.202Z",
    "dateUpdated": "2026-09-25T10:22:42.300Z",
    "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.

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.
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.
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FKIE_CVE-2026-97923

CVE-2026-97923 (GCVE-0-2026-97923)

Tags

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