CVE-2026-97923 (GCVE-0-2026-97923)
Vulnerability from cvelistv5
Published
2026-09-25 10:22
Modified
2026-10-19 09:10
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
Impacted products
Vendor Product Version
Linux Linux Version: 656fe2ba85e81d00e4447bf77b8da2be3c47acb2
Version: 656fe2ba85e81d00e4447bf77b8da2be3c47acb2
Version: 656fe2ba85e81d00e4447bf77b8da2be3c47acb2
Version: 656fe2ba85e81d00e4447bf77b8da2be3c47acb2
Version: 656fe2ba85e81d00e4447bf77b8da2be3c47acb2
Version: 656fe2ba85e81d00e4447bf77b8da2be3c47acb2
Version: 656fe2ba85e81d00e4447bf77b8da2be3c47acb2
Version: 656fe2ba85e81d00e4447bf77b8da2be3c47acb2
Version: 836717841a30d7845cdf9cb806ee0ff3bfa7135a
Version: 4.19.100   ≤
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{
  "containers": {
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        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "kernel/trace/trace_events_hist.c"
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          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
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            },
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              "lessThanOrEqual": "6.1.*",
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              "version": "7.3",
              "versionType": "original_commit_for_fix"
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      ],
      "cpeApplicability": [
        {
          "nodes": [
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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."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-19T09:10:50.106Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/608b7751926ec08fae6a1ac4e7308195da68c362"
        },
        {
          "url": "https://git.kernel.org/stable/c/4870f9071c9ea3c1423a07741b85a794db30d672"
        },
        {
          "url": "https://git.kernel.org/stable/c/352f84a381e7b4651b30366e93cb858f3fa9c91a"
        },
        {
          "url": "https://git.kernel.org/stable/c/4924328d6991f25b65bb7c8ff5d56c2a9b254851"
        },
        {
          "url": "https://git.kernel.org/stable/c/74375caa20fe5165807b4334c783d1790b01f02a"
        },
        {
          "url": "https://git.kernel.org/stable/c/222abcbe7866fef04563b6eb89fb21f627dcbc77"
        },
        {
          "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": "2026-10-19T09:10:50.106Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}


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