ocfs2: fix out-of-bounds write in ocfs2_remove_refcount_extent

{
  "id": "4b3df277f138c2d0150dfb5edcac82fe578a58c50563ee7009bcc90d0f673077",
  "url": "https://osv.dev/vulnerability/CVE-2026-80638",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "ocfs2: fix out-of-bounds write in ocfs2_remove_refcount_extent",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: ocfs2: fix out-of-bounds write in ocfs2_remove_refcount_extent [BUG] Unlinking a refcounted file whose refcount tree has leaf blocks triggers a fortify panic due to an out-of-bounds write. [CAUSE] When the last leaf block is removed from a refcount tree, ocfs2_remove_refcount_extent() converts the root back to leaf mode with a bulk memset on &rb->rf_records. rf_records sits in an anonymous union with rf_list. rf_list.l_tree_depth aliases rf_records.rl_count, and is 0 for a single-level tree. With rl_count equal to 0, the memset writes past the 16-byte declared size of rf_records, which the fortify checker catches. [FIX] Replace the bulk memset on &rb->rf_records with a correctly-bounded memset on rl_recs[] alone, after setting rl_count to the correct value.",
    "evidence": "osv:CVE-2026-80638",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "7.1.5",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-80638",
      "aliases": [
        "CVE-2026-80638"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "2f26f58df041bbcf692730ff4d8ab0f250d9670d"
                },
                {
                  "fixed": "f5255516ec7add3a6d5d37853ad5a9a9ddb14305"
                },
                {
                  "fixed": "1ec3cca2d8b6b9ff6584ca626d4c8918bbf48d44"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-80638.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.19.0"
                },
                {
                  "fixed": "7.1.5"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-80638.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:30.815847673Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/1ec3cca2d8b6b9ff6584ca626d4c8918bbf48d44",
        "https://git.kernel.org/stable/c/f5255516ec7add3a6d5d37853ad5a9a9ddb14305",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/80xxx/CVE-2026-80638.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-80638",
        "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
      ],
      "provider_metadata": {
        "cna_assigner": "Linux",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/80xxx/CVE-2026-80638.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-80638",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 497838,
  "published_at": "2026-08-28T06:48:51.439+00:00"
}