ntfs: bound the attribute-list entry in ntfs_read_inode_mount()

{
  "id": "c4e2ee7536345e2a22b18e609e73bba8d98863cb2c46e37ebf57d369d0a6bc3a",
  "url": "https://osv.dev/vulnerability/CVE-2026-80869",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "ntfs: bound the attribute-list entry in ntfs_read_inode_mount()",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: ntfs: bound the attribute-list entry in ntfs_read_inode_mount() The $MFT attribute-list walk in ntfs_read_inode_mount() validates each entry only with \"(u8 *)al_entry + 6 > al_end\" and \"(u8 *)al_entry + le16_to_cpu(al_entry->length) > al_end\", but then reads al_entry->lowest_vcn (an __le64 at offset 8) and al_entry->mft_reference (offset 16) -- fields beyond the 6 bytes proven in range. al_entry->length is attacker-controlled and only required non-zero, so a short entry (e.g. length 8) placed at the tail passes both checks while the lowest_vcn / mft_reference reads fall past al_end. al_end is ni->attr_list + attr_list_size (the on-disk size); the buffer is kvzalloc(round_up(attr_list_size, SECTOR_SIZE)), so the sector rounding usually absorbs the over-read -- but when attr_list_size is a multiple of SECTOR_SIZE there is no slack and a crafted $MFT attribute list produces an out-of-bounds read at mount time. Validate the entry with ntfs_attr_list_entry_is_valid() (added in patch 1/3) before dereferencing it, matching the bound the other attribute-list walks now use. The validator already requires the length to cover the fixed header, which makes the separate \"!al_entry->length\" check redundant, so drop it too.",
    "evidence": "osv:CVE-2026-80869",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "7.1.5",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2026-80869",
      "aliases": [
        "CVE-2026-80869"
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "1e9ea7e04472d4e5e12e58c881eaacfb3e49b669"
                },
                {
                  "fixed": "c7a7e48e71ce915ec4cbd6e9f355590c1ecbc29a"
                },
                {
                  "fixed": "98634df5b1cb56c26299b7409227025ddb0167d8"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-80869.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "7.1.0"
                },
                {
                  "fixed": "7.1.5"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-80869.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:48.310126012Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/98634df5b1cb56c26299b7409227025ddb0167d8",
        "https://git.kernel.org/stable/c/c7a7e48e71ce915ec4cbd6e9f355590c1ecbc29a",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/80xxx/CVE-2026-80869.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-80869",
        "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-2026-80869.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-80869",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 516673,
  "published_at": "2026-09-04T16:48:27.068+00:00"
}