fs/ntfs3: bound attr_off in UpdateResidentValue against data_off

{
  "id": "2bcd7d0eb52a350823a376acbfffa80b0536943fea5d5b6029b4e418f124b20d",
  "url": "https://osv.dev/vulnerability/CVE-2026-72195",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "fs/ntfs3: bound attr_off in UpdateResidentValue against data_off",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: fs/ntfs3: bound attr_off in UpdateResidentValue against data_off In do_action()'s UpdateResidentValue case (fslog.c:3307), lrh->attr_off and lrh->redo_len come from the on-disk LRH. When they satisfy aoff + dlen < attr->res.data_off, the assignment attr->res.data_size = cpu_to_le32(aoff + dlen - data_off); underflows to ~4 GiB (e.g. 0xFFFFFFF9 when aoff=0x10, dlen=1, data_off=0x18). Subsequent code that reads attr->res.data_size to walk the resident attribute payload would then read up to 4 GiB past the 1024-byte MFT record allocation. The existing mi_enum_attr() defense in fs/ntfs3/record.c:287 catches the corrupted data_size on the next attribute walk and fails the mount, but only on the path that walks all attributes. A read site that picks an attribute by name and reads its data_size without re-validating is not covered. Validate aoff against data_off and asize at the source. Reproduced under UML+KASAN on mainline 8d90b09e6741 via pr_warn-only probe: with aoff=0x10 and data_off=0x18, the post-assignment data_size is 0xfffffff9 (mount then fails at -22 from mi_enum_attr). [almaz.alexandrovich@paragon-software.com: clang-formatted the changes]",
    "evidence": "osv:CVE-2026-72195",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
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        "affected_versions": []
      }
    ],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-72195",
      "aliases": [
        "CVE-2026-72195"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"
        }
      ],
      "affected": [
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                  "introduced": "5.15.0"
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          "package": {
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            "ecosystem": "Linux"
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      ],
      "modified": "2026-10-28T02:30:51.944284629Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/50b5e83384e7fed3d11d18b79ff350e9d6d89861",
        "https://git.kernel.org/stable/c/53c12f178f584dc5f836ffe2782138a6e9348ed9",
        "https://git.kernel.org/stable/c/546518468e6c9ea469669eef78f8cc380ad6e2ca",
        "https://git.kernel.org/stable/c/97758fd9756b5f09e9ddc6a5f6a569041acc8421",
        "https://git.kernel.org/stable/c/a89c66674283a0293c0f266dc57087a6114371a3",
        "https://git.kernel.org/stable/c/ab8761676d638c5be170aaf91b7ffdd451236616",
        "https://git.kernel.org/stable/c/d1570c48f49a693974d000251030370ee2e83539",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/72xxx/CVE-2026-72195.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-72195",
        "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/2026/72xxx/CVE-2026-72195.json"
      }
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    "related_cves": [
      {
        "value": "CVE-2026-72195",
        "evidence": "/id"
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    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 520904,
  "published_at": "2026-08-15T05:53:54.869+00:00"
}