fs/ntfs3: reject restart table growth beyond U16_MAX entries

{
  "id": "8b5b40b754bb07502cacedeef8f2652c425a2a19da5bfb09a56bb8cc1aa1e443",
  "url": "https://osv.dev/vulnerability/CVE-2026-89782",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "fs/ntfs3: reject restart table growth beyond U16_MAX entries",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: fs/ntfs3: reject restart table growth beyond U16_MAX entries During $LogFile replay, log_replay() indexes the transaction table by the transact_id taken from the log record header. check_log_rec() only verifies that transact_id is non-zero and properly aligned, not its magnitude, so a crafted image can request an arbitrarily large index. alloc_rsttbl_from_idx() grows the table to cover that index via extend_rsttbl(), which passes the new entry count to init_rsttbl(): rt = init_rsttbl(esize, used + add); used + add is computed as u32 but init_rsttbl() takes a u16, and the count is stored in struct RESTART_TABLE as a __le16. When used + add exceeds U16_MAX it is truncated, init_rsttbl() allocates a table far smaller than the index requires, and alloc_rsttbl_from_idx() then dereferences and writes at the original, untruncated offset -- an out-of-bounds access past the allocation, reachable by mounting a crafted NTFS image. BUG: KASAN: use-after-free in alloc_rsttbl_from_idx (fs/ntfs3/fslog.c:950) Read of size 4 at addr ffff8880327ffff8 by task exploit alloc_rsttbl_from_idx (fs/ntfs3/fslog.c:950) log_replay (fs/ntfs3/fslog.c:4562) ntfs_loadlog_and_replay (fs/ntfs3/fsntfs.c:324) ntfs_fill_super (fs/ntfs3/super.c:1393) get_tree_bdev_flags vfs_get_tree path_mount __x64_sys_mount A restart table is limited to U16_MAX entries by its __le16 count, so a larger growth request is invalid input. Reject it in extend_rsttbl(",
    "evidence": "osv:CVE-2026-89782",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "5.15.221",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.1.188",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.6.157",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.12.110",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "6.18.52",
            "evidence": "/affected/1/ranges"
          },
          {
            "value": "7.2.6",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-89782",
      "aliases": [
        "CVE-2026-89782"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
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              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
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                  "fixed": "339e59996ff193adcf1c438cf05f19e753beb3a7"
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                  "fixed": "ecde45cd81dc28f5696c312c5ce5a509962e9ab1"
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                  "fixed": "be218a01aadffe33ed4fc73e25276d676ebbd09d"
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                  "fixed": "967a5ff8a614d10126b6d46db1ac040948d6cb42"
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                {
                  "fixed": "111f8d74a19d85942ecbb3aba78f6f3c88e59391"
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              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-89782.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "5.15.0"
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                {
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                  "introduced": "6.19.0"
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          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-89782.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:26.896610030Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/111f8d74a19d85942ecbb3aba78f6f3c88e59391",
        "https://git.kernel.org/stable/c/339e59996ff193adcf1c438cf05f19e753beb3a7",
        "https://git.kernel.org/stable/c/967a5ff8a614d10126b6d46db1ac040948d6cb42",
        "https://git.kernel.org/stable/c/aad605a450611e2a7b7cf9dd5724004d39192bfb",
        "https://git.kernel.org/stable/c/be218a01aadffe33ed4fc73e25276d676ebbd09d",
        "https://git.kernel.org/stable/c/caa0ec3fc44a13d7c21d78e4722f4f05f87ccf56",
        "https://git.kernel.org/stable/c/ecde45cd81dc28f5696c312c5ce5a509962e9ab1",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89782.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-89782",
        "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/2026/89xxx/CVE-2026-89782.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-89782",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 493564,
  "published_at": "2026-09-16T08:48:21.093+00:00"
}