{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "ccd979bdbce9fba8412beb3f1de68a9d0171b12c"
            },
            {
              "fixed": "1001fb3b69a11eaa0dc7c7428f6edfa48b88997a"
            },
            {
              "fixed": "c0c165487a2ea5a37ddcdab4259157b7a527129c"
            },
            {
              "fixed": "b53e2b271eeb6040c2a4a78230c570dc41cdcfa4"
            },
            {
              "fixed": "a63308ab426f3a3c7e33b02c150ea59054620261"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.6.16"
            },
            {
              "fixed": "6.12.109"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.50"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.2.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89490.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nocfs2: fix readdir position truncation on 32-bit kernels\n\nIn ocfs2_dir_foreach_blk_el(), the directory cookie position is\nrebuilt with\n\n\tctx-\u003epos = (ctx-\u003epos \u0026 ~(sb-\u003es_blocksize - 1)) | offset;\n\n`ctx-\u003epos` is loff_t (signed 64-bit), while `sb-\u003es_blocksize` is\nunsigned long.  On 32-bit kernels unsigned long is 32-bit, so the mask\n\n\t~(sb-\u003es_blocksize - 1)\n\nis computed as a 32-bit unsigned value (e.g. 0xfffff000 for a 4 KiB\nblock size).  In the AND expression with the 64-bit `ctx-\u003epos`, that\nunsigned operand is zero-extended to 64 bits per the usual arithmetic\nconversions, yielding 0x00000000fffff000.  The high 32 bits of\n`ctx-\u003epos` are silently cleared, even though directory size is\nallowed to exceed 4 GiB.\n\nWhen readdir() crosses the 4 GiB boundary on a 32-bit kernel the\nposition is reset back into the first 4 GiB block, making the\nre-validation path re-enumerate already-returned dirents indefinitely.\n\nThis is ocfs2_dir_foreach_blk_el(), the extent-list readdir path taken\nfor all non-inline directories, so a directory large enough to cross\n4 GiB reaches it.\n\nThis is the same class of bug that commit 3dce5bb82c97 (\"exfat: Fix\nbitwise operation having different size\") fixed in exfat, and the\nfix mirrors the equivalent ext4 fix in this series.  Cast the operand\nto loff_t so the mask is 64-bit before the AND:\n\n\tctx-\u003epos = (ctx-\u003epos \u0026 ~((loff_t)sb-\u003es_blocksize - 1)) | offset;\n\n64-bit kernels are unaffected.",
  "id": "CVE-2026-89490",
  "modified": "2026-09-13T03:30:56.346439368Z",
  "published": "2026-09-11T19:43:42.808Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/1001fb3b69a11eaa0dc7c7428f6edfa48b88997a"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a63308ab426f3a3c7e33b02c150ea59054620261"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/b53e2b271eeb6040c2a4a78230c570dc41cdcfa4"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c0c165487a2ea5a37ddcdab4259157b7a527129c"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/89xxx/CVE-2026-89490.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-89490"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.9.0",
  "summary": "ocfs2: fix readdir position truncation on 32-bit kernels"
}