{
  "affected": [
    {
      "ranges": [
        {
          "events": [
            {
              "introduced": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2"
            },
            {
              "fixed": "5902a95066883cf96fa15b2680694fc5dd0c7d11"
            },
            {
              "fixed": "87b12dc360a002eb2d498aa4f01e84347019612d"
            },
            {
              "fixed": "abde9eb33106850dfa367ad3965d3588bb8558d5"
            },
            {
              "fixed": "c9d263be26806d388129fab8c6904bed197fc6af"
            }
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "type": "GIT"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "Linux",
        "name": "Kernel"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2.6.12"
            },
            {
              "fixed": "6.12.111"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.13.0"
            },
            {
              "fixed": "6.18.53"
            }
          ],
          "type": "ECOSYSTEM"
        },
        {
          "events": [
            {
              "introduced": "6.19.0"
            },
            {
              "fixed": "7.2.7"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "database_specific": {
    "cna_assigner": "Linux",
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/97xxx/CVE-2026-97926.json"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nufs: validate cylinder group metadata before caching it\n\nufs_read_cylinder() copies the cylinder group index and the rotor\npositions straight from the on-disk group and caches them without any\ncheck:\n\n\tucpi-\u003ec_cgx    = fs32_to_cpu(sb, ucg-\u003ecg_cgx);\n\tucpi-\u003ec_rotor  = fs32_to_cpu(sb, ucg-\u003ecg_rotor);\n\tucpi-\u003ec_frotor = fs32_to_cpu(sb, ucg-\u003ecg_frotor);\n\tucpi-\u003ec_irotor = fs32_to_cpu(sb, ucg-\u003ecg_irotor);\n\nThey are then used as indices during allocation and free:\n\n  - c_cgx indexes the cylinder summary array as\n    UFS_SB(sb)-\u003efs_cs(ucpi-\u003ec_cgx), so a value past s_ncg writes a 32\n    bit count outside the s_csp allocation.\n\n  - c_frotor becomes a bitmap scan start, start = c_frotor \u003e\u003e 3, and\n    then length = ((s_fpg + 7) \u003e\u003e 3) - start. A start beyond the block\n    bitmap wraps the unsigned length to a huge value, so ubh_scanc()\n    walks far past the cylinder group buffers. c_irotor drives the\n    inode bitmap the same way.\n\nA crafted image can set any of these freely, turning an ordinary\nallocation into an out of bounds access.\n\nReject a cylinder group whose recorded index does not match the group\nbeing read, or whose rotors fall outside the group, before the metadata\nis cached. Valid filesystems keep cg_cgx equal to the group number and\nthe rotors within the group, so only malformed images are rejected.",
  "id": "CVE-2026-97926",
  "modified": "2026-09-27T03:30:18.273855040Z",
  "published": "2026-09-25T10:22:44.197Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/5902a95066883cf96fa15b2680694fc5dd0c7d11"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/87b12dc360a002eb2d498aa4f01e84347019612d"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/abde9eb33106850dfa367ad3965d3588bb8558d5"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/c9d263be26806d388129fab8c6904bed197fc6af"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/97xxx/CVE-2026-97926.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-97926"
    },
    {
      "type": "PACKAGE",
      "url": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"
    }
  ],
  "schema_version": "1.9.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "ufs: validate cylinder group metadata before caching it"
}