exfat: fix divide-by-zero in exfat_allocate_bitmap

{
  "id": "12f56319f0eca0ea6e67b41858fd06957765e24b94b476de7c38af0ab4214dec",
  "url": "https://osv.dev/vulnerability/CVE-2025-68350",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "exfat: fix divide-by-zero in exfat_allocate_bitmap",
    "summary": "In the Linux kernel, the following vulnerability has been resolved: exfat: fix divide-by-zero in exfat_allocate_bitmap The variable max_ra_count can be 0 in exfat_allocate_bitmap(), which causes a divide-by-zero error in the subsequent modulo operation (i % max_ra_count), leading to a system crash. When max_ra_count is 0, it means that readahead is not used. This patch load the bitmap without readahead.",
    "evidence": "osv:CVE-2025-68350",
    "products": [
      {
        "name": {
          "value": "Kernel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "6.18.2",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "CVE-2025-68350",
      "aliases": [
        "CVE-2025-68350"
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
              "type": "GIT",
              "events": [
                {
                  "introduced": "9fd688678dd86e3be32a35e3b2c5cc3ef0c4e257"
                },
                {
                  "fixed": "88fc3dd6e631b3e2975f898c6c2b6bc6f7058b44"
                },
                {
                  "fixed": "d70a5804c563b5e34825353ba9927509df709651"
                }
              ]
            }
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-68350.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "6.18.0"
                },
                {
                  "fixed": "6.18.2"
                }
              ]
            }
          ],
          "package": {
            "name": "Kernel",
            "ecosystem": "Linux"
          },
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-68350.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:37.359098346Z",
      "provider": "osv",
      "references": [
        "https://git.kernel.org/stable/c/88fc3dd6e631b3e2975f898c6c2b6bc6f7058b44",
        "https://git.kernel.org/stable/c/d70a5804c563b5e34825353ba9927509df709651",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/68xxx/CVE-2025-68350.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2025-68350",
        "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/2025/68xxx/CVE-2025-68350.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2025-68350",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 504850,
  "published_at": "2025-12-24T10:32:41.931+00:00"
}