github - ghsa-9mhh-qxx8-wc58

GHSA-9MHH-QXX8-WC58

Vulnerability from github – Published: 2025-12-08 03:31 – Updated: 2025-12-08 03:31

Details

In the Linux kernel, the following vulnerability has been resolved:

exfat: validate cluster allocation bits of the allocation bitmap

syzbot created an exfat image with cluster bits not set for the allocation bitmap. exfat-fs reads and uses the allocation bitmap without checking this. The problem is that if the start cluster of the allocation bitmap is 6, cluster 6 can be allocated when creating a directory with mkdir. exfat zeros out this cluster in exfat_mkdir, which can delete existing entries. This can reallocate the allocated entries. In addition, the allocation bitmap is also zeroed out, so cluster 6 can be reallocated. This patch adds exfat_test_bitmap_range to validate that clusters used for the allocation bitmap are correctly marked as in-use.

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{
  "affected": [],
  "aliases": [
    "CVE-2025-40307"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2025-12-08T01:16:02Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nexfat: validate cluster allocation bits of the allocation bitmap\n\nsyzbot created an exfat image with cluster bits not set for the allocation\nbitmap. exfat-fs reads and uses the allocation bitmap without checking\nthis. The problem is that if the start cluster of the allocation bitmap\nis 6, cluster 6 can be allocated when creating a directory with mkdir.\nexfat zeros out this cluster in exfat_mkdir, which can delete existing\nentries. This can reallocate the allocated entries. In addition,\nthe allocation bitmap is also zeroed out, so cluster 6 can be reallocated.\nThis patch adds exfat_test_bitmap_range to validate that clusters used for\nthe allocation bitmap are correctly marked as in-use.",
  "id": "GHSA-9mhh-qxx8-wc58",
  "modified": "2025-12-08T03:31:01Z",
  "published": "2025-12-08T03:31:01Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2025-40307"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/13c1d24803d5b0446b3f6f0fdd67e07ac1fdc7bf"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/6bc58b4c53795ab5fe00648344aa7d9d61175f90"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/79c1587b6cda74deb0c86fc7ba194b92958c793c"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

CVE-2025-40307 (GCVE-0-2025-40307)

Vulnerability from cvelistv5 – Published: 2025-12-08 00:46 – Updated: 2025-12-08 00:46

Summary

In the Linux kernel, the following vulnerability has been resolved: exfat: validate cluster allocation bits of the allocation bitmap syzbot created an exfat image with cluster bits not set for the allocation bitmap. exfat-fs reads and uses the allocation bitmap without checking this. The problem is that if the start cluster of the allocation bitmap is 6, cluster 6 can be allocated when creating a directory with mkdir. exfat zeros out this cluster in exfat_mkdir, which can delete existing entries. This can reallocate the allocated entries. In addition, the allocation bitmap is also zeroed out, so cluster 6 can be reallocated. This patch adds exfat_test_bitmap_range to validate that clusters used for the allocation bitmap are correctly marked as in-use.

Severity ?

No CVSS data available.

Assigner

Linux

References

URL

Tags

	https://git.kernel.org/stable/c/6bc58b4c53795ab5f…
	https://git.kernel.org/stable/c/13c1d24803d5b0446…
	https://git.kernel.org/stable/c/79c1587b6cda74deb…

Impacted products

Vendor

Product

Version

Linux

Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 6bc58b4c53795ab5fe00648344aa7d9d61175f90 (git)
Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 13c1d24803d5b0446b3f6f0fdd67e07ac1fdc7bf (git)
Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 79c1587b6cda74deb0c86fc7ba194b92958c793c (git)

Linux

Unaffected: 6.12.58 , ≤ 6.12.* (semver)
Unaffected: 6.17.8 , ≤ 6.17.* (semver)
Unaffected: 6.18 , ≤ * (original_commit_for_fix)

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  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/exfat/balloc.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
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              "status": "affected",
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              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
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              "lessThan": "79c1587b6cda74deb0c86fc7ba194b92958c793c",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            }
          ]
        },
        {
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          ],
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          "vendor": "Linux",
          "versions": [
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              "lessThanOrEqual": "6.12.*",
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              "version": "6.12.58",
              "versionType": "semver"
            },
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              "status": "unaffected",
              "version": "6.17.8",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "6.18",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
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            {
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                  "vulnerable": true
                }
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              "operator": "OR"
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        }
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          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nexfat: validate cluster allocation bits of the allocation bitmap\n\nsyzbot created an exfat image with cluster bits not set for the allocation\nbitmap. exfat-fs reads and uses the allocation bitmap without checking\nthis. The problem is that if the start cluster of the allocation bitmap\nis 6, cluster 6 can be allocated when creating a directory with mkdir.\nexfat zeros out this cluster in exfat_mkdir, which can delete existing\nentries. This can reallocate the allocated entries. In addition,\nthe allocation bitmap is also zeroed out, so cluster 6 can be reallocated.\nThis patch adds exfat_test_bitmap_range to validate that clusters used for\nthe allocation bitmap are correctly marked as in-use."
        }
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      "providerMetadata": {
        "dateUpdated": "2025-12-08T00:46:32.659Z",
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    "datePublished": "2025-12-08T00:46:32.659Z",
    "dateReserved": "2025-04-16T07:20:57.185Z",
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Sightings

Author	Source	Type	Date

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

Action not permitted

GHSA-9MHH-QXX8-WC58

CVE-2025-40307 (GCVE-0-2025-40307)

Tags

Sightings

Nomenclature