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

Vulnerability from cvelistv5 – Published: 2025-12-08 00:46 – Updated: 2025-12-08 00:46
VLAI?
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
References
Impacted products
Vendor Product Version
Linux Linux Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 6bc58b4c53795ab5fe00648344aa7d9d61175f90 (git)
Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 13c1d24803d5b0446b3f6f0fdd67e07ac1fdc7bf (git)
Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 79c1587b6cda74deb0c86fc7ba194b92958c793c (git)
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    Linux 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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          "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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    "datePublished": "2025-12-08T00:46:32.659Z",
    "dateReserved": "2025-04-16T07:20:57.185Z",
    "dateUpdated": "2025-12-08T00:46:32.659Z",
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