exfat: validate cluster allocation bits of the allocation bitmap
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.
CVE-2025-40307
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2025-40307
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "1acf1a564b6034b5af1e7fb23cb98cb3bb4f6003",
"lessThan": "87f827d53bd0688597bda63ae95908e2ad39bac0",
"versionType": "git"
},
{
"status": "affected",
"version": "1acf1a564b6034b5af1e7fb23cb98cb3bb4f6003",
"lessThan": "67ce8034dc0278ddd88cad93d4218a945180dddd",
"versionType": "git"
},
{
"status": "affected",
"version": "1acf1a564b6034b5af1e7fb23cb98cb3bb4f6003",
"lessThan": "6bc58b4c53795ab5fe00648344aa7d9d61175f90",
"versionType": "git"
},
{
"status": "affected",
"version": "1acf1a564b6034b5af1e7fb23cb98cb3bb4f6003",
"lessThan": "13c1d24803d5b0446b3f6f0fdd67e07ac1fdc7bf",
"versionType": "git"
},
{
"status": "affected",
"version": "1acf1a564b6034b5af1e7fb23cb98cb3bb4f6003",
"lessThan": "79c1587b6cda74deb0c86fc7ba194b92958c793c",
"versionType": "git"
}
],
"programFiles": [
"fs/exfat/balloc.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "5.7"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "5.7",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.1.183",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.148",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.58",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.17.8",
"versionType": "semver",
"lessThanOrEqual": "6.17.*"
},
{
"status": "unaffected",
"version": "6.18",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"fs/exfat/balloc.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2025-40307
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #30712 · Revision 1
- Added to Heist Feed
- Publisher date