udf: validate free block extents against the partition length
In the Linux kernel, the following vulnerability has been resolved: udf: validate free block extents against the partition length udf_free_blocks() checks the logical block number and count against the partition length, but drops the extent offset from that final bound. A crafted extent can pass the guard while logicalBlockNum + offset + count points past the partition, which later indexes past the space bitmap array. A single ftruncate(2) on a file backed by such an extent reliably panics the kernel. This is a local availability issue. On desktop systems where UDisks/polkit allows the active user to mount removable UDF media without CAP_SYS_ADMIN, an unprivileged local user can supply the crafted filesystem and trigger the panic by truncating a writable file on it. Systems that require root or CAP_SYS_ADMIN to mount the image have a higher prerequisite. No confidentiality or integrity impact is claimed: the reproduced primitive is an out-of-bounds read of a bitmap pointer slot followed by a kernel panic. Use the already computed logicalBlockNum + offset + count value for the partition length check. Also make load_block_bitmap() reject an out-of-range block group before indexing s_block_bitmap[], so corrupted callers cannot walk past the flexible array.
CVE-2026-64324
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-2026-64324
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": "934f815345c09c290a9b9a9cfdddc203ec2117e8",
"lessThan": "fdd6229d2ae9914c1f25d1041db0f4f312a4fa76",
"versionType": "git"
},
{
"status": "affected",
"version": "22cc7323f090646c8cfb5939e6f15bdc2ed3fd27",
"lessThan": "b54aee5652fcd7c23a0904a4623ec462c3edc70c",
"versionType": "git"
},
{
"status": "affected",
"version": "7c4fa9ebfce69619d132fe703dc2e2cf62a13723",
"lessThan": "12af328d2ee8d68e81ba612246d0b54b22d23e1f",
"versionType": "git"
},
{
"status": "affected",
"version": "5cc9745e2ea11aef7d5c9a42bc36f6cd3e1b4cc3",
"lessThan": "fb49099206c5c57af28a157249fa7bcb5518f99e",
"versionType": "git"
},
{
"status": "affected",
"version": "56e69e59751d20993f243fb7dd6991c4e522424c",
"lessThan": "9442d75429b0c556292a7454fe888d54259f5240",
"versionType": "git"
},
{
"status": "affected",
"version": "56e69e59751d20993f243fb7dd6991c4e522424c",
"lessThan": "335202ab25b01fdd45889ff25eab70864686dea3",
"versionType": "git"
},
{
"status": "affected",
"version": "56e69e59751d20993f243fb7dd6991c4e522424c",
"lessThan": "be87de7789a82a030a4896bc7683415ec9fa6f2b",
"versionType": "git"
},
{
"status": "affected",
"version": "56e69e59751d20993f243fb7dd6991c4e522424c",
"lessThan": "5f0419457f89dce1a3f1c8e62a3adf2f39ab8168",
"versionType": "git"
},
{
"status": "affected",
"version": "097420e48e30f51e8f4f650b5c946f5af63ec1a3",
"versionType": "git"
},
{
"status": "affected",
"version": "5def895b42ef16a2da6402818cba8d7ec8ede1ef",
"versionType": "git"
},
{
"status": "affected",
"version": "05fb2bf477d3fe5421bd4cb699574737f52bd88b",
"versionType": "git"
},
{
"status": "affected",
"version": "5.10.224",
"lessThan": "5.10.261",
"versionType": "semver"
},
{
"status": "affected",
"version": "5.15.165",
"lessThan": "5.15.212",
"versionType": "semver"
},
{
"status": "affected",
"version": "6.1.105",
"lessThan": "6.1.178",
"versionType": "semver"
},
{
"status": "affected",
"version": "6.6.46",
"lessThan": "6.6.145",
"versionType": "semver"
},
{
"status": "affected",
"version": "4.19.320",
"lessThan": "4.20",
"versionType": "semver"
},
{
"status": "affected",
"version": "5.4.282",
"lessThan": "5.5",
"versionType": "semver"
},
{
"status": "affected",
"version": "6.10.5",
"lessThan": "6.11",
"versionType": "semver"
}
],
"programFiles": [
"fs/udf/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": "6.11"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.11",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.10.261",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
},
{
"status": "unaffected",
"version": "5.15.212",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.178",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.145",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.96",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.39",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.1.4",
"versionType": "semver",
"lessThanOrEqual": "7.1.*"
},
{
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"fs/udf/balloc.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-64324
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #41010 · Revision 1
- Added to Heist Feed
- Publisher date