udf: validate free block extents against the partition length
Summary
| CVE | CVE-2026-64324 |
|---|---|
| State | PUBLISHED |
| Assigner | Linux |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-07-25 10:17:13 UTC |
| Updated | 2026-07-25 10:17:13 UTC |
| Description | 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. |
Risk And Classification
EPSS: 0.002100000 probability, percentile 0.113270000 (date 2026-07-25)
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Linux | Linux | affected 934f815345c09c290a9b9a9cfdddc203ec2117e8 fdd6229d2ae9914c1f25d1041db0f4f312a4fa76 git | Not specified |
| CNA | Linux | Linux | affected 22cc7323f090646c8cfb5939e6f15bdc2ed3fd27 b54aee5652fcd7c23a0904a4623ec462c3edc70c git | Not specified |
| CNA | Linux | Linux | affected 7c4fa9ebfce69619d132fe703dc2e2cf62a13723 12af328d2ee8d68e81ba612246d0b54b22d23e1f git | Not specified |
| CNA | Linux | Linux | affected 5cc9745e2ea11aef7d5c9a42bc36f6cd3e1b4cc3 fb49099206c5c57af28a157249fa7bcb5518f99e git | Not specified |
| CNA | Linux | Linux | affected 56e69e59751d20993f243fb7dd6991c4e522424c 9442d75429b0c556292a7454fe888d54259f5240 git | Not specified |
| CNA | Linux | Linux | affected 56e69e59751d20993f243fb7dd6991c4e522424c 335202ab25b01fdd45889ff25eab70864686dea3 git | Not specified |
| CNA | Linux | Linux | affected 56e69e59751d20993f243fb7dd6991c4e522424c be87de7789a82a030a4896bc7683415ec9fa6f2b git | Not specified |
| CNA | Linux | Linux | affected 56e69e59751d20993f243fb7dd6991c4e522424c 5f0419457f89dce1a3f1c8e62a3adf2f39ab8168 git | Not specified |
| CNA | Linux | Linux | affected 097420e48e30f51e8f4f650b5c946f5af63ec1a3 git | Not specified |
| CNA | Linux | Linux | affected 5def895b42ef16a2da6402818cba8d7ec8ede1ef git | Not specified |
| CNA | Linux | Linux | affected 05fb2bf477d3fe5421bd4cb699574737f52bd88b git | Not specified |
| CNA | Linux | Linux | affected 5.10.224 5.10.261 semver | Not specified |
| CNA | Linux | Linux | affected 5.15.165 5.15.212 semver | Not specified |
| CNA | Linux | Linux | affected 6.1.105 6.1.178 semver | Not specified |
| CNA | Linux | Linux | affected 6.6.46 6.6.145 semver | Not specified |
| CNA | Linux | Linux | affected 4.19.320 4.20 semver | Not specified |
| CNA | Linux | Linux | affected 5.4.282 5.5 semver | Not specified |
| CNA | Linux | Linux | affected 6.10.5 6.11 semver | Not specified |
| CNA | Linux | Linux | affected 6.11 | Not specified |
| CNA | Linux | Linux | unaffected 6.11 semver | Not specified |
| CNA | Linux | Linux | unaffected 5.10.261 5.10.* semver | Not specified |
| CNA | Linux | Linux | unaffected 5.15.212 5.15.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.1.178 6.1.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.6.145 6.6.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.12.96 6.12.* semver | Not specified |
| CNA | Linux | Linux | unaffected 6.18.39 6.18.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.1.4 7.1.* semver | Not specified |
| CNA | Linux | Linux | unaffected 7.2-rc1 * original_commit_for_fix | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| git.kernel.org/stable/c/fdd6229d2ae9914c1f25d1041db0f4f312a4fa76 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/12af328d2ee8d68e81ba612246d0b54b22d23e1f | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/b54aee5652fcd7c23a0904a4623ec462c3edc70c | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/335202ab25b01fdd45889ff25eab70864686dea3 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/5f0419457f89dce1a3f1c8e62a3adf2f39ab8168 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/fb49099206c5c57af28a157249fa7bcb5518f99e | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/be87de7789a82a030a4896bc7683415ec9fa6f2b | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| git.kernel.org/stable/c/9442d75429b0c556292a7454fe888d54259f5240 | 416baaa9-dc9f-4396-8d5f-8c081fb06d67 | git.kernel.org | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
No vendor comments have been submitted for this CVE.
There are currently no legacy QID mappings associated with this CVE.