CVE-2025-40067
Published: October 29, 2025Last modified: June 24, 2026
Description
In the Linux kernel, the following vulnerability has been resolved: fs/ntfs3: reject index allocation if $BITMAP is empty but blocks exist Index allocation requires at least one bit in the $BITMAP attribute to track usage of index entries. If the bitmap is empty while index blocks are already present, this reflects on-disk corruption. syzbot triggered this condition using a malformed NTFS image. During a rename() operation involving a long filename (which spans multiple index entries), the empty bitmap allowed the name to be added without valid tracking. Subsequent deletion of the original entry failed with -ENOENT, due to unexpected index state. Reject such cases by verifying that the bitmap is not empty when index blocks exist.
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 7.8 |
| Attack Vector | LOCAL |
| Attack complexity | LOW |
| Privileges required | NONE |
| User interaction | REQUIRED |
| Scope | UNCHANGED |
| Confidentiality | HIGH |
| Integrity impact | HIGH |
| Availability impact | HIGH |
| Vector | CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H |
Status
| Product | Release | Package | Status |
|---|---|---|---|
| Alpaquita Linux | 23 LTS | linux-lts | Not affected (6.1.33-r0) |
| 25 LTS | linux-lts | Fixed (6.12.53-r0) | |
| Stream | linux-lts | Fixed (6.18.35-r1) |
References
- https://git.kernel.org/stable/c/039ddf353cc33f6546a87ec1ac3210637d714bec
- https://git.kernel.org/stable/c/0dc7117da8f92dd5fe077d712a756eccbe377d40
- https://git.kernel.org/stable/c/978aac54e93ea35aab20b32ae393d3d33964e7ae
- https://git.kernel.org/stable/c/aab2e34b139f6df71ab2b1adeec9927c206adc79
- https://git.kernel.org/stable/c/be66551da203862c689c12e1d35ce87217c017c1