CVE-2026-89614
UnknownSummary
In the Linux kernel, the ntfs driver bounds its free-cluster bitmap scan by the size of $Bitmap rather than the volume's cluster count. An image whose $Bitmap covers more clusters than the volume allows indexing past the lcn_empty_bits_per_page array.
Risk Assessment
An attacker can mount a crafted NTFS image and extend a file, causing an out-of-bounds read (reported by KASAN) and potential system crash.
Recommendation
Update the Linux kernel to a version containing the fix that clamps the scan to the array size and rejects LCN >= nr_clusters in the mapping pairs decoder.
Other vulnerabilities in Linux kernel (ntfs)
See all- CVE-2026-89613Unknown
In the Linux kernel, the ntfs driver does not reject attributes with empty mapping pairs if they have inconsistent highest VCN and size. The lack of validation can lead to incorrect processing.
- CVE-2026-89612Unknown
In the Linux kernel, parse_ntfs_boot_sector() decodes the NTFS boot sector's 64-bit LCNs into an s64. A crafted high-bit value becomes negative and passes the upper-bound check, leading to an out-of-bounds access to lcn_empty_bits_per_page.
- CVE-2026-89611Unknown
In the Linux kernel, ntfs_attr_update_meta() does not validate the attribute name offset when converting between non-sparse and sparse attributes. A malicious MFT record can set name_offset so the name extends beyond the attribute boundary or overlaps with mapping pairs.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: ntfs: bound the free-cluster bitmap scan to the volume vol->lcn_empty_bits_per_page is sized from vol->nr_clusters at mount, but ntfs_cluster_alloc() bounds its scan of that array by the size of $Bitmap. Those are independent on-disk quantities and the mount-time check only rejects a $Bitmap that is too small, so an image whose $Bitmap covers more clusters than the volume has lets the scan index past the array. A run whose LCN lies in that gap takes the allocator straight there, since the caller passes the file's own last LCN as its locality hint. KASAN reports a slab out-of-bounds read when a file on such a volume is extended. Clamp the scan to what that array covers, mirroring the max_index calculation the mount-time scan already uses, and reject a decoded LCN at or beyond nr_clusters in the mapping pairs decoder. Conforming volumes are unaffected.