Description (CNA)
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.
Affected (CNA)
| Vendor / product | Versions |
|---|---|
| Linux / Linux | affected 11ccc9107dc460de28af90fac1f42404d9802735 before dc15a9f5307d5372aef3b64bf3ed7802f530c471; affected 11ccc9107dc460de28af90fac1f42404d9802735 before 19cac7902a8ab748e15f98ddaafcf5f8882be21d |
| Linux / Linux | affected 7.1; unaffected 0 before 7.1; unaffected 7.2.4 through 7.2.*; unaffected 7.3 through * |
CWE
No CWE identifiers supplied.