ntfs: bound the free-cluster bitmap scan to the volume
- Published
- Last modified
- Where the record stands: published, rejected by its publisher, or superseded by another id.What do these mean? →
- published
- Whether CISA lists it in its Known Exploited Vulnerabilities catalog: proof that attackers are using it.What do these mean? →
- Not listed in CISA KEV
- Fix
- Fixed in 7.2.4
- Whether working attack code is public (Exploit-DB, Metasploit, Nuclei or GitHub). Public code makes attacks easier.What do these mean? →
- None on Exploit-DB, Metasploit or GitHub
Summary
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.
Timeline
- CVE published
- Record last updated
Affected versions
- Linux Linux
From 11ccc9107dc460de28af90fac1f42404d9802735 · fixed in dc15a9f5307d5372aef3b64bf3ed7802f530c471; From 11ccc9107dc460de28af90fac1f42404d9802735 · fixed in 19cac7902a8ab748e15f98ddaafcf5f8882be21d
- Linux Linux
7.1
- KernelLinux
From 7.1.0 · fixed in 7.2.4