In the Linux kernel, the following vulnerability has been resolved:
fs/ntfs3: add bounds check to rungethighest_vcn()
rungethighest_vcn() parses a packed NTFS mapping-pairs buffer without any length bound, relying solely on a 0x00 terminator to stop. A crafted $LogFile UpdateMappingPairs record whose embedded attribute contains mapping-pairs runs without a terminator causes the function to read past the slab allocation, triggering a KASAN slab-out-of-bounds read on mount.
The sibling function rununpack() received an analogous bounds-check in commit b62567bca474 ("ntfs3: add buffer boundary checks to rununpack()"), but rungethighest_vcn() was missed.
Take a runbufsize parameter and reject any run header whose payload would extend past the buffer end, mirroring the pattern used by run_unpack(). The caller in fslog.c passes the remaining attribute bytes after the mapping-pairs offset.
KASAN report (on mainline v7.1 merge window HEAD):
BUG: KASAN: slab-out-of-bounds in rungethighestvcn+0x3c0/0x410 Read of size 1 at addr ffff88800e2d5400 by task mount/72 Call Trace: rungethighestvcn+0x3c0/0x410 doaction.isra.0+0x3ba8/0x7b50 logreplay+0x9ddd/0x10200 ntfsloadlogandreplay+0x4ad/0x610 ntfsfill_super+0x214a/0x4540
{
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/72xxx/CVE-2026-72478.json",
"cna_assigner": "Linux"
}