CVE-2026-72478

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

fs/ntfs3: add bounds check to run_get_highest_vcn()

run_get_highest_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 run_unpack() received an analogous bounds-check in

commit b62567bca474 ("ntfs3: add buffer boundary checks to run_unpack()"),

but run_get_highest_vcn() was missed.

Take a run_buf_size 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

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References