---
id: CVE-2026-72192
title: 'ntfs3: bound to_move in indx_insert_into_root before hdr_insert_head'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  ntfs3: bound to_move in indx_insert_into_root before hdr_insert_head

  indx_insert_into_root() promotes a full resident $INDEX_ROOT into
  $INDEX_ALLOCATION and copies all…
severity: critical
cvss: 9.8
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'
cvssSource: cna
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= 82cae269cfa953032fbb8980a7d554d60fb00b17 <
    0af83b8155cc848e9f5d2c36e20a70d024214649
  - >-
    Linux >= 82cae269cfa953032fbb8980a7d554d60fb00b17 <
    cb3161deebcaf8d36d3115abf452c633f2180fc1
  - >-
    Linux >= 82cae269cfa953032fbb8980a7d554d60fb00b17 <
    53c5f3b2da3774b41534728aba295c098c9efa19
  - >-
    Linux >= 82cae269cfa953032fbb8980a7d554d60fb00b17 <
    194b00c99ba971fa7cf6acd747a36032c6de54eb
  - >-
    Linux >= 82cae269cfa953032fbb8980a7d554d60fb00b17 <
    aaa1f956c0fc41089a4a534da7df91552a08a47c
  - >-
    Linux >= 82cae269cfa953032fbb8980a7d554d60fb00b17 <
    d240f5f9d036b8180224954d9873f172b6be4dd8
  - >-
    Linux >= 82cae269cfa953032fbb8980a7d554d60fb00b17 <
    9b6926ac9c970ae0b2c2fe6289b16e9aa10b6a67
  - Linux 5.15
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: total
  timestamp: '2026-10-16T18:43:32.724211Z'
published: '2026-08-15'
updated: '2026-10-16'
sourceUpdated: '2026-10-16T18:45:00.935Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-72192'
references:
  - url: 'https://git.kernel.org/stable/c/0af83b8155cc848e9f5d2c36e20a70d024214649'
  - url: 'https://git.kernel.org/stable/c/cb3161deebcaf8d36d3115abf452c633f2180fc1'
  - url: 'https://git.kernel.org/stable/c/53c5f3b2da3774b41534728aba295c098c9efa19'
  - url: 'https://git.kernel.org/stable/c/194b00c99ba971fa7cf6acd747a36032c6de54eb'
  - url: 'https://git.kernel.org/stable/c/aaa1f956c0fc41089a4a534da7df91552a08a47c'
  - url: 'https://git.kernel.org/stable/c/d240f5f9d036b8180224954d9873f172b6be4dd8'
  - url: 'https://git.kernel.org/stable/c/9b6926ac9c970ae0b2c2fe6289b16e9aa10b6a67'
tags:
  - cve.org
epss: 0.00738
epssPercentile: 0.53608
ingestedAt: '2026-10-16T19:46:24.423Z'
---

## Overview

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

ntfs3: bound to_move in indx_insert_into_root before hdr_insert_head

indx_insert_into_root() promotes a full resident $INDEX_ROOT into
$INDEX_ALLOCATION and copies all non-last resident root entries into
a newly allocated INDEX_BUFFER via hdr_insert_head(). The source
byte count 'to_move' is summed from the on-disk resident entry sizes
and is independent of the destination buffer size, which comes from
root->index_block_size (via indx->index_bits).

A crafted NTFS image that keeps a valid, full resident root but
shrinks root->index_block_size down to 512 after the root has been
populated makes hdr_insert_head() memcpy attacker-controlled resident
entry bytes past the end of the kmalloc(1u << indx->index_bits)
allocation returned by indx_new(). For a 512-byte destination and a
resident root whose non-last entries total 560 bytes, the memcpy
overruns by 120 bytes and a following memmove extends the highest
written offset to 136 bytes past the allocation. The overflow bytes
are a direct copy of on-disk entries (via kmemdup), so they are
fully attacker-controlled.

The write is reachable from unprivileged open(O_CREAT) on a mounted
crafted NTFS image: a single sufficiently long create in a directory
whose resident root is already full forces root promotion and
triggers the copy.

This is a controlled out-of-bounds write of 120-136 bytes past a
kmalloc(index_block_size) allocation, with attacker-controlled
content. It is a bounded adjacent-heap corruption primitive; it is
not an arbitrary-address write. Successful exploitation into a named
victim object depends on the surrounding slab layout.

Reject the copy at the sink. The destination's INDEX_HDR already
reports hdr_total (the payload capacity of the new buffer) and
hdr_used (the bytes already consumed by the terminal END entry
installed by indx_new()); require that to_move fits in the remaining
payload before calling hdr_insert_head(). On mismatch, fail with
-EINVAL and mark the filesystem as having a detected on-disk
inconsistency, which is the same behaviour as the surrounding
validation in this function.

## Affected

- `Linux >= 82cae269cfa953032fbb8980a7d554d60fb00b17 < 0af83b8155cc848e9f5d2c36e20a70d024214649`
- `Linux >= 82cae269cfa953032fbb8980a7d554d60fb00b17 < cb3161deebcaf8d36d3115abf452c633f2180fc1`
- `Linux >= 82cae269cfa953032fbb8980a7d554d60fb00b17 < 53c5f3b2da3774b41534728aba295c098c9efa19`
- `Linux >= 82cae269cfa953032fbb8980a7d554d60fb00b17 < 194b00c99ba971fa7cf6acd747a36032c6de54eb`
- `Linux >= 82cae269cfa953032fbb8980a7d554d60fb00b17 < aaa1f956c0fc41089a4a534da7df91552a08a47c`
- `Linux >= 82cae269cfa953032fbb8980a7d554d60fb00b17 < d240f5f9d036b8180224954d9873f172b6be4dd8`
- `Linux >= 82cae269cfa953032fbb8980a7d554d60fb00b17 < 9b6926ac9c970ae0b2c2fe6289b16e9aa10b6a67`
- `Linux 5.15`

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.