---
id: CVE-2026-64532
title: 'fs/ntfs3: bound NTFS_DE view.data_off in UpdateRecordData{Root,Allocation}'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  fs/ntfs3: bound NTFS_DE view.data_off in UpdateRecordData{Root,Allocation}

  In do_action()'s UpdateRecordDataRoot (fslog.c:3489) and
  UpdateRecordDataAllocation (fslog.c…
severity: high
cvss: 7.8
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H'
cvssSource: cna
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= b46acd6a6a627d876898e1c84d3f84902264b445 <
    b20e5a709d8bd190d6e4645606763c7423e694c1
  - >-
    Linux >= b46acd6a6a627d876898e1c84d3f84902264b445 <
    d41b382068ca4e64e421f736cdd700095464b6ac
  - >-
    Linux >= b46acd6a6a627d876898e1c84d3f84902264b445 <
    429d653ca641d38a78609b8f62e81a0a5c780a2d
  - >-
    Linux >= b46acd6a6a627d876898e1c84d3f84902264b445 <
    315d3a9a48b49f889da3d858a9307e677cb9e1bd
  - >-
    Linux >= b46acd6a6a627d876898e1c84d3f84902264b445 <
    be306b8d9143a9c076c804a7ca025d69caf9c448
  - >-
    Linux >= b46acd6a6a627d876898e1c84d3f84902264b445 <
    36feda687afebae24c472202694448738809c411
  - >-
    Linux >= b46acd6a6a627d876898e1c84d3f84902264b445 <
    3e127829e57f5190f612412ece4541cb96d5ec7a
  - Linux 5.15
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-10-16T15:41:49.104430Z'
published: '2026-07-27'
updated: '2026-10-16'
sourceUpdated: '2026-10-16T15:42:40.032Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-64532'
references:
  - url: 'https://git.kernel.org/stable/c/b20e5a709d8bd190d6e4645606763c7423e694c1'
  - url: 'https://git.kernel.org/stable/c/d41b382068ca4e64e421f736cdd700095464b6ac'
  - url: 'https://git.kernel.org/stable/c/429d653ca641d38a78609b8f62e81a0a5c780a2d'
  - url: 'https://git.kernel.org/stable/c/315d3a9a48b49f889da3d858a9307e677cb9e1bd'
  - url: 'https://git.kernel.org/stable/c/be306b8d9143a9c076c804a7ca025d69caf9c448'
  - url: 'https://git.kernel.org/stable/c/36feda687afebae24c472202694448738809c411'
  - url: 'https://git.kernel.org/stable/c/3e127829e57f5190f612412ece4541cb96d5ec7a'
tags:
  - cve.org
epss: 0.00128
epssPercentile: 0.02193
ingestedAt: '2026-10-16T17:24:46.826Z'
---

## Overview

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

fs/ntfs3: bound NTFS_DE view.data_off in UpdateRecordData{Root,Allocation}

In do_action()'s UpdateRecordDataRoot (fslog.c:3489) and
UpdateRecordDataAllocation (fslog.c:3697) cases, the memmove
destination is `Add2Ptr(e, le16_to_cpu(e->view.data_off))`,
where e->view.data_off comes from an on-disk NTFS_DE inside
an INDEX_ROOT or INDEX_BUFFER.  Neither case validates
view.data_off + dlen against e->size; the existing
check_if_index_root / check_if_alloc_index helpers walk the
entry chain and validate the entry's offset, but not its
internal view fields.

The neighbouring read sites (e.g., fs/ntfs3/index.c when
iterating view entries) check view.data_off + view.data_size
<= e->size.  Apply the same bound at the two memmove sites.

Reproduced under UML+KASAN on mainline 8d90b09e6741 via
pr_warn-only probe instrumentation: with view.data_off forced
to 0xFFFC, the memmove writes 32 bytes past the end of the
NTFS_DE.

This is similar in shape to Pavitra Jha's 2026-05-02 patch
"fs/ntfs3: prevent oob in case UpdateRecordDataRoot"
(<20260502105008.21827-1-jhapavitra98@gmail.com>) which
proposes calling ntfs3_bad_de_range(); that helper does not
exist in mainline.  This patch uses inline checks.

## Affected

- `Linux >= b46acd6a6a627d876898e1c84d3f84902264b445 < b20e5a709d8bd190d6e4645606763c7423e694c1`
- `Linux >= b46acd6a6a627d876898e1c84d3f84902264b445 < d41b382068ca4e64e421f736cdd700095464b6ac`
- `Linux >= b46acd6a6a627d876898e1c84d3f84902264b445 < 429d653ca641d38a78609b8f62e81a0a5c780a2d`
- `Linux >= b46acd6a6a627d876898e1c84d3f84902264b445 < 315d3a9a48b49f889da3d858a9307e677cb9e1bd`
- `Linux >= b46acd6a6a627d876898e1c84d3f84902264b445 < be306b8d9143a9c076c804a7ca025d69caf9c448`
- `Linux >= b46acd6a6a627d876898e1c84d3f84902264b445 < 36feda687afebae24c472202694448738809c411`
- `Linux >= b46acd6a6a627d876898e1c84d3f84902264b445 < 3e127829e57f5190f612412ece4541cb96d5ec7a`
- `Linux 5.15`

## Remediation

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