---
id: CVE-2026-72195
title: 'fs/ntfs3: bound attr_off in UpdateResidentValue against data_off'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  fs/ntfs3: bound attr_off in UpdateResidentValue against data_off

  In do_action()'s UpdateResidentValue case (fslog.c:3307),
  lrh->attr_off and lrh->redo_len come from th…
severity: high
cvss: 7.8
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'
cvssSource: cna
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= b46acd6a6a627d876898e1c84d3f84902264b445 <
    ab8761676d638c5be170aaf91b7ffdd451236616
  - >-
    Linux >= b46acd6a6a627d876898e1c84d3f84902264b445 <
    53c12f178f584dc5f836ffe2782138a6e9348ed9
  - >-
    Linux >= b46acd6a6a627d876898e1c84d3f84902264b445 <
    546518468e6c9ea469669eef78f8cc380ad6e2ca
  - >-
    Linux >= b46acd6a6a627d876898e1c84d3f84902264b445 <
    97758fd9756b5f09e9ddc6a5f6a569041acc8421
  - >-
    Linux >= b46acd6a6a627d876898e1c84d3f84902264b445 <
    50b5e83384e7fed3d11d18b79ff350e9d6d89861
  - >-
    Linux >= b46acd6a6a627d876898e1c84d3f84902264b445 <
    a89c66674283a0293c0f266dc57087a6114371a3
  - >-
    Linux >= b46acd6a6a627d876898e1c84d3f84902264b445 <
    d1570c48f49a693974d000251030370ee2e83539
  - Linux 5.15
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-10-16T18:43:39.458777Z'
published: '2026-08-15'
updated: '2026-10-16'
sourceUpdated: '2026-10-16T18:45:01.278Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-72195'
references:
  - url: 'https://git.kernel.org/stable/c/ab8761676d638c5be170aaf91b7ffdd451236616'
  - url: 'https://git.kernel.org/stable/c/53c12f178f584dc5f836ffe2782138a6e9348ed9'
  - url: 'https://git.kernel.org/stable/c/546518468e6c9ea469669eef78f8cc380ad6e2ca'
  - url: 'https://git.kernel.org/stable/c/97758fd9756b5f09e9ddc6a5f6a569041acc8421'
  - url: 'https://git.kernel.org/stable/c/50b5e83384e7fed3d11d18b79ff350e9d6d89861'
  - url: 'https://git.kernel.org/stable/c/a89c66674283a0293c0f266dc57087a6114371a3'
  - url: 'https://git.kernel.org/stable/c/d1570c48f49a693974d000251030370ee2e83539'
tags:
  - cve.org
epss: 0.00169
epssPercentile: 0.05789
ingestedAt: '2026-10-16T19:46:24.422Z'
---

## Overview

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

fs/ntfs3: bound attr_off in UpdateResidentValue against data_off

In do_action()'s UpdateResidentValue case (fslog.c:3307),
lrh->attr_off and lrh->redo_len come from the on-disk LRH.
When they satisfy aoff + dlen < attr->res.data_off, the
assignment

	attr->res.data_size = cpu_to_le32(aoff + dlen - data_off);

underflows to ~4 GiB (e.g. 0xFFFFFFF9 when aoff=0x10, dlen=1,
data_off=0x18).  Subsequent code that reads attr->res.data_size
to walk the resident attribute payload would then read up to
4 GiB past the 1024-byte MFT record allocation.

The existing mi_enum_attr() defense in fs/ntfs3/record.c:287
catches the corrupted data_size on the next attribute walk
and fails the mount, but only on the path that walks all
attributes.  A read site that picks an attribute by name and
reads its data_size without re-validating is not covered.
Validate aoff against data_off and asize at the source.

Reproduced under UML+KASAN on mainline 8d90b09e6741 via
pr_warn-only probe: with aoff=0x10 and data_off=0x18, the
post-assignment data_size is 0xfffffff9 (mount then fails
at -22 from mi_enum_attr).

[almaz.alexandrovich@paragon-software.com: clang-formatted the changes]

## Affected

- `Linux >= b46acd6a6a627d876898e1c84d3f84902264b445 < ab8761676d638c5be170aaf91b7ffdd451236616`
- `Linux >= b46acd6a6a627d876898e1c84d3f84902264b445 < 53c12f178f584dc5f836ffe2782138a6e9348ed9`
- `Linux >= b46acd6a6a627d876898e1c84d3f84902264b445 < 546518468e6c9ea469669eef78f8cc380ad6e2ca`
- `Linux >= b46acd6a6a627d876898e1c84d3f84902264b445 < 97758fd9756b5f09e9ddc6a5f6a569041acc8421`
- `Linux >= b46acd6a6a627d876898e1c84d3f84902264b445 < 50b5e83384e7fed3d11d18b79ff350e9d6d89861`
- `Linux >= b46acd6a6a627d876898e1c84d3f84902264b445 < a89c66674283a0293c0f266dc57087a6114371a3`
- `Linux >= b46acd6a6a627d876898e1c84d3f84902264b445 < d1570c48f49a693974d000251030370ee2e83539`
- `Linux 5.15`

## Remediation

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