---
id: CVE-2026-64432
title: 'fs/ntfs3: validate Dirty Page Table capacity in log_replay copy_lcns'
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  fs/ntfs3: validate Dirty Page Table capacity in log_replay copy_lcns

  In the analysis pass of $LogFile journal replay, log_replay() copies
  LCNs from each action log rec…
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 <
    964c3fae1dfc49dde5468eace940f199cda234e9
  - >-
    Linux >= b46acd6a6a627d876898e1c84d3f84902264b445 <
    3aa96956ca2200674e2a8f9c23ec6ecd45e5010f
  - >-
    Linux >= b46acd6a6a627d876898e1c84d3f84902264b445 <
    946046841013ebac8492ef49651c53638d7a9a6a
  - >-
    Linux >= b46acd6a6a627d876898e1c84d3f84902264b445 <
    c6f9e804f73ef809529865fbc7256dd189ff8c33
  - >-
    Linux >= b46acd6a6a627d876898e1c84d3f84902264b445 <
    cf28fc1658463d768657cf1c27a83980d4ba7ef2
  - >-
    Linux >= b46acd6a6a627d876898e1c84d3f84902264b445 <
    f433acc85b86f327d03ba8b03a33c105c51053de
  - >-
    Linux >= b46acd6a6a627d876898e1c84d3f84902264b445 <
    57382ec6ac63b63dce2789e835fded28b698ae79
  - Linux 5.15
ssvc:
  exploitation: none
  automatable: 'no'
  technicalImpact: total
  timestamp: '2026-10-16T15:40:33.822171Z'
published: '2026-07-25'
updated: '2026-10-16'
sourceUpdated: '2026-10-16T15:42:35.241Z'
source: CVEORG
sourceUrl: 'https://www.cve.org/CVERecord?id=CVE-2026-64432'
references:
  - url: 'https://git.kernel.org/stable/c/964c3fae1dfc49dde5468eace940f199cda234e9'
  - url: 'https://git.kernel.org/stable/c/3aa96956ca2200674e2a8f9c23ec6ecd45e5010f'
  - url: 'https://git.kernel.org/stable/c/946046841013ebac8492ef49651c53638d7a9a6a'
  - url: 'https://git.kernel.org/stable/c/c6f9e804f73ef809529865fbc7256dd189ff8c33'
  - url: 'https://git.kernel.org/stable/c/cf28fc1658463d768657cf1c27a83980d4ba7ef2'
  - url: 'https://git.kernel.org/stable/c/f433acc85b86f327d03ba8b03a33c105c51053de'
  - url: 'https://git.kernel.org/stable/c/57382ec6ac63b63dce2789e835fded28b698ae79'
tags:
  - cve.org
epss: 0.00135
epssPercentile: 0.02637
ingestedAt: '2026-10-16T17:24:46.819Z'
---

## Overview

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

fs/ntfs3: validate Dirty Page Table capacity in log_replay copy_lcns

In the analysis pass of $LogFile journal replay, log_replay() copies
LCNs from each action log record into an existing Dirty Page Table
(DPT) entry without bounding the destination index. A crafted NTFS
image with DPT entry lcns_follow=1 and an action log record with
lcns_follow=2 produces a kernel slab out-of-bounds write at mount
time:

  BUG: KASAN: slab-out-of-bounds in log_replay+0x654c/0xdb60
  Write of size 8 at addr ffff8880095e1040 by task mount

Two attacker-controlled fields can drive j+i past the allocated
page_lcns[] array:

  1. dp->lcns_follow (capacity) can be smaller than lrh->lcns_follow.
  2. lrh->target_vcn may be smaller than dp->vcn, making the u64
     subtraction wrap to a huge size_t.

Validate target VCN delta and per-record LCN count against the
DPT entry capacity, bail via the existing out: cleanup label with
-EINVAL.

This mirrors the bounds-check pattern added in commit b2bc7c44ed17
("fs/ntfs3: Fix slab-out-of-bounds read in DeleteIndexEntryRoot")
and commit 0ca0485e4b2e ("fs/ntfs3: validate rec->used in
journal-replay file record check").

## Affected

- `Linux >= b46acd6a6a627d876898e1c84d3f84902264b445 < 964c3fae1dfc49dde5468eace940f199cda234e9`
- `Linux >= b46acd6a6a627d876898e1c84d3f84902264b445 < 3aa96956ca2200674e2a8f9c23ec6ecd45e5010f`
- `Linux >= b46acd6a6a627d876898e1c84d3f84902264b445 < 946046841013ebac8492ef49651c53638d7a9a6a`
- `Linux >= b46acd6a6a627d876898e1c84d3f84902264b445 < c6f9e804f73ef809529865fbc7256dd189ff8c33`
- `Linux >= b46acd6a6a627d876898e1c84d3f84902264b445 < cf28fc1658463d768657cf1c27a83980d4ba7ef2`
- `Linux >= b46acd6a6a627d876898e1c84d3f84902264b445 < f433acc85b86f327d03ba8b03a33c105c51053de`
- `Linux >= b46acd6a6a627d876898e1c84d3f84902264b445 < 57382ec6ac63b63dce2789e835fded28b698ae79`
- `Linux 5.15`

## Remediation

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