---
id: CVE-2026-97439
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  fs/ntfs3: preserve non-DOS attribute bits in system.dos_attrib

  [BUG]
  A corrupted ntfs3 image can hit a NULL function pointer call in
  generic_perform_write() after togg…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  fs/ntfs3: preserve non-DOS attribute bits in system.dos_attrib

  [BUG]
  A corrupted ntfs3 image can hit a NULL function pointer call in
  generic_perform_write() after togg…
severity: medium
cvss: 5.5
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-476
vendor: Linux
product: Linux
affected:
  - >-
    Linux >= be71b5cba2e6485e8959da7a9f9a44461a1bb074 <
    533217b90addd57cc16f1c974e023c72d18949c7
  - >-
    Linux >= be71b5cba2e6485e8959da7a9f9a44461a1bb074 <
    f2d6bc89e2236939df189831707c8cdad199f57a
  - >-
    Linux >= be71b5cba2e6485e8959da7a9f9a44461a1bb074 <
    fdc9f65aa6631df04238c6154713bacd5133d77c
  - >-
    Linux >= be71b5cba2e6485e8959da7a9f9a44461a1bb074 <
    2de91ae285b0b878604d2bd83c3c395a8071e482
  - >-
    Linux >= be71b5cba2e6485e8959da7a9f9a44461a1bb074 <
    407ee19828a7d9700969ed9cc53be50d0f533619
  - >-
    Linux >= be71b5cba2e6485e8959da7a9f9a44461a1bb074 <
    b1c1101067d9536bcb0fe023b96ee2dde5535959
  - Linux 5.15
published: '2026-09-24'
updated: '2026-10-03'
sourceUpdated: '2026-10-03T11:17:55.520'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-97439'
references:
  - url: 'https://git.kernel.org/stable/c/2de91ae285b0b878604d2bd83c3c395a8071e482'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/407ee19828a7d9700969ed9cc53be50d0f533619'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/533217b90addd57cc16f1c974e023c72d18949c7'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/b1c1101067d9536bcb0fe023b96ee2dde5535959'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/f2d6bc89e2236939df189831707c8cdad199f57a'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/fdc9f65aa6631df04238c6154713bacd5133d77c'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-97439.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-97439'
  - url: 'https://bugzilla.redhat.com/show_bug.cgi?id=2540455'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-97439'
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-97439'
  - url: >-
      https://git.kernel.org/pub/scm/linux/security/vulns.git/plain/cve/published/2026/CVE-2026-97439.mbox
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
epss: 0.00173
epssPercentile: 0.06724
cvssSource: vendor
ingestedAt: '2026-09-24T16:47:15.879Z'
---

## Overview

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

fs/ntfs3: preserve non-DOS attribute bits in system.dos_attrib

[BUG]
A corrupted ntfs3 image can hit a NULL function pointer call in
generic_perform_write() after toggling system.ntfs_attrib and then
overwriting system.dos_attrib on the same file.

BUG: kernel NULL pointer dereference, address: 0000000000000000
\#PF: supervisor instruction fetch in kernel mode
\#PF: error_code(0x0010) - not-present page
PGD bed5067 P4D bed5067 PUD 0
Oops: Oops: 0010 [#1] SMP KASAN NOPTI
RIP: 0010:0x0
Code: Unable to access opcode bytes at 0xffffffffffffffd6.
RSP: 0018:ffff88801025f988 EFLAGS: 00010246
Call Trace:
 generic_perform_write+0x409/0x8c0 mm/filemap.c:4255
 __generic_file_write_iter+0x1bb/0x200 mm/filemap.c:4372
 ntfs_file_write_iter+0xcd9/0x1c20 fs/ntfs3/file.c:1253
 new_sync_write fs/read_write.c:593 [inline]
 vfs_write+0x63b/0xf70 fs/read_write.c:686
 ksys_write+0x133/0x250 fs/read_write.c:738
 __do_sys_write fs/read_write.c:749 [inline]
 __se_sys_write fs/read_write.c:746 [inline]
 __x64_sys_write+0x77/0xc0 fs/read_write.c:746
 ...

[CAUSE]
system.ntfs_attrib updates ATTR_DATA flags via ni_new_attr_flags()
and switches i_mapping->a_ops to ntfs_aops_cmpr when
FILE_ATTRIBUTE_COMPRESSED is set. system.dos_attrib then overwrites
ni->std_fa from a one-byte DOS attribute value, clearing the compression
bit without updating ATTR_DATA or the mapping operations.

Old buffered writes use is_compressed(ni) to choose
__generic_file_write_iter(). That leaves generic_perform_write() calling
a NULL write_begin callback from ntfs_aops_cmpr.

[FIX]
Treat system.dos_attrib as a low-byte DOS attribute update and preserve the
existing non-DOS attribute bits in ni->std_fa. This keeps compressed and
sparse state consistent with ATTR_DATA and the mapping operations while
keeping the existing DOS attribute semantics intact.

## Remediation

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

## Vendor advisories

- **Red Hat VEX** · Moderate · updated 2026-09-29 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-97439.json)