---
id: CVE-2025-40322
title: |-
  In the Linux kernel, the following vulnerability has been resolved:

  fbdev: bitblit: bound-check glyph index in bit_putcs*

  bit_putcs_aligned()/unaligned() derived the glyph pointer from the
  character value masked by 0xff/0x1ff, which ma…
summary: |-
  In the Linux kernel, the following vulnerability has been resolved:

  fbdev: bitblit: bound-check glyph index in bit_putcs*

  bit_putcs_aligned()/unaligned() derived the glyph pointer from the
  character value masked by 0xff/0x1ff, which ma…
severity: high
cvss: 7.1
cvssVector: 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H'
published: '2025-12-08'
updated: '2026-10-14'
sourceUpdated: '2026-10-14T22:10:00.210'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2025-40322'
references:
  - url: 'https://git.kernel.org/stable/c/0998a6cb232674408a03e8561dc15aa266b2f53b'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/18c4ef4e765a798b47980555ed665d78b71aeadf'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/901f44227072be60812fe8083e83e1533c04eed1'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/9ba1a7802ca9a2590cef95b253e6526f4364477f'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/a10cede006f9614b465cf25609a8753efbfd45cc'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/c12003bf91fdff381c55ef54fef3e961a5af2545'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/db5c9a162d2f42bcc842b76b3d935dcc050a0eec'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
  - url: 'https://git.kernel.org/stable/c/efaf89a75a29b2d179bf4fe63ca62852e93ad620'
    label: 416baaa9-dc9f-4396-8d5f-8c081fb06d67
tags:
  - nvd
epss: 0.00143
epssPercentile: 0.03202
ingestedAt: '2026-10-14T23:00:02.025Z'
---

## Overview

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

fbdev: bitblit: bound-check glyph index in bit_putcs*

bit_putcs_aligned()/unaligned() derived the glyph pointer from the
character value masked by 0xff/0x1ff, which may exceed the actual font's
glyph count and read past the end of the built-in font array.
Clamp the index to the actual glyph count before computing the address.

This fixes a global out-of-bounds read reported by syzbot.

## Remediation

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