Integer Overflow or Wraparound Affecting kernel-tools package, versions <1:6.1.155-176.282.amzn2023


Severity

Recommended
high

Based on Amazon Linux security rating.

Threat Intelligence

EPSS
0.08% (23rd percentile)

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  • Snyk IDSNYK-AMZN2023-KERNELTOOLS-13880649
  • published11 Nov 2025
  • disclosed15 Oct 2025

Introduced: 15 Oct 2025

CVE-2025-39967  (opens in a new tab)
CWE-190  (opens in a new tab)

How to fix?

Upgrade Amazon-Linux:2023 kernel-tools to version 1:6.1.155-176.282.amzn2023 or higher.
This issue was patched in ALAS2023-2025-1223.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel-tools package and not the kernel-tools package as distributed by Amazon-Linux. See How to fix? for Amazon-Linux:2023 relevant fixed versions and status.

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

fbcon: fix integer overflow in fbcon_do_set_font

Fix integer overflow vulnerabilities in fbcon_do_set_font() where font size calculations could overflow when handling user-controlled font parameters.

The vulnerabilities occur when:

  1. CALC_FONTSZ(h, pitch, charcount) performs h * pith * charcount multiplication with user-controlled values that can overflow.
  2. FONT_EXTRA_WORDS * sizeof(int) + size addition can also overflow
  3. This results in smaller allocations than expected, leading to buffer overflows during font data copying.

Add explicit overflow checking using check_mul_overflow() and check_add_overflow() kernel helpers to safety validate all size calculations before allocation.

CVSS Base Scores

version 3.1