Divide By Zero Affecting kernel6.12-libbpf-devel package, versions <1:6.12.46-66.121.amzn2023


Severity

Recommended
high

Based on Amazon Linux security rating.

Threat Intelligence

EPSS
0.03% (9th percentile)

Do your applications use this vulnerable package?

In a few clicks we can analyze your entire application and see what components are vulnerable in your application, and suggest you quick fixes.

Test your applications
  • Snyk IDSNYK-AMZN2023-KERNEL612LIBBPFDEVEL-13170463
  • published1 Oct 2025
  • disclosed5 Sept 2025

Introduced: 5 Sep 2025

CVE-2025-39681  (opens in a new tab)
CWE-369  (opens in a new tab)

How to fix?

Upgrade Amazon-Linux:2023 kernel6.12-libbpf-devel to version 1:6.12.46-66.121.amzn2023 or higher.
This issue was patched in ALAS2023-2025-1208.

NVD Description

Note: Versions mentioned in the description apply only to the upstream kernel6.12-libbpf-devel package and not the kernel6.12-libbpf-devel 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:

x86/cpu/hygon: Add missing resctrl_cpu_detect() in bsp_init helper

Since

923f3a2b48bd ("x86/resctrl: Query LLC monitoring properties once during boot")

resctrl_cpu_detect() has been moved from common CPU initialization code to the vendor-specific BSP init helper, while Hygon didn't put that call in their code.

This triggers a division by zero fault during early booting stage on our machines with X86_FEATURE_CQM* supported, where get_rdt_mon_resources() tries to calculate mon_l3_config with uninitialized boot_cpu_data.x86_cache_occ_scale.

Add the missing resctrl_cpu_detect() in the Hygon BSP init helper.

[ bp: Massage commit message. ]

CVSS Base Scores

version 3.1