CVE-2025-39681
MEDIUMLinux Kernel - Division by Zero via Uninitialized boot_cpu_data.x86_cache_occ_scale
Title source: llmDescription
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. ]
References (10)
Core 10
Core References
Third Party Advisory
https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html
Third Party Advisory
https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html
Vendor Advisory
https://cert-portal.siemens.com/productcert/html/ssa-032379.html
Scores
CVSS v3
5.5
EPSS
0.0002
EPSS Percentile
6.6%
Attack Vector
LOCAL
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Details
Status
published
Products (25)
debian/debian_linux
11.0
linux/Kernel
5.11.0 - 5.15.190linux
linux/Kernel
5.16.0 - 6.1.149linux
linux/Kernel
5.8.0 - 5.10.242linux
linux/Kernel
6.13.0 - 6.16.4linux
linux/Kernel
6.2.0 - 6.6.103linux
linux/Kernel
6.7.0 - 6.12.44linux
Linux/Linux
< 5.8
Linux/Linux
5.10.242 - 5.10.*
Linux/Linux
5.15.190 - 5.15.*
... and 15 more
Published
Sep 05, 2025
Tracked Since
Feb 18, 2026