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CVE-2025-39681 Not scored

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

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. ]

Exploit probability 0.2%
Published September 5, 2025
Required by Not available
Last source change July 16, 2026

02 / AFFECTED SOFTWARE

Affected packages

Linux Kernel
Unknown Unknown

03 / CONNECTIONS

Connected vulnerabilities

related OPENSUSE-SU-2025:20081-1
related SUSE-SU-2025:03600-1
related SUSE-SU-2025:03601-1
related SUSE-SU-2025:03633-1
related SUSE-SU-2025:03634-1
related SUSE-SU-2025:20851-1
related SUSE-SU-2025:20861-1
related SUSE-SU-2025:20870-1
related SUSE-SU-2025:20898-1
related SUSE-SU-2025:21074-1
related SUSE-SU-2025:21139-1
related SUSE-SU-2025:21179-1
related SUSE-SU-2025:3725-1
related SUSE-SU-2025:3751-1

04 / EVIDENCE

Source records

Open Source Vulnerabilities CVE-2025-39681

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. ]

View original source

05 / REFERENCES

Further evidence