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. ]
ProviderTypeBase ScoreAtk. VectorAtk. ComplexityPriv. RequiredVector
NISTNIST
UNKNOWN
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LinuxCNA
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Awaiting analysis
This vulnerability is currently awaiting analysis.
Base Score
CVSS 3.x
EPSS Score
Percentile: Unknown
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