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. ]

CVSS 3.1

5.5CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

EPSS

0.2% chance of exploitation in the next 30 days; higher than 7% of CVEs (scores of 2026-10-25)

Published

2025-09-05

Modified

2026-10-19

Record from

the NVD, synced 2026-10-21

Affected

• debian:debian_linux
• linux:linux_kernel

References

• https://git.kernel.org/stable/c/62f12cde10118253348a7540e85606869bd69432
• https://git.kernel.org/stable/c/7207923d8453ebfb35667c1736169f2dd796772e
• https://git.kernel.org/stable/c/873f32201df8876bdb2563e3187e79149427cab4
• https://git.kernel.org/stable/c/a9e5924daa954c9f585c1ca00358afe71d6781c4
• https://git.kernel.org/stable/c/d23264c257a70dbe021b43b3bc2ee16134cd2c69

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