CVE-2025-39681
CVE-2025-39681CVE-2025-39681
linux / linux_kernel
Description
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. ]
Scoring
| CVSS | 5.5 () |
| Vector | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
| Last modified | 2026-07-14 |