CVE-2025-39681: 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 resctrlcpudetect() in bspinit helper
Since
923f3a2b48bd ("x86/resctrl: Query LLC monitoring properties once during boot")
resctrlcpudetect() 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 X86FEATURECQM supported, where getrdtmonresources() tries to calculate monl3config with uninitialized bootcpudata.x86cacheoccscale.
Add the missing resctrlcpudetect() in the Hygon BSP init helper.
[ bp: Massage commit message. ]
Affected Software
Event History
Frequently Asked Questions
What is the severity of CVE-2025-39681?
CVE-2025-39681 has not been assigned a severity rating, but it is related to a critical component of the Linux kernel.
How do I fix CVE-2025-39681?
To fix CVE-2025-39681, update your Linux kernel to the latest stable version that includes the patch addressing this vulnerability.
Who is affected by CVE-2025-39681?
CVE-2025-39681 affects users running versions of the Linux kernel that do not include the patch for the resctrl_cpu_detect() function.
What is the main issue addressed in CVE-2025-39681?
CVE-2025-39681 addresses a missed initialization in the resctrl_cpu_detect() function within the Linux kernel's x86 architecture.
Is there a workaround for CVE-2025-39681?
Currently, the best approach for CVE-2025-39681 is to apply the kernel update rather than relying on a workaround.