Bug 2393495 (CVE-2025-39681) - CVE-2025-39681 kernel: x86/cpu/hygon: Add missing resctrl_cpu_detect() in bsp_init helper
Summary: CVE-2025-39681 kernel: x86/cpu/hygon: Add missing resctrl_cpu_detect() in bsp...
Keywords:
Status: NEW
Alias: CVE-2025-39681
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
low
low
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2025-09-05 18:02 UTC by OSIDB Bzimport
Modified: 2025-09-05 21:59 UTC (History)
0 users

Fixed In Version:
Clone Of:
Environment:
Last Closed:
Embargoed:


Attachments (Terms of Use)

Description OSIDB Bzimport 2025-09-05 18:02:21 UTC
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. ]


Note You need to log in before you can comment on or make changes to this bug.