CVE-2025-39681
What it is
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. ]
At a glance
- Exploitability
- Can be exploited locally on the machine with a low-privilege account. High risk of service disruption.
- Exploit odds
- 0.2% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.2% in the next 30 days (EPSS).
- Severity: 5.5 MEDIUM (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.2% · EPSS, next 30 days
- Record status
- Modified
Affected
- Linux Kernel < 5.10.242
- Linux Kernel < 5.15.190
- Linux Kernel < 6.1.149
- Linux Kernel < 6.6.103
- Linux Kernel < 6.12.44
- Linux Kernel < 6.16.4
- Linux Kernel 6.17
- Debian Linux 11.0
Attack profile CVSS 3.1 · 5.5
- Attack vector
- Local
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
Raw vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2025-39681.md and follow it. Check whether this project is affected by CVE-2025-39681. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- 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
- https://git.kernel.org/stable/c/d8df126349dad855cdfedd6bbf315bad2e901c2f
- https://git.kernel.org/stable/c/fb81222c1559f89bfe3aa1010f6d112531d55353
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
- https://git.kernel.org/stable/c/d8df126349dad855cdfedd6bbf315bad2e901c2f
- https://git.kernel.org/stable/c/fb81222c1559f89bfe3aa1010f6d112531d55353
- https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html
- https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html
- https://cert-portal.siemens.com/productcert/html/ssa-019113.html
- https://cert-portal.siemens.com/productcert/html/ssa-032379.html
- https://cert-portal.siemens.com/productcert/html/ssa-457936.html