Medium 5.5Published Sep 5, 2025

CVE-2025-39681x86/cpu/hygon: Add missing resctrl_cpu_detect() in bsp_init helper

Updated under an hour ago (Oct 28, 2026, 12:23 AM ET)

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No exploitation reported and no EPSS estimate yet.

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Exploited in the last 30 days

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: 5.5 MEDIUM (v3.1, NVD)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Weakness (CWE): Not given
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Linux
NVD analysis: Modified
Record last updated: Oct 14, 2026
First seen by InfoSec Signals: Oct 14, 2026

Affected products

Affected products

Linux Linux linux:linux (from the name)	923f3a2b48bdccb6a1d1f0dd48de03de7ad936d9 builds before 62f12cde10118253348a7540e85606869bd69432; 923f3a2b48bdccb6a1d1f0dd48de03de7ad936d9 builds before 873f32201df8876bdb2563e3187e79149427cab4; from 923f3a2b48bdccb6a1d1f0dd48de03de7ad936d9 before fb81222c1559f89bfe3aa1010f6d112531d55353; from 923f3a2b48bdccb6a1d1f0dd48de03de7ad936d9 before 7207923d8453ebfb35667c1736169f2dd796772e; from 923f3a2b48bdccb6a1d1f0dd48de03de7ad936d9 before a9e5924daa954c9f585c1ca00358afe71d6781c4; from 923f3a2b48bdccb6a1d1f0dd48de03de7ad936d9 before d23264c257a70dbe021b43b3bc2ee16134cd2c69; from 923f3a2b48bdccb6a1d1f0dd48de03de7ad936d9 before d8df126349dad855cdfedd6bbf315bad2e901c2f	CNA record
Siemens SIMATIC CN 4100 siemens:simatic_cn_4100 (from the name)	before V5.0	CISA ADP
Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP siemens:simatic_s7_1500_cpu_1518_4_pn_dp_mfp (from the name)	from V3.1.6	CISA ADP
Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP siemens:simatic_s7_1500_cpu_1518f_4_pn_dp_mfp (from the name)	from V3.1.6	CISA ADP
Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP siemens:siplus_s7_1500_cpu_1518_4_pn_dp_mfp (from the name)	from V3.1.6	CISA ADP
linux linux_kernel linux:linux_kernel	from 5.8 before 5.10.242; from 5.11 before 5.15.190; from 5.16 before 6.1.149; from 6.2 before 6.6.103; from 6.7 before 6.12.44; from 6.13 before 6.16.4; 6.17; 6.17	NVD
debian debian_linux debian:debian_linux	11.0	NVD

References

References

https://git.kernel.org/stable/c/62f12cde10118253348a7540e85606869bd69432	patch
https://git.kernel.org/stable/c/873f32201df8876bdb2563e3187e79149427cab4	patch
https://git.kernel.org/stable/c/fb81222c1559f89bfe3aa1010f6d112531d55353	patch
https://git.kernel.org/stable/c/7207923d8453ebfb35667c1736169f2dd796772e	patch
https://git.kernel.org/stable/c/a9e5924daa954c9f585c1ca00358afe71d6781c4	patch
https://git.kernel.org/stable/c/d23264c257a70dbe021b43b3bc2ee16134cd2c69	patch
https://git.kernel.org/stable/c/d8df126349dad855cdfedd6bbf315bad2e901c2f	patch
https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html	third-party-advisory
https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html	third-party-advisory
https://cert-portal.siemens.com/productcert/html/ssa-019113.html
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The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.