Medium severity · published Sep 5, 2025
CVE-2025-39681
x86/cpu/hygon: Add missing resctrl_cpu_detect() in bsp_init helper
5.5
CVSS
0.2%
EPSS
No
On KEV
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. ]
CVSS vector
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Attack vector
Local
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.2% · higher than 7% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
KE
Kernel · Linux
5.8 before 5.10.242; 5.11 before 5.15.190; 5.16 before 6.1.149; 6.2 before 6.6.103; 6.7 before 6.12.44; 6.13 before 6.16.4; +2 more · source: NVD
LI
Linux · Linux
923f3a2b48bdccb6a1d1f0dd48de03de7ad936d9 before 62f12cde10118253348a7540e85606869bd69432; 923f3a2b48bdccb6a1d1f0dd48de03de7ad936d9 before 873f32201df8876bdb2563e3187e79149427cab4; 923f3a2b48bdccb6a1d1f0dd48de03de7ad936d9 before fb81222c1559f89bfe3aa1010f6d112531d55353; 923f3a2b48bdccb6a1d1f0dd48de03de7ad936d9 before 7207923d8453ebfb35667c1736169f2dd796772e; 923f3a2b48bdccb6a1d1f0dd48de03de7ad936d9 before a9e5924daa954c9f585c1ca00358afe71d6781c4; 923f3a2b48bdccb6a1d1f0dd48de03de7ad936d9 before d23264c257a70dbe021b43b3bc2ee16134cd2c69; +2 more · source: vendor
DL
Debian Linux · Debian
11.0 · source: NVD
SC
SIMATIC CN 4100 · Siemens
before V5.0 · source: CISA
SS
SIMATIC S7-1500 CPU 1518-4 PN/DP MFP · Siemens
V3.1.6; V3.1.7; V3.1.6; V3.1.7 · source: CISA
SS
SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP · Siemens
V3.1.6; V3.1.7; V3.1.6; V3.1.7 · source: CISA
SS