{"id":"CVE-2025-39681","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nx86/cpu/hygon: Add missing resctrl_cpu_detect() in bsp_init helper\n\nSince\n\n  923f3a2b48bd (\"x86/resctrl: Query LLC monitoring properties once during boot\")\n\nresctrl_cpu…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nx86/cpu/hygon: Add missing resctrl_cpu_detect() in bsp_init helper\n\nSince\n\n  923f3a2b48bd (\"x86/resctrl: Query LLC monitoring properties once during boot\")\n\nresctrl_cpu…","severity":"medium","cvss":5.5,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","vendor":"linux","product":"linux_kernel","affected":["linux_kernel >= 5.8, < 5.10.242","linux_kernel >= 5.11, < 5.15.190","linux_kernel >= 5.16, < 6.1.149","linux_kernel >= 6.2, < 6.6.103","linux_kernel >= 6.7, < 6.12.44","linux_kernel >= 6.13, < 6.16.4","linux_kernel = 6.17","debian_linux = 11.0"],"patched":["linux_kernel 6.16.4"],"published":"2025-09-05","updated":"2026-10-15","sourceUpdated":"2026-10-15T02:17:58.477","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2025-39681","references":[{"url":"https://git.kernel.org/stable/c/62f12cde10118253348a7540e85606869bd69432","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/7207923d8453ebfb35667c1736169f2dd796772e","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/873f32201df8876bdb2563e3187e79149427cab4","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/a9e5924daa954c9f585c1ca00358afe71d6781c4","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/d23264c257a70dbe021b43b3bc2ee16134cd2c69","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/d8df126349dad855cdfedd6bbf315bad2e901c2f","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/fb81222c1559f89bfe3aa1010f6d112531d55353","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-019113.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-032379.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-457936.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"}],"tags":["nvd","cve.org"],"epss":0.00176,"epssPercentile":0.0704,"ingestedAt":"2026-09-08T15:33:26.997Z","slug":"CVE-2025-39681","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nx86/cpu/hygon: Add missing resctrl_cpu_detect() in bsp_init helper\n\nSince\n\n  923f3a2b48bd (\"x86/resctrl: Query LLC monitoring properties once during boot\")\n\nresctrl_cpu_detect() has been moved from common CPU initialization code to\nthe vendor-specific BSP init helper, while Hygon didn't put that call in their\ncode.\n\nThis triggers a division by zero fault during early booting stage on our\nmachines with X86_FEATURE_CQM* supported, where get_rdt_mon_resources() tries\nto calculate mon_l3_config with uninitialized boot_cpu_data.x86_cache_occ_scale.\n\nAdd the missing resctrl_cpu_detect() in the Hygon BSP init helper.\n\n  [ bp: Massage commit message. ]\n\n## Affected\n\n- `linux_kernel >= 5.8, < 5.10.242`\n- `linux_kernel >= 5.11, < 5.15.190`\n- `linux_kernel >= 5.16, < 6.1.149`\n- `linux_kernel >= 6.2, < 6.6.103`\n- `linux_kernel >= 6.7, < 6.12.44`\n- `linux_kernel >= 6.13, < 6.16.4`\n- `linux_kernel = 6.17`\n- `debian_linux = 11.0`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `linux_kernel 6.16.4`","depth":"sunlit","depthScore":30,"depthScoreParts":{"impact":30.3,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[{"seq":221539,"id":"CVE-2025-39681","ts":1792035256279,"field":"cvss","old":null,"new":"5.5"},{"seq":221538,"id":"CVE-2025-39681","ts":1792035256279,"field":"severity","old":"none","new":"medium"}]}