{"id":"CVE-2025-21840","summary":"thermal/netlink: Prevent userspace segmentation fault by adjusting UAPI header","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nthermal/netlink: Prevent userspace segmentation fault by adjusting UAPI header\n\nThe intel-lpmd tool [1], which uses the THERMAL_GENL_ATTR_CPU_CAPABILITY\nattribute to receive HFI events from kernel space, encounters a\nsegmentation fault after commit 1773572863c4 (\"thermal: netlink: Add the\ncommands and the events for the thresholds\").\n\nThe issue arises because the THERMAL_GENL_ATTR_CPU_CAPABILITY raw value\nwas changed while intel_lpmd still uses the old value.\n\nAlthough intel_lpmd can be updated to check the THERMAL_GENL_VERSION and\nuse the appropriate THERMAL_GENL_ATTR_CPU_CAPABILITY value, the commit\nitself is questionable.\n\nThe commit introduced a new element in the middle of enum thermal_genl_attr,\nwhich affects many existing attributes and introduces potential risks\nand unnecessary maintenance burdens for userspace thermal netlink event\nusers.\n\nSolve the issue by moving the newly introduced\nTHERMAL_GENL_ATTR_TZ_PREV_TEMP attribute to the end of the\nenum thermal_genl_attr. This ensures that all existing thermal generic\nnetlink attributes remain unaffected.\n\n[ rjw: Subject edits ]","modified":"2026-04-02T12:45:14.915796Z","published":"2025-03-07T09:09:58.907Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/21xxx/CVE-2025-21840.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/3a4ca365c51729143a2cab693cd40fe0bb585ef0"},{"type":"WEB","url":"https://git.kernel.org/stable/c/c195b9c6ab9c383d7aa3f4a65879b3ca90cb378b"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/21xxx/CVE-2025-21840.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2025-21840"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"1773572863c43a14a3e45f0591f28b7dec1ee52a"},{"fixed":"3a4ca365c51729143a2cab693cd40fe0bb585ef0"},{"fixed":"c195b9c6ab9c383d7aa3f4a65879b3ca90cb378b"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-21840.json"}}],"schema_version":"1.7.5"}