{"cve":"CVE-2026-90097","nvd":{"published":"2026-09-17T17:17:01.350","modified":"2026-10-21T13:20:36.800","status":"Received","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nDrivers: hv: vmbus: Skip VMBus module cleanup for non-nested root partition\n\nThe VMBus module initialization function, hv_acpi_init(), currently\ndoes nothing when running in the root partition and root is not nested\nin another VM. But the initialization function reports success, so the\nVMBus module is indeed loaded. VMBus functionality is not actually\nneeded, but the VMBus module must be loaded so that hv_vmbus_exists()\ncan answer correctly. Furthermore, the mshv_root dependency on the\nVMBus module is needed as described in the commit message for\n840b740a35bf (\"mshv: Add conditional VMBus dependency\").\n\nLoading the VMBus module without actually initializing it causes\nfailures if the module should later be unloaded. The module unload code\ntries to clean up things that were never initialized, resulting in\nmemory faults and a panic.\n\nFix this by having VMBus module exit function perform the same\ncheck for non-nested root partition, and do nothing in such a\ncase, just like hv_acpi_init().\n\nIn the long run, the code that manages the Hyper-V provided SynIC\nshould be refactored to better coordinate the requirements of\nroot partition scenarios and normal VM scenarios, and to hopefully\nremove the hv_vmbus_exists() dependnecy between mshv_root and\nVMBus modules. Preventing the current unload failure scenario is\nan expediency until such a refactoring is done.","cvss_v4":null,"cvss_v3":null,"cwes":[],"references":["https://git.kernel.org/stable/c/4c19c302cc577bd6b466f6d8e97971777392c2fa","https://git.kernel.org/stable/c/4cc1ba2b31065a48fde14e9d53ad399a3ca32e35","https://git.kernel.org/stable/c/aa17842bbccaeaba7d05c166019d1c96a41bca54","https://git.kernel.org/stable/c/ca1f4a926d08035c52c735a42200e4e5ea548f32","https://git.kernel.org/stable/c/cee0d90bceae1dee3bcc70f8d6b2ceb5b87deb42"],"products":[],"source":"nvd","synced_at":"2026-10-22T16:41:11.231219466+00:00"},"epss":{"cve":"CVE-2026-90097","score":0.00206,"percentile":0.10563,"date":"2026-10-25"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}