{"id":"CVE-2026-64172","summary":"KVM: SVM: Disable AVIC IPI virtualization on Hygon Family 18h (erratum #1235)","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: SVM: Disable AVIC IPI virtualization on Hygon Family 18h (erratum #1235)\n\nHygon Family 18h CPUs are derived from AMD Family 17h (Zen1) silicon and\nshare the same erratum #1235: hardware may read a stale IsRunning=1 bit\nduring ICR write emulation and silently fail to generate an\nAVIC_IPI_FAILURE_TARGET_NOT_RUNNING VM-Exit on the sending vCPU.\n\nThe absence of the VM-Exit causes KVM to miss the required wakeup of\nblocking target vCPUs, leading to hung vCPUs and unbounded delays in\nguest execution.\n\nExtend the existing AMD Family 17h erratum #1235 workaround to also cover\nHygon Family 18h.  With IPI virtualization disabled, KVM never sets\nIsRunning=1 in the Physical ID table, so every non-self IPI generates a\nVM-Exit and is correctly emulated.","modified":"2026-07-22T03:31:49.823845567Z","published":"2026-07-19T15:40:57.153Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64172.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/94ade38f317ea086a181db0e6b69c574b3b70a5e"},{"type":"WEB","url":"https://git.kernel.org/stable/c/9560e6fee887a9594a89fa265b5b9c79b1591803"},{"type":"WEB","url":"https://git.kernel.org/stable/c/9a12fa5213cfc391e0eed63902d3be98f0913765"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/64xxx/CVE-2026-64172.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-64172"},{"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":"8de4a1c8164e5b2e40d1df764840a31de983f40b"},{"fixed":"94ade38f317ea086a181db0e6b69c574b3b70a5e"},{"fixed":"9560e6fee887a9594a89fa265b5b9c79b1591803"},{"fixed":"9a12fa5213cfc391e0eed63902d3be98f0913765"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-64172.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.17.0"},{"fixed":"6.18.34"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.0.11"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-64172.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H"}]}