{"id":"CVE-2026-98718","summary":"KVM: SEV: Do cache maintenance on the source VM *before* clearing SEV state","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: SEV: Do cache maintenance on the source VM *before* clearing SEV state\n\nExplicitly flush caches after intra-host migration before clearing \"SEV\nactive\" on the source VM, as doing cache maintenance afterwards creates a\ntiny window where memory reclaim could return memory to the host without\nperforming a cache flush, e.g. as pointed out by Sashiko:\n\n  CPU1 in sev_migrate_from():\n    src-\u003eactive = false;\n\n  CPU2 running concurrent unmap:\n    Since active is false, the automatic cache flush in\n    sev_guest_memory_reclaimed is skipped.\n    The host frees and reallocates the page.\n\n  CPU1 in sev_migrate_from():\n    sev_writeback_caches(src_kvm);\n    Executes a hardware cache flush (wbnoinvd), which writes the guest's old\n    dirty ciphertext over the new page owner's data.","modified":"2026-10-20T02:45:46.422001503Z","published":"2026-10-18T15:46:53.611Z","database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98718.json"},"references":[{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"},{"type":"WEB","url":"https://git.kernel.org/stable/c/8b7d4f68fef96cebe0b6dbb6e5607772337f7369"},{"type":"WEB","url":"https://git.kernel.org/stable/c/973ea70393e885e540f714904e51bc6cac80e3d7"},{"type":"WEB","url":"https://git.kernel.org/stable/c/de83ff6a4d8f3618473bedb3c4400020c22e8a8a"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/98xxx/CVE-2026-98718.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98718"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"37dfb676fafd1eef36fe0bb649607afbb0d5521b"},{"fixed":"8b7d4f68fef96cebe0b6dbb6e5607772337f7369"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"d4cc2dff12116a700add601c0262132cc26e1b2c"},{"fixed":"de83ff6a4d8f3618473bedb3c4400020c22e8a8a"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"93de2a6a4b91b72607136dd656edf03fb399d27f"},{"fixed":"973ea70393e885e540f714904e51bc6cac80e3d7"}]}],"versions":["v6.18.55","v7.2.9"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98718.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.18.55"},{"fixed":"6.18.56"}]},{"type":"ECOSYSTEM","events":[{"introduced":"7.2.9"},{"fixed":"7.2.10"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-98718.json"}}],"schema_version":"1.9.0"}