{"id":"CVE-2026-98719","revision":"2ee995c9e4b043b18358b97f94458fa0","records":[{"revision":"2ee995c9e4b043b18358b97f94458fa0","observedAt":"2026-10-23T15:48:27.903+00:00","statement":{"source":"cve-program","id":"CVE-2026-98719","aliases":[],"title":"KVM: SEV: Nullify \"have run CPUs\" mask pointer when freeing it","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nKVM: SEV: Nullify \"have run CPUs\" mask pointer when freeing it\n\nNullify have_run_cpus when freeing the mask, particularly in the error path\nof __sev_guest_init(), so that KVM doesn't have to subtly use sev->active\nto track whether or not the mask has been freed.  As pointed out by Sashiko,\nblindly freeing the mask in sev_vm_destroy() results in a double-free if\nthe mask is freed if __sev_guest_init() fails.\n\nThrow the logic in a helper as nullifying the pointer is frustratingly\ndifficult and weird due to have_run_cpus being a single-entry array when\nCPUMASK_OFFSTACK=n.  Deliberately don't use CPUMASK_VAR_NULL, as it's not\ndirectly assignable when the cpumask is on-stack, e.g. requires using a\nlocal variable and a memcpy(), which is beyond ridiculous.  Furthermore,\nwhile clearing the on-stack bitmask is an unnecessary and arguably unwanted\nside effect, KVM absolutely relies on '0' being the \"null\" value given that\nthe struct is zero-allocated.\n\nOpportunistically add an alloc() helper to pair with free(); there are just\nenough call sites to make doing so worthwhile.","state":0,"publishedAt":"2026-10-18T15:46:54.631+00:00","modifiedAt":"2026-10-19T09:24:30.132+00:00","affected":[{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"arch/x86/kvm/svm/sev.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"6aef7cf800098749ff5d660222efaf6e01e98c09\",\n                            \"lessThan\": \"b1de3ebf59507e0edacaa5cfa2225bc1869e1b63\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"9784e5ca91b37b387f3f414af4340c54f7a63566\",\n                            \"lessThan\": \"0fbc7fec2242de6c3dcea6de55573c428e820173\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        },\n                        {\n                            \"version\": \"12c1f6e03f944e399bd2c88441dca5dc702b95a5\",\n                            \"lessThan\": \"8abbc76120a74bfba1851bd97528099d715e45c6\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"git\"\n                        }\n                    ]\n                }"},{"ecosystem":"Vendor product","name":"Linux","ranges":[],"versions":[],"rawVersionEvidence":"{\n                    \"product\": \"Linux\",\n                    \"vendor\": \"Linux\",\n                    \"defaultStatus\": \"unaffected\",\n                    \"repo\": \"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git\",\n                    \"programFiles\": [\n                        \"arch/x86/kvm/svm/sev.c\"\n                    ],\n                    \"versions\": [\n                        {\n                            \"version\": \"6.18.55\",\n                            \"lessThan\": \"6.18.56\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"semver\"\n                        },\n                        {\n                            \"version\": \"7.2.9\",\n                            \"lessThan\": \"7.2.10\",\n                            \"status\": \"affected\",\n                            \"versionType\": \"semver\"\n                        }\n                    ]\n                }"}],"metrics":[],"references":["https://git.kernel.org/stable/c/b1de3ebf59507e0edacaa5cfa2225bc1869e1b63","https://git.kernel.org/stable/c/0fbc7fec2242de6c3dcea6de55573c428e820173","https://git.kernel.org/stable/c/8abbc76120a74bfba1851bd97528099d715e45c6"],"sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-98719","license":"CVE Program Terms of Use","key":"cve-program:CVE-2026-98719","identifiers":["CVE-2026-98719"]},"retained":false,"historicalAffected":[]}],"coverage":[]}