{"api_version":"1","generated_at":"2026-10-24T16:08:28+00:00","cve":"CVE-2026-98719","urls":{"html":"https://cve.report/CVE-2026-98719","api":"https://cve.report/api/cve/CVE-2026-98719.json","docs":"https://cve.report/api","cve_org":"https://www.cve.org/CVERecord?id=CVE-2026-98719","nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-98719"},"summary":{"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":"PUBLISHED","assigner":"Linux","published_at":"2026-10-18 16:17:25","updated_at":"2026-10-19 10:19:36"},"problem_types":[],"metrics":[],"references":[{"url":"https://git.kernel.org/stable/c/0fbc7fec2242de6c3dcea6de55573c428e820173","name":"https://git.kernel.org/stable/c/0fbc7fec2242de6c3dcea6de55573c428e820173","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/8abbc76120a74bfba1851bd97528099d715e45c6","name":"https://git.kernel.org/stable/c/8abbc76120a74bfba1851bd97528099d715e45c6","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://git.kernel.org/stable/c/b1de3ebf59507e0edacaa5cfa2225bc1869e1b63","name":"https://git.kernel.org/stable/c/b1de3ebf59507e0edacaa5cfa2225bc1869e1b63","refsource":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","tags":[],"title":"","mime":"","httpstatus":"","archivestatus":"0"},{"url":"https://www.cve.org/CVERecord?id=CVE-2026-98719","name":"CVE Program record","refsource":"CVE.ORG","tags":["canonical"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-98719","name":"NVD vulnerability detail","refsource":"NVD","tags":["canonical","analysis"]}],"affected":[{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6aef7cf800098749ff5d660222efaf6e01e98c09 b1de3ebf59507e0edacaa5cfa2225bc1869e1b63 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 9784e5ca91b37b387f3f414af4340c54f7a63566 0fbc7fec2242de6c3dcea6de55573c428e820173 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 12c1f6e03f944e399bd2c88441dca5dc702b95a5 8abbc76120a74bfba1851bd97528099d715e45c6 git","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 6.18.55 6.18.56 semver","platforms":[]},{"source":"CNA","vendor":"Linux","product":"Linux","version":"affected 7.2.9 7.2.10 semver","platforms":[]}],"timeline":[],"solutions":[],"workarounds":[],"exploits":[],"credits":[],"nvd_cpes":[],"vendor_comments":[],"enrichments":{"kev":null,"epss":null,"legacy_qids":[]},"source_records":{"cve_program":{"containers":{"cna":{"affected":[{"defaultStatus":"unaffected","product":"Linux","programFiles":["arch/x86/kvm/svm/sev.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"b1de3ebf59507e0edacaa5cfa2225bc1869e1b63","status":"affected","version":"6aef7cf800098749ff5d660222efaf6e01e98c09","versionType":"git"},{"lessThan":"0fbc7fec2242de6c3dcea6de55573c428e820173","status":"affected","version":"9784e5ca91b37b387f3f414af4340c54f7a63566","versionType":"git"},{"lessThan":"8abbc76120a74bfba1851bd97528099d715e45c6","status":"affected","version":"12c1f6e03f944e399bd2c88441dca5dc702b95a5","versionType":"git"}]},{"defaultStatus":"unaffected","product":"Linux","programFiles":["arch/x86/kvm/svm/sev.c"],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","vendor":"Linux","versions":[{"lessThan":"6.18.56","status":"affected","version":"6.18.55","versionType":"semver"},{"lessThan":"7.2.10","status":"affected","version":"7.2.9","versionType":"semver"}]}],"cpeApplicability":[{"nodes":[{"cpeMatch":[{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"6.18.56","versionStartIncluding":"6.18.55","vulnerable":true},{"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionEndExcluding":"7.2.10","versionStartIncluding":"7.2.9","vulnerable":true}],"negate":false,"operator":"OR"}]}],"descriptions":[{"lang":"en","value":"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."}],"providerMetadata":{"dateUpdated":"2026-10-19T09:24:30.132Z","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","shortName":"Linux"},"references":[{"url":"https://git.kernel.org/stable/c/b1de3ebf59507e0edacaa5cfa2225bc1869e1b63"},{"url":"https://git.kernel.org/stable/c/0fbc7fec2242de6c3dcea6de55573c428e820173"},{"url":"https://git.kernel.org/stable/c/8abbc76120a74bfba1851bd97528099d715e45c6"}],"title":"KVM: SEV: Nullify \"have run CPUs\" mask pointer when freeing it","x_generator":{"engine":"bippy-1.2.0"}}},"cveMetadata":{"assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","assignerShortName":"Linux","cveId":"CVE-2026-98719","datePublished":"2026-10-18T15:46:54.631Z","dateReserved":"2026-09-25T10:25:14.366Z","dateUpdated":"2026-10-19T09:24:30.132Z","state":"PUBLISHED"},"dataType":"CVE_RECORD","dataVersion":"5.2"},"nvd":{"publishedDate":"2026-10-18 16:17:25","lastModifiedDate":"2026-10-19 10:19:36","problem_types":[],"metrics":[],"configurations":[]},"legacy_mitre":{"record":{"CveYear":"2026","CveId":"98719","Ordinal":"1","Title":"KVM: SEV: Nullify \"have run CPUs\" mask pointer when freeing it","CVE":"CVE-2026-98719","Year":"2026"},"notes":[{"CveYear":"2026","CveId":"98719","Ordinal":"1","NoteData":"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.","Type":"Description","Title":"KVM: SEV: Nullify \"have run CPUs\" mask pointer when freeing it"}]}}}