CVE-2026-98472
Received Received - Intake

KVM SEV Memory Leak in Linux Kernel

Publication date: 2026-10-18

Last updated on: 2026-10-18

Assigner: kernel.org

Description
In the Linux kernel, the following vulnerability has been resolved: KVM: SEV: Free have_run_cpus during VM destruction even if VM is no longer SEV Unconditionally free SEV's "have run CPUs" cpumask in the VM destroy path, i.e. even for what appear to be non-SEV VMs, as an SEV VM becomes a non-SEV VM if its state is intra-host migrated. Alternatively, the mask could be freed in sev_migrate_from() when "converting" the source VM, but that gets annoying because ideally KVM would nullify the mask to guard against UAF, and nullifying the mask would need be conditioned on CPUMASK_OFFSTACK=y. Freeing the mask during sev_migrate_from() is also not robust against other KVM bugs, though that's kind of a moot point since any such bugs would show up even if sev->active is never set. I.e. KVM must get that side of things correct. But, that's not a great reason to add more code just to make things marginally less robust.

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Meta Information

Published
2026-10-18
Last Modified
2026-10-18
Generated
2026-10-18
AI Q&A
2026-10-18
EPSS Evaluated
N/A
NVD
CVE-2026-98472
EUVD
EUVD-2026-103712

Affected Vendors & Products

Showing 4 associated CPEs
Vendor Product Version / Range
Linux Linux 6f38f8c574642a822f2e85f079fa29a49176c49c
Linux Linux 6f38f8c574642a822f2e85f079fa29a49176c49c
Linux Linux 6f38f8c574642a822f2e85f079fa29a49176c49c
Linux Linux 6.17

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Exploitability

CWE
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KEV
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CWE ID Description
CWE-UNKNOWN

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Executive Summary

This vulnerability in the Linux kernel involves improper handling of a CPU mask during virtual machine (VM) destruction. Specifically, the 'have run CPUs' cpumask is freed even for non-SEV VMs, which can occur if an SEV VM undergoes intra-host migration and becomes a non-SEV VM. This could lead to use-after-free (UAF) issues.

Impact Analysis

This vulnerability may cause system instability or crashes due to use-after-free errors. It could potentially allow unauthorized access or privilege escalation if exploited, though the exact impact depends on the system configuration and usage.

Mitigation Strategies

Update the Linux kernel to a patched version that resolves this KVM SEV vulnerability. Monitor official Linux kernel security advisories for patches and apply them promptly.

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