CVE-2026-98718

In the Linux kernel, the following vulnerability has been resolved:

KVM: SEV: Do cache maintenance on the source VM before clearing SEV state

Explicitly flush caches after intra-host migration before clearing "SEV active" on the source VM, as doing cache maintenance afterwards creates a tiny window where memory reclaim could return memory to the host without performing a cache flush, e.g. as pointed out by Sashiko:

CPU1 in sev migrate from(): src->active = false;

CPU2 running concurrent unmap: Since active is false, the automatic cache flush in sev guest memory reclaimed is skipped. The host frees and reallocates the page.

CPU1 in sev migrate from(): sev writeback caches(src kvm); Executes a hardware cache flush (wbnoinvd), which writes the guest's old dirty ciphertext over the new page owner's data.