CVE-2026-98468

/// Technical description

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

KVM: arm64: Fix spurious warning for benign stage 2 teardown race

kvmtool was used to establish an L1 guest with 8 CPUs and 8 GiB of RAM, an

L2 guest with 4 CPUs and 4 GiB of RAM and an L3 guest with 2 CPUs and 2 GiB

of RAM, all of which was then exited.

Under memory pressure in the L0 host warnings were observed due to

migration triggered by compaction:

WARNING: arch/arm64/kvm/mmu.c:336 at __unmap_stage2_range+0x64/0x80,

CPU#5: kcompactd0/66

Which was, in turn, triggered by an MMU notifier for the host invalidation:

mmu_notifier_invalidate_range_start()

-> ... -> kvm_mmu_notifier_invalidate_range_start()

-> kvm_mmu_unmap_gfn_range()

-> kvm_unmap_gfn_range()

-> kvm_nested_s2_unmap()

-> kvm_stage2_unmap_range()

-> __unmap_stage2_range()

-> stage2_apply_range()

<- -EINVAL, triggering a WARN_ON()

Racing with L0's teardown of stage 2 page tables

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References