KVM: arm64: Reassign nested_mmus array behind mmu_lock (CVE-2026-46317) | HOL Guard CVE

High · CVSS 8.8CVE-2026-46317

KVM: arm64: Reassign nested_mmus array behind mmu_lock

Answer in brief

CVE-2026-46317 records a High severity (CVSS 8.8) vulnerability in KVM: arm64: Reassign nested_mmus array behind mmu_lock. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Analysis pending evidence review

HOL Guard separates source facts from reviewed analysis. See the methodology.

Published Jun 9, 2026Updated Aug 5, 2026Source checked Sep 19, 2026First seen by HOL Jul 7, 2026Material review Aug 5, 2026

Upstream Advisory

Key facts

Risk: High · CVSS 8.8
Exploitation: Not marked as known exploited
Affected software: 2 mapped packages or products
Fix availability: Available

Why this deserves its current priority

CVSS is 8.8. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.

Analysis status

Analysis pending evidence review

Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.

Affected scope and exposure questions

The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.

Mapped affected packages and fixed versions
Package	Affected range	Fixed version
Linux/Linuxgeneric	>=4f128f8e1aaac189f83d0f828bcdb2986d8d2e51 <918450ad6010df6ecd2efde12a1409e011da22d6 \|\| >=4f128f8e1aaac189f83d0f828bcdb2986d8d2e51 <4424dbcb06d68e34e51c019a5781a7dc00731971 \|\| >=4f128f8e1aaac189f83d0f828bcdb2986d8d2e51 <70543358fa08e0f7cebc3447c3b70fe97ad7aaa8	918450ad6010df6ecd2efde12a1409e011da22d6, 4424dbcb06d68e34e51c019a5781a7dc00731971, 70543358fa08e0f7cebc3447c3b70fe97ad7aaa8
Linux/Linuxgeneric	6.11	Not reported

Recommended response

Check inventory. Check lockfiles and deployed manifests for Linux/Linux, Linux/Linux.
Review the reported fix. Update Linux/Linux to 918450ad6010df6ecd2efde12a1409e011da22d6 if you use the affected versions. Test the change in a non-production environment first.

Evidence timeline and material changes

Published upstream
Jun 9, 2026
Evidence: source:cvelist:source_dates:source-dates:record
Source modified
Aug 5, 2026
Evidence: source:cvelist:source_dates:source-dates:record
First seen by HOL
Jul 7, 2026

Sources and claim methodology

Upstream source description

In the Linux kernel, the following vulnerability has been resolved: KVM: arm64: Reassign nested_mmus array behind mmu_lock kvm->arch.nested_mmus[] is walked under kvm->mmu_lock, including from the MMU notifier path (kvm_unmap_gfn_range() -> kvm_nested_s2_unmap()), which can run at any time. kvm_vcpu_init_nested() reallocates the array and frees the old buffer while holding only kvm->arch.config_lock, so such a walker can reference the freed array. Allocate the new array outside of mmu_lock, as the allocation can sleep. Under the lock, copy the existing entries, fix up the back pointers and reassign the array. Free the old buffer after dropping the lock, as kvfree() can sleep as well.

Quoted source text, attributed separately from HOL analysis.