Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved: KVM: arm64: Make VNCR invalidation participate in MMU invalidation retry A VNCR TLB invalidation can occur on one vcpu while another vcpu is faulting in this same page. Without correctly handling this, we can end up with the following scenario: - vcpu A walks the PTs to translate VNCR - before vcpu A is able to grab the MMU lock to insert the TLB, vcpu B updates the S1 PTs with an invalid entry, and issues a TLBI S1E2 for this VA - vcpu A inserts the TLB for something that is now invalid This isn't a new problem, and we manage S2 by having the MMU notifier to bump up mmu_invalidate_seq on invalidation so that the fault can be replayed. We can perform something similar here, and extend invalidate_vncr_va() to update the same counter, clearly indicating that the context has changed under our feet. This is safe as the invalidation always happen while holding the MMU lock for write, and that we sample the sequence number before walking S1.
CVSS Score
CRITICAL
References
- https://git.kernel.org/stable/c/11ee3faab4f1755d126bead9f882e75a7a677860
- https://git.kernel.org/stable/c/2b7324f3a0c1072b9d578b8d42f199506753f26e
- https://git.kernel.org/stable/c/d8580e7aa189b0c6c5bb4d94b8352728a7c35bbd
FAQ
What is CVE-2026-89916?
CVE-2026-89916 is a vulnerability with a CVSS score of 9.3 (CRITICAL). In the Linux kernel, the following vulnerability has been resolved: KVM: arm64: Make VNCR invalidation participate in MMU invalidation retry A VNCR TLB invalidation can occur on one vcpu while anoth...
How severe is CVE-2026-89916?
CVE-2026-89916 has been rated CRITICAL with a CVSS base score of 9.3/10. This is considered a critical vulnerability requiring immediate attention.
Is there a patch for CVE-2026-89916?
Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.