CVE-2026-89912 KVM: arm64: vgic-its: Don't dereference a NULL collection on ITT save
A guest can trigger a host kernel crash via a specific sequence of ITS commands during migration, causing denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-89912?
CVE-2026-89912 is a high-severity vulnerability in Linux, published on 16 Sep 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
KVM: arm64: vgic-its: Don't dereference a NULL collection on ITT save
MAPC with V=0 drops ite->collection but leaves the ITE on the device's ITT list, and vgic_its_save_ite() dereferences it unconditionally. A guest that issues MAPD, MAPTI and then MAPC(V=0) therefore oopses the host when the VMM issues KVM_DEV_ARM_ITS_SAVE_TABLES to migrate it. That sequence is UNPREDICTABLE per the architecture, but KVM already handles the resulting state in the translate, MOVI and DISCARD paths.
Save a zeroed entry, which vgic_its_restore_ite() reads back as invalid. Skipping the ITE instead would leave the ITT slot holding whatever is in guest memory, and restore rejects an entry naming a collection the restored collection table does not have.
Which versions are affected by CVE-2026-89912?
How do I fix CVE-2026-89912?
Apply the vendor's patch.
Is CVE-2026-89912 being exploited?
There is no known exploitation of CVE-2026-89912 in the wild and no public exploit code.
Sources
Also known as AZL-101547, BELL-CVE-2026-89912, DEBIAN-CVE-2026-89912, GHSA-6q94-4246-2272, UBUNTU-CVE-2026-89912.