CVE-2026-89913

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

KVM: arm64: vgic-v3: take an LPI reference in vgic_v3_save_pending_tables

vgic_v3_save_pending_tables() iterates dist->lpi_xa using xa_for_each()

and dereferences the returned struct vgic_irq in the loop body without

holding a reference on the LPI.

The xarray iterator only provides temporary RCU coverage while looking up

the current entry. That is not sufficient for this loop body, which reads

fields from struct vgic_irq and performs guest memory accesses before the

iteration completes.

A concurrent path can trigger this race: the irqfd cached injection path

(vgic_its_inject_cached_translation) obtains a transient LPI reference

via vgic_its_check_cache() without holding kvm->lock, vcpu->mutex,

config_lock, or its_lock. If guest ITS DISCARD then drops the cache and

ITE references under its_lock, the transient inject reference may become

the final one. When vgic_put_irq() drops it, the LPI is erased from

lpi_xa and freed via kfree_rcu(). Meanwhile, vgic_v3_save_pending_tables()

may still hold a stale pointer obtained from the xarray iterator and

dereference it after the RCU grace period completes.

Fix this by re-fetching each iterated LPI via vgic_get_irq(), which takes

a stable reference, and dropping it with vgic_put_irq() on all paths.

This matches the pattern already used by other lpi_xa iterators in the

vgic ITS code.