CVE Catalog

CVE-2026-89913

HighCVSS 8.8
Published: Updated: Translated: NVD NIST

Summary

In the Linux kernel, vgic_v3_save_pending_tables() in KVM arm64 iterates over dist->lpi_xa without holding a reference to the vgic_irq structures, relying only on temporary RCU coverage. A concurrent path can free the LPI, leading to a dangling pointer dereference after the RCU grace period. The fix re-fetches each LPI via vgic_get_irq() and drops it with vgic_put_irq().

Risk Assessment

This can lead to a use-after-free in the kernel, causing a system crash or potential privilege escalation. It affects KVM on arm64 environments with virtual GIC v3.

Recommendation

Update the Linux kernel to a version containing the fix. Restrict access to VM migration features with GIC v3 to trusted users.

Other vulnerabilities in Linux kernel

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Original NVD description (English source)

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.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS