KVM: arm/arm64: vgic: Cap SPIs to the VM-defined maximum

commit bea2ef803ade3359026d5d357348842bca9edcf1 upstream.

SPIs should be checked against the VMs specific configuration, and
not the architectural maximum.

Cc: stable@vger.kernel.org
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

virt/kvm/arm/vgic/vgic.c

@@ -108,8 +108,8 @@ struct vgic_irq *vgic_get_irq(struct kvm *kvm, struct kvm_vcpu *vcpu,
 	}
 
 	/* SPIs */
-	if (intid <= VGIC_MAX_SPI) {
-		intid = array_index_nospec(intid, VGIC_MAX_SPI);
+	if (intid < (kvm->arch.vgic.nr_spis + VGIC_NR_PRIVATE_IRQS)) {
+		intid = array_index_nospec(intid, kvm->arch.vgic.nr_spis + VGIC_NR_PRIVATE_IRQS);
 		return &kvm->arch.vgic.spis[intid - VGIC_NR_PRIVATE_IRQS];
 	}