[Backport 4839ddc27b7212ec58874f62c97da7400c8523be to 4.0, 3.19, 3.18] Commit fd1d0ddf2ae9 (KVM: arm/arm64: check IRQ number on userland injection) rightly limited the range of interrupts userspace can inject in a guest, but failed to consider the (unlikely) case where a guest is configured with 1024 interrupts. In this case, interrupts ranging from 1020 to 1023 are unuseable, as they have a special meaning for the GIC CPU interface. Make sure that these number cannot be used as an IRQ. Also delete a redundant (and similarily buggy) check in kvm_set_irq. Reported-by: Peter Maydell <peter.maydell@xxxxxxxxxx> Cc: Andre Przywara <andre.przywara@xxxxxxx> Cc: <stable@xxxxxxxxxxxxxxx> Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx> --- virt/kvm/arm/vgic.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/virt/kvm/arm/vgic.c b/virt/kvm/arm/vgic.c index e5abe7c..a5ba5bd 100644 --- a/virt/kvm/arm/vgic.c +++ b/virt/kvm/arm/vgic.c @@ -1371,7 +1371,7 @@ int kvm_vgic_inject_irq(struct kvm *kvm, int cpuid, unsigned int irq_num, goto out; } - if (irq_num >= kvm->arch.vgic.nr_irqs) + if (irq_num >= min(kvm->arch.vgic.nr_irqs, 1020)) return -EINVAL; vcpu_id = vgic_update_irq_pending(kvm, cpuid, irq_num, level); -- 2.1.4 -- To unsubscribe from this list: send the line "unsubscribe stable" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html