From: Christoffer Dall <christoffer.dall@xxxxxxxxxx> commit 716139df2517fbc3f2306dbe8eba0fa88dca0189 upstream. When the vgic initializes its internal state it does so based on the number of VCPUs available at the time. If we allow KVM to create more VCPUs after the VGIC has been initialized, we are likely to error out in unfortunate ways later, perform buffer overflows etc. Acked-by: Marc Zyngier <marc.zyngier@xxxxxxx> Reviewed-by: Eric Auger <eric.auger@xxxxxxxxxx> Signed-off-by: Christoffer Dall <christoffer.dall@xxxxxxxxxx> Signed-off-by: Shannon Zhao <shannon.zhao@xxxxxxxxxx> --- arch/arm/kvm/arm.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c index 039df03..2e74a61 100644 --- a/arch/arm/kvm/arm.c +++ b/arch/arm/kvm/arm.c @@ -220,6 +220,11 @@ struct kvm_vcpu *kvm_arch_vcpu_create(struct kvm *kvm, unsigned int id) int err; struct kvm_vcpu *vcpu; + if (irqchip_in_kernel(kvm) && vgic_initialized(kvm)) { + err = -EBUSY; + goto out; + } + vcpu = kmem_cache_zalloc(kvm_vcpu_cache, GFP_KERNEL); if (!vcpu) { err = -ENOMEM; -- 2.1.0 -- 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