[patch 2/3] KVM: x86: disallow KVM_{SET,GET}_LAPIC without in kernel irqchip

[Marcelo Tosatti <mtosatti@redhat.com>]

[-- Attachment #1: get-set-lapic --]
[-- Type: text/plain, Size: 817 bytes --]

Otherwise kvm might attempt to dereference a NULL pointer.

CC: stable@kernel.org
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

Index: kvm/arch/x86/kvm/x86.c
===================================================================
--- kvm.orig/arch/x86/kvm/x86.c
+++ kvm/arch/x86/kvm/x86.c
@@ -1815,6 +1815,9 @@ long kvm_arch_vcpu_ioctl(struct file *fi
 
 	switch (ioctl) {
 	case KVM_GET_LAPIC: {
+		r = -EINVAL;
+		if (!irqchip_in_kernel(vcpu->kvm))
+			goto out;
 		lapic = kzalloc(sizeof(struct kvm_lapic_state), GFP_KERNEL);
 
 		r = -ENOMEM;
@@ -1830,6 +1833,9 @@ long kvm_arch_vcpu_ioctl(struct file *fi
 		break;
 	}
 	case KVM_SET_LAPIC: {
+		r = -EINVAL;
+		if (!irqchip_in_kernel(vcpu->kvm))
+			goto out;
 		lapic = kmalloc(sizeof(struct kvm_lapic_state), GFP_KERNEL);
 		r = -ENOMEM;
 		if (!lapic)