From 8868daebc1b6240d07d5c6428f8bc8631b2bed42 Mon Sep 17 00:00:00 2001 From: Avi Kivity Date: Tue, 19 Mar 2013 12:36:55 +0100 Subject: KVM: Ensure all vcpus are consistent with in-kernel irqchip settings commit 3e515705a1f46beb1c942bb8043c16f8ac7b1e9e upstream. If some vcpus are created before KVM_CREATE_IRQCHIP, then irqchip_in_kernel() and vcpu->arch.apic will be inconsistent, leading to potential NULL pointer dereferences. Fix by: - ensuring that no vcpus are installed when KVM_CREATE_IRQCHIP is called - ensuring that a vcpu has an apic if it is installed after KVM_CREATE_IRQCHIP This is somewhat long winded because vcpu->arch.apic is created without kvm->lock held. Based on earlier patch by Michael Ellerman. Signed-off-by: Michael Ellerman Signed-off-by: Avi Kivity Signed-off-by: Jiri Slaby Signed-off-by: Greg Kroah-Hartman --- virt/kvm/kvm_main.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'virt') diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 5841d06..88dde44 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -1619,6 +1619,10 @@ static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, u32 id) goto vcpu_destroy; mutex_lock(&kvm->lock); + if (!kvm_vcpu_compatible(vcpu)) { + r = -EINVAL; + goto unlock_vcpu_destroy; + } if (atomic_read(&kvm->online_vcpus) == KVM_MAX_VCPUS) { r = -EINVAL; goto unlock_vcpu_destroy; -- cgit v1.1