[PATCH 29/35] KVM: x86: disallow KVM_{SET,GET}_LAPIC without allocated in-kernel lapic

Avi Kivity
2009-11-19T13:35:09Z

From: Marcelo Tosatti <mtosatti@redhat.com>

Otherwise kvm might attempt to dereference a NULL pointer.

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>
---
arch/x86/kvm/x86.c | 6 ++++++
1 files changed, 6 insertions(+), 0 deletions(-)

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 97f6f95..cd6fe0a 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -1893,6 +1893,9 @@ long kvm_arch_vcpu_ioctl(struct file *filp,

switch (ioctl) {
case KVM_GET_LAPIC: {
+ r = -EINVAL;
+ if (!vcpu->arch.apic)
+ goto out;
lapic = kzalloc(sizeof(struct kvm_lapic_state), GFP_KERNEL);

r = -ENOMEM;
@@ -1908,6 +1911,9 @@ long kvm_arch_vcpu_ioctl(struct file *filp,
break;
}
case KVM_SET_LAPIC: {
+ r = -EINVAL;
+ if (!vcpu->arch.apic)
+ goto out;
lapic = kmalloc(sizeof(struct kvm_lapic_state), GFP_KERNEL);
r = -ENOMEM;
if (!lapic)
--
1.6.5.2