KVM: fix EFER read buffer overflow
Check whether index is within bounds before grabbing the element.
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
Cc: Avi Kivity <avi@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Avi Kivity <avi@redhat.com>
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 0ba706e..31c3a87 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -571,12 +571,15 @@
static void load_transition_efer(struct vcpu_vmx *vmx)
{
int efer_offset = vmx->msr_offset_efer;
- u64 host_efer = vmx->host_msrs[efer_offset].data;
- u64 guest_efer = vmx->guest_msrs[efer_offset].data;
+ u64 host_efer;
+ u64 guest_efer;
u64 ignore_bits;
if (efer_offset < 0)
return;
+ host_efer = vmx->host_msrs[efer_offset].data;
+ guest_efer = vmx->guest_msrs[efer_offset].data;
+
/*
* NX is emulated; LMA and LME handled by hardware; SCE meaninless
* outside long mode