KVM: VMX: fix use after free of vmx->loaded_vmcs
After free_loaded_vmcs executes, the "loaded_vmcs" structure
is kfreed, and now vmx->loaded_vmcs points to a kfreed area.
Subsequent free_loaded_vmcs then attempts to manipulate
vmx->loaded_vmcs.
Switch the order to avoid the problem.
https://bugzilla.redhat.com/show_bug.cgi?id=1047892
Reviewed-by: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 0abf8b7..7661eb1 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -7390,8 +7390,8 @@
struct vcpu_vmx *vmx = to_vmx(vcpu);
free_vpid(vmx);
- free_nested(vmx);
free_loaded_vmcs(vmx->loaded_vmcs);
+ free_nested(vmx);
kfree(vmx->guest_msrs);
kvm_vcpu_uninit(vcpu);
kmem_cache_free(kvm_vcpu_cache, vmx);