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Subject[PATCH 3.2 16/18] KVM: VMX: fix use after free of vmx->loaded_vmcs
3.2.57-rc1 review patch.  If anyone has any objections, please let me know.

------------------

From: Marcelo Tosatti <mtosatti@redhat.com>

commit 26a865f4aa8e66a6d94958de7656f7f1b03c6c56 upstream.

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>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
arch/x86/kvm/vmx.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -6273,8 +6273,8 @@ static void vmx_free_vcpu(struct kvm_vcp
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);


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