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From: Marcelo Tosatti <mtosatti@redhat.com>
To: kvm-devel <kvm@vger.kernel.org>
Cc: Jan Kiszka <jan.kiszka@web.de>, Paolo Bonzini <pbonzini@redhat.com>
Subject: KVM: VMX: fix use after free of vmx->loaded_vmcs
Date: Fri, 3 Jan 2014 17:00:51 -0200	[thread overview]
Message-ID: <20140103190051.GA16151@amt.cnet> (raw)


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

Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index da7837e..2efa33f0 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -7332,8 +7332,8 @@ static void vmx_free_vcpu(struct kvm_vcpu *vcpu)
 	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);

             reply	other threads:[~2014-01-03 19:03 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2014-01-03 19:00 Marcelo Tosatti [this message]
2014-01-03 19:27 ` KVM: VMX: fix use after free of vmx->loaded_vmcs Jan Kiszka
2014-01-03 19:36   ` Marcelo Tosatti
2014-01-03 19:54     ` Jan Kiszka

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