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Subject: Re: [PATCH] KVM: Add separate helper for putting borrowed reference
 to kvm
To:     Leonardo Bras <leonardo@linux.ibm.com>,
        Sean Christopherson <sean.j.christopherson@intel.com>
Cc:     Paul Mackerras <paulus@ozlabs.org>,
        =?UTF-8?B?UmFkaW0gS3LEjW3DocWZ?= <rkrcmar@redhat.com>,
        kvm-ppc@vger.kernel.org, kvm@vger.kernel.org,
        linux-kernel@vger.kernel.org
References: <20191021225842.23941-1-sean.j.christopherson@intel.com>
 <de313d549a5ae773aad6bbf04c20b395bea7811f.camel@linux.ibm.com>
 <20191126171416.GA22233@linux.intel.com>
 <0009c6c1bb635098fa68cb6db6414634555039fe.camel@linux.ibm.com>
From:   Paolo Bonzini <pbonzini@redhat.com>
Message-ID: <e1a4218f-2a70-3de3-1403-dbebf8a8abdf@redhat.com>
Date:   Wed, 27 Nov 2019 17:38:57 +0100
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On 26/11/19 18:53, Leonardo Bras wrote:
>=20
> I agree an use-after-free more problem than a memory leak, but I think
> that there is a way to solve this without leaking the memory also.
>=20
> One option would be reordering the kvm_put_kvm(), like in this patch:
> https://lkml.org/lkml/2019/11/26/517

It's a tradeoff between "fix one bug" and "mitigate all bugs of that
class", both are good things to do.  Reordering the kvm_put_kvm() fixes
the bug.  kvm_put_kvm_no_destroy() makes all bugs of that kind less
severe, but it doesn't try to fix them.

Paolo


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