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Message-ID: <6cef7c8a-10d3-9fc6-f68d-220fdfc079c1@redhat.com>
Date:   Fri, 18 Feb 2022 19:14:28 +0100
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Subject: Re: [PATCH] KVM: x86: Forcibly leave nested virt when SMM state is
 toggled
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To:     Tadeusz Struk <tadeusz.struk@linaro.org>,
        Sean Christopherson <seanjc@google.com>
Cc:     Vitaly Kuznetsov <vkuznets@redhat.com>,
        Wanpeng Li <wanpengli@tencent.com>,
        Jim Mattson <jmattson@google.com>,
        Joerg Roedel <joro@8bytes.org>, kvm@vger.kernel.org,
        linux-kernel@vger.kernel.org,
        syzbot+8112db3ab20e70d50c31@syzkaller.appspotmail.com
References: <20220125220358.2091737-1-seanjc@google.com>
 <db8a9edd-533e-3502-aed1-e084d6b55e48@linaro.org>
 <Yg/QKgxotNyZbYAI@google.com>
 <3561688b-b52c-8858-3da2-afda7c3e681f@linaro.org>
From:   Paolo Bonzini <pbonzini@redhat.com>
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On 2/18/22 18:22, Tadeusz Struk wrote:
> On 2/18/22 08:58, Sean Christopherson wrote:
>> This SMM-specific patch fixes something different, the bug that you 
>> are still
>> hitting is the FNAME(cmpxchg_gpte) mess.  The uaccess CMPXCHG 
>> series[*] that
>> properly fixes that issue hasn't been merged yet.
>>
>>    ==================================================================
>>    BUG: KASAN: use-after-free in ept_cmpxchg_gpte.constprop.0+0x3c3/0x590
>>    Write of size 8 at addr ffff888010000000 by task repro/5633
>>
>> [*]https://lore.kernel.org/all/20220202004945.2540433-1-seanjc@google.com
>>
> 
> Ok, that's good. I will keep an eye on it and give it a try then.

I'll poke PeterZ for a review next week.

Paolo