From mboxrd@z Thu Jan  1 00:00:00 1970
From: Tom Roeder <tmroeder@google.com>
Subject: Re: [RFC PATCH] kvm: x86/vmx: Use kzalloc for cached_vmcs12
Date: Thu, 24 Jan 2019 13:46:05 -0800
Message-ID: <20190124214605.GA174751@google.com>
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 <20190114234728.49239-1-tmroeder@google.com>
 <20190115024304.GD5141@linux.intel.com>
 <20190115175111.GB68985@google.com>
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 <7abea144-772d-bb3a-bd7d-a9117305c2fb@redhat.com>
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Cc: Sean Christopherson <sean.j.christopherson@intel.com>,
        Radim =?utf-8?B?S3LEjW3DocWZ?= <rkrcmar@redhat.com>,
        Liran Alon <liran.alon@oracle.com>,
        Thomas Gleixner <tglx@linutronix.de>,
        Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
        "H . Peter Anvin" <hpa@zytor.com>, x86@kernel.org,
        kvm@vger.kernel.org, linux-kernel@vger.kernel.org,
        syzbot+ded1696f6b50b615b630@syzkaller.appspotmail.com
To: Paolo Bonzini <pbonzini@redhat.com>
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On Thu, Jan 24, 2019 at 02:18:26AM +0100, Paolo Bonzini wrote:
> On 23/01/19 19:33, Tom Roeder wrote:
> > 
> > Even in vmx_set_nested_state, there are about 30 lines of code in
> > between enter_vmx_operation and copy_from_user, and there are a couple
> > of cases that cause vmx_set_nested_state to return with an error. So if
> > we want to fix this by handling all the error paths, I think it might be
> > cleanest to convert vmx_set_nested_state to use goto error handling,
> > since that would allow us to clear the allocated memory in one place.
> 
> I prefer to have kzalloc, and change vmx_get_nested_state to copy the
> whole page including the trailing zeroes.

OK, sending as a v2 patch in a new thread.