From: Paolo Bonzini <pbonzini@redhat.com>
To: Andy Lutomirski <luto@amacapital.net>
Cc: Andy Lutomirski <luto@kernel.org>,
LKML <linux-kernel@vger.kernel.org>,
kvm list <kvm@vger.kernel.org>
Subject: Re: [PATCH v2] KVM: x86: do not read FS/GS base MSRs when saving them
Date: Thu, 4 Jan 2018 02:17:06 +0100 [thread overview]
Message-ID: <f4671e9f-7d7b-8328-b9c0-ba85a97e8dce@redhat.com> (raw)
In-Reply-To: <598B48F9-4552-4442-82D2-60A2674C6241@amacapital.net>
On 04/01/2018 01:16, Andy Lutomirski wrote:
>> Note that the value I'm storing in HOST_FS_BASE and HOST_GS_BASE is
>> only used if FS/GS selector is zero. If FS/GS selector is not
>> zero, it is not used. Does that avoid this issue?
>>
> I'm not convinced that this is correct. It's not obviously a
> security problem in the context of KVM, but a lot of state can leak
> this way.
>
> My general preference would be to make the code obviously fully
> reload the host state.
I'll try to write a v3 that looks more obviously correct.
Paolo
prev parent reply other threads:[~2018-01-04 1:17 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-01-02 13:59 Paolo Bonzini
2018-01-03 22:20 ` Andy Lutomirski
2018-01-03 23:42 ` Paolo Bonzini
2018-01-04 0:16 ` Andy Lutomirski
2018-01-04 1:17 ` Paolo Bonzini [this message]
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