From: Dave Hansen <dave.hansen@intel.com>
To: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
Dave Hansen <dave.hansen@linux.intel.com>,
"H. Peter Anvin" <hpa@zytor.com>,
x86@kernel.org, Theodore Ts'o <tytso@mit.edu>,
"Jason A. Donenfeld" <Jason@zx2c4.com>,
Kuppuswamy Sathyanarayanan
<sathyanarayanan.kuppuswamy@linux.intel.com>,
Elena Reshetova <elena.reshetova@intel.com>,
Jun Nakajima <jun.nakajima@intel.com>,
Tom Lendacky <thomas.lendacky@amd.com>,
"Kalra, Ashish" <ashish.kalra@amd.com>,
Sean Christopherson <seanjc@google.com>,
linux-coco@lists.linux.dev, linux-kernel@vger.kernel.org
Subject: Re: [RFC] Randomness on confidential computing platforms
Date: Mon, 29 Jan 2024 14:18:50 -0800 [thread overview]
Message-ID: <b3f48f9c-c1c0-47b5-b55a-d9cd63d86951@intel.com> (raw)
In-Reply-To: <v6maadzwtke3z5ejp2mavsnm4mvmjbu7demvldzpobqeva74rx@r6y5fwxsyoep>
On 1/29/24 13:33, Kirill A. Shutemov wrote:
>> Let's assume buggy userspace exists. Is that userspace *uniquely*
>> exposed to a naughty VMM or is that VMM just added to the list of things
>> that can attack buggy userspace?
> This is good question.
>
> VMM has control over when a VCPU gets scheduled and on what CPU which
> gives it tighter control over the target workload. It can make a
> difference if there's small window for an attack before RDRAND is
> functional again.
This is all a bit too theoretical for my taste. I'm fine with doing
some generic mitigation (WARN_ON_ONCE(hardware_is_exhausted)), but we're
talking about a theoretical attack with theoretical buggy software when
in a theoretically unreachable hardware state.
Until it's clearly much more practical, we have much bigger problems to
worry about.
next prev parent reply other threads:[~2024-01-29 22:18 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-01-26 13:42 [RFC] Randomness on confidential computing platforms Kirill A. Shutemov
2024-01-26 14:46 ` Nikolay Borisov
2024-01-26 15:42 ` Reshetova, Elena
2024-01-26 15:57 ` Daniel P. Berrangé
2024-01-26 16:35 ` Nikolay Borisov
2024-01-29 7:15 ` Reshetova, Elena
2024-01-26 15:23 ` Sean Christopherson
2024-01-29 10:27 ` Kirill A. Shutemov
2024-01-29 16:30 ` Dave Hansen
2024-01-29 16:37 ` H. Peter Anvin
2024-01-29 16:41 ` Kirill A. Shutemov
2024-01-29 17:07 ` H. Peter Anvin
2024-01-29 18:55 ` Dave Hansen
2024-01-29 20:26 ` Kirill A. Shutemov
2024-01-29 21:04 ` Dave Hansen
2024-01-29 21:17 ` H. Peter Anvin
2024-01-29 21:38 ` H. Peter Anvin
2024-01-29 22:12 ` H. Peter Anvin
2024-01-29 21:33 ` Kirill A. Shutemov
2024-01-29 22:18 ` Dave Hansen [this message]
2024-01-29 23:32 ` H. Peter Anvin
2024-01-30 8:19 ` Reshetova, Elena
2024-01-30 8:01 ` Reshetova, Elena
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