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From: Dave Hansen <dave.hansen@intel.com>
To: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>
Cc: linux-kernel@vger.kernel.org, linux-coco@lists.linux.dev,
	Sean Christopherson <seanjc@google.com>,
	stable@vger.kernel.org
Subject: Re: [PATCH] x86/tdx: Fix data leak in mmio_read()
Date: Mon, 26 Aug 2024 09:41:49 -0700	[thread overview]
Message-ID: <7401a060-884a-4e7f-9d87-10f5c5ac754d@intel.com> (raw)
In-Reply-To: <20240826125304.1566719-1-kirill.shutemov@linux.intel.com>

On 8/26/24 05:53, Kirill A. Shutemov wrote:
> The mmio_read() function makes a TDVMCALL to retrieve MMIO data for an
> address from the VMM.
> 
> Sean noticed that mmio_read() unintentionally exposes the value of an
> initialized variable on the stack to the VMM.
> 
> Do not send the original value of *val to the VMM.

The key to this is that 'val' is only used for the _return_ value, right?

  reply	other threads:[~2024-08-26 16:42 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-08-26 12:53 [PATCH] x86/tdx: Fix data leak in mmio_read() Kirill A. Shutemov
2024-08-26 16:41 ` Dave Hansen [this message]
2024-08-26 19:44   ` Kirill A. Shutemov

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