Re: [PATCH 4/4] x86,module: Detect CRn and DRn manipulation

Jan Kiszka
2020-04-08T09:00:17Z

On 08.04.20 10:51, Peter Zijlstra wrote:
> On Wed, Apr 08, 2020 at 07:58:53AM +0200, Jan Kiszka wrote:
>> On 07.04.20 23:48, Steven Rostedt wrote:
>
>>> Hmm, wont this break jailhouse?
>
> Breaking it isn't a problem, it's out of tree and it should be fixable.
>
>> Yes, possibly. We load the hypervisor binary via request_firmware into
>> executable memory and then jump into it. So most of the "suspicious" code is
>
> W.T.H. does the firmware loader have the ability to give executable
> memory? We need to kill that too. /me goes find.
>

At the risk of cutting our own branch off: That's not the firmware
loader, it's ioremap with PAGE_KERNEL_EXEC.

Jan

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