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Date: Tue, 19 Jun 2018 10:07:53 +0100
From: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= <berrange@redhat.com>
Message-ID: <20180619090753.GJ20929@redhat.com>
Reply-To: Daniel =?utf-8?B?UC4gQmVycmFuZ8Op?= <berrange@redhat.com>
References: <20180618161729.334-1-marcandre.lureau@redhat.com>
	<20180618161729.334-10-marcandre.lureau@redhat.com>
	<20180619061903.pmiy36kznlkpmanq@sirius.home.kraxel.org>
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Subject: Re: [Qemu-devel] [PATCH v3 09/26] HACK: vhost-user-backend: allow
 to specify binary to execute
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To: Gerd Hoffmann <kraxel@redhat.com>
Cc: =?utf-8?Q?Marc-Andr=C3=A9?= Lureau <marcandre.lureau@redhat.com>, qemu-devel@nongnu.org

On Tue, Jun 19, 2018 at 08:19:03AM +0200, Gerd Hoffmann wrote:
> On Mon, Jun 18, 2018 at 06:17:12PM +0200, Marc-Andr=C3=A9 Lureau wrote:
> > An executable with its arguments may be given as 'cmd' property, ex:
> > -object vhost-user-backend,id=3Dvui,cmd=3D"./vhost-user-input
> > /dev/input..". The executable is then spawn and, by convention, the
> > vhost-user socket is passed as fd=3D3. It may be considered a securit=
y
> > breach to allow creating processes that may execute arbitrary
> > executables, so this may be restricted to some known executables (via
> > signature etc) or directory.
>=20
> Hmm, maybe let the device which uses vhost-user-backend handle this?
>=20
> So you use "-device vhost-user-input-pci,device=3D/dev/input/$dev" and
> vhost-user-input-pci translates that into ...
> =20
>   argv =3D { "$dir/vhost-user-input", "-device", "/dev/input/$dev", NUL=
L }
>=20
> ... for vhost-user-backend ?

Or just accept the binary name, but mandate a pre-determined set of
argv, in the same way we do for  TAP device ifup scripts.

Regards,
Daniel
--=20
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