[Qemu-devel] insecure git submodule URLs

[Qemu-devel] insecure git submodule URLs

[Jann Horn]

Hi!

I noticed that when I build QEMU from git for the first time, it pulls
in submodules over the insecure git:// protocol - in other words, as
far as I can tell, if I'm e.g. on an open wifi network while building
QEMU for the first time, even if I cloned the main repository over
https, anyone could smuggle in malicious code as part of e.g. a
submodule's makefile.

I'm not sure what your preferred fix for this is, so I'm not sending a
patch yet. As far as I can tell, the two options are:

 - change .gitmodules to use https for everything
 - change .gitmodules to use relative URLs

If you want, I'll send a patch that does one of these, although it's
probably faster if you just do it yourselves.

Relative URLs would have the advantage that if someone is cloning from
a mirror (in other words, github), the submodules will also
automatically come from the same mirror.

As far as I can tell, the QEMU git server only supports the "dumb" git
protocol when accessed over HTTPS, not the "smart" protocol. I'm not
sure whether that might be why QEMU is currently still using the
insecure git protocol instead of git over HTTPS?

Re: [Qemu-devel] insecure git submodule URLs

[Peter Maydell]

On 15 July 2018 at 20:50, Jann Horn via Qemu-devel
<qemu-devel@nongnu.org> wrote:
> I noticed that when I build QEMU from git for the first time, it pulls
> in submodules over the insecure git:// protocol - in other words, as
> far as I can tell, if I'm e.g. on an open wifi network while building
> QEMU for the first time, even if I cloned the main repository over
> https, anyone could smuggle in malicious code as part of e.g. a
> submodule's makefile.

Yes, this came up the other week.

> I'm not sure what your preferred fix for this is, so I'm not sending a
> patch yet. As far as I can tell, the two options are:
>
>  - change .gitmodules to use https for everything

We should probably do this...

>  - change .gitmodules to use relative URLs
>
> If you want, I'll send a patch that does one of these, although it's
> probably faster if you just do it yourselves.
>
> Relative URLs would have the advantage that if someone is cloning from
> a mirror (in other words, github), the submodules will also
> automatically come from the same mirror.

Do we mirror all our submodules to github?

> As far as I can tell, the QEMU git server only supports the "dumb" git
> protocol when accessed over HTTPS, not the "smart" protocol. I'm not
> sure whether that might be why QEMU is currently still using the
> insecure git protocol instead of git over HTTPS?

This is why we haven't switched over the submodules yet, yes.
It's on Jeff's todo list for the server, though.

thanks
-- PMM

Re: [Qemu-devel] insecure git submodule URLs

[Jann Horn]

On Sun, Jul 15, 2018 at 11:18 PM Peter Maydell <peter.maydell@linaro.org> wrote:
>
> On 15 July 2018 at 20:50, Jann Horn via Qemu-devel
> <qemu-devel@nongnu.org> wrote:
> > I noticed that when I build QEMU from git for the first time, it pulls
> > in submodules over the insecure git:// protocol - in other words, as
> > far as I can tell, if I'm e.g. on an open wifi network while building
> > QEMU for the first time, even if I cloned the main repository over
> > https, anyone could smuggle in malicious code as part of e.g. a
> > submodule's makefile.
>
> Yes, this came up the other week.
>
> > I'm not sure what your preferred fix for this is, so I'm not sending a
> > patch yet. As far as I can tell, the two options are:
> >
> >  - change .gitmodules to use https for everything
>
> We should probably do this...
>
> >  - change .gitmodules to use relative URLs
> >
> > If you want, I'll send a patch that does one of these, although it's
> > probably faster if you just do it yourselves.
> >
> > Relative URLs would have the advantage that if someone is cloning from
> > a mirror (in other words, github), the submodules will also
> > automatically come from the same mirror.
>
> Do we mirror all our submodules to github?

Looks that way - I cloned from github, patched my .submodules to use
relative URLs for everything, then tested:

$ git submodule init
Submodule 'capstone' (capstone.git) registered for path 'capstone'
Submodule 'dtc' (dtc.git) registered for path 'dtc'
Submodule 'roms/QemuMacDrivers' (QemuMacDrivers.git) registered for
path 'roms/QemuMacDrivers'
Submodule 'roms/SLOF' (SLOF.git) registered for path 'roms/SLOF'
Submodule 'roms/ipxe' (ipxe.git) registered for path 'roms/ipxe'
Submodule 'roms/openbios' (openbios.git) registered for path 'roms/openbios'
Submodule 'roms/openhackware' (openhackware.git) registered for path
'roms/openhackware'
Submodule 'roms/qemu-palcode' (qemu-palcode.git) registered for path
'roms/qemu-palcode'
Submodule 'roms/seabios' (seabios.git) registered for path 'roms/seabios'
Submodule 'roms/seabios-hppa'
(https://github.com/hdeller/seabios-hppa.git) registered for path
'roms/seabios-hppa'
Submodule 'roms/sgabios' (sgabios.git) registered for path 'roms/sgabios'
Submodule 'roms/skiboot' (skiboot.git) registered for path 'roms/skiboot'
Submodule 'roms/u-boot' (u-boot.git) registered for path 'roms/u-boot'
Submodule 'roms/u-boot-sam460ex' (u-boot-sam460ex.git) registered for
path 'roms/u-boot-sam460ex'
Submodule 'ui/keycodemapdb' (keycodemapdb.git) registered for path
'ui/keycodemapdb'
$ git submodule update
Submodule path 'capstone': checked out
'22ead3e0bfdb87516656453336160e0a37b066bf'
Submodule path 'dtc': checked out 'e54388015af1fb4bf04d0bca99caba1074d9cc42'
Submodule path 'roms/QemuMacDrivers': checked out
'd4e7d7ac663fcb55f1b93575445fcbca372f17a7'
Submodule path 'roms/SLOF': checked out
'7d37babcfa48a6eb08e726a8d13b745cb2eebe1c'
Submodule path 'roms/ipxe': checked out
'0600d3ae94f93efd10fc6b3c7420a9557a3a1670'
Submodule path 'roms/openbios': checked out
'8fe6f5f96f6ca39f1f62200be7fa130e929f13f2'
Submodule path 'roms/openhackware': checked out
'c559da7c8eec5e45ef1f67978827af6f0b9546f5'
Submodule path 'roms/qemu-palcode': checked out
'f3c7e44c70254975df2a00af39701eafbac4d471'
Submodule path 'roms/seabios': checked out
'f9626ccb91e771f990fbb2da92e427a399d7d918'
Submodule path 'roms/seabios-hppa': checked out
'1ef99a01572c2581c30e16e6fe69e9ea2ef92ce0'
Submodule path 'roms/sgabios': checked out
'cbaee52287e5f32373181cff50a00b6c4ac9015a'
Submodule path 'roms/skiboot': checked out
'e0ee24c27a172bcf482f6f2bc905e6211c134bcc'
Submodule path 'roms/u-boot': checked out
'd85ca029f257b53a96da6c2fb421e78a003a9943'
Submodule path 'roms/u-boot-sam460ex': checked out
'60b3916f33e617a815973c5a6df77055b2e3a588'
Submodule path 'ui/keycodemapdb': checked out
'6b3d716e2b6472eb7189d3220552280ef3d832ce'

> > As far as I can tell, the QEMU git server only supports the "dumb" git
> > protocol when accessed over HTTPS, not the "smart" protocol. I'm not
> > sure whether that might be why QEMU is currently still using the
> > insecure git protocol instead of git over HTTPS?
>
> This is why we haven't switched over the submodules yet, yes.
> It's on Jeff's todo list for the server, though.
>
> thanks
> -- PMM

Re: [Qemu-devel] insecure git submodule URLs

[Eric Blake]

On 7/15/18 7:56 PM, Jann Horn via Qemu-devel wrote:
> On Sun, Jul 15, 2018 at 11:18 PM Peter Maydell <peter.maydell@linaro.org> wrote:
>>
>> On 15 July 2018 at 20:50, Jann Horn via Qemu-devel
>> <qemu-devel@nongnu.org> wrote:
>>> I noticed that when I build QEMU from git for the first time, it pulls
>>> in submodules over the insecure git:// protocol - in other words, as
>>> far as I can tell, if I'm e.g. on an open wifi network while building
>>> QEMU for the first time, even if I cloned the main repository over
>>> https, anyone could smuggle in malicious code as part of e.g. a
>>> submodule's makefile.
>>
>> Yes, this came up the other week.
>>
>>> I'm not sure what your preferred fix for this is, so I'm not sending a
>>> patch yet. As far as I can tell, the two options are:
>>>
>>>   - change .gitmodules to use https for everything
>>
>> We should probably do this...
>>

>>> As far as I can tell, the QEMU git server only supports the "dumb" git
>>> protocol when accessed over HTTPS, not the "smart" protocol. I'm not
>>> sure whether that might be why QEMU is currently still using the
>>> insecure git protocol instead of git over HTTPS?
>>
>> This is why we haven't switched over the submodules yet, yes.
>> It's on Jeff's todo list for the server, though.

Did we ever get this done? (And updating this thread to pull in Jeff's 
new email). (Reminded of this now that there is yet another submodule 
being proposed for mirroring)

-- 
Eric Blake, Principal Software Engineer
Red Hat, Inc.           +1-919-301-3266
Virtualization:  qemu.org | libvirt.org

Re: [Qemu-devel] insecure git submodule URLs

[Stefan Hajnoczi]

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On Mon, Oct 08, 2018 at 02:17:39PM -0500, Eric Blake wrote:
> On 7/15/18 7:56 PM, Jann Horn via Qemu-devel wrote:
> > On Sun, Jul 15, 2018 at 11:18 PM Peter Maydell <peter.maydell@linaro.org> wrote:
> > > 
> > > On 15 July 2018 at 20:50, Jann Horn via Qemu-devel
> > > <qemu-devel@nongnu.org> wrote:
> > > > I noticed that when I build QEMU from git for the first time, it pulls
> > > > in submodules over the insecure git:// protocol - in other words, as
> > > > far as I can tell, if I'm e.g. on an open wifi network while building
> > > > QEMU for the first time, even if I cloned the main repository over
> > > > https, anyone could smuggle in malicious code as part of e.g. a
> > > > submodule's makefile.
> > > 
> > > Yes, this came up the other week.
> > > 
> > > > I'm not sure what your preferred fix for this is, so I'm not sending a
> > > > patch yet. As far as I can tell, the two options are:
> > > > 
> > > >   - change .gitmodules to use https for everything
> > > 
> > > We should probably do this...
> > > 
> 
> > > > As far as I can tell, the QEMU git server only supports the "dumb" git
> > > > protocol when accessed over HTTPS, not the "smart" protocol. I'm not
> > > > sure whether that might be why QEMU is currently still using the
> > > > insecure git protocol instead of git over HTTPS?
> > > 
> > > This is why we haven't switched over the submodules yet, yes.
> > > It's on Jeff's todo list for the server, though.
> 
> Did we ever get this done? (And updating this thread to pull in Jeff's new
> email). (Reminded of this now that there is yet another submodule being
> proposed for mirroring)

For the record, Jeff Cody set up smart HTTP for https://git.qemu.org/
and QEMU 3.1.0 will use https for submodules.

Stefan

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