[LEDE-DEV] Open and secure firmware for Quectel 4G modems [Was: Re: Quectel EC20 QMI autoconnect issues [Was: Re: [LEDE-DEV, 3/3, v3] uqmi: Prevent 'POLICY MISMATCH' error.]]

Harald Welte laforge at gnumonks.org
Mon Jan 9 01:04:51 PST 2017

Hi Petr,

On Sun, Jan 08, 2017 at 08:26:23PM +0100, Petr Štetiar wrote:
> Indeed, it's very interesting and very scary. This modems are quite powerful
> devices, usually equiped with very good, but limited uplink connection, still
> making it ideal candidate for DDoS botnet for example, like any other router,

I agree. In days of LTE and LTE-A, the connectivity of cellular modems
is sometimes better than that of DSL-modems/routers ;)

> It's just a matter of time we see something like this in the wild.

Equally agreed.

> The probability is very high, 1.5M lines of just kernel code done
> probably in a hurry, without proper review, this is very big attack surface.

The kernel code is the same (or close to?) what is in all the Qualcomm
based Android devices.  That could mean a lot of things, among them that
Google Project Zero guys or other people doing android security might
find issues.  But i could also mean that the attack surfaces is much
larger than those modems ;)

> Guys at Osmocom already started working on completely open and more secure
> firmware using OpenEmbedded, but I would like to see it supported in LEDE
> also, probably with more mainline kernel if possible. 

Our goal at this point is not to modify / strip down the kernel.  The
primary goals at this point are:
a) more work on osmo-cqdiag and my wiershark DIAG protocol decoder
b) establish libqmi-glib interoperability with qmuxd
c) gradually replace existing proprietary userspace programs
d) build custom images + package feeds from OE/poky.
e) understand + document more parts of the Qualcomm Android Kernel

> Still, it's quite strange to see such a big embedded systems running
> in the 4G modem. It seems like 2017 is era of SITSes, Systems In The
> Systems.

I wanted to state this in my talk, but forgot: If software complexity
continues ti increase in cellular modems like we have seen it increase
in the 2006-2016 timeframe, then in ten years we will have
virtualization with orchestration managers in them.

I think the main problem is that 32bit CPU cores with MMU and memory is
getting so small and cheap cheap, that people just put full-blown Linux
systems everywhere.  Whether it makes sense, and how to maintain that in
the long term is apparently no concern.

- Harald Welte <laforge at gnumonks.org>           http://laforge.gnumonks.org/
"Privacy in residential applications is a desirable marketing option."
                                                  (ETSI EN 300 175-7 Ch. A6)

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