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A Kernel Hacker Meets Fuchsia OS

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Re: A Kernel Hacker Meets Fuchsia OS

#131

Earlier quoted context omitted.

It's relevant because it reflects their priorities and how they view developers. The giant banners say this: although these are technical docs you may need to do your job, the most important thing you must see above all is an announcement of how morally pure we (think we) are. Once isn't enough. On our blog isn't enough. It must be the biggest and most eyecatching thing on literally every single page of our documenta…

> Steve Ballmer ... was ridiculed because the outburst of energy ... It was much, much worse than that. Putting aside the crass yelling and dancing; also putting aside any rumor of cocaine abuse; putting aside how cultish it looks... Having a large crowd of adults yelling "dentists! dentists!" or be it lawyers, accountants, etc in a frenzy would be seen as very unprofessional. > But many of us appreciated the sentime…

>Are all people with principles hypocritical?

I think the issue here is not "People With Principles", but "People With Principles They Are Dying To Tell You About". This makes the standard for judging you much much higher : You not only think those principles are superior to a lot of other competing ones, You not only advocate (sometimes, a lot of times to be honest, obnoxiously) for those principles, You do all of those things in times and places where it doesn't make much sense, and right in the middle of other people who might very well disagree with you to heaven and back on those things but choose to stay silent and cooperate with you on unrelated matters nonetheless, cooperation which you break and impede by loudly and non-ceaseingly declaring views they find disagreeable. This makes the people around you, understandbly, model you as the truest possible expression of an X-ism follower: you're at least as sincere as any other X-ist, so any failings or deviation from you principles you have or do is something that the whole X-ism movement along with all its followers also have or do.

I'm biased against what typical US progressives advocate for, so I will choose one of my own principles to make an example of.

I'm a (still booting up) vegetarian, I try not to eat any meat for ethical reasons. I did manage to successfully banish meat from my food for about 2 years now, but I'm not strong-willed enough yet to stop eating marine life. (Technically this makes me not a vegetarian at all, but the weird-sounding word "Pescetarian", but "vegetarian" is more well known and more in alignment with my mental self-image and future plans.) Now, if I started advocating for vegetarianism very loudly and in every single chance and place I find, not only will this make some people very annoyed, but they will start asking : What sort of life do you lead by following this principle you're very passionate about ? If my life deviates from my principles (and it does), I expect people will be even more annoyed, outraged even, and become resistent to and critical of my advocacy. A similar thing happens with nearly every major religion or religion-like ideology, which vegetarianism and progressivism indeed are.

Re: A Kernel Hacker Meets Fuchsia OS

#132

Earlier quoted context omitted.

Just because they have those banners up doesn't mean those point to some latent reason for whatever is responsible for their woes. Granted it gives a window in to the culture of the Fuschia team at Google, but to me, personally, it doesn't come off as virtue-signalling at all but rather a conscious effort to put diversity and inclusion in the front and center of what they do. As another example, Google has had socio-…

It's relevant because it reflects their priorities and how they view developers. The giant banners say this: although these are technical docs you may need to do your job, the most important thing you must see above all is an announcement of how morally pure we (think we) are. Once isn't enough. On our blog isn't enough. It must be the biggest and most eyecatching thing on literally every single page of our documenta…

> It's relevant because it reflects their priorities and how they view developers.

Yes, that they constantly think about diversity and inclusion. Though, I agree that encouraging workplace / employee activism is a tricky slippery slope. Companies like coinbase and basecamp eschew it, for instance.

Re: a: You gotta start somewhere. Besides, work to add a banner is probably a one-day / one-week low-hanging fruit, whereas i18n is not. In comparing those, you're comparing something that takes months to deride something that probably took hours to build and ship.

Re: b: Not privvy to today's culture at Google, so can't say for sure other than speculate.

Re: c: You view that as a bad thing. Such markers (drastic measures as it may seem to you) is how any of this changes. As a thought-experiment / deriving example from tech: do you oppose DNS encryption (a drastic measure in many a eyes [0]) because it nullifies existing cheaper surveillance apparatus deployed by schools, corps, governments; or do you embrace it and firmly want Browser and OS vendors to push forward with it?

[0] https://www.zdnet.com/article/uk-isp-group-names-mozilla-int...

Re: A Kernel Hacker Meets Fuchsia OS

#133
post #20

Earlier quoted context omitted.

That would be too hard, it's a kernel that's actually developed with security in mind and is subject to active research (e.g. by DARPA).

If you try using sel4 in a project, you soon realise it is extremely limited and not at all useful for general purpose computers

Hmm. By not providing a POSIX lemonade stand, would-be users are required to basically figure everything out for themselves; I wonder what the net impact of that is.

On the one hand POSIX et al is effectively impossible to deploy in a secure way, so there is a reasonable argument for going back to the drawing board; but on the other hand there isn't really a well-defined go-to alternative How To Computer model that is friendly to provable security, so everyone has gets to reinvent that wheel every time

Considering the contemporary status quo in terms of independently-implemented OS projects and platforms (eg, my ever-so-slightly-wobbly VxWorks-based TP-LINK consumer ADSL modem), I do wonder how good seL4 implementations end up working out in practice - the kernel might be rock solid, but what about all the bits on top of it, some of which presumably communicate with the outside world, consume various protocols, need to control the hardware in various ways (which includes relying upon reading the hardware state/status), etc?

Re: A Kernel Hacker Meets Fuchsia OS

#134

I think the more interesting thing here is the fact that so much code in their repository appears to be bit-rotted or half baked, despite being documented. KASLR is mentioned all over the place but doesn't work and the answer is "we know, it's there only to stop it bit-rotting". You need to patch the system to do kernel debugging because otherwise the toolchain hangs. Syscalls are documented as enforcing security rul…

Building an OS takes time, they're doing it incrementally, the bugs were known and even had issues for them already. I wouldn't draw any crazy conclusions from this research, this is a hacker's exploration of a foreign OS, which is very interesting, but isn't something I'd draw judgments from.

Re: A Kernel Hacker Meets Fuchsia OS

#135
post #65

The objective of computer security seems to have shifted from preventing someone else from running unauthoirzed software on your computer to preventing you from running unauthorized software on your computer. I would not describe this as security.

How do you draw this conclusion from the article at all? In what way was this hacker 'restricted' ?

Re: A Kernel Hacker Meets Fuchsia OS

#136

The people who work on fuchsia are very good engineers - I’ve worked with many of them in person. But the project itself has always been a staff retention project. It only existed to keep said engineers from going to a competitor. I don’t know how any understanding of fuchsia is possible without this crucial fact

Unlike Linux, Fuchsia is not under GPL. Another attempt at making Android less open.

>Unlike Linux, Fuchsia is not under GPL.

It's under MIT (the kernel Zircon specifically since comparing with Linux). Whether a license allowing even more freedom is worse is arguable.

Re: A Kernel Hacker Meets Fuchsia OS

#137
post #116

Earlier quoted context omitted.

Yes - you can't run untrusted native code in the first place outside of the emulator ;) That's why the bug says: "The overall impact of this bug is pretty minimal in our current set of supported products, since none support running untrusted native code, and if you can run your own code on the system, then (at present) you can also use other existing supported workflows to obtain kernel logs, but it does seem to be a…

The intent of the post isn’t to claim that any Fuschia device currently sold is vulnerable. Unless Fuschia never graduates to running third-party code, that seemed like the right assessment to me.

Sure - but he also added the vulnerability he exploited in the first place?

Re: A Kernel Hacker Meets Fuchsia OS

#138

Earlier quoted context omitted.

You know a limited kind of capability - file descriptors (or kernel handles). Those are just a number that allow you to manipulate some object in a defined way. You can give this number to someone else, and they can't make use of it at all, you have to go ask the kernel (using e.g. a unix socket and ancillary messages) to pass the capability to another process.

That is sort of the opposite of a capability. In fact, files are capabilities exactly because you can hand off a file descriptor and, by virtue of that handle, you grant access. File systems aren't actually capability based (generally, in practice) because you can 'ls' and 'cd ../'. Otherwise they could be. Dropbox Paper is a good example of a capability based system. Anyone with a URL can perform actions on a page,…

>File systems aren't actually capability based (generally, in practice) because you can 'ls' and 'cd ../'. Otherwise they could be.

That's precisely how it works in FreeBSD (https://www.freebsd.org/cgi/man.cgi?capsicum).

Re: A Kernel Hacker Meets Fuchsia OS

#139
post #88

It sounds like a really bad idea to have all software "components" be resolved, downloaded, and executed from over the internet. Seems like a supply chain/waterhole attack just waiting to happen. Not to mention it would seem to sign away the devices ability to act autonomously or offline. Of course, with my views of Google, it seems very like them to design everything to constantly rely on them to even function. Corr…

This sounds like exactly the kind of enterprise OS running on Servers that Google wants for itself. Not something for consumer devices.

Re: A Kernel Hacker Meets Fuchsia OS

#140
post #72

Earlier quoted context omitted.

If you read the article it mentions that ASLR doesn't work, and it's treated as a "known bug".

Do you assume I didn't read the article? Calling it insecure based on this is absurd.

Exactly I also find it slightly silly to immediately declare this 'insecure' in this case here.

If it was directly end-to-end on say a Nest Hub running a release version of Fuchsia then that would be a more convincing here, as that would confirm that it can be deployed and the bug can be exploited in the wild and in production and not on a newly built developer version running in an emulator.

The writeup of finding and exploiting this bug is impressive, but whether if you can use that exploit to directly attack a production version of Fuchsia on a device like the Nest Hub is another thing, which is the same way security researchers do to break live versions of other OSes like macOS, Windows, Android and Linux.

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