Messages in this thread | | | Date | Fri, 30 Jan 2015 11:48:04 -0800 | From | Casey Schaufler <> | Subject | Re: [PATCH v2] kernel: Conditionally support non-root users, groups and capabilities |
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On 1/30/2015 11:13 AM, josh@joshtriplett.org wrote: > On Thu, Jan 29, 2015 at 06:25:23PM -0800, Casey Schaufler wrote: >> On 1/29/2015 5:36 PM, Paul E. McKenney wrote: >>> A few K here, a few K there, and pretty soon you actually fit into the >>> small-memory 32-bit SoCs. I do not believe that the processing time >>> is the issue. >> And UNIX, with UID and GID processing, used to run in 64K of RAM, >> without swap or paging. Bluntly, there are many other places to look >> before you go here. > And we're looking in all those places too. Each patch is worth > evaluating independently. We've *already* gone here, the code is > written (and being revised based on feedback), and "go work over there > out of my backyard" is not going to work. One of these days, we're > going to run in 64k again.
Oh good heavens. Don't take this personally. I don't.
>>>> As for LSMs, I can easily see putting in the security model from the old >>>> RTOS on top of a NON_ROOT configuration. Won't that be fun when the CVEs >>>> start to fly? > The security model is "there's one process on this system". (Expect > patches for CONFIG_FORK=n and CONFIG_EXEC=n at some point.)
Ok. Why not use Bada?
>>>> Do you think you'll be running system services like systemd on top of this? >>>> Anyone *else* remember what happened when they put capability handling into >>>> sendmail? >>> Nope, I don't expect these systems to be using LSM, systemd, or sendmail. >>> I think that many of these will instead run the application directly >>> out of the init process. >> Where an "application" might be something like CrossWalk, > No, not a chance. If you're running a web runtime, you're on a much > larger system, and you're going to be less concerned about shaving > kilobytes; you're also going to want many of the kernel facilities for > sandboxing code. > > The kinds of applications we're talking about here run entirely in one > binary, serving a few very narrow functions. We're not talking > "automobile IVI system" here; we're talking "two buttons and an output", > or "a few sensors and an SD card".
Linux is an insane choice for such a system. Why would you even consider it?
> > - Josh Triplett >
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