Re: [PATCH v6 0/1] ns: introduce binfmt_misc namespace

[Laurent Vivier]

On 01/11/2018 04:51, Jann Horn wrote:
> On Thu, Nov 1, 2018 at 3:59 AM James Bottomley
> <James.Bottomley@xxxxxxxxxxxxxxxxxxxxx> wrote:
>>
>> On Tue, 2018-10-16 at 11:52 +0200, Laurent Vivier wrote:
>>> Hi,
>>>
>>> Any comment on this last version?
>>>
>>> Any chance to be merged?
>>
>> I've got a use case for this:  I went to one of the Graphene talks in
>> Edinburgh and it struck me that we seem to keep reinventing the type of
>> sandboxing that qemu-user already does.  However if you want to do an
>> x86 on x86 sandbox, you can't currently use the binfmt_misc mechanism
>> because that has you running *every* binary on the system emulated.
>> Doing it per user namespace fixes this problem and allows us to at
>> least cut down on all the pointless duplication.
> 
> Waaaaaait. What? qemu-user does not do "sandboxing". qemu-user makes
> your code slower and *LESS* secure. As far as I know, qemu-user is
> only intended for purposes like development and testing.
> 

I think the idea here is not to run qemu, but to use an interpreter
(something like gVisor) into a container to control the binaries
execution inside the container without using this interpreter on the
host itself (container and host shares the same binfmt_misc magic/mask).

Thanks,
Laurent