Re: [PATCH 00/12] Add kdbus implementation

From: Andy Lutomirski
Date: Wed Oct 29 2014 - 18:28:53 EST


On Wed, Oct 29, 2014 at 3:25 PM, Greg Kroah-Hartman
<gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
> On Wed, Oct 29, 2014 at 03:19:21PM -0700, Andy Lutomirski wrote:
>> On Wed, Oct 29, 2014 at 3:00 PM, Greg Kroah-Hartman
>> <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
>> > * Attachment of trustable metadata to each message on demand, such as
>> > the sending peer's timestamp, creds, auxgroups, comm, exe, cmdline,
>> > cgroup path, capabilities, security label, audit information, etc,
>> > each taken at the time the sender issued the ioctl to send the
>> > message. Which of those are actually recorded and attached is
>> > controlled by the receiving peer.
>>
>> I think that each piece of trustable metadata needs to be explicitly
>> opted-in to by the sender at the time of capture. Otherwise you're
>> asking for lots of information leaks and privilege escalations. This
>> is especially important given that some of the items in the current
>> list could be rather sensitive.
>
> You do have to opt-in for this information at time of capture, so I
> don't understand the issue here. This is the same type of thing that
> dbus does today, and I don't see the information leaks happening there,
> do you?
>

The docs suggest that the *receiver* opts in.

I don't think that current dbus has severe information leaks because
the total scope for information transparently sent to dbus is rather
small (struct ucred only, presumably).

--Andy
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