Re: [AppArmor 39/45] AppArmor: Profile loading and manipulation,pathname matching
From: david
Date: Sun Jun 24 2007 - 17:57:27 EST
On Sun, 24 Jun 2007, David Wagner wrote:
Argument 3. AA isn't complete until it mediates network and IPC.
Let me comment on these one-by-one.
3. This one I agree with. If you want to sandbox network daemons that
you're concerned might get hacked, then you really want your sandbox to
mediate everything. Right now the security provided by AA (if that's
what you are using it for) will be limited by its incomplete mediation,
since a knowledgeable motivated attacker who hacks your daemon may be
able to use network or IPC to break out of the sandbox, depending upon
the network and host configuration. Filesystem mediation alone might be
better than nothing, I suppose, if you're worried about script kiddies,
but it's certainly not a basis for strong security claims. The state of
the art in sandboxing obviously requires complete mediation, and we've
known that for a decade.
the issue I see is that AA may not have to implement any new in-kernel
infrastructure to do this.
as recently as yesterday there have been discussions on the netfilter list
about how to implement filter rules based on the application name (see the
thread titled 'filter by application name') if this gets implemented
independantly of AA then AA could provide a policy implementation layer
over netfilter if desired (or sysadmins could just use their current
favorite tool to control the network and AA to control the filesystem)
so holding up AA becouse this isn't implemented yet seems to be counter
productive. people are working on this, and it is going to go in at some
point independantly of AA, so why tie AA to it?
IPC is a very imprecise term. it includes lots of different ways for
processes to communicate with each other. some forms of IPC are covered by
AA today (unix sockets), others aren't. but each of the different methods
is going to involve some difference in how it's controlled. if you want to
talk IPC be specific about what IPC methods you are talking bout limiting.
David Lang
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