Re: [PATCH v2 net-next 1/3] bpf: enable non-root eBPF programs

From: Alexei Starovoitov
Date: Fri Oct 09 2015 - 13:59:32 EST


On 10/9/15 10:45 AM, Daniel Borkmann wrote:
On 10/09/2015 07:30 PM, Alexei Starovoitov wrote:
...
Openstack use case is different. There it will be prog_type_sched_cls
that can mangle packets, change skb metadata, etc under TC framework.
These are not suitable for all users and this patch leaves
them root-only. If you're proposing to add CAP_BPF_TC to let containers
use them without being CAP_SYS_ADMIN, then I agree, it is useful, but
needs a lot more safety analysis on tc side.

Well, I think if so, then this would need to be something generic for
tc instead of being specific to a single (out of various) entities
inside the tc framework, but I currently doubt that this makes much
sense. If we allow to operate already at that level, then restricting
to CAP_SYS_ADMIN makes more sense in that specific context/subsys to me.

Let me rephrase. I think it would be useful, but I have my doubts that
it's manageable, since analyzing dark corners of TC is not trivial.
Probably easier to allow prog_type_sched_cls/act under CAP_NET_ADMIN
and grant that to trusted apps. Though only tiny bit better than
requiring CAP_SYS_ADMIN.

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