Re: [PATCH net-next 1/3] bpf: introduce current->pid, tgid, uid, gid, comm accessors

On Fri, Jun 12, 2015 at 4:38 PM, Alexei Starovoitov [off-list ref] wrote:

On 6/12/15 4:25 PM, Andy Lutomirski wrote:

quoted

It's a dangerous tool.  Also, shouldn't the returned uid match the
namespace of the task that installed the probe, not the task that's
being probed?

so leaking info to unprivileged apps is the concern?
The whole thing is for root only as you know.
The non-root is still far away. Today root needs to see the whole
kernel. That was the goal from the beginning.

This is more of a correctness issue than a security issue.  ISTM using
current_user_ns() in a kprobe is asking for trouble.  It certainly
allows any unprivilege user to show any uid it wants to the probe,
which is probably not what the installer of the probe expects.

--Andy