Re: [RFC] procfs: add hidepid and hidenet modes

On Sun, Jun 12, 2011 at 11:51:01AM +0400, Vasiliy Kulikov wrote:

hidenet means /proc/PID/net will be accessible to processes with
CAP_NET_ADMIN capability or to members of a special group.

gid=XXX defines a group that will be able to gather all processes' info
and network connections info.

Similar features are implemented for old kernels in -ow patches (for
Linux 2.2 and 2.4) and for Linux 2.6 in -grsecurity (but both of them
are implemented as configure options, not cofigurable in runtime).


In current version hidenet works for CONFIG_NET_NS=y via creating a
"fake" net namespace and slipping it to nonauthorized users, resulting
in users observing blank net files (like nobody use the network).  If
CONFIG_NET_NS=n I don't see anything better than just fully denying
access to /proc/<pid>/net.  More elegant ideas are welcome.

This fake netns concept is ugly.
If you wan't deny something, why don't you return -E?

Regardless, these should be separate patch from PID stuff.