Re: [PATCH v3] openvswitch: allow management from inside user namespaces

On Fri, Feb 5, 2016 at 5:20 PM, Tycho Andersen
[off-list ref] wrote:

Operations with the GENL_ADMIN_PERM flag fail permissions checks because
this flag means we call netlink_capable, which uses the init user ns.

Instead, let's introduce a new flag, GENL_UNS_ADMIN_PERM for operations
which should be allowed inside a user namespace.

The motivation for this is to be able to run openvswitch in unprivileged
containers. I've tested this and it seems to work, but I really have no
idea about the security consequences of this patch, so thoughts would be
much appreciated.

v2: use the GENL_UNS_ADMIN_PERM flag instead of a check in each function
v3: use separate ifs for UNS_ADMIN_PERM and ADMIN_PERM, instead of one
    massive one

Reported-by: James Page <redacted>
Signed-off-by: Tycho Andersen <redacted>
CC: Eric Biederman <redacted>
CC: Pravin Shelar <redacted>
CC: Justin Pettit <redacted>
CC: "David S. Miller" <davem@davemloft.net>
---
 include/uapi/linux/genetlink.h |  1 +
 net/netlink/genetlink.c        |  4 ++++
 net/openvswitch/datapath.c     | 20 ++++++++++----------
 3 files changed, 15 insertions(+), 10 deletions(-)

Looks good.

Acked-by: Pravin B Shelar <redacted>