Commit 5bb8ed07 authored Jan 29, 2018 by Christian Brauner Committed by David S. Miller Jan 31, 2018

rtnetlink: enable IFLA_IF_NETNSID for RTM_NEWLINK



- Backwards Compatibility:
  If userspace wants to determine whether RTM_NEWLINK supports the
  IFLA_IF_NETNSID property they should first send an RTM_GETLINK request
  with IFLA_IF_NETNSID on lo. If either EACCESS is returned or the reply
  does not include IFLA_IF_NETNSID userspace should assume that
  IFLA_IF_NETNSID is not supported on this kernel.
  If the reply does contain an IFLA_IF_NETNSID property userspace
  can send an RTM_NEWLINK with a IFLA_IF_NETNSID property. If they receive
  EOPNOTSUPP then the kernel does not support the IFLA_IF_NETNSID property
  with RTM_NEWLINK. Userpace should then fallback to other means.

- Security:
  Callers must have CAP_NET_ADMIN in the owning user namespace of the
  target network namespace.

Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 91e6dd82

net/core/rtnetlink.c

+1 −5

Original line number	Diff line number	Diff line
		@@ -2952,14 +2952,10 @@ static int rtnl_newlink(struct sk_buff skb, struct nlmsghdr nlh,
		name_assign_type = NET_NAME_ENUM;
		}

		dest_net = rtnl_link_get_net(net, tb);
		dest_net = rtnl_link_get_net_capable(skb, net, tb, CAP_NET_ADMIN);
		if (IS_ERR(dest_net))
		return PTR_ERR(dest_net);

		err = -EPERM;
		if (!netlink_ns_capable(skb, dest_net->user_ns, CAP_NET_ADMIN))
		goto out;

		if (tb[IFLA_LINK_NETNSID]) {
		int id = nla_get_s32(tb[IFLA_LINK_NETNSID]);