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>
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 061e27c..204297d 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -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]);