[RFC PATCH 08/14] af_netlink.c: make netlink_capable userns-aware

[Serge Hallyn <serge@hallyn.com>]

From: Serge E. Hallyn <serge.hallyn@canonical.com>

netlink_capable should check for permissions against the user
namespace owning the socket in question.

Signed-off-by: Serge E. Hallyn <serge.hallyn@canonical.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
---
 net/netlink/af_netlink.c |   11 +++++++++--
 1 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index 6ef64ad..81c1099 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -580,8 +580,15 @@ retry:
 
 static inline int netlink_capable(struct socket *sock, unsigned int flag)
 {
-	return (nl_table[sock->sk->sk_protocol].nl_nonroot & flag) ||
-	       capable(CAP_NET_ADMIN);
+	struct net *net;
+	if (nl_table[sock->sk->sk_protocol].nl_nonroot & flag)
+		return 1;
+#ifdef CONFIG_NET_NS
+	net = sock->sk->sk_net;
+#else
+	net = &init_net;
+#endif
+	return ns_capable(net->user_ns, CAP_NET_ADMIN);
 }
 
 static void
-- 
1.7.4.1