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authorJulian Orth <ju.orth@gmail.com>2018-09-11 19:17:48 +0200
committerJulian Orth <ju.orth@gmail.com>2018-12-15 17:19:05 +0100
commitc862d7df67f26d86bb0de2ea863231d48d1396e9 (patch)
tree4a68aaa2545c9b9f0a98b7a9fe0eb8ae0e0c0f50
parentnetlink: allow specifying the device namespace (diff)
downloadwireguard-monolithic-historical-c862d7df67f26d86bb0de2ea863231d48d1396e9.tar.xz
wireguard-monolithic-historical-c862d7df67f26d86bb0de2ea863231d48d1396e9.zip
netlink: restrict access to the UDP socket
To interact with the UDP socket the caller must either be in the network namespace of the socket or have CAP_NET_ADMIN in that network namespace.
-rw-r--r--src/netlink.c21
-rw-r--r--src/uapi/wireguard.h7
2 files changed, 25 insertions, 3 deletions
diff --git a/src/netlink.c b/src/netlink.c
index 96ad555..e17c3e1 100644
--- a/src/netlink.c
+++ b/src/netlink.c
@@ -173,6 +173,14 @@ static struct net *get_attr_net(struct nlattr *net_pid, struct nlattr *net_fd)
return NULL;
}
+static int test_socket_net_capable(struct net *net)
+{
+ if (net != current->nsproxy->net_ns &&
+ !ns_capable(net->user_ns, CAP_NET_ADMIN))
+ return -EPERM;
+ return 0;
+}
+
static int wg_get_device_start(struct netlink_callback *cb)
{
struct nlattr **attrs = genl_family_attrbuf(&genl_family);
@@ -249,9 +257,12 @@ static int wg_get_device_dump(struct sk_buff *skb, struct netlink_callback *cb)
genl_dump_check_consistent(cb, hdr);
if (!last_peer_cursor) {
- if (nla_put_u16(skb, WGDEVICE_A_LISTEN_PORT,
- wg->incoming_port) ||
- nla_put_u32(skb, WGDEVICE_A_FWMARK, wg->fwmark) ||
+ if (test_socket_net_capable(wg->creating_net) == 0) {
+ if (nla_put_u16(skb, WGDEVICE_A_LISTEN_PORT,
+ wg->incoming_port))
+ goto out;
+ }
+ if (nla_put_u32(skb, WGDEVICE_A_FWMARK, wg->fwmark) ||
nla_put_u32(skb, WGDEVICE_A_IFINDEX, wg->dev->ifindex) ||
nla_put_string(skb, WGDEVICE_A_IFNAME, wg->dev->name))
goto out;
@@ -338,7 +349,11 @@ static int wg_get_device_done(struct netlink_callback *cb)
static int set_port(struct wg_device *wg, u16 port)
{
struct wg_peer *peer;
+ int ret;
+ ret = test_socket_net_capable(wg->creating_net);
+ if (ret)
+ return ret;
if (wg->incoming_port == port)
return 0;
list_for_each_entry(peer, &wg->peer_list, peer_list)
diff --git a/src/uapi/wireguard.h b/src/uapi/wireguard.h
index bcfcf4f..8b60ad1 100644
--- a/src/uapi/wireguard.h
+++ b/src/uapi/wireguard.h
@@ -30,6 +30,9 @@
* socket. The caller must have CAP_NET_ADMIN in the namespace of the Wireguard
* device.
*
+ * If the caller is not in the transit namespace and does not have CAP_NET_ADMIN
+ * in the transit namespace, then the WGDEVICE_A_LISTEN_PORT is not returned.
+ *
* The kernel will then return several messages (NLM_F_MULTI) containing the
* following tree of nested items:
*
@@ -92,6 +95,10 @@
* of the netlink socket. The caller must have CAP_NET_ADMIN in the namespace of
* the Wireguard device.
*
+ * If WGDEVICE_A_LISTEN_PORT is provided and the calling process is not in the
+ * transit namespace, then the calling process must have CAP_NET_ADMIN the
+ * transit namespace.
+ *
* WGDEVICE_A_IFINDEX: NLA_U32
* WGDEVICE_A_IFNAME: NLA_NUL_STRING, maxlen IFNAMESIZ - 1
* WGDEVICE_A_FLAGS: NLA_U32, 0 or WGDEVICE_F_REPLACE_PEERS if all current