1 files changed, 75 insertions, 5 deletions

diff --git a/net/netlink/af_netlink.c b/net/netlink/af_netlink.c
index 894cda0206bb..f22757a29cd0 100644
--- a/net/netlink/af_netlink.c
+++ b/net/netlink/af_netlink.c
@@ -1360,7 +1360,74 @@ retry:
         return err;
 }
 
-static inline int netlink_capable(const struct socket *sock, unsigned int flag)
+/**
+ * __netlink_ns_capable - General netlink message capability test
+ * @nsp: NETLINK_CB of the socket buffer holding a netlink command from userspace.
+ * @user_ns: The user namespace of the capability to use
+ * @cap: The capability to use
+ *
+ * Test to see if the opener of the socket we received the message
+ * from had when the netlink socket was created and the sender of the
+ * message has has the capability @cap in the user namespace @user_ns.
+ */
+bool __netlink_ns_capable(const struct netlink_skb_parms *nsp,
+                        struct user_namespace *user_ns, int cap)
+{
+        return ((nsp->flags & NETLINK_SKB_DST) ||
+                file_ns_capable(nsp->sk->sk_socket->file, user_ns, cap)) &&
+                ns_capable(user_ns, cap);
+}
+EXPORT_SYMBOL(__netlink_ns_capable);
+
+/**
+ * netlink_ns_capable - General netlink message capability test
+ * @skb: socket buffer holding a netlink command from userspace
+ * @user_ns: The user namespace of the capability to use
+ * @cap: The capability to use
+ *
+ * Test to see if the opener of the socket we received the message
+ * from had when the netlink socket was created and the sender of the
+ * message has has the capability @cap in the user namespace @user_ns.
+ */
+bool netlink_ns_capable(const struct sk_buff *skb,
+                        struct user_namespace *user_ns, int cap)
+{
+        return __netlink_ns_capable(&NETLINK_CB(skb), user_ns, cap);
+}
+EXPORT_SYMBOL(netlink_ns_capable);
+
+/**
+ * netlink_capable - Netlink global message capability test
+ * @skb: socket buffer holding a netlink command from userspace
+ * @cap: The capability to use
+ *
+ * Test to see if the opener of the socket we received the message
+ * from had when the netlink socket was created and the sender of the
+ * message has has the capability @cap in all user namespaces.
+ */
+bool netlink_capable(const struct sk_buff *skb, int cap)
+{
+        return netlink_ns_capable(skb, &init_user_ns, cap);
+}
+EXPORT_SYMBOL(netlink_capable);
+
+/**
+ * netlink_net_capable - Netlink network namespace message capability test
+ * @skb: socket buffer holding a netlink command from userspace
+ * @cap: The capability to use
+ *
+ * Test to see if the opener of the socket we received the message
+ * from had when the netlink socket was created and the sender of the
+ * message has has the capability @cap over the network namespace of
+ * the socket we received the message from.
+ */
+bool netlink_net_capable(const struct sk_buff *skb, int cap)
+{
+        return netlink_ns_capable(skb, sock_net(skb->sk)->user_ns, cap);
+}
+EXPORT_SYMBOL(netlink_net_capable);
+
+static inline int netlink_allowed(const struct socket *sock, unsigned int flag)
 {
         return (nl_table[sock->sk->sk_protocol].flags & flag) ||
                 ns_capable(sock_net(sock->sk)->user_ns, CAP_NET_ADMIN);
@@ -1428,7 +1495,7 @@ static int netlink_bind(struct socket *sock, struct sockaddr *addr,
 
         /* Only superuser is allowed to listen multicasts */
         if (nladdr->nl_groups) {
-                if (!netlink_capable(sock, NL_CFG_F_NONROOT_RECV))
+                if (!netlink_allowed(sock, NL_CFG_F_NONROOT_RECV))
                         return -EPERM;
                 err = netlink_realloc_groups(sk);
                 if (err)
@@ -1490,7 +1557,7 @@ static int netlink_connect(struct socket *sock, struct sockaddr *addr,
                 return -EINVAL;
 
         if ((nladdr->nl_groups || nladdr->nl_pid) &&
-            !netlink_capable(sock, NL_CFG_F_NONROOT_SEND))
+            !netlink_allowed(sock, NL_CFG_F_NONROOT_SEND))
                 return -EPERM;
 
         if (!nlk->portid)
@@ -2096,7 +2163,7 @@ static int netlink_setsockopt(struct socket *sock, int level, int optname,
                 break;
         case NETLINK_ADD_MEMBERSHIP:
         case NETLINK_DROP_MEMBERSHIP: {
-                if (!netlink_capable(sock, NL_CFG_F_NONROOT_RECV))
+                if (!netlink_allowed(sock, NL_CFG_F_NONROOT_RECV))
                         return -EPERM;
                 err = netlink_realloc_groups(sk);
                 if (err)
@@ -2228,6 +2295,7 @@ static int netlink_sendmsg(struct kiocb *kiocb, struct socket *sock,
         struct sk_buff *skb;
         int err;
         struct scm_cookie scm;
+        u32 netlink_skb_flags = 0;
 
         if (msg->msg_flags&MSG_OOB)
                 return -EOPNOTSUPP;
@@ -2247,8 +2315,9 @@ static int netlink_sendmsg(struct kiocb *kiocb, struct socket *sock,
                 dst_group = ffs(addr->nl_groups);
                 err =  -EPERM;
                 if ((dst_group || dst_portid) &&
-                    !netlink_capable(sock, NL_CFG_F_NONROOT_SEND))
+                    !netlink_allowed(sock, NL_CFG_F_NONROOT_SEND))
                         goto out;
+                netlink_skb_flags |= NETLINK_SKB_DST;
         } else {
                 dst_portid = nlk->dst_portid;
                 dst_group = nlk->dst_group;
@@ -2278,6 +2347,7 @@ static int netlink_sendmsg(struct kiocb *kiocb, struct socket *sock,
         NETLINK_CB(skb).portid  = nlk->portid;
         NETLINK_CB(skb).dst_group = dst_group;
         NETLINK_CB(skb).creds   = siocb->scm->creds;
+        NETLINK_CB(skb).flags   = netlink_skb_flags;
 
         err = -EFAULT;
         if (memcpy_fromiovec(skb_put(skb, len), msg->msg_iov, len)) {