nfc: enforce CAP_NET_RAW for raw sockets

When creating a raw AF_NFC socket, CAP_NET_RAW needs to be checked
first.
Signed-off-by: Ori Nimron <orinimron123@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

CVE-2019-17056

(cherry picked from commit 3a359798)
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Acked-by: Seth Forshee <seth.forshee@canonical.com>
Acked-by: Connor Kuehl <connor.kuehl@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

net/nfc/llcp_sock.c

@@ -1005,10 +1005,13 @@ static int llcp_sock_create(struct net *net, struct socket *sock,
 	    sock->type != SOCK_RAW)
 		return -ESOCKTNOSUPPORT;
 
-	if (sock->type == SOCK_RAW)
+	if (sock->type == SOCK_RAW) {
+		if (!capable(CAP_NET_RAW))
+			return -EPERM;
 		sock->ops = &llcp_rawsock_ops;
-	else
+	} else {
 		sock->ops = &llcp_sock_ops;
+	}
 
 	sk = nfc_llcp_sock_alloc(sock, sock->type, GFP_ATOMIC, kern);
 	if (sk == NULL)