tipc: Abort excessive send requests as early as possible

Adds checks to TIPC's socket send routines to promptly detect and
abort attempts to send more than 66,000 bytes in a single TIPC
message or more than 2**31-1 bytes in a single TIPC byte stream request.
In addition, this ensures that the number of iovecs in a send request
does not exceed the limits of a standard integer variable.

Signed-off-by: Allan Stephens <Allan.Stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
diff --git a/net/tipc/socket.c b/net/tipc/socket.c
index 29d94d5..e1c7917 100644
--- a/net/tipc/socket.c
+++ b/net/tipc/socket.c
@@ -535,6 +535,9 @@
 	if (unlikely((m->msg_namelen < sizeof(*dest)) ||
 		     (dest->family != AF_TIPC)))
 		return -EINVAL;
+	if ((total_len > TIPC_MAX_USER_MSG_SIZE) ||
+	    (m->msg_iovlen > (unsigned)INT_MAX))
+		return -EMSGSIZE;
 
 	if (iocb)
 		lock_sock(sk);
@@ -640,6 +643,10 @@
 	if (unlikely(dest))
 		return send_msg(iocb, sock, m, total_len);
 
+	if ((total_len > TIPC_MAX_USER_MSG_SIZE) ||
+	    (m->msg_iovlen > (unsigned)INT_MAX))
+		return -EMSGSIZE;
+
 	if (iocb)
 		lock_sock(sk);
 
@@ -723,6 +730,12 @@
 		goto exit;
 	}
 
+	if ((total_len > (unsigned)INT_MAX) ||
+	    (m->msg_iovlen > (unsigned)INT_MAX)) {
+		res = -EMSGSIZE;
+		goto exit;
+	}
+
 	/*
 	 * Send each iovec entry using one or more messages
 	 *