tipc: Add sanity check to detect rejection of non-payload messages

Introduces an internal sanity check to ensure that the only undeliverable
messages TIPC attempts to return to their origin are application payload
messages.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

diff --git a/net/tipc/port.c b/net/tipc/port.c
index 3946b5b10c7478b9ee100af14c825fc45c2e4e6f..756e64cbff96d3718aac12326d74de2d62ef561a 100644 (file)
--- a/net/tipc/port.c
+++ b/net/tipc/port.c
@@ -367,6 +367,12 @@ int tipc_reject_msg(struct sk_buff *buf, u32 err)
                imp++;
 
        /* discard rejected message if it shouldn't be returned to sender */
+
+       if (WARN(!msg_isdata(msg),
+                "attempt to reject message with user=%u", msg_user(msg))) {
+               dump_stack();
+               goto exit;
+       }
        if (msg_errcode(msg) || msg_dest_droppable(msg))
                goto exit;