If SCTP receives a badly formatted HB-ACK chunk, it is possible
that we may access invalid memory and potentially have a buffer
overflow.  We should really make sure that the chunk format is
what we expect, before attempting to touch the data.
Signed-off-by: NVlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: NSridhar Samudrala <sri@us.ibm.com>