Description of problem:
iproute does not check its parameters for correctness enough, see for 
instance:
# ip xfrm state update src 10.34.34.15 dst 10.34.34.72 proto esp enc 
replay-seq 1234

The parameters are incorrect, but despite that, iproute should not crash :)

Version-Release number of selected component (if applicable):
iproute-2.6.18-7.el5

How reproducible:
always

Steps to Reproduce:
1. ip xfrm state update src 10.34.34.15 dst 10.34.34.72 proto esp enc 
replay-seq 1234
2.
3.
  
Actual results:
crash

Expected results:
no crash