Cipso: cipso_v4_optptr enter infinite loop

Cipso: cipso_v4_optptr enter infinite loop

Orabug: 28563992
CVE: CVE-2018-10938

in for(),if((optlen > 0) && (optptr[1] == 0)), enter infinite loop.

Test: receive a packet which the ip length > 20 and the first byte of ip option is 0, produce this issue

Signed-off-by: yujuan.qi <yujuan.qi@mediatek.com>
Acked-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit 40413955ee265a5e42f710940ec78f5450d49149)
Signed-off-by: Somasundaram Krishnasamy <somasundaram.krishnasamy@oracle.com>
Reviewed-by: Brian Maly <brian.maly@oracle.com
Signed-off-by: Brian Maly <brian.maly@oracle.com>