Cipso: cipso_v4_optptr enter infinite loop

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>
This commit is contained in:
yujuan.qi 2017-07-31 11:23:01 +08:00 committed by David S. Miller
parent fdaa419bb2
commit 40413955ee
1 changed files with 10 additions and 2 deletions

View File

@ -1523,9 +1523,17 @@ unsigned char *cipso_v4_optptr(const struct sk_buff *skb)
int taglen;
for (optlen = iph->ihl*4 - sizeof(struct iphdr); optlen > 0; ) {
if (optptr[0] == IPOPT_CIPSO)
switch (optptr[0]) {
case IPOPT_CIPSO:
return optptr;
case IPOPT_END:
return NULL;
case IPOPT_NOOP:
taglen = 1;
break;
default:
taglen = optptr[1];
}
optlen -= taglen;
optptr += taglen;
}