From: "yujuan.qi" <yujuan.qi@mediatek.com>
Date: Mon, 31 Jul 2017 11:23:01 +0800
Subject: Cipso: cipso_v4_optptr enter infinite loop
Patch-mainline: v4.13-rc5
Git-commit: 40413955ee265a5e42f710940ec78f5450d49149
References: CVE-2018-10938 bsc#1106016
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>
Acked-by: Michal Kubecek <mkubecek@suse.cz>
---
net/ipv4/cipso_ipv4.c | 12 ++++++++++--
1 file changed, 10 insertions(+), 2 deletions(-)
diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c
index 972353cd1778..65a15889d432 100644
--- a/net/ipv4/cipso_ipv4.c
+++ b/net/ipv4/cipso_ipv4.c
@@ -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;
- taglen = optptr[1];
+ case IPOPT_END:
+ return NULL;
+ case IPOPT_NOOP:
+ taglen = 1;
+ break;
+ default:
+ taglen = optptr[1];
+ }
optlen -= taglen;
optptr += taglen;
}
--
2.18.0