Cipso: cipso_v4_optptr enter infinite loop
commit 40413955ee265a5e42f710940ec78f5450d49149 upstream.
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>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/net/ipv4/cipso_ipv4.c b/net/ipv4/cipso_ipv4.c
index 972353c..65a1588 100644
--- a/net/ipv4/cipso_ipv4.c
+++ b/net/ipv4/cipso_ipv4.c
@@ -1523,9 +1523,17 @@
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;
}