From: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Date: Thu, 27 Jun 2019 08:10:44 +0000 (+0300)
Subject: net: sched: em_ipt: match only on ip/ipv6 traffic
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=9e10edd7dcd37ddf55d30d1f8f85ae9306306879;p=linux.git

net: sched: em_ipt: match only on ip/ipv6 traffic

Restrict matching only to ip/ipv6 traffic and make sure we can use the
headers, otherwise matches will be attempted on any protocol which can
be unexpected by the xt matches. Currently policy supports only ipv4/6.

Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/sched/em_ipt.c b/net/sched/em_ipt.c
index 243fd22f22487..64dbafe4e94cf 100644
--- a/net/sched/em_ipt.c
+++ b/net/sched/em_ipt.c
@@ -185,6 +185,19 @@ static int em_ipt_match(struct sk_buff *skb, struct tcf_ematch *em,
 	struct nf_hook_state state;
 	int ret;
 
+	switch (tc_skb_protocol(skb)) {
+	case htons(ETH_P_IP):
+		if (!pskb_network_may_pull(skb, sizeof(struct iphdr)))
+			return 0;
+		break;
+	case htons(ETH_P_IPV6):
+		if (!pskb_network_may_pull(skb, sizeof(struct ipv6hdr)))
+			return 0;
+		break;
+	default:
+		return 0;
+	}
+
 	rcu_read_lock();
 
 	if (skb->skb_iif)