netfilter: conntrack: clamp l4proto array size at largers supported protocol

All higher l4proto numbers are handled by the generic tracker; the
l4proto lookup function already returns generic one in case the l4proto
number exceeds max size.
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

include/net/netfilter/nf_conntrack_l4proto.h

@@ -102,7 +102,7 @@ int nf_conntrack_icmpv6_error(struct nf_conn *tmpl,
 /* Existing built-in generic protocol */
 extern const struct nf_conntrack_l4proto nf_conntrack_l4proto_generic;
 
-#define MAX_NF_CT_PROTO 256
+#define MAX_NF_CT_PROTO IPPROTO_UDPLITE
 
 const struct nf_conntrack_l4proto *__nf_ct_l4proto_find(u8 l4proto);
 

net/netfilter/nf_conntrack_proto.c

@@ -43,7 +43,7 @@
 
 extern unsigned int nf_conntrack_net_id;
 
-static struct nf_conntrack_l4proto __rcu *nf_ct_protos[MAX_NF_CT_PROTO] __read_mostly;
+static struct nf_conntrack_l4proto __rcu *nf_ct_protos[MAX_NF_CT_PROTO + 1] __read_mostly;
 
 static DEFINE_MUTEX(nf_ct_proto_mutex);