[NETFILTER]: nf_conntrack: check address family when finding protocol module

__nf_conntrack_{l3}proto_find() doesn't check the passed protocol family,
then it's possible to touch out of the array which has only AF_MAX items.

Spotted by Pablo Neira Ayuso.

Signed-off-by: Yasuyuki Kozakai <yasuyuki.kozakai@toshiba.co.jp>
Signed-off-by: YOSHIFUJI Hideaki <yoshfuji@linux-ipv6.org>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 9 insertions, 6 deletions

diff --git a/include/net/netfilter/nf_conntrack_l3proto.h b/include/net/netfilter/nf_conntrack_l3proto.h
index 67856eb93b43..dac43b15a5b0 100644
--- a/include/net/netfilter/nf_conntrack_l3proto.h
+++ b/include/net/netfilter/nf_conntrack_l3proto.h
@@ -88,12 +88,6 @@ extern struct nf_conntrack_l3proto *nf_ct_l3protos[AF_MAX];
 extern int nf_conntrack_l3proto_register(struct nf_conntrack_l3proto *proto);
 extern void nf_conntrack_l3proto_unregister(struct nf_conntrack_l3proto *proto);
 
-static inline struct nf_conntrack_l3proto *
-__nf_ct_l3proto_find(u_int16_t l3proto)
-{
-        return nf_ct_l3protos[l3proto];
-}
-
 extern struct nf_conntrack_l3proto *
 nf_ct_l3proto_find_get(u_int16_t l3proto);
 
@@ -103,4 +97,13 @@ extern void nf_ct_l3proto_put(struct nf_conntrack_l3proto *p);
 extern struct nf_conntrack_l3proto nf_conntrack_l3proto_ipv4;
 extern struct nf_conntrack_l3proto nf_conntrack_l3proto_ipv6;
 extern struct nf_conntrack_l3proto nf_conntrack_generic_l3proto;
+
+static inline struct nf_conntrack_l3proto *
+__nf_ct_l3proto_find(u_int16_t l3proto)
+{
+        if (unlikely(l3proto >= AF_MAX))
+                return &nf_conntrack_generic_l3proto;
+        return nf_ct_l3protos[l3proto];
+}
+
 #endif /*_NF_CONNTRACK_L3PROTO_H*/