ipv6: Initialize the struct rt6_info behind the dst_enty field

We start initializing the struct rt6_info at the first field
behind the struct dst_enty. This is error prone because it
might leave a new field uninitialized. So start initializing
the struct rt6_info right behind the dst_entry.

Suggested-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 3151aab..2a4c8d4 100644 (file)
--- a/net/ipv6/route.c
+++ b/net/ipv6/route.c
@@ -280,8 +280,9 @@ static inline struct rt6_info *ip6_dst_alloc(struct net *net,
                                        0, 0, flags);
 
        if (rt) {
-               memset(&rt->n, 0,
-                      sizeof(*rt) - sizeof(struct dst_entry));
+               struct dst_entry *dst = &rt->dst;
+
+               memset(dst + 1, 0, sizeof(*rt) - sizeof(*dst));
                rt6_init_peer(rt, table ? &table->tb6_peers : net->ipv6.peers);
        }
        return rt;
@@ -982,11 +983,11 @@ struct dst_entry *ip6_blackhole_route(struct net *net, struct dst_entry *dst_ori
 
        rt = dst_alloc(&ip6_dst_blackhole_ops, ort->dst.dev, 1, 0, 0);
        if (rt) {
-               memset(&rt->rt6i_table, 0, sizeof(*rt) - sizeof(struct dst_entry));
-               rt6_init_peer(rt, net->ipv6.peers);
-
                new = &rt->dst;
 
+               memset(new + 1, 0, sizeof(*rt) - sizeof(*new));
+               rt6_init_peer(rt, net->ipv6.peers);
+
                new->__use = 1;
                new->input = dst_discard;
                new->output = dst_discard;