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>

1 files changed, 6 insertions, 5 deletions

diff --git a/net/ipv6/route.c b/net/ipv6/route.c
index 3151aabff5fd..2a4c8d48977f 100644
--- 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;