inet: fix request sock refcounting

While testing last patch series, I found req sock refcounting was wrong.

We must set skc_refcnt to 1 for all request socks added in hashes,
but also on request sockets created by FastOpen or syncookies.

It is tricky because we need to defer this initialization so that
future RCU lookups do not try to take a refcount on a not yet
fully initialized request socket.

Also get rid of ireq_refcnt alias.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Fixes: 13854e5a6046 ("inet: add proper refcounting to request sock")
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 6 insertions, 5 deletions

diff --git a/net/ipv4/syncookies.c b/net/ipv4/syncookies.c
index 574b67765a06..34e755403715 100644
--- a/net/ipv4/syncookies.c
+++ b/net/ipv4/syncookies.c
@@ -227,11 +227,12 @@ static struct sock *get_cookie_sock(struct sock *sk, struct sk_buff *skb,
         struct sock *child;
 
         child = icsk->icsk_af_ops->syn_recv_sock(sk, skb, req, dst);
-        if (child)
+        if (child) {
+                atomic_set(&req->rsk_refcnt, 1);
                 inet_csk_reqsk_queue_add(sk, req, child);
-        else
+        } else {
                 reqsk_free(req);
-
+        }
         return child;
 }
 
@@ -356,7 +357,7 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb)
         ireq->opt = tcp_v4_save_options(skb);
 
         if (security_inet_conn_request(sk, skb, req)) {
-                reqsk_put(req);
+                reqsk_free(req);
                 goto out;
         }
 
@@ -377,7 +378,7 @@ struct sock *cookie_v4_check(struct sock *sk, struct sk_buff *skb)
         security_req_classify_flow(req, flowi4_to_flowi(&fl4));
         rt = ip_route_output_key(sock_net(sk), &fl4);
         if (IS_ERR(rt)) {
-                reqsk_put(req);
+                reqsk_free(req);
                 goto out;
         }