net: make skb_set_owner_w() more robust
skb_set_owner_w() is called from various places that assume
skb->sk always point to a full blown socket (as it changes
sk->sk_wmem_alloc)
We'd like to attach skb to request sockets, and in the future
to timewait sockets as well. For these kind of pseudo sockets,
we need to take a traditional refcount and use sock_edemux()
as the destructor.
It is now time to un-inline skb_set_owner_w(), being too big.
Fixes: ca6fb0651883 ("tcp: attach SYNACK messages to request sockets instead of listener")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Bisected-by: Haiyang Zhang <haiyangz@microsoft.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/net/sock.h b/include/net/sock.h
index aeed5c9..f570e75e 100644
--- a/include/net/sock.h
+++ b/include/net/sock.h
@@ -1951,6 +1951,8 @@
}
}
+void skb_set_owner_w(struct sk_buff *skb, struct sock *sk);
+
/*
* Queue a received datagram if it will fit. Stream and sequenced
* protocols can't normally use this as they need to fit buffers in
@@ -1959,21 +1961,6 @@
* Inlined as it's very short and called for pretty much every
* packet ever received.
*/
-
-static inline void skb_set_owner_w(struct sk_buff *skb, struct sock *sk)
-{
- skb_orphan(skb);
- skb->sk = sk;
- skb->destructor = sock_wfree;
- skb_set_hash_from_sk(skb, sk);
- /*
- * We used to take a refcount on sk, but following operation
- * is enough to guarantee sk_free() wont free this sock until
- * all in-flight packets are completed
- */
- atomic_add(skb->truesize, &sk->sk_wmem_alloc);
-}
-
static inline void skb_set_owner_r(struct sk_buff *skb, struct sock *sk)
{
skb_orphan(skb);
diff --git a/net/core/sock.c b/net/core/sock.c
index 0ef30aa..7529eb9 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1656,6 +1656,28 @@
}
EXPORT_SYMBOL(sock_wfree);
+void skb_set_owner_w(struct sk_buff *skb, struct sock *sk)
+{
+ skb_orphan(skb);
+ skb->sk = sk;
+#ifdef CONFIG_INET
+ if (unlikely(!sk_fullsock(sk))) {
+ skb->destructor = sock_edemux;
+ sock_hold(sk);
+ return;
+ }
+#endif
+ skb->destructor = sock_wfree;
+ skb_set_hash_from_sk(skb, sk);
+ /*
+ * We used to take a refcount on sk, but following operation
+ * is enough to guarantee sk_free() wont free this sock until
+ * all in-flight packets are completed
+ */
+ atomic_add(skb->truesize, &sk->sk_wmem_alloc);
+}
+EXPORT_SYMBOL(skb_set_owner_w);
+
void skb_orphan_partial(struct sk_buff *skb)
{
/* TCP stack sets skb->ooo_okay based on sk_wmem_alloc,
diff --git a/net/ipv4/tcp_output.c b/net/ipv4/tcp_output.c
index f4f9793..cb7ca56 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -2963,9 +2963,7 @@
skb_reserve(skb, MAX_TCP_HEADER);
if (attach_req) {
- skb->destructor = sock_edemux;
- sock_hold(req_to_sk(req));
- skb->sk = req_to_sk(req);
+ skb_set_owner_w(skb, req_to_sk(req));
} else {
/* sk is a const pointer, because we want to express multiple
* cpu might call us concurrently.