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authorEric Dumazet <edumazet@google.com>2015-11-01 15:36:55 -0800
committerDavid S. Miller <davem@davemloft.net>2015-11-02 16:28:49 -0500
commit9e17f8a475fca81950fdddc08df428ed66cf441f (patch)
tree417a79910266f08806f78be2dd970102afa3356f /net
parenteca1e006cf6f6f66a1a90c055a8a6d393475c3f9 (diff)
downloadlinux-9e17f8a475fca81950fdddc08df428ed66cf441f.tar.bz2
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>
Diffstat (limited to 'net')
-rw-r--r--net/core/sock.c22
-rw-r--r--net/ipv4/tcp_output.c4
2 files changed, 23 insertions, 3 deletions
diff --git a/net/core/sock.c b/net/core/sock.c
index 0ef30aa90132..7529eb9463be 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1656,6 +1656,28 @@ void sock_wfree(struct sk_buff *skb)
}
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 f4f9793eb025..cb7ca569052c 100644
--- a/net/ipv4/tcp_output.c
+++ b/net/ipv4/tcp_output.c
@@ -2963,9 +2963,7 @@ struct sk_buff *tcp_make_synack(const struct sock *sk, struct dst_entry *dst,
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.