[PATCH RFC net-next 3/3] net/core/sock.c: sk_clone_lock() should only do get_net() if the parent is not a kernel socket
From: Sowmini Varadhan <hidden>
Date: 2015-07-30 08:56:22
Subsystem:
networking [general], networking [sockets], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Kuniyuki Iwashima, Willem de Bruijn, Linus Torvalds
The newsk returned by sk_clone_lock should hold a get_net() reference if, and only if, the parent is not a kernel socket (making this similar to sk_alloc()). E.g,. for the SYN_RECV call path, tcp_v4_syn_recv_sock->..inet_csk_clone_lock sets up the syn_recv newsk from sk_clone_lock. When the parent (listen) socket is a kernel socket (defined in sk_alloc() as having sk_net_refcnt == 0), then the newsk should also have a 0 sk_net_refcnt and should not hold a get_net() reference. Signed-off-by: Sowmini Varadhan <redacted> --- net/core/sock.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-)
diff --git a/net/core/sock.c b/net/core/sock.c
index 08f16db..371d1b7 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c@@ -1497,7 +1497,8 @@ struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority) sock_copy(newsk, sk); /* SANITY */ - get_net(sock_net(newsk)); + if (likely(newsk->sk_net_refcnt)) + get_net(sock_net(newsk)); sk_node_init(&newsk->sk_node); sock_lock_init(newsk); bh_lock_sock(newsk);
--
1.7.1