Messages in this thread Patch in this message | | | Date | Thu, 30 Jul 2015 15:50:36 +0200 | From | Sowmini Varadhan <> | Subject | [PATCH v2 net] net: sk_clone_lock() should only do get_net() if the parent is not a kernel socket |
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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 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.
Fixes: 26abe14379f8 ("net: Modify sk_alloc to not reference count the netns of kernel sockets.") Acked-by: Eric Dumazet <edumazet@google.com> Cc: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: Sowmini Varadhan <sowmini.varadhan@oracle.com> --- v2: pulled patch #3 out of the RFC patch-set for RDS-TCP netns fixes; Added Fixes, Acked-by, Cc fields based on mailing list feedback from Eric Dumazet.
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
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