From: Tuong Lien <tuong.t.lien@xxxxxxxxxxxxxx> [ Upstream commit 980d69276f3048af43a045be2925dacfb898a7be ] When an application connects to the TIPC topology server and subscribes to some services, a new connection is created along with some objects - 'tipc_subscription' to store related data correspondingly... However, there is one omission in the connection handling that when the connection or application is orderly shutdown (e.g. via SIGQUIT, etc.), the connection is not closed in kernel, the 'tipc_subscription' objects are not freed too. This results in: - The maximum number of subscriptions (65535) will be reached soon, new subscriptions will be rejected; - TIPC module cannot be removed (unless the objects are somehow forced to release first); The commit fixes the issue by closing the connection if the 'recvmsg()' returns '0' i.e. when the peer is shutdown gracefully. It also includes the other unexpected cases. Acked-by: Jon Maloy <jmaloy@xxxxxxxxxx> Acked-by: Ying Xue <ying.xue@xxxxxxxxxxxxx> Signed-off-by: Tuong Lien <tuong.t.lien@xxxxxxxxxxxxxx> Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- net/tipc/topsrv.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) --- a/net/tipc/topsrv.c +++ b/net/tipc/topsrv.c @@ -402,10 +402,11 @@ static int tipc_conn_rcv_from_sock(struc read_lock_bh(&sk->sk_callback_lock); ret = tipc_conn_rcv_sub(srv, con, &s); read_unlock_bh(&sk->sk_callback_lock); + if (!ret) + return 0; } - if (ret < 0) - tipc_conn_close(con); + tipc_conn_close(con); return ret; }
