From 980d69276f3048af43a045be2925dacfb898a7be Mon Sep 17 00:00:00 2001 From: Tuong Lien Date: Mon, 4 May 2020 11:15:54 +0700 Subject: [PATCH] tipc: fix partial topology connection closure 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 Acked-by: Ying Xue Signed-off-by: Tuong Lien Signed-off-by: David S. Miller --- net/tipc/topsrv.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/net/tipc/topsrv.c b/net/tipc/topsrv.c index 3a12fc18239b..73dbed0c4b6b 100644 --- a/net/tipc/topsrv.c +++ b/net/tipc/topsrv.c @@ -402,10 +402,11 @@ static int tipc_conn_rcv_from_sock(struct tipc_conn *con) 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; }