From f726214d9b23e5fce8c11937577a289a3202498f Mon Sep 17 00:00:00 2001 From: Guillaume Nault Date: Thu, 12 Apr 2018 20:50:35 +0200 Subject: l2tp: hold reference on tunnels printed in l2tp/tunnels debugfs file Use l2tp_tunnel_get_nth() instead of l2tp_tunnel_find_nth(), to be safe against concurrent tunnel deletion. Use the same mechanism as in l2tp_ppp.c for dropping the reference taken by l2tp_tunnel_get_nth(). That is, drop the reference just before looking up the next tunnel. In case of error, drop the last accessed tunnel in l2tp_dfs_seq_stop(). That was the last use of l2tp_tunnel_find_nth(). Fixes: 0ad6614048cf ("l2tp: Add debugfs files for dumping l2tp debug info") Signed-off-by: Guillaume Nault Signed-off-by: David S. Miller --- net/l2tp/l2tp_core.c | 20 -------------------- 1 file changed, 20 deletions(-) (limited to 'net/l2tp/l2tp_core.c') diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c index c8c4183f0f37..40261cb68e83 100644 --- a/net/l2tp/l2tp_core.c +++ b/net/l2tp/l2tp_core.c @@ -355,26 +355,6 @@ err_tlock: } EXPORT_SYMBOL_GPL(l2tp_session_register); -struct l2tp_tunnel *l2tp_tunnel_find_nth(const struct net *net, int nth) -{ - struct l2tp_net *pn = l2tp_pernet(net); - struct l2tp_tunnel *tunnel; - int count = 0; - - rcu_read_lock_bh(); - list_for_each_entry_rcu(tunnel, &pn->l2tp_tunnel_list, list) { - if (++count > nth) { - rcu_read_unlock_bh(); - return tunnel; - } - } - - rcu_read_unlock_bh(); - - return NULL; -} -EXPORT_SYMBOL_GPL(l2tp_tunnel_find_nth); - /***************************************************************************** * Receive data handling *****************************************************************************/ -- cgit v1.2.3