diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c index e19905fb8aec..21d771f5a4fb 100644 --- a/net/l2tp/l2tp_core.c +++ b/net/l2tp/l2tp_core.c @@ -224,6 +224,26 @@ struct l2tp_tunnel *l2tp_tunnel_get(const struct net *net, u32 tunnel_id) } EXPORT_SYMBOL_GPL(l2tp_tunnel_get); +struct l2tp_tunnel *l2tp_tunnel_get_nth(const struct net *net, int nth) +{ + const 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) { + l2tp_tunnel_inc_refcount(tunnel); + rcu_read_unlock_bh(); + return tunnel; + } + } + rcu_read_unlock_bh(); + + return NULL; +} +EXPORT_SYMBOL_GPL(l2tp_tunnel_get_nth); + /* Like l2tp_session_find() but takes a reference on the returned session. * Optionally calls session->ref() too if do_ref is true. */ diff --git a/net/l2tp/l2tp_core.h b/net/l2tp/l2tp_core.h index 96036cfd1816..af57e4d287bd 100644 --- a/net/l2tp/l2tp_core.h +++ b/net/l2tp/l2tp_core.h @@ -223,6 +223,8 @@ static inline void *l2tp_session_priv(struct l2tp_session *session) } struct l2tp_tunnel *l2tp_tunnel_get(const struct net *net, u32 tunnel_id); +struct l2tp_tunnel *l2tp_tunnel_get_nth(const struct net *net, int nth); + void l2tp_tunnel_free(struct l2tp_tunnel *tunnel); struct l2tp_session *l2tp_session_get(const struct net *net, diff --git a/net/l2tp/l2tp_netlink.c b/net/l2tp/l2tp_netlink.c index 82e35aeecfdd..dc497ed61099 100644 --- a/net/l2tp/l2tp_netlink.c +++ b/net/l2tp/l2tp_netlink.c @@ -384,14 +384,17 @@ static int l2tp_nl_cmd_tunnel_dump(struct sk_buff *skb, struct netlink_callback struct net *net = sock_net(skb->sk); for (;;) { - tunnel = l2tp_tunnel_find_nth(net, ti); + tunnel = l2tp_tunnel_get_nth(net, ti); if (tunnel == NULL) goto out; if (l2tp_nl_tunnel_send(skb, NETLINK_CB(cb->skb).portid, cb->nlh->nlmsg_seq, NLM_F_MULTI, - tunnel) <= 0) + tunnel) <= 0) { + l2tp_tunnel_dec_refcount(tunnel); goto out; + } + l2tp_tunnel_dec_refcount(tunnel); ti++; } @@ -739,7 +742,7 @@ static int l2tp_nl_cmd_session_dump(struct sk_buff *skb, struct netlink_callback for (;;) { if (tunnel == NULL) { - tunnel = l2tp_tunnel_find_nth(net, ti); + tunnel = l2tp_tunnel_get_nth(net, ti); if (tunnel == NULL) goto out; } @@ -747,6 +750,7 @@ static int l2tp_nl_cmd_session_dump(struct sk_buff *skb, struct netlink_callback session = l2tp_session_get_nth(tunnel, si, false); if (session == NULL) { ti++; + l2tp_tunnel_dec_refcount(tunnel); tunnel = NULL; si = 0; continue; @@ -756,6 +760,7 @@ static int l2tp_nl_cmd_session_dump(struct sk_buff *skb, struct netlink_callback cb->nlh->nlmsg_seq, NLM_F_MULTI, session) <= 0) { l2tp_session_dec_refcount(session); + l2tp_tunnel_dec_refcount(tunnel); break; } l2tp_session_dec_refcount(session);