Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

Pull networking fixes from David Miller:

 1) Unbalanced refcounting in TIPC, from Jon Maloy.

 2) Only allow TCP_MD5SIG to be set on sockets in close or listen state.
    Once the connection is established it makes no sense to change this.
    From Eric Dumazet.

 3) Missing attribute validation in neigh_dump_table(), also from Eric
    Dumazet.

 4) Fix address comparisons in SCTP, from Xin Long.

 5) Neigh proxy table clearing can deadlock, from Wolfgang Bumiller.

 6) Fix tunnel refcounting in l2tp, from Guillaume Nault.

 7) Fix double list insert in team driver, from Paolo Abeni.

 8) af_vsock.ko module was accidently made unremovable, from Stefan
    Hajnoczi.

 9) Fix reference to freed llc_sap object in llc stack, from Cong Wang.

10) Don't assume netdevice struct is DMA'able memory in virtio_net
    driver, from Michael S. Tsirkin.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (62 commits)
  net/smc: fix shutdown in state SMC_LISTEN
  bnxt_en: Fix memory fault in bnxt_ethtool_init()
  virtio_net: sparse annotation fix
  virtio_net: fix adding vids on big-endian
  virtio_net: split out ctrl buffer
  net: hns: Avoid action name truncation
  docs: ip-sysctl.txt: fix name of some ipv6 variables
  vmxnet3: fix incorrect dereference when rxvlan is disabled
  llc: hold llc_sap before release_sock()
  MAINTAINERS: Direct networking documentation changes to netdev
  atm: iphase: fix spelling mistake: "Tansmit" -> "Transmit"
  net: qmi_wwan: add Wistron Neweb D19Q1
  net: caif: fix spelling mistake "UKNOWN" -> "UNKNOWN"
  net: stmmac: Disable ACS Feature for GMAC >= 4
  net: mvpp2: Fix DMA address mask size
  net: change the comment of dev_mc_init
  net: qualcomm: rmnet: Fix warning seen with fill_info
  tun: fix vlan packet truncation
  tipc: fix infinite loop when dumping link monitor summary
  tipc: fix use-after-free in tipc_nametbl_stop
  ...

5 files changed, 60 insertions, 33 deletions

diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c
index 0fbd3ee26165..40261cb68e83 100644
--- a/net/l2tp/l2tp_core.c
+++ b/net/l2tp/l2tp_core.c
@@ -183,6 +183,26 @@ 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);
+
 /* Lookup a session. A new reference is held on the returned session. */
 struct l2tp_session *l2tp_session_get(const struct net *net,
 				      struct l2tp_tunnel *tunnel,
@@ -335,26 +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
  *****************************************************************************/
diff --git a/net/l2tp/l2tp_core.h b/net/l2tp/l2tp_core.h
index ba33cbec71eb..c199020f8a8a 100644
--- a/net/l2tp/l2tp_core.h
+++ b/net/l2tp/l2tp_core.h
@@ -212,6 +212,8 @@ 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,
@@ -220,7 +222,6 @@ struct l2tp_session *l2tp_session_get(const struct net *net,
 struct l2tp_session *l2tp_session_get_nth(struct l2tp_tunnel *tunnel, int nth);
 struct l2tp_session *l2tp_session_get_by_ifname(const struct net *net,
 						const char *ifname);
-struct l2tp_tunnel *l2tp_tunnel_find_nth(const struct net *net, int nth);
 
 int l2tp_tunnel_create(struct net *net, int fd, int version, u32 tunnel_id,
 		       u32 peer_tunnel_id, struct l2tp_tunnel_cfg *cfg,
diff --git a/net/l2tp/l2tp_debugfs.c b/net/l2tp/l2tp_debugfs.c
index 72e713da4733..b8f9d45bfeb1 100644
--- a/net/l2tp/l2tp_debugfs.c
+++ b/net/l2tp/l2tp_debugfs.c
@@ -47,7 +47,11 @@ struct l2tp_dfs_seq_data {
 
 static void l2tp_dfs_next_tunnel(struct l2tp_dfs_seq_data *pd)
 {
-	pd->tunnel = l2tp_tunnel_find_nth(pd->net, pd->tunnel_idx);
+	/* Drop reference taken during previous invocation */
+	if (pd->tunnel)
+		l2tp_tunnel_dec_refcount(pd->tunnel);
+
+	pd->tunnel = l2tp_tunnel_get_nth(pd->net, pd->tunnel_idx);
 	pd->tunnel_idx++;
 }
 
@@ -96,7 +100,14 @@ static void *l2tp_dfs_seq_next(struct seq_file *m, void *v, loff_t *pos)
 
 static void l2tp_dfs_seq_stop(struct seq_file *p, void *v)
 {
-	/* nothing to do */
+	struct l2tp_dfs_seq_data *pd = v;
+
+	if (!pd || pd == SEQ_START_TOKEN)
+		return;
+
+	/* Drop reference taken by last invocation of l2tp_dfs_next_tunnel() */
+	if (pd->tunnel)
+		l2tp_tunnel_dec_refcount(pd->tunnel);
 }
 
 static void l2tp_dfs_seq_tunnel_show(struct seq_file *m, void *v)
diff --git a/net/l2tp/l2tp_netlink.c b/net/l2tp/l2tp_netlink.c
index b05dbd9ffcb2..6616c9fd292f 100644
--- a/net/l2tp/l2tp_netlink.c
+++ b/net/l2tp/l2tp_netlink.c
@@ -487,14 +487,17 @@ 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, L2TP_CMD_TUNNEL_GET) < 0)
+					tunnel, L2TP_CMD_TUNNEL_GET) < 0) {
+			l2tp_tunnel_dec_refcount(tunnel);
 			goto out;
+		}
+		l2tp_tunnel_dec_refcount(tunnel);
 
 		ti++;
 	}
@@ -848,7 +851,7 @@ 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;
 		}
@@ -856,6 +859,7 @@ static int l2tp_nl_cmd_session_dump(struct sk_buff *skb, struct netlink_callback
 		session = l2tp_session_get_nth(tunnel, si);
 		if (session == NULL) {
 			ti++;
+			l2tp_tunnel_dec_refcount(tunnel);
 			tunnel = NULL;
 			si = 0;
 			continue;
@@ -865,6 +869,7 @@ static int l2tp_nl_cmd_session_dump(struct sk_buff *skb, struct netlink_callback
 					 cb->nlh->nlmsg_seq, NLM_F_MULTI,
 					 session, L2TP_CMD_SESSION_GET) < 0) {
 			l2tp_session_dec_refcount(session);
+			l2tp_tunnel_dec_refcount(tunnel);
 			break;
 		}
 		l2tp_session_dec_refcount(session);
diff --git a/net/l2tp/l2tp_ppp.c b/net/l2tp/l2tp_ppp.c
index 896bbca9bdaa..7d0c963680e6 100644
--- a/net/l2tp/l2tp_ppp.c
+++ b/net/l2tp/l2tp_ppp.c
@@ -1551,16 +1551,19 @@ struct pppol2tp_seq_data {
 
 static void pppol2tp_next_tunnel(struct net *net, struct pppol2tp_seq_data *pd)
 {
+	/* Drop reference taken during previous invocation */
+	if (pd->tunnel)
+		l2tp_tunnel_dec_refcount(pd->tunnel);
+
 	for (;;) {
-		pd->tunnel = l2tp_tunnel_find_nth(net, pd->tunnel_idx);
+		pd->tunnel = l2tp_tunnel_get_nth(net, pd->tunnel_idx);
 		pd->tunnel_idx++;
 
-		if (pd->tunnel == NULL)
-			break;
+		/* Only accept L2TPv2 tunnels */
+		if (!pd->tunnel || pd->tunnel->version == 2)
+			return;
 
-		/* Ignore L2TPv3 tunnels */
-		if (pd->tunnel->version < 3)
-			break;
+		l2tp_tunnel_dec_refcount(pd->tunnel);
 	}
 }
 
@@ -1609,7 +1612,14 @@ static void *pppol2tp_seq_next(struct seq_file *m, void *v, loff_t *pos)
 
 static void pppol2tp_seq_stop(struct seq_file *p, void *v)
 {
-	/* nothing to do */
+	struct pppol2tp_seq_data *pd = v;
+
+	if (!pd || pd == SEQ_START_TOKEN)
+		return;
+
+	/* Drop reference taken by last invocation of pppol2tp_next_tunnel() */
+	if (pd->tunnel)
+		l2tp_tunnel_dec_refcount(pd->tunnel);
 }
 
 static void pppol2tp_seq_tunnel_show(struct seq_file *m, void *v)