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

Pull networking fixes from David Miller:

 1) Fix memory leak in nftables, from Liping Zhang.

 2) Need to check result of vlan_insert_tag() in batman-adv otherwise we
    risk NULL skb derefs, from Sven Eckelmann.

 3) Check for dev_alloc_skb() failures in cfg80211, from Gregory
    Greenman.

 4) Handle properly when we have ppp_unregister_channel() happening in
    parallel with ppp_connect_channel(), from WANG Cong.

 5) Fix DCCP deadlock, from Eric Dumazet.

 6) Bail out properly in UDP if sk_filter() truncates the packet to be
    smaller than even the space that the protocol headers need.  From
    Michal Kubecek.

 7) Similarly for rose, dccp, and sctp, from Willem de Bruijn.

 8) Make TCP challenge ACKs less predictable, from Eric Dumazet.

 9) Fix infinite loop in bgmac_dma_tx_add() from Florian Fainelli.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (65 commits)
  packet: propagate sock_cmsg_send() error
  net/mlx5e: Fix del vxlan port command buffer memset
  packet: fix second argument of sock_tx_timestamp()
  net: switchdev: change ageing_time type to clock_t
  Update maintainer for EHEA driver.
  net/mlx4_en: Add resilience in low memory systems
  net/mlx4_en: Move filters cleanup to a proper location
  sctp: load transport header after sk_filter
  net/sched/sch_htb: clamp xstats tokens to fit into 32-bit int
  net: cavium: liquidio: Avoid dma_unmap_single on uninitialized ndata
  net: nb8800: Fix SKB leak in nb8800_receive()
  et131x: Fix logical vs bitwise check in et131x_tx_timeout()
  vlan: use a valid default mtu value for vlan over macsec
  net: bgmac: Fix infinite loop in bgmac_dma_tx_add()
  mlxsw: spectrum: Prevent invalid ingress buffer mapping
  mlxsw: spectrum: Prevent overwrite of DCB capability fields
  mlxsw: spectrum: Don't emit errors when PFC is disabled
  mlxsw: spectrum: Indicate support for autonegotiation
  mlxsw: spectrum: Force link training according to admin state
  r8152: add MODULE_VERSION
  ...

2 files changed, 11 insertions, 6 deletions

diff --git a/net/8021q/vlan_dev.c b/net/8021q/vlan_dev.c
index 86ae75b77390..516b0e73263c 100644
--- a/net/8021q/vlan_dev.c
+++ b/net/8021q/vlan_dev.c
@@ -146,10 +146,12 @@ static netdev_tx_t vlan_dev_hard_start_xmit(struct sk_buff *skb,
 
 static int vlan_dev_change_mtu(struct net_device *dev, int new_mtu)
 {
-	/* TODO: gotta make sure the underlying layer can handle it,
-	 * maybe an IFF_VLAN_CAPABLE flag for devices?
-	 */
-	if (vlan_dev_priv(dev)->real_dev->mtu < new_mtu)
+	struct net_device *real_dev = vlan_dev_priv(dev)->real_dev;
+	unsigned int max_mtu = real_dev->mtu;
+
+	if (netif_reduces_vlan_mtu(real_dev))
+		max_mtu -= VLAN_HLEN;
+	if (max_mtu < new_mtu)
 		return -ERANGE;
 
 	dev->mtu = new_mtu;
diff --git a/net/8021q/vlan_netlink.c b/net/8021q/vlan_netlink.c
index c92b52f37d38..1270207f3d7c 100644
--- a/net/8021q/vlan_netlink.c
+++ b/net/8021q/vlan_netlink.c
@@ -118,6 +118,7 @@ static int vlan_newlink(struct net *src_net, struct net_device *dev,
 {
 	struct vlan_dev_priv *vlan = vlan_dev_priv(dev);
 	struct net_device *real_dev;
+	unsigned int max_mtu;
 	__be16 proto;
 	int err;
 
@@ -144,9 +145,11 @@ static int vlan_newlink(struct net *src_net, struct net_device *dev,
 	if (err < 0)
 		return err;
 
+	max_mtu = netif_reduces_vlan_mtu(real_dev) ? real_dev->mtu - VLAN_HLEN :
+						     real_dev->mtu;
 	if (!tb[IFLA_MTU])
-		dev->mtu = real_dev->mtu;
-	else if (dev->mtu > real_dev->mtu)
+		dev->mtu = max_mtu;
+	else if (dev->mtu > max_mtu)
 		return -EINVAL;
 
 	err = vlan_changelink(dev, tb, data);