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

Pull networking fixes from David Miller:

 1) Use after free in vlan, from Cong Wang.

 2) Handle NAPI poll with a zero budget properly in mlx5 driver, from
    Saeed Mahameed.

 3) If DMA mapping fails in mlx5 driver, NULL out page, from Inbar
    Karmy.

 4) Handle overrun in RX FIFO of sun4i CAN driver, from Gerhard
    Bertelsmann.

 5) Missing return in mdb and vlan prepare phase of DSA layer, from
    Vivien Didelot.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net:
  vlan: fix a use-after-free in vlan_device_event()
  net: dsa: return after vlan prepare phase
  net: dsa: return after mdb prepare phase
  can: ifi: Fix transmitter delay calculation
  tcp: fix tcp_fastretrans_alert warning
  tcp: gso: avoid refcount_t warning from tcp_gso_segment()
  can: peak: Add support for new PCIe/M2 CAN FD interfaces
  can: sun4i: handle overrun in RX FIFO
  can: c_can: don't indicate triple sampling support for D_CAN
  net/mlx5e: Increase Striding RQ minimum size limit to 4 multi-packet WQEs
  net/mlx5e: Set page to null in case dma mapping fails
  net/mlx5e: Fix napi poll with zero budget
  net/mlx5: Cancel health poll before sending panic teardown command
  net/mlx5: Loop over temp list to release delay events
  rds: ib: Fix NULL pointer dereference in debug code

5 files changed, 23 insertions, 12 deletions

diff --git a/net/8021q/vlan.c b/net/8021q/vlan.c
index 9649579b5b9f..4a72ee4e2ae9 100644
--- a/net/8021q/vlan.c
+++ b/net/8021q/vlan.c
@@ -376,6 +376,9 @@ static int vlan_device_event(struct notifier_block *unused, unsigned long event,
 			dev->name);
 		vlan_vid_add(dev, htons(ETH_P_8021Q), 0);
 	}
+	if (event == NETDEV_DOWN &&
+	    (dev->features & NETIF_F_HW_VLAN_CTAG_FILTER))
+		vlan_vid_del(dev, htons(ETH_P_8021Q), 0);
 
 	vlan_info = rtnl_dereference(dev->vlan_info);
 	if (!vlan_info)
@@ -423,9 +426,6 @@ static int vlan_device_event(struct notifier_block *unused, unsigned long event,
 		struct net_device *tmp;
 		LIST_HEAD(close_list);
 
-		if (dev->features & NETIF_F_HW_VLAN_CTAG_FILTER)
-			vlan_vid_del(dev, htons(ETH_P_8021Q), 0);
-
 		/* Put all VLANs for this dev in the down state too.  */
 		vlan_group_for_each_dev(grp, i, vlandev) {
 			flgs = vlandev->flags;
diff --git a/net/dsa/switch.c b/net/dsa/switch.c
index e6c06aa349a6..1e2929f4290a 100644
--- a/net/dsa/switch.c
+++ b/net/dsa/switch.c
@@ -133,6 +133,8 @@ static int dsa_switch_mdb_add(struct dsa_switch *ds,
 			if (err)
 				return err;
 		}
+
+		return 0;
 	}
 
 	for_each_set_bit(port, group, ds->num_ports)
@@ -180,6 +182,8 @@ static int dsa_switch_vlan_add(struct dsa_switch *ds,
 			if (err)
 				return err;
 		}
+
+		return 0;
 	}
 
 	for_each_set_bit(port, members, ds->num_ports)
diff --git a/net/ipv4/tcp_input.c b/net/ipv4/tcp_input.c
index b2fc7163bd40..b6bb3cdfad09 100644
--- a/net/ipv4/tcp_input.c
+++ b/net/ipv4/tcp_input.c
@@ -2615,7 +2615,6 @@ void tcp_simple_retransmit(struct sock *sk)
 	struct tcp_sock *tp = tcp_sk(sk);
 	struct sk_buff *skb;
 	unsigned int mss = tcp_current_mss(sk);
-	u32 prior_lost = tp->lost_out;
 
 	tcp_for_write_queue(skb, sk) {
 		if (skb == tcp_send_head(sk))
@@ -2632,7 +2631,7 @@ void tcp_simple_retransmit(struct sock *sk)
 
 	tcp_clear_retrans_hints_partial(tp);
 
-	if (prior_lost == tp->lost_out)
+	if (!tp->lost_out)
 		return;
 
 	if (tcp_is_reno(tp))
diff --git a/net/ipv4/tcp_offload.c b/net/ipv4/tcp_offload.c
index 11f69bbf9307..b6a2aa1dcf56 100644
--- a/net/ipv4/tcp_offload.c
+++ b/net/ipv4/tcp_offload.c
@@ -149,11 +149,19 @@ struct sk_buff *tcp_gso_segment(struct sk_buff *skb,
 	 * is freed by GSO engine
 	 */
 	if (copy_destructor) {
+		int delta;
+
 		swap(gso_skb->sk, skb->sk);
 		swap(gso_skb->destructor, skb->destructor);
 		sum_truesize += skb->truesize;
-		refcount_add(sum_truesize - gso_skb->truesize,
-			   &skb->sk->sk_wmem_alloc);
+		delta = sum_truesize - gso_skb->truesize;
+		/* In some pathological cases, delta can be negative.
+		 * We need to either use refcount_add() or refcount_sub_and_test()
+		 */
+		if (likely(delta >= 0))
+			refcount_add(delta, &skb->sk->sk_wmem_alloc);
+		else
+			WARN_ON_ONCE(refcount_sub_and_test(-delta, &skb->sk->sk_wmem_alloc));
 	}
 
 	delta = htonl(oldlen + (skb_tail_pointer(skb) -
diff --git a/net/rds/ib_recv.c b/net/rds/ib_recv.c
index 9722bf839d9d..b4e421aa9727 100644
--- a/net/rds/ib_recv.c
+++ b/net/rds/ib_recv.c
@@ -410,14 +410,14 @@ void rds_ib_recv_refill(struct rds_connection *conn, int prefill, gfp_t gfp)
 			break;
 		}
 
-		/* XXX when can this fail? */
-		ret = ib_post_recv(ic->i_cm_id->qp, &recv->r_wr, &failed_wr);
-		rdsdebug("recv %p ibinc %p page %p addr %lu ret %d\n", recv,
+		rdsdebug("recv %p ibinc %p page %p addr %lu\n", recv,
 			 recv->r_ibinc, sg_page(&recv->r_frag->f_sg),
 			 (long) ib_sg_dma_address(
 				ic->i_cm_id->device,
-				&recv->r_frag->f_sg),
-			ret);
+				&recv->r_frag->f_sg));
+
+		/* XXX when can this fail? */
+		ret = ib_post_recv(ic->i_cm_id->qp, &recv->r_wr, &failed_wr);
 		if (ret) {
 			rds_ib_conn_error(conn, "recv post on "
 			       "%pI4 returned %d, disconnecting and "