[SRU][F:linux-bluefield][PATCH 05/32] netpoll: accept NULL np argument in netpoll_send_skb()

[Daniel Jurgens]

From: Eric Dumazet <edumazet at google.com>

BugLink: https://bugs.launchpad.net/bugs/1926994

netpoll_send_skb() callers seem to leak skb if
the np pointer is NULL. While this should not happen, we
can make the code more robust.

Signed-off-by: Eric Dumazet <edumazet at google.com>
Signed-off-by: David S. Miller <davem at davemloft.net>
(cherry picked from commit f78ed2204db9fc35b545d693865bddbe0149aa1f)
Signed-off-by: Daniel Jurgens <danielj at nvidia.com>
---
 drivers/net/macvlan.c   |  5 ++---
 include/linux/if_team.h |  5 +----
 include/net/bonding.h   |  5 +----
 net/8021q/vlan_dev.c    |  5 ++---
 net/bridge/br_private.h |  5 +----
 net/core/netpoll.c      | 11 ++++++++---
 net/dsa/slave.c         |  5 ++---
 7 files changed, 17 insertions(+), 24 deletions(-)

diff --git a/drivers/net/macvlan.c b/drivers/net/macvlan.c
index 07622cf..e3bb4a7 100644
--- a/drivers/net/macvlan.c
+++ b/drivers/net/macvlan.c
@@ -545,12 +545,11 @@ static int macvlan_queue_xmit(struct sk_buff *skb, struct net_device *dev)
 static inline netdev_tx_t macvlan_netpoll_send_skb(struct macvlan_dev *vlan, struct sk_buff *skb)
 {
 #ifdef CONFIG_NET_POLL_CONTROLLER
-	if (vlan->netpoll)
-		netpoll_send_skb(vlan->netpoll, skb);
+	return netpoll_send_skb(vlan->netpoll, skb);
 #else
 	BUG();
-#endif
 	return NETDEV_TX_OK;
+#endif
 }
 
 static netdev_tx_t macvlan_start_xmit(struct sk_buff *skb,
diff --git a/include/linux/if_team.h b/include/linux/if_team.h
index ec7e4bd..537dc2b8 100644
--- a/include/linux/if_team.h
+++ b/include/linux/if_team.h
@@ -102,10 +102,7 @@ static inline bool team_port_dev_txable(const struct net_device *port_dev)
 static inline void team_netpoll_send_skb(struct team_port *port,
 					 struct sk_buff *skb)
 {
-	struct netpoll *np = port->np;
-
-	if (np)
-		netpoll_send_skb(np, skb);
+	netpoll_send_skb(port->np, skb);
 }
 #else
 static inline void team_netpoll_send_skb(struct team_port *port,
diff --git a/include/net/bonding.h b/include/net/bonding.h
index 1bee8fd..4eca655 100644
--- a/include/net/bonding.h
+++ b/include/net/bonding.h
@@ -513,10 +513,7 @@ static inline unsigned long slave_last_rx(struct bonding *bond,
 static inline void bond_netpoll_send_skb(const struct slave *slave,
 					 struct sk_buff *skb)
 {
-	struct netpoll *np = slave->np;
-
-	if (np)
-		netpoll_send_skb(np, skb);
+	netpoll_send_skb(slave->np, skb);
 }
 #else
 static inline void bond_netpoll_send_skb(const struct slave *slave,
diff --git a/net/8021q/vlan_dev.c b/net/8021q/vlan_dev.c
index 2a78da4..3860710 100644
--- a/net/8021q/vlan_dev.c
+++ b/net/8021q/vlan_dev.c
@@ -88,12 +88,11 @@ static int vlan_dev_hard_header(struct sk_buff *skb, struct net_device *dev,
 static inline netdev_tx_t vlan_netpoll_send_skb(struct vlan_dev_priv *vlan, struct sk_buff *skb)
 {
 #ifdef CONFIG_NET_POLL_CONTROLLER
-	if (vlan->netpoll)
-		netpoll_send_skb(vlan->netpoll, skb);
+	return netpoll_send_skb(vlan->netpoll, skb);
 #else
 	BUG();
-#endif
 	return NETDEV_TX_OK;
+#endif
 }
 
 static netdev_tx_t vlan_dev_hard_start_xmit(struct sk_buff *skb,
diff --git a/net/bridge/br_private.h b/net/bridge/br_private.h
index 7615c22..5478d40 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -519,10 +519,7 @@ void br_boolopt_multi_get(const struct net_bridge *br,
 static inline void br_netpoll_send_skb(const struct net_bridge_port *p,
 				       struct sk_buff *skb)
 {
-	struct netpoll *np = p->np;
-
-	if (np)
-		netpoll_send_skb(np, skb);
+	netpoll_send_skb(p->np, skb);
 }
 
 int br_netpoll_enable(struct net_bridge_port *p);
diff --git a/net/core/netpoll.c b/net/core/netpoll.c
index 6162faf..fb74e26 100644
--- a/net/core/netpoll.c
+++ b/net/core/netpoll.c
@@ -368,9 +368,14 @@ netdev_tx_t netpoll_send_skb(struct netpoll *np, struct sk_buff *skb)
 	unsigned long flags;
 	netdev_tx_t ret;
 
-	local_irq_save(flags);
-	ret = __netpoll_send_skb(np, skb);
-	local_irq_restore(flags);
+	if (unlikely(!np)) {
+		dev_kfree_skb_irq(skb);
+		ret = NET_XMIT_DROP;
+	} else {
+		local_irq_save(flags);
+		ret = __netpoll_send_skb(np, skb);
+		local_irq_restore(flags);
+	}
 	return ret;
 }
 EXPORT_SYMBOL(netpoll_send_skb);
diff --git a/net/dsa/slave.c b/net/dsa/slave.c
index 06f8874..4a9045b 100644
--- a/net/dsa/slave.c
+++ b/net/dsa/slave.c
@@ -450,12 +450,11 @@ static inline netdev_tx_t dsa_slave_netpoll_send_skb(struct net_device *dev,
 #ifdef CONFIG_NET_POLL_CONTROLLER
 	struct dsa_slave_priv *p = netdev_priv(dev);
 
-	if (p->netpoll)
-		netpoll_send_skb(p->netpoll, skb);
+	return netpoll_send_skb(p->netpoll, skb);
 #else
 	BUG();
-#endif
 	return NETDEV_TX_OK;
+#endif
 }
 
 static void dsa_skb_tx_timestamp(struct dsa_slave_priv *p,
-- 
1.8.3.1