From f78ed2204db9fc35b545d693865bddbe0149aa1f Mon Sep 17 00:00:00 2001
From: Eric Dumazet <edumazet@google.com>
Date: Thu, 7 May 2020 09:32:21 -0700
Subject: [PATCH] netpoll: accept NULL np argument in netpoll_send_skb()
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@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---
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 34eb073cdd74..9a419d5102ce 100644
--- a/drivers/net/macvlan.c
+++ b/drivers/net/macvlan.c
@@ -542,12 +542,11 @@ xmit_world:
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 ec7e4bd07f82..537dc2b8c879 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 0b696da5c115..f211983cd52a 100644
--- a/include/net/bonding.h
+++ b/include/net/bonding.h
@@ -507,10 +507,7 @@ 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 319220b2341d..f00bb57f0f60 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 78d3a951180d..4dc21e8f7e33 100644
--- a/net/bridge/br_private.h
+++ b/net/bridge/br_private.h
@@ -598,10 +598,7 @@ netdev_tx_t br_dev_xmit(struct sk_buff *skb, struct net_device *dev);
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 40d2753aa47d..093e90e52bc2 100644
--- a/net/core/netpoll.c
+++ b/net/core/netpoll.c
@@ -367,9 +367,14 @@ 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 dfb4282fc339..61b0de52040a 100644
--- a/net/dsa/slave.c
+++ b/net/dsa/slave.c
@@ -445,12 +445,11 @@ 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,