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Date: Tue, 03 Mar 2020 15:01:46 +0000
From: Russell King <rmk+kernel@...linux.org.uk>
To: Andrew Lunn <andrew@...n.ch>,
Florian Fainelli <f.fainelli@...il.com>,
Vivien Didelot <vivien.didelot@...il.com>
Cc: "David S. Miller" <davem@...emloft.net>,
Jakub Kicinski <kuba@...nel.org>,
Vladimir Oltean <olteanv@...il.com>,
Ioana Ciornei <ioana.ciornei@....com>, netdev@...r.kernel.org
Subject: [PATCH net v2] net: dsa: fix phylink_start()/phylink_stop() calls
Place phylink_start()/phylink_stop() inside dsa_port_enable() and
dsa_port_disable(), which ensures that we call phylink_stop() before
tearing down phylink - which is a documented requirement. Failure
to do so can cause use-after-free bugs.
Fixes: 0e27921816ad ("net: dsa: Use PHYLINK for the CPU/DSA ports")
Signed-off-by: Russell King <rmk+kernel@...linux.org.uk>
---
v2: reorder phylink_start() / phylink_stop() as per Andrew's comment.
net/dsa/dsa_priv.h | 2 ++
net/dsa/port.c | 32 ++++++++++++++++++++++++++------
net/dsa/slave.c | 8 ++------
3 files changed, 30 insertions(+), 12 deletions(-)
diff --git a/net/dsa/dsa_priv.h b/net/dsa/dsa_priv.h
index 65ba1f0c195a..36bb934dc36e 100644
--- a/net/dsa/dsa_priv.h
+++ b/net/dsa/dsa_priv.h
@@ -117,7 +117,9 @@ static inline struct net_device *dsa_master_find_slave(struct net_device *dev,
/* port.c */
int dsa_port_set_state(struct dsa_port *dp, u8 state,
struct switchdev_trans *trans);
+int dsa_port_enable_rt(struct dsa_port *dp, struct phy_device *phy);
int dsa_port_enable(struct dsa_port *dp, struct phy_device *phy);
+void dsa_port_disable_rt(struct dsa_port *dp);
void dsa_port_disable(struct dsa_port *dp);
int dsa_port_bridge_join(struct dsa_port *dp, struct net_device *br);
void dsa_port_bridge_leave(struct dsa_port *dp, struct net_device *br);
diff --git a/net/dsa/port.c b/net/dsa/port.c
index ae1bd6d3edcb..2c8f87117f2c 100644
--- a/net/dsa/port.c
+++ b/net/dsa/port.c
@@ -63,7 +63,7 @@ static void dsa_port_set_state_now(struct dsa_port *dp, u8 state)
pr_err("DSA: failed to set STP state %u (%d)\n", state, err);
}
-int dsa_port_enable(struct dsa_port *dp, struct phy_device *phy)
+int dsa_port_enable_rt(struct dsa_port *dp, struct phy_device *phy)
{
struct dsa_switch *ds = dp->ds;
int port = dp->index;
@@ -78,14 +78,31 @@ int dsa_port_enable(struct dsa_port *dp, struct phy_device *phy)
if (!dp->bridge_dev)
dsa_port_set_state_now(dp, BR_STATE_FORWARDING);
+ if (dp->pl)
+ phylink_start(dp->pl);
+
return 0;
}
-void dsa_port_disable(struct dsa_port *dp)
+int dsa_port_enable(struct dsa_port *dp, struct phy_device *phy)
+{
+ int err;
+
+ rtnl_lock();
+ err = dsa_port_enable_rt(dp, phy);
+ rtnl_unlock();
+
+ return err;
+}
+
+void dsa_port_disable_rt(struct dsa_port *dp)
{
struct dsa_switch *ds = dp->ds;
int port = dp->index;
+ if (dp->pl)
+ phylink_stop(dp->pl);
+
if (!dp->bridge_dev)
dsa_port_set_state_now(dp, BR_STATE_DISABLED);
@@ -93,6 +110,13 @@ void dsa_port_disable(struct dsa_port *dp)
ds->ops->port_disable(ds, port);
}
+void dsa_port_disable(struct dsa_port *dp)
+{
+ rtnl_lock();
+ dsa_port_disable_rt(dp);
+ rtnl_unlock();
+}
+
int dsa_port_bridge_join(struct dsa_port *dp, struct net_device *br)
{
struct dsa_notifier_bridge_info info = {
@@ -621,10 +645,6 @@ static int dsa_port_phylink_register(struct dsa_port *dp)
goto err_phy_connect;
}
- rtnl_lock();
- phylink_start(dp->pl);
- rtnl_unlock();
-
return 0;
err_phy_connect:
diff --git a/net/dsa/slave.c b/net/dsa/slave.c
index 54529543ce87..eb114531bef8 100644
--- a/net/dsa/slave.c
+++ b/net/dsa/slave.c
@@ -90,12 +90,10 @@ static int dsa_slave_open(struct net_device *dev)
goto clear_allmulti;
}
- err = dsa_port_enable(dp, dev->phydev);
+ err = dsa_port_enable_rt(dp, dev->phydev);
if (err)
goto clear_promisc;
- phylink_start(dp->pl);
-
return 0;
clear_promisc:
@@ -119,9 +117,7 @@ static int dsa_slave_close(struct net_device *dev)
cancel_work_sync(&dp->xmit_work);
skb_queue_purge(&dp->xmit_queue);
- phylink_stop(dp->pl);
-
- dsa_port_disable(dp);
+ dsa_port_disable_rt(dp);
dev_mc_unsync(master, dev);
dev_uc_unsync(master, dev);
--
2.20.1
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