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Message-Id: <E1j7lU0-0003pp-Ff@rmk-PC.armlinux.org.uk>
Date: Fri, 28 Feb 2020 19:39:36 +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>,
Ioana Ciornei <ioana.ciornei@....com>,
Vladimir Oltean <olteanv@...il.com>, netdev@...r.kernel.org
Subject: [PATCH net] 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>
---
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 a7662e7a691d..5099a337c9cc 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_locked(struct dsa_port *dp, struct phy_device *phy);
int dsa_port_enable(struct dsa_port *dp, struct phy_device *phy);
+void dsa_port_disable_locked(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 774facb8d547..96f074670140 100644
--- a/net/dsa/port.c
+++ b/net/dsa/port.c
@@ -63,12 +63,15 @@ 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_locked(struct dsa_port *dp, struct phy_device *phy)
{
struct dsa_switch *ds = dp->ds;
int port = dp->index;
int err;
+ if (dp->pl)
+ phylink_start(dp->pl);
+
if (ds->ops->port_enable) {
err = ds->ops->port_enable(ds, port, phy);
if (err)
@@ -81,7 +84,18 @@ int dsa_port_enable(struct dsa_port *dp, struct phy_device *phy)
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_locked(dp, phy);
+ rtnl_unlock();
+
+ return err;
+}
+
+void dsa_port_disable_locked(struct dsa_port *dp)
{
struct dsa_switch *ds = dp->ds;
int port = dp->index;
@@ -91,6 +105,16 @@ void dsa_port_disable(struct dsa_port *dp)
if (ds->ops->port_disable)
ds->ops->port_disable(ds, port);
+
+ if (dp->pl)
+ phylink_stop(dp->pl);
+}
+
+void dsa_port_disable(struct dsa_port *dp)
+{
+ rtnl_lock();
+ dsa_port_disable_locked(dp);
+ rtnl_unlock();
}
int dsa_port_bridge_join(struct dsa_port *dp, struct net_device *br)
@@ -614,10 +638,6 @@ 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 088c886e609e..36523e942983 100644
--- a/net/dsa/slave.c
+++ b/net/dsa/slave.c
@@ -88,12 +88,10 @@ static int dsa_slave_open(struct net_device *dev)
goto clear_allmulti;
}
- err = dsa_port_enable(dp, dev->phydev);
+ err = dsa_port_enable_locked(dp, dev->phydev);
if (err)
goto clear_promisc;
- phylink_start(dp->pl);
-
return 0;
clear_promisc:
@@ -114,9 +112,7 @@ static int dsa_slave_close(struct net_device *dev)
struct net_device *master = dsa_slave_to_master(dev);
struct dsa_port *dp = dsa_slave_to_port(dev);
- phylink_stop(dp->pl);
-
- dsa_port_disable(dp);
+ dsa_port_disable_locked(dp);
dev_mc_unsync(master, dev);
dev_uc_unsync(master, dev);
--
2.20.1
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