There are several error handling bugs in mscc_ocelot_init_ports(). I
went through the code, and carefully audited it and made fixes and
cleanups.
1) The ocelot_probe_port() function didn't have a mirror release function
so it was hard to follow. I created the ocelot_release_port()
function.
2) In the ocelot_probe_port() function, if the register_netdev() call
failed, then it lead to a double free_netdev(dev) bug. Fix this by
setting "ocelot->ports[port] = NULL" on the error path.
3) I was concerned that the "port" which comes from of_property_read_u32()
might be out of bounds so I added a check for that.
4) In the original code if ocelot_regmap_init() failed then the driver
tried to continue but I think that should be a fatal error.
5) If ocelot_probe_port() failed then the most recent devlink was leaked.
The fix for mostly came Vladimir Oltean. Get rid of "registered_ports"
and just set a bit in "devlink_ports_registered" to say when the
devlink port has been registered (and needs to be unregistered on
error). There are fewer than 32 ports so a u32 is large enough for
this purpose.
6) The error handling if the final ocelot_port_devlink_init() failed had
two problems. The "while (port-- >= 0)" loop should have been
"--port" pre-op instead of a post-op to avoid a buffer underflow.
The "if (!registered_ports[port])" condition was reversed leading to
resource leaks and double frees.
Fixes: 6c30384eb1de ("net: mscc: ocelot: register devlink ports")
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
Reviewed-by: Vladimir Oltean <vladimir.oltean@xxxxxxx>
Tested-by: Vladimir Oltean <vladimir.oltean@xxxxxxx>
---
v2: Part of the commit was missing
v3: The first version introduced a bug which completely broke the
driver. I moved the "ocelot->ports[port] = ocelot_port;"
assignment in ocelot_probe_port() and that was wrong.
Thanks to Vladimir for catching this.
Also v3 has additional cleanups in mscc_ocelot_init_ports().
drivers/net/ethernet/mscc/ocelot.h | 1 +
drivers/net/ethernet/mscc/ocelot_net.c | 14 +++++-
drivers/net/ethernet/mscc/ocelot_vsc7514.c | 52 ++++++++--------------
3 files changed, 33 insertions(+), 34 deletions(-)
diff --git a/drivers/net/ethernet/mscc/ocelot.h b/drivers/net/ethernet/mscc/ocelot.h
index e8621dbc14f7..76b8d8ce3b48 100644
--- a/drivers/net/ethernet/mscc/ocelot.h
+++ b/drivers/net/ethernet/mscc/ocelot.h
@@ -121,6 +121,7 @@ void ocelot_port_writel(struct ocelot_port *port, u32 val, u32 reg);
int ocelot_probe_port(struct ocelot *ocelot, int port, struct regmap *target,
struct phy_device *phy);
+void ocelot_release_port(struct ocelot_port *ocelot_port);
int ocelot_devlink_init(struct ocelot *ocelot);
void ocelot_devlink_teardown(struct ocelot *ocelot);
int ocelot_port_devlink_init(struct ocelot *ocelot, int port,
diff --git a/drivers/net/ethernet/mscc/ocelot_net.c b/drivers/net/ethernet/mscc/ocelot_net.c
index 05142803a463..e6b33d9df184 100644
--- a/drivers/net/ethernet/mscc/ocelot_net.c
+++ b/drivers/net/ethernet/mscc/ocelot_net.c
@@ -1283,7 +1283,19 @@ int ocelot_probe_port(struct ocelot *ocelot, int port, struct regmap *target,
if (err) {
dev_err(ocelot->dev, "register_netdev failed\n");
free_netdev(dev);
+ ocelot->ports[port] = NULL;
+ return err;
}
- return err;
+ return 0;
+}
+
+void ocelot_release_port(struct ocelot_port *ocelot_port)
+{
+ struct ocelot_port_private *priv = container_of(ocelot_port,
+ struct ocelot_port_private,
+ port);
+
+ unregister_netdev(priv->dev);
+ free_netdev(priv->dev);
}
diff --git a/drivers/net/ethernet/mscc/ocelot_vsc7514.c b/drivers/net/ethernet/mscc/ocelot_vsc7514.c
index 407244fe5b17..b52e24826b10 100644
--- a/drivers/net/ethernet/mscc/ocelot_vsc7514.c
+++ b/drivers/net/ethernet/mscc/ocelot_vsc7514.c
@@ -1064,7 +1064,6 @@ static void mscc_ocelot_release_ports(struct ocelot *ocelot)
int port;
for (port = 0; port < ocelot->num_phys_ports; port++) {
- struct ocelot_port_private *priv;
struct ocelot_port *ocelot_port;
ocelot_port = ocelot->ports[port];
@@ -1072,12 +1071,7 @@ static void mscc_ocelot_release_ports(struct ocelot *ocelot)
continue;
ocelot_deinit_port(ocelot, port);
-
- priv = container_of(ocelot_port, struct ocelot_port_private,
- port);
-
- unregister_netdev(priv->dev);
- free_netdev(priv->dev);
+ ocelot_release_port(ocelot_port);
}
}
@@ -1085,8 +1079,8 @@ static int mscc_ocelot_init_ports(struct platform_device *pdev,
struct device_node *ports)
{
struct ocelot *ocelot = platform_get_drvdata(pdev);
+ u32 devlink_ports_registered = 0;
struct device_node *portnp;
- bool *registered_ports;
int port, err;
u32 reg;
@@ -1102,11 +1096,6 @@ static int mscc_ocelot_init_ports(struct platform_device *pdev,
if (!ocelot->devlink_ports)
return -ENOMEM;
- registered_ports = kcalloc(ocelot->num_phys_ports, sizeof(bool),
- GFP_KERNEL);
- if (!registered_ports)
- return -ENOMEM;
-
for_each_available_child_of_node(ports, portnp) {
struct ocelot_port_private *priv;
struct ocelot_port *ocelot_port;
@@ -1123,14 +1112,22 @@ static int mscc_ocelot_init_ports(struct platform_device *pdev,
continue;
port = reg;
+ if (port < 0 || port >= ocelot->num_phys_ports) {
+ dev_err(ocelot->dev,
+ "invalid port number: %d >= %d\n", port,
+ ocelot->num_phys_ports);
+ continue;
+ }
snprintf(res_name, sizeof(res_name), "port%d", port);
res = platform_get_resource_byname(pdev, IORESOURCE_MEM,
res_name);
target = ocelot_regmap_init(ocelot, res);
- if (IS_ERR(target))
- continue;
+ if (IS_ERR(target)) {
+ err = PTR_ERR(target);
+ goto out_teardown;
+ }
phy_node = of_parse_phandle(portnp, "phy-handle", 0);
if (!phy_node)
@@ -1147,6 +1144,7 @@ static int mscc_ocelot_init_ports(struct platform_device *pdev,
of_node_put(portnp);
goto out_teardown;
}
+ devlink_ports_registered |= BIT(port);
err = ocelot_probe_port(ocelot, port, target, phy);
if (err) {
@@ -1154,8 +1152,6 @@ static int mscc_ocelot_init_ports(struct platform_device *pdev,
goto out_teardown;
}
- registered_ports[port] = true;
-
ocelot_port = ocelot->ports[port];
priv = container_of(ocelot_port, struct ocelot_port_private,
port);
@@ -1208,23 +1204,16 @@ static int mscc_ocelot_init_ports(struct platform_device *pdev,
/* Initialize unused devlink ports at the end */
for (port = 0; port < ocelot->num_phys_ports; port++) {
- if (registered_ports[port])
+ if (devlink_ports_registered & BIT(port))
continue;
err = ocelot_port_devlink_init(ocelot, port,
DEVLINK_PORT_FLAVOUR_UNUSED);
- if (err) {
- while (port-- >= 0) {
- if (!registered_ports[port])
- continue;
- ocelot_port_devlink_teardown(ocelot, port);
- }
-
+ if (err)
goto out_teardown;
- }
- }
- kfree(registered_ports);
+ devlink_ports_registered |= BIT(port);
+ }
return 0;
@@ -1233,12 +1222,9 @@ static int mscc_ocelot_init_ports(struct platform_device *pdev,
mscc_ocelot_release_ports(ocelot);
/* Tear down devlink ports for the registered network interfaces */
for (port = 0; port < ocelot->num_phys_ports; port++) {
- if (!registered_ports[port])
- continue;
-
- ocelot_port_devlink_teardown(ocelot, port);
+ if (devlink_ports_registered & BIT(port))
+ ocelot_port_devlink_teardown(ocelot, port);
}
- kfree(registered_ports);
return err;
}
--
2.30.0
