Commit e0c16233 authored by Dan Carpenter's avatar Dan Carpenter Committed by Jakub Kicinski

net: mscc: ocelot: fix error handling bugs in mscc_ocelot_init_ports()

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: 6c30384e ("net: mscc: ocelot: register devlink ports")
Signed-off-by: default avatarDan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: default avatarVladimir Oltean <vladimir.oltean@nxp.com>
Tested-by: default avatarVladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/YBkXhqRxHtRGzSnJ@mwandaSigned-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 2d912da0
......@@ -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,
......
......@@ -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);
}
......@@ -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;
if (devlink_ports_registered & BIT(port))
ocelot_port_devlink_teardown(ocelot, port);
}
kfree(registered_ports);
return err;
}
......
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