[PATCH AUTOSEL 4.19 53/68] leds: trigger: netdev: fix refcnt leak on interface rename

[PATCH AUTOSEL 4.19 53/68] leds: trigger: netdev: fix refcnt leak on interface rename

[Sasha Levin]

From: Rafał Miłecki <rafal@milecki.pl>

[ Upstream commit 4cb6560514fa19d556954b88128f3846fee66a03 ]

Renaming a netdev-trigger-tracked interface was resulting in an
unbalanced dev_hold().

Example:
> iw phy phy0 interface add foo type __ap
> echo netdev > trigger
> echo foo > device_name
> ip link set foo name bar
> iw dev bar del
[  237.355366] unregister_netdevice: waiting for bar to become free. Usage count = 1
[  247.435362] unregister_netdevice: waiting for bar to become free. Usage count = 1
[  257.545366] unregister_netdevice: waiting for bar to become free. Usage count = 1

Above problem was caused by trigger checking a dev->name which obviously
changes after renaming an interface. It meant missing all further events
including the NETDEV_UNREGISTER which is required for calling dev_put().

This change fixes that by:
1) Comparing device struct *address* for notification-filtering purposes
2) Dropping unneeded NETDEV_CHANGENAME code (no behavior change)

Fixes: 06f502f57d0d ("leds: trigger: Introduce a NETDEV trigger")
Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>
Signed-off-by: Sasha Levin (Microsoft) <sashal@kernel.org>
---
 drivers/leds/trigger/ledtrig-netdev.c | 13 +++++--------
 1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/drivers/leds/trigger/ledtrig-netdev.c b/drivers/leds/trigger/ledtrig-netdev.c
index 3dd3ed46d473..167a94c02d05 100644
--- a/drivers/leds/trigger/ledtrig-netdev.c
+++ b/drivers/leds/trigger/ledtrig-netdev.c
@@ -301,11 +301,11 @@ static int netdev_trig_notify(struct notifier_block *nb,
 		container_of(nb, struct led_netdev_data, notifier);
 
 	if (evt != NETDEV_UP && evt != NETDEV_DOWN && evt != NETDEV_CHANGE
-	    && evt != NETDEV_REGISTER && evt != NETDEV_UNREGISTER
-	    && evt != NETDEV_CHANGENAME)
+	    && evt != NETDEV_REGISTER && evt != NETDEV_UNREGISTER)
 		return NOTIFY_DONE;
 
-	if (strcmp(dev->name, trigger_data->device_name))
+	if (!(dev == trigger_data->net_dev ||
+	      (evt == NETDEV_REGISTER && !strcmp(dev->name, trigger_data->device_name))))
 		return NOTIFY_DONE;
 
 	cancel_delayed_work_sync(&trigger_data->work);
@@ -320,12 +320,9 @@ static int netdev_trig_notify(struct notifier_block *nb,
 		dev_hold(dev);
 		trigger_data->net_dev = dev;
 		break;
-	case NETDEV_CHANGENAME:
 	case NETDEV_UNREGISTER:
-		if (trigger_data->net_dev) {
-			dev_put(trigger_data->net_dev);
-			trigger_data->net_dev = NULL;
-		}
+		dev_put(trigger_data->net_dev);
+		trigger_data->net_dev = NULL;
 		break;
 	case NETDEV_UP:
 	case NETDEV_CHANGE:
-- 
2.19.1

[PATCH AUTOSEL 4.19 67/68] leds: pca9532: fix a potential NULL pointer dereference

[Sasha Levin]

From: Kangjie Lu <kjlu@umn.edu>

[ Upstream commit 0aab8e4df4702b31314a27ec4b0631dfad0fae0a ]

In case of_match_device cannot find a match, return -EINVAL to avoid
NULL pointer dereference.

Fixes: fa4191a609f2 ("leds: pca9532: Add device tree support")
Signed-off-by: Kangjie Lu <kjlu@umn.edu>
Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>
Signed-off-by: Sasha Levin (Microsoft) <sashal@kernel.org>
---
 drivers/leds/leds-pca9532.c | 8 ++++++--
 1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/leds/leds-pca9532.c b/drivers/leds/leds-pca9532.c
index 7fea18b0c15d..7cb4d685a1f1 100644
--- a/drivers/leds/leds-pca9532.c
+++ b/drivers/leds/leds-pca9532.c
@@ -513,6 +513,7 @@ static int pca9532_probe(struct i2c_client *client,
 	const struct i2c_device_id *id)
 {
 	int devid;
+	const struct of_device_id *of_id;
 	struct pca9532_data *data = i2c_get_clientdata(client);
 	struct pca9532_platform_data *pca9532_pdata =
 			dev_get_platdata(&client->dev);
@@ -528,8 +529,11 @@ static int pca9532_probe(struct i2c_client *client,
 			dev_err(&client->dev, "no platform data\n");
 			return -EINVAL;
 		}
-		devid = (int)(uintptr_t)of_match_device(
-			of_pca9532_leds_match, &client->dev)->data;
+		of_id = of_match_device(of_pca9532_leds_match,
+				&client->dev);
+		if (unlikely(!of_id))
+			return -EINVAL;
+		devid = (int)(uintptr_t) of_id->data;
 	} else {
 		devid = id->driver_data;
 	}
-- 
2.19.1

[PATCH AUTOSEL 4.19 68/68] leds: trigger: netdev: use memcpy in device_name_store

[Sasha Levin]

From: Rasmus Villemoes <linux@rasmusvillemoes.dk>

[ Upstream commit 909346433064b8d840dc82af26161926b8d37558 ]

If userspace doesn't end the input with a newline (which can easily
happen if the write happens from a C program that does write(fd,
iface, strlen(iface))), we may end up including garbage from a
previous, longer value in the device_name. For example

# cat device_name

# printf 'eth12' > device_name
# cat device_name
eth12
# printf 'eth3' > device_name
# cat device_name
eth32

I highly doubt anybody is relying on this behaviour, so switch to
simply copying the bytes (we've already checked that size is <
IFNAMSIZ) and unconditionally zero-terminate it; of course, we also
still have to strip a trailing newline.

This is also preparation for future patches.

Fixes: 06f502f57d0d ("leds: trigger: Introduce a NETDEV trigger")
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>
Signed-off-by: Sasha Levin (Microsoft) <sashal@kernel.org>
---
 drivers/leds/trigger/ledtrig-netdev.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/leds/trigger/ledtrig-netdev.c b/drivers/leds/trigger/ledtrig-netdev.c
index 167a94c02d05..136f86a1627d 100644
--- a/drivers/leds/trigger/ledtrig-netdev.c
+++ b/drivers/leds/trigger/ledtrig-netdev.c
@@ -122,7 +122,8 @@ static ssize_t device_name_store(struct device *dev,
 		trigger_data->net_dev = NULL;
 	}
 
-	strncpy(trigger_data->device_name, buf, size);
+	memcpy(trigger_data->device_name, buf, size);
+	trigger_data->device_name[size] = 0;
 	if (size > 0 && trigger_data->device_name[size - 1] == '\n')
 		trigger_data->device_name[size - 1] = 0;
 
-- 
2.19.1