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| author |   Rafał Miłecki <rafal@milecki.pl> | 2019-02-28 22:57:33 +0100 |
|---|---|---|
| committer |   Jacek Anaszewski <jacek.anaszewski@gmail.com> | 2019-03-26 20:25:37 +0100 |
| commit | 4cb6560514fa19d556954b88128f3846fee66a03 (patch) | |
| tree | 9dd276209cb3df77c581cb4c31b04310b5a35b92 /drivers/leds | |
| parent | Linux 5.1-rc1 (diff) | |
| download | linux-dev-4cb6560514fa19d556954b88128f3846fee66a03.tar.xz linux-dev-4cb6560514fa19d556954b88128f3846fee66a03.zip | |
leds: trigger: netdev: fix refcnt leak on interface rename
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>
Diffstat (limited to 'drivers/leds')
| -rw-r--r-- | drivers/leds/trigger/ledtrig-netdev.c | 13 |
1 files 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: |