On Wed, 02 Jun 2021 05:41:36 +0200, Dongliang Mu wrote: > > The snd_ctl_led_sysfs_add and snd_ctl_led_sysfs_remove should contain > the refcount operations in pair. However, snd_ctl_led_sysfs_remove fails > to decrease the refcount to zero, which causes device_release never to > be invoked. This leads to memory leak to some resources, like struct > device_private. In addition, we also free some other similar memory > leaks in snd_ctl_led_init/snd_ctl_led_exit. > > Fix this by replacing device_del to device_unregister > in snd_ctl_led_sysfs_remove/snd_ctl_led_init/snd_ctl_led_exit. > > Note that, when CONFIG_DEBUG_KOBJECT_RELEASE is enabled, put_device will > call kobject_release and delay the release of kobject, which will cause > use-after-free when the memory backing the kobject is freed at once. > > Reported-by: syzbot+08a7d8b51ea048a74ffb@xxxxxxxxxxxxxxxxxxxxxxxxx > Fixes: a135dfb5de1 ("ALSA: led control - add sysfs kcontrol LED marking layer") > Signed-off-by: Dongliang Mu <mudongliangabcd@xxxxxxxxx> Applied now. Thanks. Takashi