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.
Fix this by calling put_device at the end of snd_ctl_led_sysfs_remove
Reported-by: syzbot+08a7d8b51ea048a74ffb@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: a135dfb5de1 ("ALSA: led control - add sysfs kcontrol LED marking layer")
Signed-off-by: Dongliang Mu <mudongliangabcd@xxxxxxxxx>
---
sound/core/control_led.c | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/sound/core/control_led.c b/sound/core/control_led.c
index 25f57c14f294..fff2688b5019 100644
--- a/sound/core/control_led.c
+++ b/sound/core/control_led.c
@@ -371,6 +371,10 @@ static void snd_ctl_led_disconnect(struct snd_card *card)
snd_ctl_led_refresh();
}
+static void snd_ctl_led_release(struct device *dev)
+{
+}
+
/*
* sysfs
*/
@@ -663,6 +667,7 @@ static void snd_ctl_led_sysfs_add(struct snd_card *card)
led_card->number = card->number;
led_card->led = led;
device_initialize(&led_card->dev);
+ led_card->dev.release = snd_ctl_led_release;
if (dev_set_name(&led_card->dev, "card%d", card->number) < 0)
goto cerr;
led_card->dev.parent = &led->dev;
@@ -701,6 +706,7 @@ static void snd_ctl_led_sysfs_remove(struct snd_card *card)
sysfs_remove_link(&card->ctl_dev.kobj, link_name);
sysfs_remove_link(&led_card->dev.kobj, "card");
device_del(&led_card->dev);
+ put_device(&led_card->dev);
kfree(led_card);
led->cards[card->number] = NULL;
}
--
2.25.1
