diff options
author | Takashi Iwai <tiwai@suse.de> | 2021-11-05 12:15:17 +0300 |
---|---|---|
committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-11-17 13:03:26 +0300 |
commit | 3d96ccb1ef2a74ddf7440469eaebb1dc33972fd5 (patch) | |
tree | 4d9826239a5949297adad87a3e6b10946265ba56 | |
parent | 147405da05f59aa9c2b97ba4b70d10f3aa81d6b3 (diff) | |
download | linux-3d96ccb1ef2a74ddf7440469eaebb1dc33972fd5.tar.xz |
ALSA: timer: Unconditionally unlink slave instances, too
commit ffdd98277f0a1d15a67a74ae09bee713df4c0dbc upstream.
Like the previous fix (commit c0317c0e8709 "ALSA: timer: Fix
use-after-free problem"), we have to unlink slave timer instances
immediately at snd_timer_stop(), too. Otherwise it may leave a stale
entry in the list if the slave instance is freed before actually
running.
Cc: <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20211105091517.21733-1-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r-- | sound/core/timer.c | 13 |
1 files changed, 6 insertions, 7 deletions
diff --git a/sound/core/timer.c b/sound/core/timer.c index 4f9bab931951..b3214baa8919 100644 --- a/sound/core/timer.c +++ b/sound/core/timer.c @@ -665,23 +665,22 @@ static int snd_timer_stop1(struct snd_timer_instance *timeri, bool stop) static int snd_timer_stop_slave(struct snd_timer_instance *timeri, bool stop) { unsigned long flags; + bool running; spin_lock_irqsave(&slave_active_lock, flags); - if (!(timeri->flags & SNDRV_TIMER_IFLG_RUNNING)) { - spin_unlock_irqrestore(&slave_active_lock, flags); - return -EBUSY; - } + running = timeri->flags & SNDRV_TIMER_IFLG_RUNNING; timeri->flags &= ~SNDRV_TIMER_IFLG_RUNNING; if (timeri->timer) { spin_lock(&timeri->timer->lock); list_del_init(&timeri->ack_list); list_del_init(&timeri->active_list); - snd_timer_notify1(timeri, stop ? SNDRV_TIMER_EVENT_STOP : - SNDRV_TIMER_EVENT_PAUSE); + if (running) + snd_timer_notify1(timeri, stop ? SNDRV_TIMER_EVENT_STOP : + SNDRV_TIMER_EVENT_PAUSE); spin_unlock(&timeri->timer->lock); } spin_unlock_irqrestore(&slave_active_lock, flags); - return 0; + return running ? 0 : -EBUSY; } /* |