@@ -83,7 +83,6 @@ struct snd_timer_user {
unsigned int filter;
struct timespec64 tstamp; /* trigger tstamp */
wait_queue_head_t qchange_sleep;
- struct fasync_struct *fasync;
struct mutex ioctl_lock;
};
@@ -1345,7 +1344,6 @@ static void snd_timer_user_interrupt(struct snd_timer_instance *timeri,
}
__wake:
spin_unlock(&tu->qlock);
- kill_fasync(&tu->fasync, SIGIO, POLL_IN);
wake_up(&tu->qchange_sleep);
}
@@ -1383,7 +1381,6 @@ static void snd_timer_user_ccallback(struct snd_timer_instance *timeri,
spin_lock_irqsave(&tu->qlock, flags);
snd_timer_user_append_to_tqueue(tu, &r1);
spin_unlock_irqrestore(&tu->qlock, flags);
- kill_fasync(&tu->fasync, SIGIO, POLL_IN);
wake_up(&tu->qchange_sleep);
}
@@ -1453,7 +1450,6 @@ static void snd_timer_user_tinterrupt(struct snd_timer_instance *timeri,
spin_unlock(&tu->qlock);
if (append == 0)
return;
- kill_fasync(&tu->fasync, SIGIO, POLL_IN);
wake_up(&tu->qchange_sleep);
}
@@ -2130,14 +2126,6 @@ static long snd_timer_user_ioctl(struct file *file, unsigned int cmd,
return ret;
}
-static int snd_timer_user_fasync(int fd, struct file * file, int on)
-{
- struct snd_timer_user *tu;
-
- tu = file->private_data;
- return fasync_helper(fd, file, on, &tu->fasync);
-}
-
static ssize_t snd_timer_user_read(struct file *file, char __user *buffer,
size_t count, loff_t *offset)
{
@@ -2280,7 +2268,6 @@ static const struct file_operations snd_timer_f_ops =
.poll = snd_timer_user_poll,
.unlocked_ioctl = snd_timer_user_ioctl,
.compat_ioctl = snd_timer_user_ioctl_compat,
- .fasync = snd_timer_user_fasync,
};
/* unregister the system timer */
The async signal (SIGIO) support for ALSA timer API has been never used by real applications, but yet it can be a cause of various potential deadlocks, as spotted by syzkaller. Let's drop the feature as the simplest solution. Reported-by: syzbot+1ee0910eca9c94f71f25@syzkaller.appspotmail.com Reported-by: syzbot+49b10793b867871ee26f@syzkaller.appspotmail.com Reported-by: syzbot+8285e973a41b5aa68902@syzkaller.appspotmail.com Signed-off-by: Takashi Iwai <tiwai@suse.de> --- sound/core/timer.c | 13 ------------- 1 file changed, 13 deletions(-)