ALSA: timer: Use deferred fasync helper

[ Upstream commit 95cc637c1afd83fb7dd3d7c8a53710488f4caf9c ]

For avoiding the potential deadlock via kill_fasync() call, use the
new fasync helpers to defer the invocation from PCI API.  Note that
it's merely a workaround.

Reported-by: syzbot+1ee0910eca9c94f71f25@syzkaller.appspotmail.com
Reported-by: syzbot+49b10793b867871ee26f@syzkaller.appspotmail.com
Reported-by: syzbot+8285e973a41b5aa68902@syzkaller.appspotmail.com
Link: https://lore.kernel.org/r/20220728125945.29533-3-tiwai@suse.de
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
Takashi Iwai 2022-07-28 14:59:43 +02:00 committed by Greg Kroah-Hartman
parent 76f87b11a4
commit dd9d894b41

View File

@ -61,7 +61,7 @@ struct snd_timer_user {
unsigned int filter;
struct timespec tstamp; /* trigger tstamp */
wait_queue_head_t qchange_sleep;
struct fasync_struct *fasync;
struct snd_fasync *fasync;
struct mutex ioctl_lock;
};
@ -1317,7 +1317,7 @@ static void snd_timer_user_interrupt(struct snd_timer_instance *timeri,
}
__wake:
spin_unlock(&tu->qlock);
kill_fasync(&tu->fasync, SIGIO, POLL_IN);
snd_kill_fasync(tu->fasync, SIGIO, POLL_IN);
wake_up(&tu->qchange_sleep);
}
@ -1354,7 +1354,7 @@ 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);
snd_kill_fasync(tu->fasync, SIGIO, POLL_IN);
wake_up(&tu->qchange_sleep);
}
@ -1421,7 +1421,7 @@ 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);
snd_kill_fasync(tu->fasync, SIGIO, POLL_IN);
wake_up(&tu->qchange_sleep);
}
@ -1487,6 +1487,7 @@ static int snd_timer_user_release(struct inode *inode, struct file *file)
if (tu->timeri)
snd_timer_close(tu->timeri);
mutex_unlock(&tu->ioctl_lock);
snd_fasync_free(tu->fasync);
kfree(tu->queue);
kfree(tu->tqueue);
kfree(tu);
@ -2050,7 +2051,7 @@ 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);
return snd_fasync_helper(fd, file, on, &tu->fasync);
}
static ssize_t snd_timer_user_read(struct file *file, char __user *buffer,