Commit dafb28f0 authored by Takashi Iwai's avatar Takashi Iwai
Browse files

ALSA: usx2y: Use snd_card_free_when_closed() at disconnection 



The USB disconnect callback is supposed to be short and not too-long
waiting.  OTOH, the current code uses snd_card_free() at
disconnection, but this waits for the close of all used fds, hence it
can take long.  It eventually blocks the upper layer USB ioctls, which
may trigger a soft lockup.

An easy workaround is to replace snd_card_free() with
snd_card_free_when_closed().  This variant returns immediately while
the release of resources is done asynchronously by the card device
release at the last close.

Fixes: 230cd5e2 ("[ALSA] prevent oops & dead keyboard on usb unplugging while the device is be ing used")
Reported-by: default avatar <syzbot+73582d08864d8268b6fd@syzkaller.appspotmail.com>
Closes: https://syzkaller.appspot.com/bug?extid=73582d08864d8268b6fd


Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
Link: https://patch.msgid.link/20241113111042.15058-2-tiwai@suse.de
parent f69c2861

sound/usb/usx2y/usbusx2y.c

+1 −1
Original line number Diff line number Diff line
@@ -422,7 +422,7 @@ static void snd_usx2y_disconnect(struct usb_interface *intf) 
	}

	if (usx2y->us428ctls_sharedmem)

		wake_up(&usx2y->us428ctls_wait_queue_head);

	snd_card_free(card);

	snd_card_free_when_closed(card);

}



static int snd_usx2y_probe(struct usb_interface *intf,