This is a note to let you know that I've just added the patch titled
ALSA: usx2y: Use snd_card_free_when_closed() at disconnection
to the 6.1-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
alsa-usx2y-use-snd_card_free_when_closed-at-disconne.patch
and it can be found in the queue-6.1 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
commit 08835b4f4a50108e3f102b20f87e01af5e36232b
Author: Takashi Iwai <tiwai@xxxxxxx>
Date: Wed Nov 13 12:10:35 2024 +0100
ALSA: usx2y: Use snd_card_free_when_closed() at disconnection
[ Upstream commit dafb28f02be407e07a6f679e922a626592b481b0 ]
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: 230cd5e24853 ("[ALSA] prevent oops & dead keyboard on usb unplugging while the device is be ing used")
Reported-by: syzbot+73582d08864d8268b6fd@xxxxxxxxxxxxxxxxxxxxxxxxx
Closes: https://syzkaller.appspot.com/bug?extid=73582d08864d8268b6fd
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
Link: https://patch.msgid.link/20241113111042.15058-2-tiwai@xxxxxxx
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
diff --git a/sound/usb/usx2y/usbusx2y.c b/sound/usb/usx2y/usbusx2y.c
index 52f4e6652407d..4c4ce0319d624 100644
--- a/sound/usb/usx2y/usbusx2y.c
+++ b/sound/usb/usx2y/usbusx2y.c
@@ -423,7 +423,7 @@ 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,
