This is a note to let you know that I've just added the patch titled
ALSA: usb-audio: Drop snd_BUG_ON() from snd_usbmidi_output_open()
to the 5.15-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-usb-audio-drop-snd_bug_on-from-snd_usbmidi_output_open.patch
and it can be found in the queue-5.15 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@xxxxxxxxxxxxxxx> know about it.
>From ad72c3c3f6eb81d2cb189ec71e888316adada5df Mon Sep 17 00:00:00 2001
From: Takashi Iwai <tiwai@xxxxxxx>
Date: Sat, 12 Nov 2022 15:12:23 +0100
Subject: ALSA: usb-audio: Drop snd_BUG_ON() from snd_usbmidi_output_open()
From: Takashi Iwai <tiwai@xxxxxxx>
commit ad72c3c3f6eb81d2cb189ec71e888316adada5df upstream.
snd_usbmidi_output_open() has a check of the NULL port with
snd_BUG_ON(). snd_BUG_ON() was used as this shouldn't have happened,
but in reality, the NULL port may be seen when the device gives an
invalid endpoint setup at the descriptor, hence the driver skips the
allocation. That is, the check itself is valid and snd_BUG_ON()
should be dropped from there. Otherwise it's confusing as if it were
a real bug, as recently syzbot stumbled on it.
Reported-by: syzbot+9abda841d636d86c41da@xxxxxxxxxxxxxxxxxxxxxxxxx
Cc: <stable@xxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/r/syzbot+9abda841d636d86c41da@xxxxxxxxxxxxxxxxxxxxxxxxx
Link: https://lore.kernel.org/r/20221112141223.6144-1-tiwai@xxxxxxx
Signed-off-by: Takashi Iwai <tiwai@xxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
sound/usb/midi.c | 4 +---
1 file changed, 1 insertion(+), 3 deletions(-)
--- a/sound/usb/midi.c
+++ b/sound/usb/midi.c
@@ -1133,10 +1133,8 @@ static int snd_usbmidi_output_open(struc
port = &umidi->endpoints[i].out->ports[j];
break;
}
- if (!port) {
- snd_BUG();
+ if (!port)
return -ENXIO;
- }
substream->runtime->private_data = port;
port->state = STATE_UNKNOWN;
Patches currently in stable-queue which might be from tiwai@xxxxxxx are
queue-5.15/alsa-usb-audio-drop-snd_bug_on-from-snd_usbmidi_output_open.patch
queue-5.15/alsa-hda-realtek-fix-speakers-for-samsung-galaxy-book-pro.patch
queue-5.15/alsa-hda-realtek-fix-the-speaker-output-on-samsung-galaxy-book-pro-360.patch
