From: Takashi Iwai <tiwai@xxxxxxx> commit 60849562a5db4a1eee2160167e4dce4590d3eafe upstream. The previous addition of descriptor validation may lead to a NULL dereference at create_yamaha_midi_quirk() when either injd or outjd is NULL. Add proper non-NULL checks. Fixes: 57f8770620e9 ("ALSA: usb-audio: More validations of descriptor units") Reported-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx> Signed-off-by: Takashi Iwai <tiwai@xxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- sound/usb/quirks.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/sound/usb/quirks.c +++ b/sound/usb/quirks.c @@ -259,8 +259,8 @@ static int create_yamaha_midi_quirk(stru NULL, USB_MS_MIDI_OUT_JACK); if (!injd && !outjd) return -ENODEV; - if (!snd_usb_validate_midi_desc(injd) || - !snd_usb_validate_midi_desc(outjd)) + if (!(injd && snd_usb_validate_midi_desc(injd)) || + !(outjd && snd_usb_validate_midi_desc(outjd))) return -ENODEV; if (injd && (injd->bLength < 5 || (injd->bJackType != USB_MS_EMBEDDED &&