diff --git a/sound/usb/pcm.c b/sound/usb/pcm.c index 48afae053c56..8e8db4ddf365 100644 --- a/sound/usb/pcm.c +++ b/sound/usb/pcm.c @@ -343,6 +343,15 @@ static int set_sync_ep_implicit_fb_quirk(struct snd_usb_substream *subs, ep = 0x81; iface = usb_ifnum_to_if(dev, 2); + if (!iface || iface->num_altsetting == 0) + return -EINVAL; + + alts = &iface->altsetting[1]; + goto add_sync_ep; + case USB_ID(0x1397, 0x0002): + ep = 0x81; + iface = usb_ifnum_to_if(dev, 1); + if (!iface || iface->num_altsetting == 0) return -EINVAL;