ALSA: usb-audio: WARN_ON when alts is passed as NULL
Prevent NULL dereference in snd_usb_add_endpoints(), when
alts is passed as NULL. In this case, WARN (since this is
a non-fatal bug) and return NULL ep. Call sites treat a NULL
return value as an error.
Signed-off-by: Eldad Zack <eldad@fogrefinery.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/usb/endpoint.c b/sound/usb/endpoint.c
index 7a444b5..92ea945 100644
--- a/sound/usb/endpoint.c
+++ b/sound/usb/endpoint.c
@@ -418,6 +418,9 @@
struct snd_usb_endpoint *ep;
int is_playback = direction == SNDRV_PCM_STREAM_PLAYBACK;
+ if (WARN_ON(!alts))
+ return NULL;
+
mutex_lock(&chip->mutex);
list_for_each_entry(ep, &chip->ep_list, list) {