From: Eldad Zack <eldad@fogrefinery.com>
Date: Sat, 3 Aug 2013 08:51:15 +0000 (+0200)
Subject: ALSA: usb-audio: WARN_ON when alts is passed as NULL
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=e7e58df8ef3c9edb09a240084b4e0523c12bcb71;p=GitHub%2FLineageOS%2Fandroid_kernel_motorola_exynos9610.git

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 7a444b5501d9..92ea945ff486 100644
--- a/sound/usb/endpoint.c
+++ b/sound/usb/endpoint.c
@@ -418,6 +418,9 @@ struct snd_usb_endpoint *snd_usb_add_endpoint(struct snd_usb_audio *chip,
 	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) {