From: Jaejoong Kim <climbbb.kim@gmail.com>
Date: Mon, 4 Dec 2017 06:31:49 +0000 (+0900)
Subject: ALSA: usb-audio: Add check return value for usb_string()
X-Git-Tag: v3.18.88~46
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=7a3638bbec14afafd3322c7fc2f68cfad0ac3550;p=thirdparty%2Fkernel%2Fstable.git

ALSA: usb-audio: Add check return value for usb_string()

commit 89b89d121ffcf8d9546633b98ded9d18b8f75891 upstream.

snd_usb_copy_string_desc() returns zero if usb_string() fails.
In case of failure, we need to check the snd_usb_copy_string_desc()'s
return value and add an exception case

Signed-off-by: Jaejoong Kim <climbbb.kim@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/sound/usb/mixer.c b/sound/usb/mixer.c
index 4e780d59a995b..92ad24ef1c5bd 100644
--- a/sound/usb/mixer.c
+++ b/sound/usb/mixer.c
@@ -2099,13 +2099,14 @@ static int parse_audio_selector_unit(struct mixer_build *state, int unitid,
 	if (len)
 		;
 	else if (nameid)
-		snd_usb_copy_string_desc(state, nameid, kctl->id.name,
+		len = snd_usb_copy_string_desc(state, nameid, kctl->id.name,
 					 sizeof(kctl->id.name));
-	else {
+	else
 		len = get_term_name(state, &state->oterm,
 				    kctl->id.name, sizeof(kctl->id.name), 0);
-		if (!len)
-			strlcpy(kctl->id.name, "USB", sizeof(kctl->id.name));
+
+	if (!len) {
+		strlcpy(kctl->id.name, "USB", sizeof(kctl->id.name));
 
 		if (desc->bDescriptorSubtype == UAC2_CLOCK_SELECTOR)
 			append_ctl_name(kctl, " Clock Source");